Determinants of patient recruitment in a multicenter clinical trials group: trends, seasonality and the effect of large studies

BACKGROUND: We examined whether quarterly patient enrollment in a large multicenter clinical trials group could be modeled in terms of predictors including time parameters (such as long-term trends and seasonality), the effect of large trials and the number of new studies launched each quarter. We used the database of all clinical studies launched by the AIDS Clinical Trials Group (ACTG) between October 1986 and November 1999. Analyses were performed in two datasets: one included all studies and substudies (n = 475, total enrollment 69,992 patients) and the other included only main studies (n = 352, total enrollment 57,563 patients). RESULTS: Enrollment differed across different months of the year with peaks in spring and late fall. Enrollment accelerated over time (+27 patients per quarter for all studies and +16 patients per quarter for the main studies, p < 0.001) and was affected by the performance of large studies with target sample size > 1,000 (p < 0.001). These relationships remained significant in multivariate autoregressive modeling. A time series based on enrollment during the first 32 quarters could forecast adequately the remaining 21 quarters. CONCLUSIONS: The fate and popularity of large trials may determine the overall recruitment of multicenter groups. Modeling of enrollment rates may be used to comprehend long-term patterns and to perform future strategic planning

The evaluation and surgical management of cyclodialysis clefts that have failed to respond to conservative management

Purpose To investigate factors that may influence successful correction of hypotony in a consecutive series of patients with cyclodialysis clefts repaired surgically over a 10-year period. Design Retrospective interventional case series. Methods Interventional case series of consecutive patients with cyclodialysis clefts and hypotony treated surgically after failure of conservative treatment. Results Eighteen patients (18 eyes) of mean (SD) age 48.3 (15.8) years at the time of surgery were included (16 male, 2 female). All were diagnosed using gonioscopy, usually assisted with intracameral viscoelastic injection. Imaging used in three cases was not found to be sufficiently precise to plan surgical intervention, without prior gonioscopic cleft visualisation. The intraocular pressure (IOP) was restored in nine cases (50%) after one procedure with a postoperative IOP (mean±SD) of 13.6±4.5 mm Hg (6/11 who had cyclopexy as a first procedure and 3/6 who had cryopexy). 2?3 procedures were required in the remaining nine patients. There was a trend towards the use of cyclopexy for larger clefts and cryopexy for saller clefts (NS). We observed a trend for a lower likelihood of successful closure of larger clefts after one intervention. Two eyes that had cyclopexy required later IOP-lowering surgery to achieve IOP control. Conclusions Most clefts were closed with one procedure. A trend towards larger cleft size as a preoperative risk factor for failure to achieve closure with one procedure was observed. In this series, imaging was not found to be sufficiently precise to replace viscoelastic-Assisted gonioscopy in the diagnosis and evaluation of cyclodialysis clefts

The Value of p-Value in Biomedical Research

Significance tests and the corresponding p-values play a crucial role in decision making. In this commentary the meaning, interpretation and misinterpretation of p-values is presented. Alternatives for evaluating the reported evidence are also discussed

Guidelines on Chemotherapy in Advanced Stage Gynecological Malignancies: An Evaluation of 224 Professional Societies and Organizations

BACKGROUND: Clinical practice guidelines are important for guiding practice, but it is unclear if they are commensurate with the available evidence. METHODS: We examined guidelines produced by cancer and gynecological societies and organizations and evaluated their coverage of and stance towards chemotherapy for advanced stage disease among 4 gynecological malignancies (breast, ovarian, cervical, endometrial cancer) where the evidence for the use of chemotherapy is very different (substantial and conclusive for breast and ovarian cancer, limited and suggesting no major benefit for cervical and endometrial cancer). Eligible societies and organizations were identified through systematic internet searches (last update June 2009). Pertinent websites were scrutinized for presence of clinical practice guidelines, and relative guidelines were analyzed. RESULTS: Among 224 identified eligible societies and organizations, 69 (31%) provided any sort of guidelines, while recommendations for chemotherapy on advanced stage gynecological malignancies were available in 20 of them. Only 14 had developed their own guideline, and only 5 had developed guidelines for all 4 malignancies. Use of levels of evidence and grades of recommendations, and aspects of the production, implementation, and timeliness of the guidelines did not differ significantly across malignancies. Guidelines on breast and ovarian cancer utilized significantly more randomized trials and meta-analyses. Guidelines differed across malignancies on their coverage of disease-free survival (p = 0.033), response rates (p = 0.024), symptoms relief (p = 0.005), quality of life (p = 0.001) and toxicity (p = 0.039), with breast and ovarian cancer guidelines typically covering more frequently these outcomes. All guidelines explicitly or implicitly endorsed the use of chemotherapy. CONCLUSIONS: Clinical practice guidelines are provided by the minority of professional societies and organizations. Available guidelines tend to recommend chemotherapy even for diseases where the effect of chemotherapy is controversial and recommendations are based on scant evidence

Evidence maps and evidence gaps: evidence review mapping as a method for collating and appraising evidence reviews to inform research and policy

Evidence reviews are a key mechanism for incorporating extensive, complex and specialised evidence into policy and practice, and in guiding future research. However, evidence reviews vary in scope and methodological rigour, creating several risks for decision-makers: decisions may be informed by less reliable reviews; apparently conflicting interpretations of evidence may obfuscate decisions; and low quality reviews may create the perception that a topic has been adequately addressed, deterring new syntheses (cryptic evidence gaps). We present a new approach, evidence review mapping, designed to produce a visual representation and critical assessment of the review landscape for a particular environmental topic or question. By systematically selecting and describing the scope and rigour of each review, this helps guide non-specialists to the most relevant and methodologically reliable reviews. The map can also direct future research through the identification of evidence gaps (whether cryptic or otherwise) and redundancy (multiple reviews on similar questions). We consider evidence review mapping a complementary approach to systematic reviews and systematic maps of primary literature and an important tool for facilitating evidence-based decision-making and research efficiency

Reporting of harm in randomized controlled trials evaluating stents for percutaneous coronary intervention

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to assess the reporting of harm in randomized controlled trials evaluating stents for percutaneous coronary intervention.</p> <p>Methods</p> <p>The study design was a methodological systematic review of randomized controlled trials. The data sources were MEDLINE and the Cochrane Central Register of Controlled Trials. All reports of randomized controlled trials assessing stent treatment for coronary disease published between January 1, 2003, and September 30, 2008 were selected.</p> <p>A standardized abstraction form was used to extract data.</p> <p>Results</p> <p>132 articles were analyzed. Major cardiac adverse events (death, cardiac death, myocardial infarction or stroke) were reported as primary or secondary outcomes in 107 reports (81%). However, 19% of the articles contained no data on cardiac events. The mode of data collection of adverse events was given in 29 reports (22%) and a definition of expected adverse events was provided in 47 (36%). The length of follow-up was reported in 95 reports (72%). Assessment of adverse events by an adjudication committee was described in 46 reports (35%), and adverse events were described as being followed up for 6 months in 24% of reports (n = 32), between 7 to 12 months in 42% (n = 55) and for more than 1 year in 4% (n = 5). In 115 reports (87%), numerical data on the nature of the adverse events were reported per treatment arm. Procedural complications were described in 30 articles (23%). The causality of adverse events was reported in only 4 articles.</p> <p>Conclusion</p> <p>Several harm-related data were not adequately accounted for in articles of randomized controlled trials assessing stents for percutaneous coronary intervention.</p> <p>Trials Registration</p> <p>Trials manuscript: 5534201182098351 (T80802P)</p

Meta-Analysis of the Immunogenicity and Tolerability of Pandemic Influenza A 2009 (H1N1) Vaccines

Background: Although the 2009 (H1N1) influenza pandemic officially ended in August 2010, the virus will probably circulate in future years. Several types of H1N1 vaccines have been tested including various dosages and adjuvants, and meta-analysis is needed to identify the best formulation. Methods: We searched MEDLINE, EMBASE, and nine clinical trial registries to April 2011, in any language for randomized clinical trials (RCTs) on healthy children, adolescents, adults and the elderly. Primary outcome was the seroconversion rate according to hemagglutinination-inhibition (HI); secondary outcomes were adverse events. For the primary outcome, we used head-to-head meta-analysis and multiple-treatments meta-analysis. Results: Eighteen RCTs could be included in all primary analyses, for a total of 76 arms (16,725 subjects). After 2 doses, all 2009 H1N1 split/subunit inactivated vaccines were highly immunogenic and overcome CPMP seroconversion criteria. After 1 dose only, all split/subunit vaccines induced a satisfactory immunogenicity (> = 70%) in adults and adolescents, while only some formulations showed acceptable results for children and elderly (non-adjuvanted at high-doses and oil-in-water adjuvanted vaccines). Vaccines with oil-in-water adjuvants were more immunogenic than both nonadjuvanted and aluminum-adjuvanted vaccines at equal doses and their immunogenicity at doses < = 6 μg (even with as little as 1.875 μg of hemagglutinin antigen) was not significantly lower than that achieved after higher doses. Finally, the rate of serious vaccine-related adverse events was low for all 2009 H1N1 vaccines (3 cases, resolved in 10 days, out of 22826 vaccinated subjects). However, mild to moderate adverse reactions were more (and very) frequent for oil-in-water adjuvanted vaccines. Conclusions: Several one-dose formulations might be valid for future vaccines, but 2 doses may be needed for children, especially if a low-dose non-adjuvanted vaccine is used. Given that 15 RCTs were sponsored by vaccine manufacturers, future trials sponsored by non-industry agencies and comparing vaccines using different types of adjuvants are needed

Short-term efficacy of physical interventions in osteoarthritic knee pain. A systematic review and meta-analysis of randomised placebo-controlled trials.

BACKGROUND: Treatment efficacy of physical agents in osteoarthritis of the knee (OAK) pain has been largely unknown, and this systematic review was aimed at assessing their short-term efficacies for pain relief. METHODS: Systematic review with meta-analysis of efficacy within 1-4 weeks and at follow up at 1-12 weeks after the end of treatment. RESULTS: 36 randomised placebo-controlled trials (RCTs) were identified with 2434 patients where 1391 patients received active treatment. 33 trials satisfied three or more out of five methodological criteria (Jadad scale). The patient sample had a mean age of 65.1 years and mean baseline pain of 62.9 mm on a 100 mm visual analogue scale (VAS). Within 4 weeks of the commencement of treatment manual acupuncture, static magnets and ultrasound therapies did not offer statistically significant short-term pain relief over placebo. Pulsed electromagnetic fields offered a small reduction in pain of 6.9 mm [95% CI: 2.2 to 11.6] (n = 487). Transcutaneous electrical nerve stimulation (TENS, including interferential currents), electro-acupuncture (EA) and low level laser therapy (LLLT) offered clinically relevant pain relieving effects of 18.8 mm [95% CI: 9.6 to 28.1] (n = 414), 21.9 mm [95% CI: 17.3 to 26.5] (n = 73) and 17.7 mm [95% CI: 8.1 to 27.3] (n = 343) on VAS respectively versus placebo control. In a subgroup analysis of trials with assumed optimal doses, short-term efficacy increased to 22.2 mm [95% CI: 18.1 to 26.3] for TENS, and 24.2 mm [95% CI: 17.3 to 31.3] for LLLT on VAS. Follow-up data up to 12 weeks were sparse, but positive effects seemed to persist for at least 4 weeks after the course of LLLT, EA and TENS treatment was stopped. CONCLUSION: TENS, EA and LLLT administered with optimal doses in an intensive 2-4 week treatment regimen, seem to offer clinically relevant short-term pain relief for OAK

Ethical implications of the use of whole genome methods in medical research

The use of genome-wide association studies (GWAS) in medical research and the increased ability to share data give a new twist to some of the perennial ethical issues associated with genomic research. GWAS create particular challenges because they produce fine, detailed, genotype information at high resolution, and the results of more focused studies can potentially be used to determine genetic variation for a wide range of conditions and traits. The information from a GWA scan is derived from DNA that is a powerful personal identifier, and can provide information not just on the individual, but also on the individual's relatives, related groups, and populations. Furthermore, it creates large amounts of individual-specific digital information that is easy to share across international borders. This paper provides an overview of some of the key ethical issues around GWAS: consent, feedback of results, privacy, and the governance of research. Many of the questions that lie ahead of us in terms of the next generation sequencing methods will have been foreshadowed by GWAS and the debates around ethical and policy issues that these have created