Placebo Arm (placebo + arm)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Prognosis and Mechanism of Death in Treated Heart Failure: Data From the Placebo Arm of Val-HeFT

CONGESTIVE HEART FAILURE, Issue 3 2006
Jay N. Cohn MD
The magnitude of benefit on mortality of combined angiotensin-converting enzyme inhibitor (ACEI) and ,-blocker (BB) therapy for heart failure cannot be reliably assessed from prospective randomized trials of individual drugs with intent-to-treat analysis. The placebo arm of the Valsartan Heart Failure Trial (Val-HeFT) included patients who remained on background therapy with ACEIs, BBs, neither, or both. The outcomes in these four subgroups should provide a better guide to mortality benefit. Overall mortality (mean follow-up, 23 months) was 31.6% in those receiving neither neurohormonal blocker, 29% and 39% lower in those on ACEIs or BBs, respectively, and 62% lower (11.9% mortality) in those receiving both drugs. In the neither neurohormonal inhibitor group, 48% of the heart failure-related deaths were adjudicated as sudden, whereas in the group receiving ACEIs and BBs, 79% of the deaths were sudden, and pump failure mortality was only 1% per year. The combination of ACEIs and BBs exerts a greater mortality reduction than suggested from clinical trials and reduces pump failure mortality to 1% per year. [source]


Effect of Metoprolol on Quality of Life in the Prevention of Syncope Trial

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2009
Ph.D., ROBERT S. SHELDON M.D.
Introduction: Vasovagal syncope is common, often recurrent, and reduces quality of life. No therapies have proven useful to improve quality of life in adequately designed randomized clinical trials. Beta-blockers have mixed evidence for effectiveness in preventing syncope. Methods: The Prevention of Syncope Trial was a randomized, placebo-controlled, double-blind, multinational, clinical trial that tested the hypothesis that metoprolol improves quality of life in adult patients with vasovagal syncope in a 1-year observation period. Randomization was stratified in strata of patients <42 and ,42 years old. The quality of life questionnaires Short Form-36 (SF-36) and Euroqol EQ-5D were completed at baseline and after 6 and 12 months of treatment by 204, 132, and 121 patients, respectively. Results: There were 208 patients, mean age 42 18, of whom 134 (64%) were females. All had positive tilt tests. There was no improvement in quality of life during the trial in the entire group or in either treatment arm. Patients in the metoprolol treatment arm did not have improved quality of life compared to the patients in the placebo arm using either the SF-36 or EQ5D after either 6 or 12 months. Finally, there was no improvement in quality of life associated with metoprolol use in patients either <42 or ,42 years of age. Conclusion: Metoprolol does not improve quality of life in patients with recurrent vasovagal syncope and a positive tilt test. [source]


Effect of a gastro-protective agent, rebamipide, on symptom improvement in patients with functional dyspepsia: A double-blind placebo-controlled study in Japan

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 12 2006
Hiroto Miwa
Abstract Background and Aim:, Although mucosal protective agents have been used frequently for treatment of symptomatic gastritis, there has been no well-controlled study of functional dyspepsia. The aim of this study was to assess the efficacy of a 4-week treatment with rebamipide for the relief of overall dyspeptic symptoms and the improvement in quality of life from an untreated baseline in Japanese patients with functional dyspepsia. Methods:, In a double-blinded, randomized, placebo-controlled, single-center study, 81 patients with functional dyspepsia were recruited and treated with rebamipide (100 mg, t.i.d.) or placebo for 4 weeks. Symptoms were assessed at baseline and at the end of the study period by a symptom questionnaire. Quality of life was evaluated by the QPD 32. Results:, Data was analyzed for symptoms from 38 patients who received rebamipide and 33 patients who received placebo treatment. Overall symptoms were significantly improved in both the rebamipide and placebo treatment groups from the untreated baseline after 4 weeks of treatment, and the mean changes in overall symptoms were not significantly different between the groups. However, the improvement in symptom score was significantly greater in the treatment arm than in the placebo arm for three items, which were bloating, belching, and pain or discomfort that was relieved after a meal. Regarding quality of life, social restriction and pain intensity were significantly improved in the rebamipide treatment group in per-protocol analysis (P = 0.048 and P = 0.031, respectively). Conclusions:, Although rebamipide was not significantly better than placebo in reducing overall symptoms by 4 weeks' treatment, it may partially improve the symptoms. It may also be beneficial in improvement of quality of life in Japanese patients with functional dyspepsia. [source]


Soy extract phytoestrogens with high dose of isoflavones for menopausal symptoms

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 6 2009
Augusto Ferrari
Abstract Aim:, The aim of the present study was to assess the efficacy and safety of a standardized compound based on an extract of soy phytoestrogens, with high doses of isoflavones in the management of menopausal hot flushes. Methods:, A total of 180 women aged 40,65 years with a minimum of five moderate-to-severe hot flushes in the last 7 days at baseline and absence of menstruation for at least 6 months participated in a 12-week prospective, randomized, double-blind, placebo-controlled multicenter trial. After a 2-week run-in period, women received one tablet a day of 80 mg isoflavones (corresponding to 60 mg of genistein) or a matching placebo. Results:, The mean daily number of moderate-to-severe hot flushes decreased in both study groups, but the reduction was greater in the isoflavones arm at 6 (36.2%) and 12 weeks (41.2%) than in the placebo arm (24.0% at 6 weeks, 29.3% at 12 weeks), with a difference of 1.1 (95% CI [,2.0 to ,0.06]) (P = 0.038) at 6 weeks and 1.1 (95% CI [,2.05 to ,0.15]) (P = 0.023) at 12 weeks. Similar findings were obtained for hot flushes of any intensity. The Kupperman index decreased in both study groups. Relief of hot flushes was greater when time to menopause was ,12 months and in cases of BMI ,27 kg/m2. Conclusion:, In daily practice conditions, high doses of isoflavones, particularly genistein, can be used for the management of hot flushes in postmenopausal women not treated with hormone replacement therapy due to their superior efficacy to placebo and very good safety profile. [source]


Urodynamic standardization in a large-scale, multicenter clinical trial examining the effects of daily tadalafil in men with lower urinary tract symptoms with or without benign prostatic obstruction,

NEUROUROLOGY AND URODYNAMICS, Issue 5 2010
Stephen R. Kraus
Abstract Aims To present the methodology, standardization techniques, and results from post hoc test,retest reproducibility analyses for a large, placebo-controlled, multicenter trial, employing urodynamic studies (UDS) to assess the impact of daily tadalafil on men with lower urinary tract symptoms (LUTS) with or without benign prostatic obstruction (BPO). Methods UDS implemented International Continence Society (ICS) Good Urodynamic Practice guidelines and standardized urodynamic and LUTS terminology. Further standardization procedures included: equipment calibration; a detailed procedure manual and centralized training; and implementation of a central reader. Measures included: monitoring of invalid studies, comparison of actual versus expected standard deviation (SD) for primary outcome (detrusor pressure at maximum urinary flow rate [pdetQmax]), and test,retest reproducibility of the placebo arm at baseline and endpoint. Results Two hundred men with moderate to severe LUTS (baseline IPSS ,13) at 20 sites were randomized to receive either tadalafil 20,mg or placebo. All men underwent non-invasive uroflow and pressure-flow studies. Numbers of invalid studies at baseline and endpoint were 9.3% and 0.6%, respectively. Variability of pdetQmax was lower than anticipated based on actual versus expected SD of 15 and 30, respectively. Correlation coefficients were very good for pressure-flow parameters including pdetQmax (r,=,.83). Conclusions Multicenter clinical trials using urodynamic outcomes require additional standardized procedures to limit inter-site variability. By implementing centralized training with a detailed procedure manual and use of a central reader, we were able to limit common difficulties arising in multicenter clinical trials, as well as demonstrate good test,retest reproducibility of pressure flow measures. Neurourol. Urodynam. 29:741,747, 2010. 2010 Wiley-Liss, Inc. [source]


Combination antibiotics as a treatment for chronic Chlamydia -induced reactive arthritis: A double-blind, placebo-controlled, prospective trial,

ARTHRITIS & RHEUMATISM, Issue 5 2010
J. D. Carter
Objective Chlamydia trachomatis and Chlamydophila (Chlamydia) pneumoniae are known triggers of reactive arthritis (ReA) and exist in a persistent metabolically active infection state in the synovium, suggesting that they may be susceptible to antimicrobial agents. The goal of this study was to investigate whether a 6-month course of combination antibiotics is an effective treatment for patients with chronic Chlamydia- induced ReA. Methods This study was a 9-month, prospective, double-blind, triple-placebo trial assessing a 6-month course of combination antibiotics as a treatment for Chlamydia -induced ReA. Eligible patients had to be positive for C trachomatis or C pneumoniae by polymerase chain reaction (PCR). Groups received 1) doxycycline and rifampin plus placebo instead of azithromycin; 2) azithromycin and rifampin plus placebo instead of doxycycline; or 3) placebos instead of azithromycin, doxycycline, and rifampin. The primary end point was the number of patients who improved by 20% or more in at least 4 of 6 variables without worsening in any 1 variable in both combination antibiotic groups combined and in the placebo group at month 6 compared with baseline. Results The primary end point was achieved in 17 of 27 patients (63%) receiving combination antibiotics and in 3 of 15 patients (20%) receiving placebo. Secondary efficacy end points showed similar results. Six of 27 patients (22%) randomized to combination antibiotics believed that their disease went into complete remission during the trial, whereas no patient in the placebo arm achieved remission. Significantly more patients in the active treatment group became negative for C trachomatis or C pneumoniae by PCR at month 6. Adverse events were mild, with no significant differences between the groups. Conclusion These data suggest that a 6-month course of combination antibiotics is an effective treatment for chronic Chlamydia -induced ReA. [source]


Challenges and regulatory experiences with non-inferiority trial design without placebo arm

BIOMETRICAL JOURNAL, Issue 2 2009
H. M. James Hung
Abstract For a non-inferiority trial without a placebo arm, the direct comparison between the test treatment and the selected positive control is in principle the only basis for statistical inference. Therefore, evaluating the test treatment relative to the non-existent placebo presents extreme challenges and requires some kind of bridging from the past to the present with no current placebo data. For such inference based partly on an indirect bridging manipulation, fixed margin method and synthesis method are the two widely discussed methods in the recent literature. There are major differences in statistical inference paradigm between the two methods. The fixed margin method employs the historical data that assess the performances of the active control versus a placebo to guide the selection of the non-inferiority margin. Such guidance is not part of the ultimate statistical inference in the non-inferiority trial. In contrast, the synthesis method connects the historical data to the non-inferiority trial data for making broader inferences relating the test treatment to the non-existent current placebo. On the other hand, the type I error rate associated with the direct comparison between the test treatment and the active control cannot shed any light on the appropriateness of the indirect inference for faring the test treatment against the non-existent placebo. This work explores an approach for assessing the impact of potential bias due to violation of a key statistical assumption to guide determination of the non-inferiority margin. [source]


Sensitivity Analyses Comparing Outcomes Only Existing in a Subset Selected Post-Randomization, Conditional on Covariates, with Application to HIV Vaccine Trials

BIOMETRICS, Issue 2 2006
Bryan E. Shepherd
Summary In many experiments, researchers would like to compare between treatments and outcome that only exists in a subset of participants selected after randomization. For example, in preventive HIV vaccine efficacy trials it is of interest to determine whether randomization to vaccine causes lower HIV viral load, a quantity that only exists in participants who acquire HIV. To make a causal comparison and account for potential selection bias we propose a sensitivity analysis following the principal stratification framework set forth by Frangakis and Rubin (2002, Biometrics58, 21,29). Our goal is to assess the average causal effect of treatment assignment on viral load at a given baseline covariate level in the always infected principal stratum (those who would have been infected whether they had been assigned to vaccine or placebo). We assume stable unit treatment values (SUTVA), randomization, and that subjects randomized to the vaccine arm who became infected would also have become infected if randomized to the placebo arm (monotonicity). It is not known which of those subjects infected in the placebo arm are in the always infected principal stratum, but this can be modeled conditional on covariates, the observed viral load, and a specified sensitivity parameter. Under parametric regression models for viral load, we obtain maximum likelihood estimates of the average causal effect conditional on covariates and the sensitivity parameter. We apply our methods to the world's first phase III HIV vaccine trial. [source]


A randomised controlled trial to evaluate the effect of self-administered analgesia on women's experience of outpatient treatment at colposcopy

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 12 2005
M.E. Cruickshank
Objective To evaluate the effect of self-administered isoflurane and desflurane on women's experience of outpatient treatment at colposcopy. Design A prospective double-blinded randomised controlled trial. Setting A colposcopy clinic serving a regional population. Population Three hundred and ninety-six women scheduled for treatment of cervical intraepithelial neoplasia (CIN) by large loop excision of the transformation zone (LLETZ). Methods Self-administration of trial gas during a LLETZ procedure. One hundred and ninety-eight women were randomised to use isoflurane and desflurane and 198 to use placebo. Main outcome measures Patient satisfaction, pain and anxiety. Results The mean pain score for cervical surgery was significantly lower for women using isoflurane and desflurane (22.4) than the placebo arm (29.6) (P= 0.003). There was no significant difference between arms in anxiety levels before or after treatment. More women using isoflurane and desflurane (78%) reported ,total helpfulness' of the trial gas than those using placebo (67%) (P= 0.012). A subgroup analysis of trial participants classified as anxious by Hospital Anxiety and Depression Scale (HADS) score at recruitment showed that using isoflurane and desflurane significantly increased total treatment acceptability, helpfulness of the gas and willingness to undergo a similar procedure at six-month follow up. Conclusion Satisfaction with outpatient treatment at colposcopy is generally high. The main effect of isoflurane and desflurane evaluated in this trial was to reduce pain. It appeared to be effective for women with clinically significant anxiety and could be offered as an alternative to general anaesthesia. [source]


The impact of targeted training, a dedicated protocol and on-site training material in reducing observer variability of prostate and transition zone dimensions measured by transrectal ultrasonography, in multicentre multinational clinical trials of men with symptomatic benign prostatic enlargement

BJU INTERNATIONAL, Issue 1 2007
Philip S. Murphy
OBJECTIVE To assess the variability of a standardized protocol of transrectal ultrasonography (TRUS), with targeted training, and compare it to the variability in other multicentre clinical trials, as TRUS-estimated total prostate volume (TPV) and transition zone volume (TZV) are considered important efficacy endpoints in assessing new drug therapies for benign prostatic enlargement (BPE), but standardizing TRUS remains a challenge in such studies. PATIENTS AND METHODS In all, 174 patients with BPE in the placebo arm of a 30-centre clinical trial were analysed at baseline, 13 and 26 weeks with TRUS, to extract TPV and TZV values. All TRUS operators received training in the standardized methods, which was supplemented at the outset by a compact disc-based video. RESULTS The mean (sd) changes from baseline in TPV at 13 and 26 weeks were ,,2.9 (8.9) and ,1.9 (8.5) mL, respectively; the respective mean changes from baseline in TZV were ,1.2 (6.4) and +,0.7 (7.8) mL. For TPV, 80% of the measurements had differences of +,5.2 to ,13.4 mL at 13 weeks, and +,8.0 to ,,10.9 mL at 26 weeks. For TZV, 80% of the differences were +,5.8 to ,,7.4 at 13 weeks, and +,9.3 to ,6.5 mL at 26 weeks. CONCLUSION The performance of TRUS compared favourably with similar published multicentre studies, which we suggest relates in part to the careful implementation of the protocol. We showed that diligent implementation of a detailed protocol, supplemented by targeted training of investigators and provision of on-site training material, promoted consistent acquisition and successful derivation of key clinical trial endpoints. Quantifying the variability of such endpoints will enable us to track deployment quality for future clinical trials, and will ensure that trials are sufficiently powered to define small changes in prostate size. [source]


Effect of homeopathy on analgesic intake following knee ligament reconstruction: a phase III monocentre randomized placebo controlled study

BRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 2 2008
A. Paris
What is already known about this subject ,,The efficacy of homeopathy is still under debate and a recent meta-analysis recommended further randomized double-blind clinical trials to identify any clinical situation in which homeopathy might be effective. What this study adds ,,The complex of homeopathy tested in this study (Arnica montana 5 CH, Bryonia alba 5 CH, Hypericum perforatum 5 CH and Ruta graveolens 3 DH) is not superior to placebo in reducing 24 h morphine consumption after knee ligament reconstruction. Aims The efficacy of homeopathy is still under debate. The objective of this study was to assess the efficacy of homeopathic treatment (Arnica montana 5 CH, Bryonia alba 5 CH, Hypericum perforatum 5 CH and Ruta graveolens 3 DH) on cumulated morphine intake delivered by PCA over 24 h after knee ligament reconstruction. Methods This was an add-on randomized controlled study with three parallel groups: a double-blind homeopathic or placebo arm and an open-label noninterventional control arm. Eligible patients were 18,60 years old candidates for surgery of the anterior cruciate ligament. Treatment was administered the evening before surgery and continued for 3 days. The primary end-point was cumulated morphine intake delivered by PCA during the first 24 h inferior or superior/equal to 10 mg day,1. Results One hundred and fifty-eight patients were randomized (66 in the placebo arm, 67 in the homeopathic arm and 25 in the noninterventional group). There was no difference between the treated and the placebo group for primary end-point (mean (95% CI) 48% (35.8, 56.3), and 56% (43.7, 68.3), required less than 10 mg day,1 of morphine in each group, respectively). The homeopathy treatment had no effect on morphine intake between 24 and 72 h or on the visual analogue pain scale, or on quality of life assessed by the SF-36 questionnaire. In addition, these parameters were not different in patients enrolled in the open-label noninterventional control arm. Conclusions The complex of homeopathy tested in this study was not superior to placebo in reducing 24 h morphine consumption after knee ligament reconstruction. [source]


Clinical Characteristics as Predictors of Recurrent Alcohol-related Seizures

ACADEMIC EMERGENCY MEDICINE, Issue 8 2000
Niels K. Rathlev MD
Abstract. Objective: To determine whether clinical data available in the emergency department can accurately predict a subset of patients at low risk of developing recurrent seizures following one or more initial alcohol-related seizures in the out-of-hospital arena. Methods: This was a retrospective secondary analysis of data obtained from the placebo arms of two prospective, randomized trials of drug treatments for the prevention of recurrent alcohol-related seizures. Subjects with and without one or more recurrent alcohol-related seizures during the study period were compared according to the following characteristics: 1) age, 2) gender, 3) daily ethanol consumption, 4) years of ethanol abuse, 5) previous alcohol-related seizure, 6) previous seizure of other etiology, 7) temperature, 8) heart rate, 9) systolic blood pressure, 10) diastolic blood pressure, 11) respiratory rate, and 12) ethanol level. Data were analyzed with t-tests and chi-square where appropriate. Results: One hundred five placebo-treated patients were analyzed and 31 (30%) developed recurrent alcohol-related seizures. None of the listed characteristics were statistically different between the two groups except for the initial ethanol level. Subjects with an ethanol level higher than 100 mg/dL were less likely (0%) to develop recurrent seizures than patients with a level equal to or below 100 mg/dL (36%) (p < 0.01). Conclusions: An initial ethanol level higher than 100 mg/dL was significantly associated with a low risk for recurrent alcohol-related seizures during the observation period. No other low-risk clinical characteristics could be identified. [source]


Paliperidone palmitate , review of the efficacy, safety and cost of a new second-generation depot antipsychotic medication

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2010
L. Citrome
Summary Objective:, To describe the efficacy, safety and cost of paliperidone palmitate, a depot antipsychotic medication recently approved for the treatment of schizophrenia. Data sources:, A literature search was conducted by querying the websites http://www.pubmed.gov, http://www.fda.gov, http://www.accessdata.fda.gov/scripts/cder/drugsatfda and http://www.clinicaltrials.gov for the search term ,paliperidone palmitate'. Cost information was obtained from the pharmaceutical vendor servicing a local state-operated psychiatric facility. Study selection:, All available reports of studies were identified. Product labelling provided additional information. Data extraction:, Descriptions of the principal results and calculation of the number needed to treat (NNT) and number needed to harm (NNH) for relevant dichotomous outcomes were extracted from the study reports and synopses. Additional safety outcomes subject to NNH analysis were obtained from product labelling. Data synthesis:, Paliperidone palmitate is a newly available depot formulation of paliperidone (the 9-OH metabolite of risperidone). Upon injection into the deltoid or gluteal muscle, the release of the drug starts as early as day 1, reaches maximum plasma concentrations at 13 days and lasts for as long as 126 days. Maximum concentration following deltoid injection is approximately 28% higher compared with injection into the gluteal muscle, and thus paliperidone palmitate requires initiation by two initial deltoid injections spread 1 week apart to achieve therapeutic concentrations rapidly. Subsequent injections are at 4-week intervals. Acute efficacy was evidenced by four short-term double-blind, randomised, placebo-controlled, fixed-dose studies of acutely relapsed adult inpatients who met DSM-IV criteria for schizophrenia. NNT for a 30% or greater decrease in the Positive and Negative Syndrome Scale total score compared with placebo was consistently lower for the higher dose strengths of 156 and 234 mg, suggesting a therapeutic dose,response. Treatment with paliperidone palmitate at doses between 39 and 156 mg significantly delayed the time to recurrence of symptoms of schizophrenia after 24 weeks of maintained symptom stability. The NNT vs. placebo to avoid a recurrence of symptoms was 5 (95% CI 4,7). Overall, paliperidone palmitate was reasonably well tolerated, with low rates of extrapyramidal symptoms or body weight gain; however, these may be more common at higher doses. Injection site reactions occurred at a rate ranging from 4% to 10%, depending on the dose regimen, compared with 2% for the pooled placebo arms. The acquisition cost of a maintenance dose of paliperidone palmitate calculated on a per day basis is similar to that for risperidone microspheres, but about double the cost for oral paliperidone and approximately 19 times the cost of oral generic risperidone. Conclusions:, Paliperidone palmitate is efficacious for the acute and maintenance treatment of schizophrenia and is reasonably well tolerated. It offers several advantages over other available second-generation depot antipsychotics: it comes in prefilled syringes in a number of different dosage strengths; it does not require refrigeration; it does not require supplementation with oral antipsychotics; it can be administered once monthly; it can be administered with a very small bore needle; the injection volume is small; the injection site can be either the deltoid or gluteal muscles; it does not require an additional precautionary observation period after the injection. For patients for whom oral risperidone or paliperidone is otherwise effective, paliperidone palmitate offers a guaranteed delivery system that enhances adherence. However, the high acquisition cost of paliperidone palmitate will likely be an important obstacle to its routine use. [source]


The impact of psychological factors on placebo responses in a randomized controlled trial comparing sham device to dummy pill

JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 1 2009
Suzanne M. Bertisch MD MPH
Abstract Objectives, To explore to what extent psychological factors such as expectation, depression, anxiety and belief in alternative medicine impact placebo response and differential responses to separate placebo interventions. Methods, We analysed data from a randomized controlled trial designed to compare the clinical response of two distinct placebo treatments (sham acupuncture device and placebo pill) in 119 participants with persistent distal upper arm pain due to repetitive stress injury. We used a multivariable linear regression model to identify potential correlates of self-reported upper extremity pain at the end of treatment in both placebo arms of the study combined. We also performed stratified analyses by placebo treatment. Results, We did not find any of the psychological factors of interest to be associated with pain at the end of treatment in our combined analysis. We found higher baseline pain score and pain for longer than 1 year's duration to be significantly associated with higher pain scores at the end of treatment for the placebo treatments combined. In stratified analyses, for the sham acupuncture group, we found higher baseline depression score, higher baseline pain score and younger age to be independently correlated with higher pain score at the end of treatment. For the placebo pill group, only baseline pain was significantly correlated to pain score at the end of treatment. Conclusion, In this trial, neither expectancy nor psychological states were associated with response to placebo, with the exception of baseline depression score for the sham acupuncture arm. [source]


Meta-analysis: incidence of endoscopic gastric and duodenal ulcers in placebo arms of randomized placebo-controlled NSAID trials

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2009
Y.-H. YUAN
Summary Background, The safety of NSAIDs is often evaluated by comparison with placebo in clinical trials. Aim, To investigate the incidence of gastric and duodenal ulcers (GDU) in placebo arms in NSAID trials over the last three decades. Methods, Randomized placebo-controlled trials of oral NSAIDs from 1975 to 2006 were systematically reviewed. The pooled incidence of GDU in placebo arms was calculated and compared. Meta-regression was used to identify risk factors related to the incidence of the placebo ulcer at the study level. Results, Thirty-six studies met inclusion criteria (duration of 6.5 days to 24 weeks). In total, 3.29% GDUs were reported in 36 placebo arms. The incidence of GDU in placebo arms was 0, 4.20% and 3.03% in the studies from 1975,1989, 1990,1999 and 2000,2006 respectively (P > 0.05). Eligible subjects with previous GI events and eligible subjects on co-therapy with low-lose aspirin/corticosteroids were associated with the increase in placebo ulcer incidence after adjusting for other factors. Conclusions, The incidence of GDU in placebo arms has not changed significantly over the last three decades, although has decreased in the past 10 years. Studies show that previous GI events and co-therapy with low-dose aspirin/corticosteroids were associated with increasing GDU in placebo arms. [source]