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Sample records for klastere nnts khfti

  1. Atomistic Level Studies on the Tensile Behavior of GaN Nanotubes under Uniaxial Tension

    SciTech Connect

    Wang, Zhiguo; Zu, Xiaotao T.; Gao, Fei; Weber, William J.

    2008-02-01

    Molecular dynamics method with the Stillinger-Weber (SW) potential has been employed to study the responses of GaN nanotubes (Ga NNTs) to a uniaxial tensile load along the axial direction. It has been revealed that GaNNTs exhibits a completely different tensile behavior at different temperatures, i.e., ductility at higher deformation temperatures and brittleness at lower temperatures, leading to a brittle to ductile transition (BDT). Both the BDT temperature and the critical stress increases with increasing thickness of GaNNTs and the critical stress at higher tmperature are lower than those at lower temperature. These results on the tensile behaviors of GaNNTs in an atomic level will provide a good reference to its promising applications.

  2. First-principles study of silicon nitride nanotubes

    NASA Astrophysics Data System (ADS)

    Gao, Guohua; Kang, Hong Seok

    2008-10-01

    We have made a first-principles calculation of the topological, geometric, and electronic structures of nitrogen-doped armchair and zigzag silicon carbide nanotubes, where we have assumed that all carbon atoms have been substituted by nitrogen atoms. The doping was found to be substantially easier than for analogous carbon nanotubes. In addition, the doping process is cooperative, leading us to theoretically predict the stable existence of silicon nitride nanotubes (SiNNTs). For (n,n) SiNNTs, all kinds of chiral indices n are possible. These armchair tubes are semiconductors with much smaller band gaps than those of corresponding silicon carbide nanotubes, and the gap decreases with the tube diameter. For (n,0) chirality, only even-numbered chiral indices (n=2l) are possible. These nanotubes are also semiconductors with band gaps larger than those of armchair SiNNTs of similar diameters.

  3. Practising evidence-based medicine in an era of high placebo response: number needed to treat reconsidered.

    PubMed

    Roose, Steven P; Rutherford, Bret R; Wall, Melanie M; Thase, Michael E

    2016-05-01

    The number needed to treat (NNT) statistic was developed to facilitate the practice of evidence-based medicine. Placebo was assumed to be therapeutically inert when the NNT was originally conceived, but more recent data for conditions such as major depressive disorder (MDD) suggest that the placebo control condition can have considerable therapeutic effects. Complications arise because the NNT calculated from randomised controlled trials (RCTs) reflects a comparison between medication plus clinical management and placebo plus clinical management, whereas, in the clinical setting, physicians choose between prescribing open medication, observing a patient over time with a supportive approach, and doing nothing. Thus, NNTs derived from clinical trials are not directly relevant to clinical decision-making, because they are based on control conditions that do not exist in standard practice. Additional difficulties may arise when using NNTs to compare alternative treatments for MDD, such as medication and psychotherapy, since these comparisons require the control conditions upon which the respective NNTs are based to be similar.Whereas pill placebo conditions include intensive clinical management and elicit expectations of improvement, attention control conditions for psychotherapy research are less well developed. Often the effects of psychotherapy are gauged against a wait-list control condition, which has substantially fewer therapeutic components than a pill placebo control condition. To improve the clinical utility of NNTs for the treatment of MDD, we advocate effectiveness studies that include treatment conditions resembling actual clinical practice, rather than using placebo-controlled RCTs for this purpose. Until such studies are performed, the effect of bias in comparing NNTs across treatments can be controlled by ensuring that the RCT control conditions upon which the NNTs are based are comparable. PMID:27143006

  4. Epoxy monomer adsorption on Group III (B, Al, Ga) nitride nanotubes: vdW-DF studies on mechanical and electronic properties

    NASA Astrophysics Data System (ADS)

    Ganji, M. D.; Sharifi, N.; Fereidoon, A.; Ghorbanzadeh Ahangari, M.

    2014-03-01

    The present work investigates the interaction of (6,6) and (10,0) B, Al, and Ga nitride nanotubes (BNNT, AlNNT, and GaNNT) with bisphenol-A epoxy monomers using the first-principles van der Waals density functional (vdW-DF) approach with respect to geometrical structures, interaction energies, and electronic properties. Two types of orientations for monomer adsorption are considered: (I) parallel and (II) perpendicular with the tube axis. The interaction energy for epoxy that is adsorbed on the surface of different nanotubes (for both of these states of adsorption) is calculated, and the results indicate that state (II) is more stable than state (I) for nanotube adsorption. Unlike results obtained with BNNTs/(10,0) AlNNT, the results reported herein indicate that (6,6) AlNNTs/GaNNTs can effectively interact with the epoxy monomer, and their interaction properties are dramatically changed upon exposure to these monomers. In addition, density functional calculations are performed within the generalized gradient approximation in the elastic deformation range to obtain the Young's modulus of (6,6) nanotubes and their complexes in their most stable orientation. Our results reveal that the amounts of modulus downfall of complexes are strongly influenced by the interaction between the monomer and the nanotubes. Among the investigated nanotubes, AlNNT and GaNNTs possesses the strongest interaction to the monomer, but the Young's modulus of GaNNT complex is higher than that another one. Thus, we believe that AlNNTs might be a good strategy for improving the mechanical properties of epoxy nanocomposites.

  5. A quantum chemistry study on surface reactivity of pristine and carbon-substituted AlN nanotubes

    NASA Astrophysics Data System (ADS)

    Mahdaviani, Amir; Esrafili, Mehdi D.; Esrafili, Ali; Behzadi, Hadi

    2013-09-01

    A density functional theory investigation was performed to predict the surface reactivity of pristine and carbon-substituted (6,0) single-walled aluminum nitride nanotubes (AlNNTs). The properties determined include the electrostatic potentials VS(r) and average local ionization energies ĪS(r) on the surfaces of the investigated tubes. According to computed VS(r) results, the Al/N atoms in edge or cap regions show a different reactivity pattern than those at the middle portion of the tubes. Due to the carbon-substitution at the either Al or N sites of the tubes, the negative regions associated with nitrogen atoms are stronger than before. The prediction of surface reactivity and regioselectivity using average local ionization energies has been verified by atomic hydrogen chemisorption energies calculated for AlNNTs at the B3LYP/6-31 G* level. There is an acceptable correlation between the minima of ĪS(r) and the atomic hydrogen chemisorption energies, demonstrating that ĪS(r) provides an effective means for rapidly and economically assessing the relative reactivities of finite sized AlNNTs.

  6. Estimating the number needed to treat from continuous outcomes in randomised controlled trials: methodological challenges and worked example using data from the UK Back Pain Exercise and Manipulation (BEAM) trial

    PubMed Central

    2009-01-01

    Background Reporting numbers needed to treat (NNT) improves interpretability of trial results. It is unusual that continuous outcomes are converted to numbers of individual responders to treatment (i.e., those who reach a particular threshold of change); and deteriorations prevented are only rarely considered. We consider how numbers needed to treat can be derived from continuous outcomes; illustrated with a worked example showing the methods and challenges. Methods We used data from the UK BEAM trial (n = 1, 334) of physical treatments for back pain; originally reported as showing, at best, small to moderate benefits. Participants were randomised to receive 'best care' in general practice, the comparator treatment, or one of three manual and/or exercise treatments: 'best care' plus manipulation, exercise, or manipulation followed by exercise. We used established consensus thresholds for improvement in Roland-Morris disability questionnaire scores at three and twelve months to derive NNTs for improvements and for benefits (improvements gained+deteriorations prevented). Results At three months, NNT estimates ranged from 5.1 (95% CI 3.4 to 10.7) to 9.0 (5.0 to 45.5) for exercise, 5.0 (3.4 to 9.8) to 5.4 (3.8 to 9.9) for manipulation, and 3.3 (2.5 to 4.9) to 4.8 (3.5 to 7.8) for manipulation followed by exercise. Corresponding between-group mean differences in the Roland-Morris disability questionnaire were 1.6 (0.8 to 2.3), 1.4 (0.6 to 2.1), and 1.9 (1.2 to 2.6) points. Conclusion In contrast to small mean differences originally reported, NNTs were small and could be attractive to clinicians, patients, and purchasers. NNTs can aid the interpretation of results of trials using continuous outcomes. Where possible, these should be reported alongside mean differences. Challenges remain in calculating NNTs for some continuous outcomes. Trial Registration UK BEAM trial registration: ISRCTN32683578. PMID:19519911

  7. Spatio-temporal variations in the structure of the attenuation field of the S-wave in the region of Nevada nuclear test site

    NASA Astrophysics Data System (ADS)

    Kopnichev, Yu. F.; Sokolova, I. N.; Sokolov, K. N.

    2013-11-01

    The characteristics of the attenuation field of short-period shear waves in the region of Nevada nuclear test site (NNTS) are studied. The seismograms of underground nuclear explosions (UNEs) and earthquakes recorded by three seismic stations in 1975-2012 at the epicentral distances of up to 1000 km are processed by the methods based on the analysis of the amplitude ratios of Sn to Pn and Lg to Pg waves, as well as the S-coda envelopes for close events. It is shown that the structure of the attenuation field in the Earth's crust and upper mantle in the NNTS region experienced significant temporal variations during the interval of nuclear operations. The strongest variations were associated with UNEs conducted in the Pahute Mesa area, which held about two-thirds of the most intense explosions. Our data indicate that temporal variations in the structure of the attenuation field are related to the migration of deep fluids. A comparison of the general characteristics of the attenuation field in the regions of the three large nuclear test sites is presented.

  8. Important clinical features of atypical antipsychotics in acute bipolar depression that inform routine clinical care: a review of pivotal studies with number needed to treat.

    PubMed

    Gao, Keming; Yuan, Chengmei; Wu, Renrong; Chen, Jun; Wang, Zuowei; Fang, Yiru; Calabrese, Joseph R

    2015-10-01

    English-language literature cited in MEDLINE from January, 1980 to October 30, 2014 was searched by using terms of antipsychotic, generic and brand names of atypical antipsychotics, "bipolar depression/bipolar disorder", "placebo", and "trial". The parameters of response (≥50% improvement on MADRS, Montgomery-Asberg Depression Rating Scale total score), remission (either ≤12 or 8 on MADRS total score at endpoint), discontinuation due to adverse events (DAEs), somnolence, ≥7% weight gain, overall extrapyramidal side-effects (EPSs), and akathisia, were extracted from originally published primary outcome papers. The number needed to treat to benefit (NNT) for response and remission or harm (NNH) for DAEs or other side effects relative to placebo were estimated and presented with the estimate and 95% confidence interval. Olanzapine monotherapy, olanzapine-fluoxetine combination (OFC), quetiapine-IR monotherapy, quetiapine-XR monotherapy, lurasidone monotherapy, and lurasidone adjunctive therapy were superior to placebo with NNTs for responses of 11-12, 4, 7-8, 4, 4-5, and 7, and NNTs for remission of 11-12, 4, 5-11, 7, 6-7, and 6, respectively. There was no significant difference between OFC and lamotrigine, and between aripiprazole or ziprasidone and placebo in response and remission. Olanzapine monotherapy, quetiapine-IR, quetiapine-XR, aripiprazole, and ziprasidone 120-160 mg/day had significantly increased risk for DAEs with NNHs of 24, 8-14, 9, 12, and 10, respectively. For somnolence, quetiapine-XR had the smallest NNH of 4. For ≥7% weight gain, olanzapine monotherapy and OFC had the smallest NNHs with both of 5. For akathisia, aripiprazole had the smallest NNH of 5. These findings suggest that among the FDA-approved agents including OFC, quetiapine-IR and -XR, lurasidone monotherapy and adjunctive therapy to a mood stabilizer, the differences in the NNTs for response and remission are small, but the differences in NNHs for DAEs and common side

  9. Stability, electronic structures and transport properties of armchair (10, 10) BN/C nanotubes

    SciTech Connect

    Xiao, H.P.; He, Chaoyu; Zhang, C.X.; Sun, L.Z.; Zhou, Pan; Zhong, Jianxin

    2013-04-15

    Using the first-principle calculations, the stability and electronic properties of two novel types of four-segment armchair (10, 10) BN/C hybrid nanotubes ((BN){sub 5}C{sub 5}(BN){sub 5}C{sub 5}NT and (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT) as well as two-segment armchair (10, 10) BN/C hybrid nanotubes ((BN{sub 20−n}C{sub n}NTs) are systematically investigated. When n increases from 1 to 4, the band gap of (BN){sub 20−n}C{sub n}NTs gradually decreases to a narrow one. When 4≤n≤17, the electronic structure of carbon segment in (BN){sub 20−n}C{sub n}NTs behaves as zigzag graphene nanoribbons whose band gap is modulated by an inherent electric field of the BN segment. ZGNR-like segments in (BN){sub 5}C{sub 5}(BN){sub 5}C{sub 5}NT and (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT behave as narrow gap semiconductor and metal, respectively, due to their different chemical environment. Moreover, the (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT can separate electron and hole carriers, indicating its potential application in solar cell materials. Obvious transport enhancement around the Fermi level is found in the four-segment nanotubes, especially a 6G{sub 0} transmission peak in the metallic (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT. - Graphical abstract: Structural diagram of four-segment (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT and its typical two-probe system. The band structures and transport spectra of (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT are shown in upper and lower panels. Highlights: ► Transport properties of two types of four-segment BNC hybrid nanotubes are studied. ► Transport enhancements are realized in the four-segment BNC hybrid nanotubes. ► Electron and hole separation is found in four-segment BNC hybrid nanotubes.

  10. Electrical breakdown of carbon nanotube devices and the predictability of breakdown position

    NASA Astrophysics Data System (ADS)

    Goswami, Gopal Krishna; Nanda, Karuna Kar

    2012-06-01

    We have investigated electrical transport properties of long (>10 μm) multiwalled carbon nanotubes (NTs) by dividing individuals into several segments of identical length. Each segment has different resistance because of the random distribution of defect density in an NT and is corroborated by Raman studies. Higher is the resistance, lower is the current required to break the segments indicating that breakdown occurs at the highly resistive segment/site and not necessarily at the middle. This is consistent with the one-dimensional thermal transport model. We have demonstrated the healing of defects by annealing at moderate temperatures or by current annealing. To strengthen our mechanism, we have carried out electrical breakdown of nitrogen doped NTs (NNTs) with diameter variation from one end to the other. It reveals that the electrical breakdown occurs selectively at the narrower diameter region. Overall, we believe that our results will help to predict the breakdown position of both semiconducting and metallic NTs.

  11. Sumatriptan (oral route of administration) for acute migraine attacks in adults

    PubMed Central

    Derry, Christopher J; Derry, Sheena; Moore, R Andrew

    2014-01-01

    Background Migraine is a highly disabling condition for the individual and also has wide-reaching implications for society, healthcare services, and the economy. Sumatriptan is an abortive medication for migraine attacks, belonging to the triptan family. Objectives To determine the efficacy and tolerability of oral sumatriptan compared to placebo and other active interventions in the treatment of acute migraine attacks in adults. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, online databases, and reference lists for studies through 13 October 2011. Selection criteria We included randomised, double-blind, placebo- and/or active-controlled studies using oral sumatriptan to treat a migraine headache episode, with at least 10 participants per treatment arm. Data collection and analysis Two review authors independently assessed trial quality and extracted data. We used numbers of participants achieving each outcome to calculate relative risk (or ‘risk ratio’) and numbers needed to treat to benefit (NNT) or harm (NNH) compared to placebo or a different active treatment. Main results Sixty-one studies (37,250 participants) compared oral sumatriptan with placebo or an active comparator. Most of the data were for the 50 mg and 100 mg doses. Sumatriptan surpassed placebo for all efficacy outcomes. For sumatriptan 50 mg versus placebo the NNTs were 6.1, 7.5, and 4.0 for pain-free at two hours and headache relief at one and two hours, respectively. NNTs for sustained pain-free and sustained headache relief during the 24 hours postdose were 9.5 and 6.0, respectively. For sumatriptan 100 mg versus placebo the NNTs were 4.7, 6.8, 3.5, 6.5, and 5.2, respectively, for the same outcomes. Results for the 25 mg dose were similar to the 50 mg dose, while sumatriptan 100 mg was significantly better than 50 mg for pain-free and headache relief at two hours, and for sustained pain-free during 24 hours. Treating early, during

  12. Hormone therapy and radiotherapy for early prostate cancer: A utility-adjusted number needed to treat (NNT) analysis

    SciTech Connect

    Jani, Ashesh B.; Kao, Johnny; Heimann, Ruth; Hellman, Samuel . E-mail: s-hellman@uchicago.edu

    2005-03-01

    Purpose: To quantify, using the number needed to treat (NNT) methodology, the benefit of short-term ({<=}6 months) hormone therapy adjuvant to radiotherapy in the group of patients with early (clinical stage T1-T2c) prostate cancer. Methods and materials: The absolute biochemical control benefit for the use of hormones adjuvant to radiotherapy in early-stage disease was determined by literature review. A model was developed to estimate the utility-adjusted survival detriment due to the side effects of hormone therapy. The NNTs before and after the incorporation of hormone sequelae were computed; the sign and magnitude of the NNTs were used to gauge the effect of the hormones. Results: The absolute NNT analysis, based on summarizing the results of 8 reports including a total of 3652 patients, demonstrated an advantage to the addition of hormones for the general early-stage prostate cancer population as well as for all prognostic groups. After adjustment for hormone-induced functional loss, the advantage of hormones remained considerable in the high- and intermediate-risk groups, with the utility-adjusted NNT becoming weakened in the low-risk group when the utility compromise from complications of hormones was assumed to be considerable. Conclusions: Short-term hormone therapy seems to be beneficial for selected early-stage prostate cancer patients. The advantage seems to be greatest in the intermediate- and high-risk groups; with current follow-up, the side effects of hormones may outweigh their benefit in certain clinical situations in the favorable group. The present investigation demonstrates the significant role of the NNT technique for oncologic and radiotherapeutic management decisions when treatment complications need to be considered and balanced with the beneficial effects of the treatment.

  13. Combination analgesic efficacy: individual patient data meta-analysis of single-dose oral tramadol plus acetaminophen in acute postoperative pain.

    PubMed

    Edwards, Jayne E; McQuay, Henry J; Moore, R Andrew

    2002-02-01

    The primary aims of this study were to assess the analgesic efficacy and adverse effects of single-dose oral tramadol plus acetaminophen in acute postoperative pain and to use meta-analysis to demonstrate the efficacy of the combination drug compared with its components. Individual patient data from seven randomized, double blind, placebo controlled trials of tramadol plus acetaminophen were supplied for analysis by the R.W. Johnson Pharmaceutical Research Institute, Raritan, New Jersey, USA. All trials used identical methods and assessed single-dose oral tramadol (75 mg or 112.5 mg) plus acetaminophen (650 mg or 975 mg) in adult patients with moderate or severe postoperative pain. Summed pain intensity and pain relief data over six and eight hours and global evaluations of treatment effect after eight hours were extracted. Number-needed-to-treat (NNT) for one patient to obtain at least 50% pain relief was calculated. NNTs derived from pain relief data were compared with those derived from pain intensity data and global evaluations. Information on adverse effects was collected. Combination analgesics (tramadol plus acetaminophen) had significantly lower (better) NNTs than the components alone, and comparable efficacy to ibuprofen 400 mg. This could be shown for dental but not postsurgical pain, because more patients were available for the former. Adverse effects were similar for the combination drugs and the opioid component alone. Common adverse effects were dizziness, drowsiness, nausea, vomiting, and headache. In sum, this meta-analysis demonstrated analgesic superiority of the combination drug over its components, without additional toxicity. PMID:11844632

  14. Single dose oral ketoprofen and dexketoprofen for acute postoperative pain in adults

    PubMed Central

    Barden, Jodie; Derry, Sheena; McQuay, Henry J; Moore, R Andrew

    2014-01-01

    . Ketoprofen at doses between 12.5 mg and 100 mg produced NNTs for at least 50% pain relief over 4 to 6 hours of 2.4 to 3.3. For dental studies only there was a trend to more efficacy at higher doses, with NNT decreasing from 2.4 at 12.5 mg to 1.6 at 100 mg. Dexketoprofen at doses of 10/12.5 mg and 20/25 mg produced NNTs for at least 50% pain relief over 4 to 6 hours of 3.2 and 3.6, with no obvious dose response. Significantly fewer participants used rescue medication with ketoprofen and dexketoprofen than placebo. The median time to remedication was about 5 hours with ketoprofen and 4 hours with dexketoprofen. The expected equivalent efficacy with a half dose of dexketoprofen compared to ketoprofen was not demonstrated. Adverse events were uncommon with both drugs, and not significantly different from placebo. Authors’ conclusions Ketoprofen at doses of 25 mg to 100 mg is an effective analgesic in moderate to severe acute postoperative pain with an NNT for at least 50% pain relief of 3.3 with a 50 mg dose. This is similar to that of commonly used NSAIDs such as ibuprofen (NNT 2.5 for 400 mg dose) and diclofenac (NNT 2.7 at 50 mg dose). Duration of action is about 5 hours. Dexketoprofen is also effective with NNTs of 3.2 to 3.6 in the dose range 10 mg to 25 mg. Both drugs were well tolerated in single doses. PMID:19821407

  15. Pregabalin for acute and chronic pain in adults

    PubMed Central

    Moore, R Andrew; Straube, Sebastian; Wiffen, Philip J; Derry, Sheena; McQuay, Henry J

    2014-01-01

    Background Antiepileptic drugs have been used in pain management since the 1960s. Pregabalin is a recently developed antiepileptic drug also used in management of chronic neuropathic pain conditions. Objectives To assess analgesic efficacy and associated adverse events of pregabalin in acute and chronic pain. Search methods We searched MEDLINE, EMBASE, and CENTRAL to May 2009 for randomised controlled trials (RCTs). Additional studies were identified from the reference lists of retrieved papers and on-line clinical trial databases. Selection criteria Randomised, double blind trials reporting on the analgesic effect of pregabalin, with subjective pain assessment by the patient as either the primary or a secondary outcome. Data collection and analysis Two independent review authors extracted data and assessed trial quality. Numbers-needed-to-treat-to-benefit (NNTs) were calculated, where possible, from dichotomous data for effectiveness, adverse events and study withdrawals. Main results There was no clear evidence of beneficial effects of pregabalin in established acute postoperative pain. No studies evaluated pregabalin in chronic nociceptive pain, like arthritis. Pregabalin at doses of 300 mg, 450 mg, and 600 mg daily was effective in patients with postherpetic neuralgia, painful diabetic neuropathy, central neuropathic pain, and fibromyalgia (19 studies, 7003 participants). Pregabalin at 150 mg daily was generally ineffective. Efficacy was demonstrated for dichotomous outcomes equating to moderate or substantial pain relief, alongside lower rates for lack of efficacy discontinuations with increasing dose. The best (lowest) NNT for each condition for at least 50% pain relief over baseline (substantial benefit) for 600 mg pregabalin daily compared with placebo were 3.9 (95% confidence interval 3.1 to 5.1) for postherpetic neuralgia, 5.0 (4.0 to 6.6) for painful diabetic neuropathy, 5.6 (3.5 to 14) for central neuropathic pain, and 11 (7.1 to 21) for fibromyalgia

  16. Ibuprofen with or without an antiemetic for acute migraine headaches in adults

    PubMed Central

    Rabbie, Roy; Derry, Sheena; Moore, R Andrew; McQuay, Henry J

    2014-01-01

    Background Migraine is a common, disabling condition and a burden for the individual, health services and society. Many sufferers do not seek professional help, relying instead on over-the-counter analgesics. Co-therapy with an antiemetic should help to reduce symptoms commonly associated with migraine headaches. Objectives To determine efficacy and tolerability of ibuprofen, alone or in combination with an antiemetic, compared to placebo and other active interventions in the treatment of acute migraine headaches in adults. Search methods We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies through 22 April 2010. Selection criteria We included randomised, double-blind, placebo- or active-controlled studies using self-administered ibuprofen to treat a migraine headache episode, with at least 10 participants per treatment arm. Data collection and analysis Two review authors independently assessed trial quality and extracted data. Numbers of participants achieving each outcome were used to calculate relative risk and number needed to treat (NNT) or harm (NNH) compared to placebo or other active treatment. Main results Nine studies (4373 participants, 5223 attacks) compared ibuprofen with placebo or other active comparators; none combined ibuprofen with a self-administered antiemetic. All studies treated attacks with single doses of medication. For ibuprofen 400 mg versus placebo, NNTs for 2-hour pain-free (26% versus 12% with placebo), 2-hour headache relief (57% versus 25%) and 24-hour sustained headache relief (45% versus 19%) were 7.2, 3.2 and 4.0, respectively. For ibuprofen 200 mg versus placebo, NNTs for 2-hour pain-free (20% versus 10%) and 2-hour headache relief (52% versus 37%) were 9.7 and 6.3, respectively. The higher dose was significantly better for 2-hour headache relief than the lower dose. Soluble formulations of ibuprofen 400 mg were better than standard tablets for 1-hour, but not 2-hour headache relief

  17. Pharmacotherapy for neuropathic pain in adults: systematic review, meta-analysis and updated NeuPSIG recommendations

    PubMed Central

    Finnerup, Nanna B; Attal, Nadine; Haroutounian, Simon; McNicol, Ewan; Baron, Ralf; Dworkin, Robert H; Gilron, Ian; Haanpaa, Maija; Hansson, Per; Jensen, Troels S; Kamerman, Peter R; Lund, Karen; Moore, Andrew; Raja, Srinivasa N; Rice, Andrew SC; Rowbotham, Michael; Sena, Emily; Siddall, Philip; Smith, Blair H; Wallace, Mark

    2015-01-01

    Summary Background Neuropathic pain is difficult to treat. New treatments, clinical trials and standards of quality for assessing evidence justify an update of evidence-based recommendations for its pharmacological treatment. Methods The Neuropathic Pain Special Interest Group (NeuPSIG) of the International Association for the Study of Pain conducted a systematic review of randomised double-blind studies of oral and topical pharmacotherapy for neuropathic pain, including unpublished trials (retrieved from clinicaltrials.gov and pharmaceutical websites). Meta-analysis used Numbers Needed to Treat (NNT) for 50 % pain relief as primary measure and assessed publication bias. Recommendations used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Findings In total 229 studies were included. Analysis of publication bias suggested a 10% overstatement of treatment effects. Studies published in peer-review journals reported greater effects than online studies (R2=9·3%, p<0·01). Trial outcomes were generally modest even for effective drugs : in particular NNTs were 3·6 (95 % CI 3·0–4·4) for tricyclic antidepressants (TCAs), 6·4 (95 % CI 5·2–8·4) for serotonin- noradrenaline reuptake inbibitor (SNRI) antidepressants duloxetine and venlafaxine, 7·7 (95 % CI 6·5–9·4) for pregabalin and 6·3 (95 % CI 5·0–8·3) for gabapentin. NNTs were higher for gabapentin ER/enacarbil and capsaicin high concentration patches, lower for opioids and botulinum toxin A (BTX-A) and undetermined for lidocaine patches. Final quality of evidence was lower for lidocaine patches and BTX-A. Tolerability/safety and values/preferences were high for lidocaine patches and lower for opioids and TCAs. This permitted a strong GRADE recommendation for use and proposal as first line for TCAs, SNRIs, pregabalin, gabapentin and gabapentin ER/enacarbil in neuropathic pain, a weak recommendation for use and proposal as second line for lidocaine patches, capsaicin

  18. Economic analysis of endovascular drug-eluting treatments for femoropopliteal artery disease in the UK

    PubMed Central

    Katsanos, Konstantinos; Garner, Abigail M; Zayed, Hany; Cleveland, Trevor; Pietzsch, Jan B

    2016-01-01

    Objectives To estimate the clinical and economic impact of drug-eluting endovascular treatment strategies for femoropopliteal artery disease compared with current standard of care. Design Systematic literature search to pool target lesion revascularisations (TLR). Model-based per-patient cost impact and quasi-cost-effectiveness projection over 24 months based on pooled TLRs and current reimbursement. Setting The UK's National Health Service (NHS). Participants Patients presenting with symptomatic femoropopliteal disease eligible for endovascular treatment. Interventions Current National Institute for Health and Care Excellence (NICE) guideline-recommended treatment with percutaneous transluminal balloon angioplasty (PTA) and bailout bare metal stenting (BMS) versus primary BMS placement, or drug-coated balloon (DCB), or drug-eluting stent (DES) treatment. Primary and secondary outcome measures 24-month per-patient cost impact to NHS (primary outcome). Secondary outcomes: pooled 24-month TLR rates; numbers needed to treat (NNTs); cost per TLR avoided and estimated incremental cost-effectiveness ratio (ICER) in £ per quality-adjusted life year (QALY). Results N=28 studies were identified, reporting on 5167 femoropopliteal lesions. Over 24 months, DCB, DES and BMS reduced TLRs of de novo lesions from 36.2% to 17.6%, 19.4% and 26.9%, respectively, at an increased cost of £43, £44 and £112. NNTs to avoid 1 TLR in 24 months were 5.4, 6.0 and 10.8, resulting in cost per TLR avoided of £231, £264 and £1204. DCB was estimated to add 0.011 QALYs, DES 0.010 QALYs and BMS 0.005 QALYs, resulting in estimated ICERs of £3983, £4534 and £20 719 per QALY gained. A subset analysis revealed more favourable clinical and economic outcomes for a 3.5 µg/mm2 DCB with urea excipient, compared with the rest of DCBs. A modest reduction of 10% in DCB and DES prices made drug-eluting treatments dominant. Conclusions Widespread adoption of drug-eluting endovascular

  19. Single dose oral diclofenac for acute postoperative pain in adults

    PubMed Central

    Derry, Philip; Derry, Sheena; Moore, R Andrew; McQuay, Henry J

    2014-01-01

    Background Diclofenac is a non-steroidal anti-inflammatory drug (NSAID), available as a potassium salt (immediate-release) or sodium salt (delayed-release). This review updates an earlier review published in The Cochrane Database of Systematic Reviews (Issue 2, 2004) on ‘Single dose oral diclofenac for postoperative pain’. Objectives To assess single dose oral diclofenac for the treatment of acute postoperative pain. Search methods Cochrane CENTRAL, MEDLINE, EMBASE, Biological Abstracts, the Oxford Pain Relief Database, and reference lists of articles were searched; last search December 2008. Selection criteria Randomised, double-blind, placebo-controlled clinical trials of single dose, oral diclofenac (sodium or potassium) for acute postoperative pain in adults. Data collection and analysis Two review authors independently assessed studies for inclusion and quality, and extracted data. The area under the pain relief versus time curve was used to derive the proportion of participants with at least 50% pain relief over 4 to 6 hours, using validated equations. Relative benefit (risk) and number needed to treat to benefit (NNT) were calculated. Information on adverse events, time to remedication, and participants needing additional analgesia was also collected. Main results Fifteen studies (eight additional studies) with 1512 participants more than doubled the information available at each dose. Overall 50% to 60% of participants experienced at least 50% pain relief over 4 to 6 hours at any dose with diclofenac, compared to 10 to 20% with placebo, giving NNTs of about 2.5 for doses of 25 mg to 100 mg (similar to earlier review); no dose response was demonstrated. At 50 mg and 100 mg, NNTs for diclofenac potassium (2.1 (1.8 to 2.4) and 1.9 (1.7 to 2.2)) were significantly lower (better) than for diclofenac sodium (6.7 (4.2 to 17) and 4.5 (3.2 to 7.7)). The median time to use of rescue medication was 2 hours for placebo, 4.3 hours for diclofenac 50 mg and 4.9 hours

  20. NMR and NQR study of Si-doped (6,0) zigzag single-walled aluminum nitride nanotube as n or P-semiconductors.

    PubMed

    Baei, Mohammad T; Peyghan, Ali Ahmadi; Tavakoli, Khadijeh; Babaheydari, Ali Kazemi; Moghimi, Masoumeh

    2012-09-01

    Density functional theory (DFT) calculations were performed to investigate the electronic structure properties of pristine and Si-doped aluminum nitride nanotubes as n or P-semiconductors at the B3LYP/6-31G* level of theory in order to evaluate the influence of Si-doped in the (6,0) zigzag AlNNTs. We extended the DFT calculation to predict the electronic structure properties of Si-doped aluminum nitride nanotubes, which are very important for production of solid-state devices and other applications. To this aim, pristine and Si-doped AlNNT structures in two models (Si(N) and Si(Al)) were optimized, and then the electronic properties, the isotropic (CS(I)) and anisotropic (CS(A)) chemical shielding parameters for the sites of various (27)Al and (14)N atoms, NQR parameters for the sites of various of (27)Al and (14)N atoms, and quantum molecular descriptors were calculated in the optimized structures. The optimized structures, the electronic properties, NMR and NQR parameters, and quantum molecular descriptors for the Si(N) and Si(Al) models show that the Si(N) model is a more reactive material than the pristine or Si(Al) model. PMID:22588584

  1. Population Attributable Risk Fractions of Maternal Overweight and Obesity for Adverse Perinatal Outcomes.

    PubMed

    MacInnis, Natasha; Woolcott, Christy G; McDonald, Sarah; Kuhle, Stefan

    2016-01-01

    The objective of the current study was to determine the proportion of adverse perinatal outcomes that could be potentially prevented if maternal obesity were to be reduced or eliminated (population attributable risk fractions, PARF); and the number needed to treat (NNT) of overweight or obese women to prevent one case of adverse perinatal outcome. Data from the Atlee Perinatal Database on 66,689 singleton infants born in Nova Scotia, Canada, between 2004 and 2014, and their mothers were used. Multivariable-adjusted PARFs and NNTs of maternal pre-pregnancy weight status were determined for various perinatal outcomes under three scenarios: If all overweight and obese women were to i) become normal weight before pregnancy; ii) shift down one weight class; or iii) lose 10% of their body weight, significant relative reductions would be seen for gestational diabetes mellitus (GDM, 57/33/15%), hypertensive disorders of pregnancy (HDP, 26/16/6%), caesarean section (CS, 18/10/3%), and large for gestational age births (LGA, 24/14/3%). The NNT were lowest for the outcomes GDM, induction of labour, CS, and LGA, where they ranged from 13 to 73. The study suggests that a substantial proportion of adverse perinatal outcomes may be preventable through reductions in maternal pre-pregnancy weight. PMID:26961675

  2. Electric field effect on (6,0) zigzag single-walled aluminum nitride nanotube.

    PubMed

    Baei, Mohammad T; Peyghan, Ali Ahmadi; Moghimi, Masoumeh

    2012-09-01

    Structural, electronic, and electrical responses of the H-capped (6,0) zigzag single-walled aluminum nitride nanotube was studied under the parallel and transverse electric fields with strengths 0-140 × 10(-4) a.u. by using density functional calculations. Geometry optimizations were carried out at the B3LYP/6-31G* level of theory using a locally modified version of the GAMESS electronic structure program. The dipole moments, atomic charge variations, and total energy of the (6,0) zigzag AlNNT show increases with increase in the applied external electric field strengths. The length, tip diameters, electronic spatial extent, and molecular volume of the nanotube do not significantly change with increasing electric field strength. The energy gap of the nanotube decreases with increases of the electric field strength and its reactivity is increased. Increase of the ionization potential, electron affinity, chemical potential, electrophilicity, and HOMO and LUMO in the nanotube with increase of the applied parallel electric field strengths shows that the parallel field has a much stronger interaction with the nanotube with respect to the transverse electric field strengths. Analysis of the parameters indicates that the properties of AlNNTs can be controlled by the proper external electric field. PMID:22643968

  3. Microcantilever technology for law enforcement and anti-terrorism applications: chemical, biological, and explosive material detection

    NASA Astrophysics Data System (ADS)

    Adams, J. D.; Rogers, B.; Whitten, R.

    2005-05-01

    The remarkable sensitivity, compactness, low cost, low power-consumption, scalability, and versatility of microcantilever sensors make this technology among the most promising solutions for detection of chemical and biological agents, as well as explosives. The University of Nevada, Reno, and Nevada Nanotech Systems, Inc (NNTS) are currently developing a microcantilever-based detection system that will measure trace concentrations of explosives, toxic chemicals, and biological agents in air. A baseline sensor unit design that includes the sensor array, electronics, power supply and air handling has been created and preliminary demonstrations of the microcantilever platform have been conducted. The envisioned device would measure about two cubic inches, run on a small watch battery and cost a few hundred dollars. The device could be operated by untrained law enforcement personnel. Microcantilever-based devices could be used to "sniff out" illegal and/or hazardous chemical and biological agents in high traffic public areas, or be packaged as a compact, low-power system used to monitor cargo in shipping containers. Among the best detectors for such applications at present is the dog, an animal which is expensive, requires significant training and can only be made to work for limited time periods. The public is already accustomed to explosives and metal detection systems in airports and other public venues, making the integration of the proposed device into such security protocols straightforward.

  4. Bias from industry trial funding? A framework, a suggested approach, and a negative result.

    PubMed

    Barden, Jodie; Derry, Sheena; McQuay, Henry J; Moore, R Andrew

    2006-04-01

    Bias from funding sources of trials would threaten their validity. Meta-analyses of high quality acute pain and migraine trials were used to explore the hypothesis that industry funding of clinical trials produced more favourable results than non-profit sponsorship. Analyses were planned to evaluate whether industry-sponsored trials had different results from trials funded by academic or other non-profit sources, but of 176 trials, only two were supported by non-profit sources, while 31 provided no statement of support. An alternative method is proposed within industry-sponsored trials, looking at conflicting industry interests for the same drug, used either as test or comparator treatment. Fifty-three trials used an analgesic as test and 90 as comparator, allowing comparisons to be made for aspirin 600/650 mg, ibuprofen 400 mg, paracetamol (acetaminophen) 1000 mg, rofecoxib 50 mg and sumatriptan 50 and 100 mg. Only for sumatriptan 50 and 100 mg, with the outcome of headache response at 2 h, was there any significant difference between the drug used as a test or as a comparator. The direction was for higher (worse) NNTs with sumatriptan as comparator. Investigating potential industry bias through the funding source of trials is unlikely to be adequate because of a dearth of trials funded by non-profit organisations. We propose a method based on potential conflict of interest within industry-sponsored trials. Using this method, established clinical trial results in acute pain and migraine appear to be unbiased. PMID:16495012

  5. A computational NMR study on zigzag aluminum nitride nanotubes

    NASA Astrophysics Data System (ADS)

    Bodaghi, Ali; Mirzaei, Mahmoud; Seif, Ahmad; Giahi, Masoud

    2008-12-01

    A computational nuclear magnetic resonance (NMR) study is performed to investigate the electronic structure properties of the single-walled zigzag aluminum nitride nanotubes (AlNNTs). The chemical-shielding (CS) tensors are calculated at the sites of Al-27 and N-15 nuclei in three structural forms of AlNNT including H-saturated, Al-terminated, and N-terminated ones. The structural forms are firstly optimized and then the calculated CS tensors in the optimized structures are converted to chemical-shielding isotropic (CSI) and chemical-shielding anisotropic (CSA) parameters. The calculated parameters reveal that various Al-27 and N-15 nuclei are divided into some layers with equivalent electrostatic properties; furthermore, Al and N can act as Lewis base and acid, respectively. In the Al-terminated and N-terminated forms of AlNNT, in which one mouth of the nanotube is terminated by aluminum and nitrogen nuclei, respectively, just the CS tensors of the nearest nuclei to the mouth of the nanotube are significantly changed due to removal of saturating hydrogen atoms. Density functional theory (DFT) calculations are performed using GAUSSIAN 98 package of program.

  6. Psychological treatments for adults with posttraumatic stress disorder: A systematic review and meta-analysis.

    PubMed

    Cusack, Karen; Jonas, Daniel E; Forneris, Catherine A; Wines, Candi; Sonis, Jeffrey; Middleton, Jennifer Cook; Feltner, Cynthia; Brownley, Kimberly A; Olmsted, Kristine Rae; Greenblatt, Amy; Weil, Amy; Gaynes, Bradley N

    2016-02-01

    Numerous guidelines have been developed over the past decade regarding treatments for Posttraumatic stress disorder (PTSD). However, given differences in guideline recommendations, some uncertainty exists regarding the selection of effective PTSD therapies. The current manuscript assessed the efficacy, comparative effectiveness, and adverse effects of psychological treatments for adults with PTSD. We searched MEDLINE, Cochrane Library, PILOTS, Embase, CINAHL, PsycINFO, and the Web of Science. Two reviewers independently selected trials. Two reviewers assessed risk of bias and graded strength of evidence (SOE). We included 64 trials; patients generally had severe PTSD. Evidence supports efficacy of exposure therapy (high SOE) including the manualized version Prolonged Exposure (PE); cognitive therapy (CT), cognitive processing therapy (CPT), cognitive behavioral therapy (CBT)-mixed therapies (moderate SOE); eye movement desensitization and reprocessing (EMDR) and narrative exposure therapy (low-moderate SOE). Effect sizes for reducing PTSD symptoms were large (e.g., Cohen's d ~-1.0 or more compared with controls). Numbers needed to treat (NNTs) were <4 to achieve loss of PTSD diagnosis for exposure therapy, CPT, CT, CBT-mixed, and EMDR. Several psychological treatments are effective for adults with PTSD. Head-to-head evidence was insufficient to determine these treatments' comparative effectiveness, and data regarding adverse events was absent from most studies. PMID:26574151

  7. Paracetamol (acetaminophen) with or without an antiemetic for acute migraine headaches in adults

    PubMed Central

    Derry, Sheena; Moore, R Andrew; McQuay, Henry J

    2014-01-01

    Background Migraine is a common, disabling condition and a burden for the individual, health services and society. Many sufferers choose not to, or are unable to, seek professional help and rely on over-the-counter analgesics. Co-therapy with an antiemetic should help to reduce nausea and vomiting commonly associated with migraine. Objectives To determine the efficacy and tolerability of paracetamol (acetaminophen), alone or in combination with an antiemetic, compared to placebo and other active interventions in the treatment of acute migraine in adults. Search methods We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies through 4 October 2010. Selection criteria We included randomised, double-blind, placebo- or active-controlled studies using self-administered paracetamol to treat a migraine headache episode, with at least 10 participants per treatment arm. Data collection and analysis Two review authors independently assessed trial quality and extracted data. Numbers of participants achieving each outcome were used to calculate relative risk and numbers needed to treat (NNT) or harm (NNH) compared to placebo or other active treatment. Main results Ten studies (2769 participants, 4062 attacks) compared paracetamol 1000 mg, alone or in combination with an antiemetic, with placebo or other active comparators, mainly sumatriptan 100 mg. For all efficacy outcomes paracetamol was superior to placebo, with NNTs of 12, 5.2 and 5.0 for 2-hour pain-free and 1- and 2-hour headache relief, respectively, when medication was taken for moderate to severe pain. Nausea, photophobia and phonophobia were reduced more with paracetamol than with placebo at 2 hours (NNTs of 7 to 11); more individuals were free of any functional disability at 2 hours with paracetamol (NNT 10); and fewer participants needed rescue medication over 6 hours (NNT 6). Paracetamol 1000 mg plus metoclopramide 10 mg was not significantly different from oral sumatriptan

  8. Ecological momentary assessment versus standard assessment instruments for measuring mindfulness, depressed mood, and anxiety among older adults.

    PubMed

    Moore, Raeanne C; Depp, Colin A; Wetherell, Julie Loebach; Lenze, Eric J

    2016-04-01

    As mobile data capture tools for patient-reported outcomes proliferate in clinical research, a key dimension of measure performance is sensitivity to change. This study compared performance of patient-reported measures of mindfulness, depression, and anxiety symptoms using traditional paper-and-pencil forms versus real-time, ambulatory measurement of symptoms via ecological momentary assessment (EMA). Sixty-seven emotionally distressed older adults completed paper-and-pencil measures of mindfulness, depression, and anxiety along with two weeks of identical items reported during ambulatory monitoring via EMA before and after participation in a randomized trial of Mindfulness-Based Stress Reduction (MBSR) or a health education intervention. We calculated effect sizes for these measures across both measurement approaches and estimated the Number-Needed-to-Treat (NNT) in both measurement conditions. Study outcomes greatly differed depending on which measurement method was used. When EMA was used to measure clinical symptoms, older adults who participated in the MBSR intervention had significantly higher mindfulness and significantly lower depression and anxiety than participants in the health education intervention at post-treatment. However, these significant changes in symptoms were not found when outcomes were measured with paper-and-pencil measures. The NNT for mindfulness and depression measures administered through EMA were approximately 25-50% lower than NNTs derived from paper-and-pencil administration. Sensitivity to change in anxiety was similar across administration modes. In conclusion, EMA measures of depression and mindfulness substantially outperformed paper-and-pencil measures with the same items. The additional resources associated with EMA in clinical trials would seem to be offset by its greater sensitivity to detect change in key outcome variables. PMID:26851494

  9. Ketoanalogue-Supplemented Vegetarian Very Low-Protein Diet and CKD Progression.

    PubMed

    Garneata, Liliana; Stancu, Alexandra; Dragomir, Diana; Stefan, Gabriel; Mircescu, Gabriel

    2016-07-01

    Dietary protein restriction may improve determinants of CKD progression. However, the extent of improvement and effect of ketoanalogue supplementation are unclear. We conducted a prospective, randomized, controlled trial of safety and efficacy of ketoanalogue-supplemented vegetarian very low-protein diet (KD) compared with conventional low-protein diet (LPD). Primary end point was RRT initiation or >50% reduction in initial eGFR. Nondiabetic adults with stable eGFR<30 ml/min per 1.73 m(2), proteinuria <1 g/g urinary creatinine, good nutritional status, and good diet compliance entered a run-in phase on LPD. After 3 months, compliant patients were randomized to KD (0.3 g/kg vegetable proteins and 1 cps/5 kg ketoanalogues per day) or continue LPD (0.6 g/kg per day) for 15 months. Only 14% of screened patients patients were randomized, with no differences between groups. Adjusted numbers needed to treat (NNTs; 95% confidence interval) to avoid composite primary end point in intention to treat and per-protocol analyses in one patient were 4.4 (4.2 to 5.1) and 4.0 (3.9 to 4.4), respectively, for patients with eGFR<30 ml/min per 1.73 m(2) Adjusted NNT (95% confidence interval) to avoid dialysis was 22.4 (21.5 to 25.1) for patients with eGFR<30 ml/min per 1.73 m(2) but decreased to 2.7 (2.6 to 3.1) for patients with eGFR<20 ml/min per 1.73 m(2) in intention to treat analysis. Correction of metabolic abnormalities occurred only with KD. Compliance to diet was good, with no changes in nutritional parameters and no adverse reactions. Thus, this KD seems nutritionally safe and could defer dialysis initiation in some patients with CKD. PMID:26823552

  10. Linaclotide: Promising IBS-C Efficacy in an Era of Provisional Study Endpoints

    PubMed Central

    Sayuk, Gregory S.

    2013-01-01

    Recent disappointing developments in the pharmacotherapy of irritable bowel syndrome (IBS) have not dampened the enthusiasm surrounding linaclotide, a novel guanylate cyclase-C agonist for the management of constipation-predominant IBS (IBS-C). Two recent phase 3 studies reporting on a single, daily dose of linaclotide are presented in this issue of the American Journal of Gastroenterology. Importantly, these studies are the first to examine a provisional Food and Drug Administration (FDA) combined response endpoint for IBS-C, which mandates improvements of both abdominal pain and defecatory symptoms. Potential limitations of this FDA endpoint relate to a lack of inclusion of other potentially important IBS symptoms and an inability to directly compare findings with other recent IBS-C trials. Both studies successfully reached this endpoint in approximately one-third of study subjects, resulting in numbers needed to treat (NNT) of five to eight, to achieve an FDA responder. Individual symptom responses to linaclotide were seen in nearly 50% of participants, and potential explanations for these discrepancies when compared with the FDA endpoint are offered. Adequate relief measures also were assessed and, with NNTs of 3.4–6.8, compared favorably with other contemporary IBS-C studies. Overall, both linaclotide trials found the medication to be safe in terms of serious adverse events, though the secretagogue mechanism of action led to diarrhea in approximately one in five subjects. Together, these studies inspire several other important questions regarding linaclotide, including its role in the management of IBS-C relative to existing treatment options, such as lubiprostone. Greater clinical use of linaclotide will reveal whether the observed responses measured with the FDA provisional endpoint will translate into real-world experiences of improvement in IBS patients. “ In seeking absolute truth we aim at the unattainable and must be content with broken portions

  11. Linaclotide: promising IBS-C efficacy in an era of provisional study endpoints.

    PubMed

    Sayuk, Gregory S

    2012-11-01

    Recent disappointing developments in the pharmacotherapy of irritable bowel syndrome (IBS) have not dampened the enthusiasm surrounding linaclotide, a novel guanylate cyclase-C agonist for the management of constipation-predominant IBS (IBS-C). Two recent phase 3 studies reporting on a single, daily dose of linaclotide are presented in this issue of the American Journal of Gastroenterology. Importantly, these studies are the first to examine a provisional Food and Drug Administration (FDA) combined response endpoint for IBS-C, which mandates improvements of both abdominal pain and defecatory symptoms. Potential limitations of this FDA endpoint relate to a lack of inclusion of other potentially important IBS symptoms and an inability to directly compare findings with other recent IBS-C trials. Both studies successfully reached this endpoint in approximately one-third of study subjects, resulting in numbers needed to treat (NNT) of five to eight, to achieve an FDA responder. Individual symptom responses to linaclotide were seen in nearly 50% of participants, and potential explanations for these discrepancies when compared with the FDA endpoint are offered. Adequate relief measures also were assessed and, with NNTs of 3.4-6.8, compared favorably with other contemporary IBS-C studies. Overall, both linaclotide trials found the medication to be safe in terms of serious adverse events, though the secretagogue mechanism of action led to diarrhea in approximately one in five subjects. Together, these studies inspire several other important questions regarding linaclotide, including its role in the management of IBS-C relative to existing treatment options, such as lubiprostone. Greater clinical use of linaclotide will reveal whether the observed responses measured with the FDA provisional endpoint will translate into real-world experiences of improvement in IBS patients. PMID:23160292

  12. The Number Needed to Treat: 25 Years of Trials and Tribulations in Clinical Research

    PubMed Central

    Suissa, Samy

    2015-01-01

    The number needed to treat (NNT) is a simple measure of a treatment’s impact, increasingly reported in randomized trials and observational studies, but often incorrectly calculated in studies involving varying follow-up times. We discuss the NNT in these contexts and illustrate the concept using several published studies. While the computation of the NNT is founded on the cumulative incidence of the outcome, several published studies use simple proportions that do not account for varying follow-up times, or use incidence rates per person-time. We show how these approaches can lead to erroneous values of the NNT and misleading interpretations. For example, a trial of 3,845 very elderly hypertensives randomized to a diuretic or placebo reported a NNT of 94 treated for 2 years to prevent one stroke, though the correct approach results in a NNT of 63. Also, meta-analyses involving trials of differing lengths often report a single NNT, such as the meta-analysis of 22 trials of the anticholinergic tiotropium in chronic obstructive pulmonary disease that reported a NNT of 16 patients “over one year,” even if the trials varied in duration from 3 to 48 months, with the actual NNTs varying widely from 15 to 250. Finally, we describe the value of the NNT in assessing benefit–risk, such as low-dose aspirin use in secondary prevention of mortality assessed against the risk of gastrointestinal bleeding. As the “number needed to treat” becomes increasingly used in the comparative effectiveness and safety of therapies, its accurate estimation and interpretation become crucial to avoid distorting clinical, economic, and public health decisions. PMID:26241223

  13. An indirect comparison and cost per responder analysis of adalimumab, methotrexate and apremilast in the treatment of methotrexate-naïve patients with psoriatic arthritis.

    PubMed

    Betts, Keith A; Griffith, Jenny; Friedman, Alan; Zhou, Zheng-Yi; Signorovitch, James E; Ganguli, Arijit

    2016-04-01

    Objective Apremilast was recently approved for the treatment of active psoriatic arthritis (PsA). However, no studies compare apremilast with methotrexate or biologic therapies, so its relative comparative efficacy remains unknown. This study compared the response rates and incremental costs per responder associated with methotrexate, apremilast, and biologics for the treatment of active PsA. Methods A systematic literature review was performed to identify phase 3 randomized controlled clinical trials of approved biologics, methotrexate, and apremilast in the methotrexate-naïve PsA population. Using Bayesian methods, a network meta-analysis was conducted to indirectly compare rates of achieving a ≥20% improvement in American College of Rheumatology component scores (ACR20). The number needed to treat (NNT) and the incremental costs per ACR20 responder (2014 US$) relative to placebo were estimated for each of the therapies. Results Three trials (MIPA for methotrexate, PALACE-4 for apremilast, and ADEPT for adalimumab) met all inclusion criteria. The NNTs relative to placebo were 2.63 for adalimumab, 6.69 for apremilast, and 8.31 for methotrexate. Among methotrexate-naïve PsA patients, the 16 week incremental costs per ACR20 responder were $3622 for methotrexate, $26,316 for adalimumab, and $45,808 for apremilast. The incremental costs per ACR20 responder were $222,488 for apremilast vs. methotrexate. Conclusion Among methotrexate-naive PsA patients, adalimumab was found to have the lowest NNT for one additional ACR20 response and methotrexate was found to have the lowest incremental costs per ACR20 responder. There was no statistical evidence of greater efficacy for apremilast vs. methotrexate. A head-to-head trial between apremilast and methotrexate is recommended to confirm this finding. PMID:26743448

  14. Sumatriptan (subcutaneous route of administration) for acute migraine attacks in adults

    PubMed Central

    Derry, Christopher J; Derry, Sheena; Moore, R Andrew

    2014-01-01

    Background Migraine is a highly disabling condition for the individual and also has wide-reaching implications for society, healthcare services, and the economy. Sumatriptan is an abortive medication for migraine attacks, belonging to the triptan family. Subcutaneous administration may be preferable to oral for individuals experiencing nausea and/or vomiting Objectives To determine the efficacy and tolerability of subcutaneous sumatriptan compared to placebo and other active interventions in the treatment of acute migraine attacks in adults. Search methods We searched Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, online databases, and reference lists for studies through 13 October 2011. Selection criteria We included randomised, double-blind, placebo- and/or active-controlled studies using subcutaneous sumatriptan to treat a migraine headache episode, with at least 10 participants per treatment arm. Data collection and analysis Two review authors independently assessed trial quality and extracted data. We used numbers of participants achieving each outcome to calculate relative risk (or ‘risk ratio’) and numbers needed to treat to benefit (NNT) or harm (NNH) compared to placebo or a different active treatment. Main results Thirty-five studies (9365 participants) compared subcutaneous sumatriptan with placebo or an active comparator. Most of the data were for the 6 mg dose. Sumatriptan surpassed placebo for all efficacy outcomes. For sumatriptan 6 mg versus placebo the NNTs were 2.9, 2.3, 2.2, and 2.1 for pain-free at one and two hours, and headache relief at one and two hours, respectively, and 6.1 for sustained pain-free at 24 hours. Results for the 4 mg and 8 mg doses were similar to the 6 mg dose, with 6 mg significantly better than 4 mg only for pain-free at one hour, and 8 mg significantly better than 6 mg only for headache relief at one hour. There was no evidence of increased migraine relief if a second dose of sumatriptan 6

  15. Nasal continuous positive airway pressure (nCPAP) treatment for obstructive sleep apnea, road traffic accidents and driving simulator performance: a meta-analysis.

    PubMed

    Antonopoulos, Constantine N; Sergentanis, Theodoros N; Daskalopoulou, Styliani S; Petridou, Eleni Th

    2011-10-01

    We used meta-analysis to synthesize current evidence regarding the effect of nasal continuous positive airway pressure (nCPAP) on road traffic accidents in patients with obstructive sleep apnea (OSA) as well as on their performance in driving simulator. The primary outcomes were real accidents, near miss accidents, and accident-related events in the driving simulator. Pooled odds ratios (ORs), incidence rate ratios (IRRs) and standardized mean differences (SMDs) were appropriately calculated through fixed or random effects models after assessing between-study heterogeneity. Furthermore, risk differences (RDs) and numbers needed to treat (NNTs) were estimated for real and near miss accidents. Meta-regression analysis was performed to examine the effect of moderator variables and publication bias was also evaluated. Ten studies on real accidents (1221 patients), five studies on near miss accidents (769 patients) and six studies on the performance in driving simulator (110 patients) were included. A statistically significant reduction in real accidents (OR=0.21, 95% CI=0.12-0.35, random effects model; IRR=0.45, 95% CI=0.34-0.59, fixed effects model) and near miss accidents (OR=0.09, 95% CI=0.04-0.21, random effects model; IRR=0.23, 95% CI=0.08-0.67, random effects model) was observed. Likewise, a significant reduction in accident-related events was observed in the driving simulator (SMD=-1.20, 95% CI=-1.75 to -0.64, random effects). The RD for real accidents was -0.22 (95% CI=-0.32 to -0.13, random effects), with NNT equal to five patients (95% CI=3-8), whereas for near miss accidents the RD was -0.47 (95% CI=-0.69 to -0.25, random effects), with NNT equal to two patients (95% CI=1-4). For near miss accidents, meta-regression analysis suggested that nCPAP seemed more effective among patients entering the studies with higher baseline accident rates. In conclusion, all three meta-analyses demonstrated a sizeable protective effect of nCPAP on road traffic accidents, both

  16. Single dose oral ibuprofen for acute postoperative pain in adults

    PubMed Central

    Derry, Christopher J; Derry, Sheena; Moore, R Andrew; McQuay, Henry J

    2014-01-01

    frequent with higher doses, with 48% remedicating with 200 mg and 42% with 400 mg. The median time to remedication was 4.7 hours with 200 mg and 5.4 hours with 400 mg. Sensitivity analysis indicated that pain model and ibuprofen formulation may both affect the result, with dental impaction models and soluble ibuprofen salts producing better efficacy estimates. Adverse events were uncommon, and not different from placebo. Authors’ conclusions The very substantial amount of high quality evidence demonstrates that ibuprofen is an effective analgesic in treating postoperative pain. NNTs for 200 mg and 400 mg ibuprofen did not change significantly from the previous review even when a substantial amount of new information was added. New information is provided on remedication. PMID:19588326

  17. Lamotrigine for acute and chronic pain

    PubMed Central

    Wiffen, Philip J; Derry, Sheena; Moore, R Andrew

    2014-01-01

    Background This is an update of the original Cochrane review published in Issue 2, 2007. Some antiepileptic medicines have a place in the treatment of neuropathic pain (pain due to nerve damage). This updated review adds five new additional studies looking at evidence for Lamotrigine as an effective treatment for acute and chronic pain. Objectives To assess analgesic efficacy and adverse effects of the antiepileptic drug lamotrigine in acute and chronic pain. Search methods Randomised controlled trials (RCTs) of lamotrigine in acute, and chronic pain (including cancer pain) were identified from MEDLINE, EMBASE and CENTRAL up to January 2011. Additional studies were sought from the reference list of the retrieved papers. Selection criteria RCTs investigating the use of lamotrigine (any dose, by any route, and for any study duration) for the treatment of acute or chronic pain. Assessment of pain intensity or pain relief, or both, using validated scales. Participants were adults aged 18 and over. Only full journal publication articles were included. Data collection and analysis Dichotomous data (ideally for the outcome of at least 50% pain relief) were used to calculate relative risk with 95% confidence intervals. Meta-analysis was undertaken using a fixed-effect model. Numbers needed to treat to benefit (NNTs) were calculated as the reciprocal of the absolute risk reduction. For unwanted effects, the NNT becomes the number needed to harm (NNH) and was calculated. Main results Twelve included studies in 11 publications (1511 participants), all with chronic neuropathic pain: central post stroke pain (1), chemotherapy induced neuropathic pain (1), diabetic neuropathy (4), HIV related neuropathy (2), mixed neuropathic pain (2), spinal cord injury related pain (1), and trigeminal neuralgia (1); none investigated lamotrigine in acute pain. The update had five additional studies (1111 additional participants). Participants were aged between 26 and 77 years. Study duration

  18. Aspirin with or without an antiemetic for acute migraine headaches in adults

    PubMed Central

    Kirthi, Varo; Derry, Sheena; Moore, R Andrew; McQuay, Henry J

    2014-01-01

    Background Migraine is a common, disabling condition and a burden for the individual, health services and society. Many sufferers choose not to, or are unable to, seek professional help and rely on over-the-counter analgesics. Co-therapy with an antiemetic should help to reduce nausea and vomiting commonly associated with migraine headaches. Objectives To determine the efficacy and tolerability of aspirin, alone or in combination with an antiemetic, compared to placebo and other active interventions in the treatment of acute migraine headaches in adults. Search methods We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies through 10 March 2010. Selection criteria We included randomised, double-blind, placebo- or active-controlled studies using aspirin to treat a discrete migraine headache episode, with at least 10 participants per treatment arm. Data collection and analysis Two review authors independently assessed trial quality and extracted data. Numbers of participants achieving each outcome were used to calculate relative risk and numbers needed to treat (NNT) or harm (NNH) compared to placebo or other active treatment. Main results Thirteen studies (4222 participants) compared aspirin 900 mg or 1000 mg, alone or in combination with metoclopramide 10 mg, with placebo or other active comparators, mainly sumatriptan 50 mg or 100 mg. For all efficacy outcomes, all active treatments were superior to placebo, with NNTs of 8.1, 4.9 and 6.6 for 2-hour pain-free, 2-hour headache relief, and 24-hour headache relief with aspirin alone versus placebo, and 8.8, 3.3 and 6.2 with aspirin plus metoclopramide versus placebo. Sumatriptan 50 mg did not differ from aspirin alone for 2-hour pain-free and headache relief, while sumatriptan 100 mg was better than the combination of aspirin plus metoclopramide for 2-hour pain-free, but not headache relief; there were no data for 24-hour headache relief. Associated symptoms of nausea, vomiting

  19. Single-patient data meta-analysis of 3453 postoperative patients: oral tramadol versus placebo, codeine and combination analgesics.

    PubMed

    Moore, R A; McQuay, H J

    1997-02-01

    The analgesic effectiveness and safety of oral tramadol were compared with standard analgesics using a meta-analysis of individual patient data from randomised controlled trials in patients with moderate or severe pain after surgery or dental extraction. Calculation of %maxTOTPAR from individual patient data, and the use of > 50%maxTOTPAR defined clinically acceptable pain relief. Number-needed-to-treat (NNT) for one patient to have > 50%maxTOTPAR compared with placebo was used to examine the effectiveness of different single oral doses of tramadol and comparator drugs. Eighteen randomised, double-blind, parallel-group single-dose trials with 3453 patients using categorical pain relief scales allowed the calculation of %maxTOTPAR. The use of > 50%maxTOTPAR was a sensitive measure to discriminate between analgesics. Tramadol and comparator drugs gave significantly more analgesia than placebo. In postsurgical pain tramadol 50, 100 and 150 mg had NNTs for > 50%maxTOTPAR of 7.1 (95% confidence intervals 4.6-18), 4.8 (3.4-8.2) and 2.4 (2.0-3.1), comparable with aspirin 650 mg plus codeine 60 mg (NNT 3.6 (2.5-6.3)) and acetaminophen 650 mg plus propoxyphene 100 mg (NNT 4.0 (3.0-5.7)). With the same dose of drug postsurgical patients had more pain relief than those having dental surgery. Tramadol showed a dose-response for analgesia in both postsurgical and dental pain patients. With the same dose of drug postsurgical pain patients had fewer adverse events than those having dental surgery. Adverse events (headache, nausea, vomiting, dizziness, somnolence) with tramadol 50 mg and 100 mg had a similar incidence to comparator drugs. There was a dose response with tramadol, tending towards higher incidences at higher doses. Single-patient meta-analysis using more than half pain relief provides a sensitive description of the analgesic properties of a drug, and NNT calculations allow comparisons to be made with standard analgesics. Absolute ranking of analgesic performance

  20. Single dose oral analgesics for acute postoperative pain in adults

    PubMed Central

    Moore, R Andrew; Derry, Sheena; McQuay, Henry J; Wiffen, Philip J

    2014-01-01

    mg, diflunisal 125 mg, etoricoxib 60 mg, fenbufen, and indometacin. Where there was adequate information for drug/dose combinations (at least 200 participants, in at least two studies), we defined the addition of four comparisons of typical size (400 participants in total) with zero effect as making the result potentially subject to publication bias and therefore unreliable. Reliable results were obtained for 46 drug/dose combinations in all painful postsurgical conditions; 45 in dental pain and 14 in other painful conditions. NNTs varied from about 1.5 to 20 for at least 50% maximum pain relief over four to six hours compared with placebo. The proportion of participants achieving this level of benefit varied from about 30% to over 70%, and the time to remedication varied from two hours (placebo) to over 20 hours in the same pain condition. Participants reporting at least one adverse event were few and generally no different between active drug and placebo, with a few exceptions, principally for aspirin and opioids. Drug/dose combinations with good (low) NNTs were ibuprofen 400 mg (2.5; 95% confidence interval (CI) 2.4 to 2.6), diclofenac 50 mg (2.7; 95% CI 2.4 to 3.0), etoricoxib 120 mg (1.9; 95% CI 1.7 to 2.1), codeine 60 mg + paracetamol 1000 mg (2.2; 95% CI 1.8 to 2.9), celecoxib 400 mg (2.5; 95% CI 2.2 to 2.9), and naproxen 500/550 mg (2.7; 95% CI 2.3 to 3.3). Long duration of action (8 hours) was found for etoricoxib 120 mg, diflunisal 500 mg, oxycodone 10 mg + paracetamol 650 mg, naproxen 500/550 mg, and celecoxib 400 mg. Not all participants had good pain relief and for many drug/dose combinations 50% or more did not achieve at last 50% maximum pain relief over four to six hours. Authors’ conclusions There is a wealth of reliable evidence on the analgesic efficacy of single dose oral analgesics. There is also important information on drugs for which there are no data, inadequate data, or where results are unreliable due to susceptibility to publication bias

  1. Single dose oral paracetamol (acetaminophen) for postoperative pain in adults

    PubMed Central

    Toms, Laurence; McQuay, Henry J; Derry, Sheena; Moore, R Andrew

    2014-01-01

    Background This is an updated version of the original Cochrane review published in Issue 1, 2004 - this original review had been split from a previous title on ‘Single dose paracetamol (acetaminophen) with and without codeine for postoperative pain’. The last version of this review concluded that paracetamol is an effective analgesic for postoperative pain, but additional trials have since been published. This review sought to evaluate the efficacy and safety of paracetamol using current data, and to compare the findings with other analgesics evaluated in the same way. Objectives To assess the efficacy of single dose oral paracetamol for the treatment of acute postoperative pain. Search methods We searched The Cochrane Library, MEDLINE, EMBASE, the Oxford Pain Relief Database and reference lists of articles to update an existing version of the review in July 2008. Selection criteria Randomised, double-blind, placebo-controlled clinical trials of paracetamol for acute postoperative pain in adults. Data collection and analysis Two review authors independently assessed trial quality and extracted data. Area under the “pain relief versus time” curve was used to derive the proportion of participants with paracetamol or placebo experiencing at least 50% pain relief over four to six hours, using validated equations. Number-needed-to-treat-to-benefit (NNT) was calculated, with 95% confidence intervals (CI). The proportion of participants using rescue analgesia over a specified time period, and time to use, were sought as measures of duration of analgesia. Information on adverse events and withdrawals was also collected. Main results Fifty-one studies, with 5762 participants, were included: 3277 participants were treated with a single oral dose of paracetamol and 2425 with placebo. About half of participants treated with paracetamol at standard doses achieved at least 50% pain relief over four to six hours, compared with about 20% treated with placebo. NNTs for at

  2. Medical treatment of vertebral osteoporosis.

    PubMed

    Lippuner, K

    2003-10-01

    to conclude about efficacy (calcium, clodronate, etidronate, hormone replacement therapy, pamidronate, strontium, tiludronate, vitamin D). The low NNTs for the leading substances (ranges: 15-64 for alendronate, 8-26 for risedronate, 23 for calcitonin and 28-31 for raloxifene) confirm that effective and efficient drug interventions for treatment and prevention of osteoporotic vertebral fractures are available. Bisphosphonates have demonstrated similar efficacy in treatment and prevention of steroid-induced and male osteoporosis as in postmenopausal osteoporosis. The selection of the appropriate drug for treatment of vertebral osteoporosis from among a bisphosphonate (alendronate or risedronate), PTH, calcitonin or raloxifene will mainly depend on the efficacy, tolerability and safety profile, together with the patient's willingness to comply with a long-term treatment. Although reduction of vertebral fracture risk is an important criterion for decision making, drugs with proven additional fracture risk reduction at all clinically relevant sites (especially at the hip) should be the preferred options. PMID:13680313

  3. Diclofenac with or without an antiemetic for acute migraine headaches in adults

    PubMed Central

    Derry, Sheena; Rabbie, Roy; Moore, R Andrew

    2014-01-01

    potassium 50 mg versus placebo (two studies), the NNTs were 6.2, 8.9, and 9.5 for pain-free at two hours, headache relief at two hours, and pain-free responses at 24 hours, respectively. Associated symptoms of nausea, photophobia and phonophobia, and functional disability were reduced within two hours, and similar numbers of participants experienced adverse events, which were mostly mild and transient. There were insufficient data to evaluate other doses of oral diclofenac, or to compare different formulations or different dosing regimens; only one study compared oral diclofenac with an active comparator (oral sumatriptan 100 mg). Authors’ conclusions Oral diclofenac potassium 50 mg is an effective treatment for acute migraine, providing relief from pain and associated symptoms, although only a minority of patients experience pain-free responses. Adverse events are mostly mild and transient and occur at the same rate as with placebo. PMID:22336852

  4. Single dose oral paracetamol (acetaminophen) with codeine for postoperative pain in adults

    PubMed Central

    Toms, Laurence; Derry, Sheena; Moore, R Andrew; McQuay, Henry J

    2014-01-01

    relief over four-to-six hours, with NNTs of 2.2 (95% CI 1.8 to 2.9) for 800 to 1000 mg paracetamol plus 60 mg codeine, 3.9 (2.9 to 4.5) for 600 to 650 mg paracetamol plus 60 mg codeine, and 6.9 (4.8 to 12) for 300 mg paracetamol plus 30 mg codeine. Time to use of rescue medication was over four hours with paracetamol plus codeine and two hours with placebo. The NNT to prevent remedication was 5.6 (4.0 to 9.0) for 600 mg paracetamol plus 60 mg codeine over four to six hours. Adverse events increased of mainly mild to moderate severity with paracetamol plus codeine than placebo. Fourteen studies, with 926 participants, were included in the comparison of paracetamol plus codeine with the same dose of paracetamol alone. Addition of codeine increased proportion of participants achieving at least 50% pain relief over four-to-six hours by 10 to 15%, increased time to use of rescue medication by about one hour, and reduced proportion of participants needing rescue medication by about 15% (NNT to prevent remedication 6.9 (4.2 to 19). Adverse events were mainly mild to moderate in severity and incidence did not differ between groups. Authors’ conclusions This update confirms previous findings that combining paracetamol with codeine provided clinically useful levels of pain relief in about 50% of patients with moderate to severe postoperative pain, compared with under 20% with placebo. New information for remedication shows that the combination extended the duration of analgesia by about one hour compared to treatment with the same dose of paracetamol alone. At higher doses, more participants experienced adequate pain relief, but the amount of information available for the 1000 mg paracetamol plus 60 mg codeine dose was small, and based on limited information. PMID:19160199

  5. Topical NSAIDs for chronic musculoskeletal pain in adults

    PubMed Central

    Derry, Sheena; Moore, R Andrew; Rabbie, Roy

    2014-01-01

    compared a topical NSAID with placebo. Topical NSAIDs were significantly more effective than placebo for reducing pain due to chronic musculoskeletal conditions. The best data were for topical diclofenac in osteoarthritis, where the NNT for at least 50% pain relief over 8 to 12 weeks compared with placebo was 6.4 for the solution, and 11 for the gel formulation. There were too few data of good quality to calculate NNTs for other individual topical NSAIDs compared with placebo. Direct comparison of topical NSAID with an oral NSAID did not show any difference in efficacy. There was an increase in local adverse events (mostly mild skin reactions) with topical NSAIDs compared with placebo or oral NSAIDs, but no increase in serious adverse events. Gastrointestinal adverse events with topical NSAID did not differ from placebo, but were less frequent than with oral NSAIDs. A substantial amount of data from unpublished studies was unavailable. Much of this probably relates to formulations that have never been marketed. Authors’ conclusions Topical NSAIDs can provide good levels of pain relief; topical diclofenac solution is equivalent to that of oral NSAIDs in knee and hand osteoarthritis, but there is no evidence for other chronic painful conditions. Formulation can influence efficacy. The incidence of local adverse events is increased with topical NSAIDs, but gastrointestinal adverse events are reduced compared with oral NSAIDs. PMID:22972108