Poor reporting of scientific leadership information in clinical trial registers

Background

In September 2004, the International Committee of Medical Journal Editors (ICMJE) issued a Statement requiring that all clinical trials be registered at inception in a public register in order to be considered for publication. The World Health Organization (WHO) and ICMJE have identified 20 items that should be provided before a trial is considered registered, including contact information. Identifying those scientifically responsible for trial conduct increases accountability. The objective is to examine the proportion of registered clinical trials providing valid scientific leadership information.

Methodology/Principal Findings

We reviewed clinical trial entries listing Canadian investigators in the two largest international and public trial registers, the International Standard Randomized Controlled Trial Number (ISRCTN) register, and ClinicalTrials.gov. The main outcome measures were the proportion of clinical trials reporting valid contact information for the trials'' Principal Investigator (PI)/Co-ordinating Investigator/Study Chair/Site PI, and trial e-mail contact address, stratified by funding source, recruiting status, and register. A total of 1388 entries (142 from ISRCTN and 1246 from ClinicalTrials.gov) comprised our sample. We found non-compliance with mandatory registration requirements regarding scientific leadership and trial contact information. Non-industry and partial industry funded trials were significantly more likely to identify the individual responsible for scientific leadership (OR = 259, 95% CI: 95–701) and to provide a contact e-mail address (OR = 9.6, 95% CI: 6.6–14) than were solely industry funded trials.

Conclusions/Significance

Despite the requirements set by WHO and ICMJE, data on scientific leadership and contact e-mail addresses are frequently omitted from clinical trials registered in the two leading public clinical trial registers. To promote accountability and transparency in clinical trials research, public clinical trials registers should ensure adequate monitoring of trial registration to ensure completion of mandatory contact information fields identifying scientific leadership     

The Quality of Registration of Clinical Trials: Still a Problem

Introduction

The benefits of clinical trials registration include improved transparency on clinical trials for healthcare workers and patients, increased accountability of trialists, the potential to address publication bias and selective reporting, and possibilities for research collaboration and prioritization. However, poor quality of information in registered records of trials has been found to undermine these benefits in the past. Trialists'' increasing experience with trial registration and recent developments in registration systems may have positively affected data quality. This study was conducted to investigate whether the quality of registration has improved.

Methods

We repeated a study from 2009, using the same methods and the same research team. A random sample of 400 records of clinical trials that were registered between 01/01/2012 and 01/01/2013 was taken from the International Clinical Trials Registry Platform (ICTRP) and assessed for the quality of information on 1) contact details, 2) interventions and 3) primary outcomes. Results were compared to the equivalent assessments from our previous study.

Results

There was a small and not statistically significant increase from 81.0% to 85.5% in the percentage of records that provided a name of a contact person. There was a significant increase from 68.7% to 74.9% in the number of records that provided either an email address or a telephone number. There was a significant increase from 44.2% to 51.9% in the number of intervention arms that were complete in registering intervention specifics. There was a significant increase from 38.2% to 57.6% in the number of primary outcomes that were specific measures with a meaningful timeframe. Approximately half of all trials continued to be retrospectively registered.

Discussion

There have been small but significant improvements in the quality of registration since 2009. Important problems with quality remain and continue to constitute an impediment to the meaningful utilization of registered trial information.     

Completeness and changes in registered data and reporting bias of randomized controlled trials in ICMJE journals after trial registration policy

Objective

We assessed the adequacy of randomized controlled trial (RCT) registration, changes to registration data and reporting completeness for articles in ICMJE journals during 2.5 years after registration requirement policy.

Methods

For a set of 149 reports of 152 RCTs with ClinicalTrials.gov registration number, published from September 2005 to April 2008, we evaluated the completeness of 9 items from WHO 20-item Minimum Data Set relevant for assessing trial quality. We also assessed changes to the registration elements at the Archive site of ClinicalTrials.gov and compared published and registry data.

Results

RCTs were mostly registered before 13 September 2005 deadline (n = 101, 66.4%); 118 (77.6%) started recruitment before and 31 (20.4%) after registration. At the time of registration, 152 RCTs had a total of 224 missing registry fields, most commonly ‘Key secondary outcomes’ (44.1% RCTs) and ‘Primary outcome’ (38.8%). More RCTs with post-registration recruitment had missing Minimum Data Set items than RCTs with pre-registration recruitment: 57/118 (48.3%) vs. 24/31 (77.4%) (χ² ₁ = 7.255, P = 0.007). Major changes in the data entries were found for 31 (25.2%) RCTs. The number of RCTs with differences between registered and published data ranged from 21 (13.8%) for Study type to 118 (77.6%) for Target sample size.

Conclusions

ICMJE journals published RCTs with proper registration but the registration data were often not adequate, underwent substantial changes in the registry over time and differed in registered and published data. Editors need to establish quality control procedures in the journals so that they continue to contribute to the increased transparency of clinical trials.     

Result Publication of Chinese Trials in World Health Organization Primary Registries

Background

Result publication is the key step to improve the transparency of clinical trials.

Objective

To investigate the result publication rate of Chinese trials registered in World Health Organization (WHO) primary registries.

Method

We searched 11 WHO primary registries for Chinese trials records. The progress of each trial was analyzed. We searched for the full texts of result publications cited in the registration records. For completed trials without citations, we searched PubMed, Embase, Chinese Biomedical Literature Database (Chinese), China Knowledge Resource Integrated Database, and Chinese Science and Technology Periodicals Database for result publications. The search was conducted on July 14, 2009. We also called the investigators of completed trials to ask about results publication.

Results

We identified 1294 Chinese trials records (428 in ChiCTR,743 in clinicaltrials.gov,55 in ISRCTN, 21 in ACTRN). A total of 443 trials had been completed. The publication rate of the Chinese trials in WHO primary registries is 35.2%(156/443).The publication rate of Chinese trials in clinicaltrials.gov, ChiCTR, ISRCTN, and ACRTN was 36.5% (53/145), 36.3% (89/245), 26.0%(9/44), and 55.6%(5/9), respectively. The publication rate of trials sponsored by industry(23.8%) was lower than that of sponsored by central and local government(31.7%), hospital(35.1%), and universities (40.7%). The publication rate for randomized trials was higher than that of cohort study and case-control study (33.2% versus 16.7%, 22.2%). The publication rate for interventional studies and observational studies was similar(33.4% versus 33.3%).

Conclusion

The publication rate of the registered Chinese trials was low, with no significant difference between ChiCTR and clinicaltrials.gov. An effective mechanism is needed to promote publication of results for registered trials in China.     

Room for improvement in conducting and reporting non-inferiority randomized controlled trials on drugs: a systematic review

Background

A non-inferiority (NI) trial is intended to show that the effect of a new treatment is not worse than the comparator. We conducted a review to identify how NI trials were conducted and reported, and whether the standard requirements from the guidelines were followed.

Methodology and Principal Findings

From 300 randomly selected articles on NI trials registered in PubMed at 5 February 2009, we included 227 NI articles that referred to 232 trials. We excluded studies on bioequivalence, trials on healthy volunteers, non-drug trials, and articles of which the full-text version could not be retrieved. A large proportion of trials (34.0%) did not use blinding. The NI margin was reported in 97.8% of the trials, but only 45.7% of the trials reported the method to determine the margin. Most of the trials used either intention to treat (ITT) (34.9%) or per-protocol (PP) analysis (19.4%), while 41.8% of the trials used both methods. Less than 10% of the trials included a placebo arm to confirm the efficacy of the new drug and active comparator against placebo, and less than 5.0% were reporting the similarity of the current trial with the previous comparator''s trials. In general, no difference was seen in the quality of reporting before and after the release of the CONSORT statement extension 2006 or between the high-impact and low-impact journals.

Conclusion

The conduct and reporting of NI trials can be improved, particularly in terms of maximizing the use of blinding, the use of both ITT and PP analysis, reporting the similarity with the previous comparator''s trials to guarantee a valid constancy assumption, and most importantly reporting the method to determine the NI margin.     

How Psychiatry Journals Support the Unbiased Translation of Clinical Research. A Cross-Sectional Study of Editorial Policies

Introduction

Reporting guidelines (e.g. CONSORT) have been developed as tools to improve quality and reduce bias in reporting research findings. Trial registration has been recommended for countering selective publication. The International Committee of Medical Journal Editors (ICMJE) encourages the implementation of reporting guidelines and trial registration as uniform requirements (URM). For the last two decades, however, biased reporting and insufficient registration of clinical trials has been identified in several literature reviews and other investigations. No study has so far investigated the extent to which author instructions in psychiatry journals encourage following reporting guidelines and trial registration.

Method

Psychiatry Journals were identified from the 2011 Journal Citation Report. Information given in the author instructions and during the submission procedure of all journals was assessed on whether major reporting guidelines, trial registration and the ICMJE’s URM in general were mentioned and adherence recommended.

Results

We included 123 psychiatry journals (English and German language) in our analysis. A minority recommend or require 1) following the URM (21%), 2) adherence to reporting guidelines such as CONSORT, PRISMA, STROBE (23%, 7%, 4%), or 3) registration of clinical trials (34%). The subsample of the top-10 psychiatry journals (ranked by impact factor) provided much better but still improvable rates. For example, 70% of the top-10 psychiatry journals do not ask for the specific trial registration number.

Discussion

Under the assumption that better reported and better registered clinical research that does not lack substantial information will improve the understanding, credibility, and unbiased translation of clinical research findings, several stakeholders including readers (physicians, patients), authors, reviewers, and editors might benefit from improved author instructions in psychiatry journals. A first step of improvement would consist in requiring adherence to the broadly accepted reporting guidelines and to trial registration.     

African HIV/AIDS trials are more likely to report adequate allocation concealment and random generation than North American trials

Background

Adherence to good methodological quality is necessary to minimise bias in randomised conrolled trials (RCTs). Specific trial characteristics are associated with better trial quality, but no studies to date are specific to HIV/AIDS or African trials. We postulated that location may negatively impact on trial quality in regions where resources are scarce.

Methods

1) To compare the methodological quality of all HIV/AIDS RCTs conducted in Africa with a random sample of similar trials conducted in North America; 2) To assess whether location is predictive of trial quality. We searched MEDLINE, EMBASE, CENTRAL and LILACS. Eligible trials were 1) randomized, 2) evaluations of preventive or treatment interventions for HIV/AIDS, 3) reported before 2004, and 4) conducted wholly or partly (if multi-centred) in Africa or North America. We assessed adequacy of random generation, allocation concealment and masking of assessors. Using univariate and multivariate logistic regression analyses we evaluated the association between location (Africa versus North America) and these domains.

Findings

The African search yielded 12,815 records, from which 80 trials were identified. The North American search yielded 13,158 records from which 785 trials were identified and a random sample of 114 selected for analysis. African trials were three times more likely than North American trials to report adequate allocation concealment (OR = 3.24; 95%CI: 1.59 to 6.59; p<0.01) and twice as likely to report adequate generation of the sequence (OR = 2.36; 95%CI: 1.20 to 4.67; p = 0.01), after adjusting for other confounding factors. Additional significant factors positively associated with quality were an a priori sample size power calculation, restricted randomization and inclusion of a flow diagram detailing attrition. We did not detect an association between location and outcome assessor masking.

Conclusions

The higher quality of reporting of methodology in African trials is noteworthy. Most African trials are externally funded, and it is possible that stricter agency requirements when leading trials in other countries and greater experience and training of principal investigators of an international stature, may account for this difference.     

Trial Publication after Registration in ClinicalTrials.Gov: A Cross-Sectional Analysis

Background

ClinicalTrials.gov is a publicly accessible, Internet-based registry of clinical trials managed by the US National Library of Medicine that has the potential to address selective trial publication. Our objectives were to examine completeness of registration within ClinicalTrials.gov and to determine the extent and correlates of selective publication.

Methods and Findings

We examined reporting of registration information among a cross-section of trials that had been registered at ClinicalTrials.gov after December 31, 1999 and updated as having been completed by June 8, 2007, excluding phase I trials. We then determined publication status among a random 10% subsample by searching MEDLINE using a systematic protocol, after excluding trials completed after December 31, 2005 to allow at least 2 y for publication following completion. Among the full sample of completed trials (n = 7,515), nearly 100% reported all data elements mandated by ClinicalTrials.gov, such as intervention and sponsorship. Optional data element reporting varied, with 53% reporting trial end date, 66% reporting primary outcome, and 87% reporting trial start date. Among the 10% subsample, less than half (311 of 677, 46%) of trials were published, among which 96 (31%) provided a citation within ClinicalTrials.gov of a publication describing trial results. Trials primarily sponsored by industry (40%, 144 of 357) were less likely to be published when compared with nonindustry/nongovernment sponsored trials (56%, 110 of 198; p<0.001), but there was no significant difference when compared with government sponsored trials (47%, 57 of 122; p = 0.22). Among trials that reported an end date, 75 of 123 (61%) completed prior to 2004, 50 of 96 (52%) completed during 2004, and 62 of 149 (42%) completed during 2005 were published (p = 0.006).

Conclusions

Reporting of optional data elements varied and publication rates among completed trials registered within ClinicalTrials.gov were low. Without greater attention to reporting of all data elements, the potential for ClinicalTrials.gov to address selective publication of clinical trials will be limited. Please see later in the article for the Editors'' Summary     

Publication delay of randomized trials on 2009 influenza A (H1N1) vaccination

Background

Randomized evidence for vaccine immunogenicity and safety is urgently needed in the setting of pandemics with new emerging infectious agents. We carried out an observational survey to evaluate how many randomized controlled trials testing 2009 H1N1 vaccines were published among those registered, and what was the time lag from their start to publication and from their completion to publication.

Methods

PubMed, EMBASE and 9 clinical trial registries were searched for eligible randomized controlled trials. The units of the analysis were single randomized trials on any individual receiving influenza vaccines in any setting.

Results

73 eligible trials were identified that had been registered in 2009–2010. By June 30, 2011 only 21 (29%) of these trials had been published, representing 38% of the randomized sample size (19905 of 52765). Trials starting later were published less rapidly (hazard ratio 0.42 per month; 95% Confidence Interval: 0.27 to 0.64; p<0.001). Similarly, trials completed later were published less rapidly (hazard ratio 0.43 per month; 95% CI: 0.27 to 0.67; p<0.001). Randomized controlled trials were completed promptly (median, 5 months from start to completion), but only a minority were subsequently published.

Conclusions

Most registered randomized trials on vaccines for the H1N1 pandemic are not published in the peer-reviewed literature.     

Is Mandatory Prospective Trial Registration Working to Prevent Publication of Unregistered Trials and Selective Outcome Reporting? An Observational Study of Five Psychiatry Journals That Mandate Prospective Clinical Trial Registration

Objective

To address the bias occurring in the medical literature associated with selective outcome reporting, in 2005, the International Committee of Medical Journal Editors (ICMJE) introduced mandatory trial registration guidelines and member journals required prospective registration of trials prior to patient enrolment as a condition of publication. No research has examined whether these guidelines are impacting psychiatry publications. Our objectives were to determine the extent to which articles published in psychiatry journals adhering to ICMJE guidelines were correctly prospectively registered, whether there was evidence of selective outcome reporting and changes to participant numbers, and whether there was a relationship between registration status and source of funding.

Materials and Methods

Any clinical trial (as defined by ICMJE) published between 1 January 2009 and 31 July 2013 in the top five psychiatry journals adhering to ICMJE guidelines (The American Journal of Psychiatry, Archives of General Psychiatry/JAMA Psychiatry, Biological Psychiatry, Journal of the American Academy of Child and Adolescent Psychiatry, and The Journal of Clinical Psychiatry) and conducted after July 2005 (or 2007 for two journals) was included. For each identified trial, where possible we extracted trial registration information, changes to POMs between publication and registry to assess selective outcome reporting, changes to participant numbers, and funding type.

Results

Out of 3305 articles, 181 studies were identified as clinical trials requiring registration: 21 (11.6%) were deemed unregistered, 61 (33.7%) were retrospectively registered, 37 (20.4%) had unclear POMs either in the article or the registry and 2 (1.1%) were registered in an inaccessible trial registry. Only 60 (33.1%) studies were prospectively registered with clearly defined POMs; 17 of these 60 (28.3%) showed evidence of selective outcome reporting and 16 (26.7%) demonstrated a change in participant numbers of 20% or more; only 26 (14.4%) of the 181 the trials were prospectively registered and did not alter their POMs or the time frames at which they were measured. Prospective registration with no changes in POMs occurred more frequently with pharmaceutical funding.

Discussion

Although standards are in place to improve prospective registration and transparency in clinical trials, less than 15% of psychiatry trials were prospectively registered with no changes in POMs. Most trials were either not prospectively registered, changed POMs or the timeframes at some point after registration or changed participant numbers. Authors, journal editors and reviewers need to further efforts to highlight the value of prospective trial registration.     

Registration Quality Assessment of Acupuncture Clinical Trials

Background

Registration can help with transparency of acupuncture clinical trials (ACTs) by making protocol information and results available to the public. Recently, the number of registered ACTs has increased greatly, but only a few researchers have focused on the quality of ACTs registration. This review provides the first assessment of the registration quality of ACTs and the baseline information for future development.

Methods

All records of ACTs registered in the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) were collected. Data was extracted and input to Excel spreadsheets. The current 20 items of the WHO Trial Registration Data Set (TRDS) and the special prepared items for acupuncture intervention details were used to assess the registration quality of ACTs.

Results

A total of 740 records, found in 11 registries, were examined. The number of registered ACTs increased rapidly and involved a number of different diseases. The completeness of 20 items was not too poor due to 16 of them had a higher reported percentage (>85%). The completeness of the 20 items was different among registries. For example, the average registration percentage of 20 items in Clinicaltrials.gov, ChiCTR, ISRCTN and ANZCTR were 89.6%, 92.2%, 82.4% and 91.6% respectively. Detailed information regarding acupuncture intervention was seriously insufficient. Among the 740 registration records, 89.2% lacked information on the style of acupuncture, 80.8% did not contain details regarding the needles used, 53.5% lacked information on the treatment regimen and 76.2% did not give details of other interventions administered with acupuncture.

Conclusions

The overall registration quality of ACTs is not high enough due to the serious lack of information on the specifics of acupuncture intervention. It is vital that a number of special items be set regarding acupuncture in order to develop a suitable system for the registration of ACTs.     

Trial Registration Numbers Are Underreported in Biomedical Publications

Context

Since September 2005, the International Committee of Medical Journal Editors (ICMJE) has required that randomised controlled trials (RCTs) are prospectively registered in a publicly accessible database. After registration, a trial registration number (TRN) is assigned to each RCT, which should make it easier to identify future publications and cross-check published results with associated registry entries, as long as the unique identification number is reported in the article.

Objective

Our primary objective was to evaluate the reporting of trial registration numbers in biomedical publications. Secondary objectives were to evaluate how many published RCTs had been registered and how many registered RCTs had resulted in a publication, using a sample of trials from the Netherlands Trials Register (NTR).

Design, Setting

Two different samples of RCTs were examined: 1) RCTs published in November 2010 in core clinical journals identified in MEDLINE; 2) RCTs registered in the NTR with a latest expected end date of 31 August 2008.

Results

Fifty-five percent (166/302) of the reports of RCTs found in MEDLINE and 60% (186/312) of the published reports of RCTs from the NTR cohort contained a TRN. In both samples, reporting of a TRN was more likely in RCTs published in ICMJE member journals as compared to non-ICMJE member journals (MEDLINE 58% vs. 45%; NTR: 70% vs. 49%). Thirty-nine percent of published RCTs in the MEDLINE sample appear not to have been registered, and 48% of RCTs registered in the NTR seemed not to have been published at least two years after the expected date for study completion.

Conclusion

Our results show that further promotion and implementation of trial registration and accurate reporting of TRN is still needed. This might be helped by inclusion of the TRN as an item on the CONSORT checklist.     

Does HAART Efficacy Translate to Effectiveness? Evidence for a Trial Effect

Background

Patients who participate in clinical trials may experience better clinical outcomes than patients who initiate similar therapy within clinical care (trial effect), but no published studies have evaluated a trial effect in HIV clinical trials.

Methods

To examine a trial effect we compared virologic suppression (VS) among patients who initiated HAART in a clinical trial versus in routine clinical care. VS was defined as a plasma HIV RNA ≤400 copies/ml at six months after HAART initiation and was assessed within strata of early (1996–99) or current (2000–06) HAART periods. Risk ratios (RR) were estimated using binomial models.

Results

Of 738 persons initiating HAART, 30.6% were women, 61.7% were black, 30% initiated therapy in a clinical trial and 67% (n = 496) had an evaluable six month HIV RNA result. HAART regimens differed between the early and current periods (p<0.001); unboosted PI regimens (55.6%) were more common in the early and NNRTI regimens (46.4%) were more common in the current period. Overall, 78% (95%CI 74, 82%) of patients achieved VS and trial participants were 16% more likely to achieve VS (unadjusted RR 1.16, 95%CI 1.06, 1.27). Comparing trial to non-trial participants, VS differed by study period. In the early period, trial participants initiating HAART were significantly more likely to achieve VS than non-trial participants (adjusted RR 1.33; 95%CI 1.15, 1.54), but not in the current period (adjusted RR 0.98; 95%CI 0.87, 1.11).

Conclusions

A clear clinical trial effect on suppression of HIV replication was observed in the early HAART period but not in the current period.     

Impact of reporting bias in network meta-analysis of antidepressant placebo-controlled trials

Background

Indirect comparisons of competing treatments by network meta-analysis (NMA) are increasingly in use. Reporting bias has received little attention in this context. We aimed to assess the impact of such bias in NMAs.

Methods

We used data from 74 FDA-registered placebo-controlled trials of 12 antidepressants and their 51 matching publications. For each dataset, NMA was used to estimate the effect sizes for 66 possible pair-wise comparisons of these drugs, the probabilities of being the best drug and ranking the drugs. To assess the impact of reporting bias, we compared the NMA results for the 51 published trials and those for the 74 FDA-registered trials. To assess how reporting bias affecting only one drug may affect the ranking of all drugs, we performed 12 different NMAs for hypothetical analysis. For each of these NMAs, we used published data for one drug and FDA data for the 11 other drugs.

Findings

Pair-wise effect sizes for drugs derived from the NMA of published data and those from the NMA of FDA data differed in absolute value by at least 100% in 30 of 66 pair-wise comparisons (45%). Depending on the dataset used, the top 3 agents differed, in composition and order. When reporting bias hypothetically affected only one drug, the affected drug ranked first in 5 of the 12 NMAs but second (n = 2), fourth (n = 1) or eighth (n = 2) in the NMA of the complete FDA network.

Conclusions

In this particular network, reporting bias biased NMA-based estimates of treatments efficacy and modified ranking. The reporting bias effect in NMAs may differ from that in classical meta-analyses in that reporting bias affecting only one drug may affect the ranking of all drugs.     

Systematic review of the empirical evidence of study publication bias and outcome reporting bias

Background

The increased use of meta-analysis in systematic reviews of healthcare interventions has highlighted several types of bias that can arise during the completion of a randomised controlled trial. Study publication bias has been recognised as a potential threat to the validity of meta-analysis and can make the readily available evidence unreliable for decision making. Until recently, outcome reporting bias has received less attention.

Methodology/Principal Findings

We review and summarise the evidence from a series of cohort studies that have assessed study publication bias and outcome reporting bias in randomised controlled trials. Sixteen studies were eligible of which only two followed the cohort all the way through from protocol approval to information regarding publication of outcomes. Eleven of the studies investigated study publication bias and five investigated outcome reporting bias. Three studies have found that statistically significant outcomes had a higher odds of being fully reported compared to non-significant outcomes (range of odds ratios: 2.2 to 4.7). In comparing trial publications to protocols, we found that 40–62% of studies had at least one primary outcome that was changed, introduced, or omitted. We decided not to undertake meta-analysis due to the differences between studies.

Conclusions

Recent work provides direct empirical evidence for the existence of study publication bias and outcome reporting bias. There is strong evidence of an association between significant results and publication; studies that report positive or significant results are more likely to be published and outcomes that are statistically significant have higher odds of being fully reported. Publications have been found to be inconsistent with their protocols. Researchers need to be aware of the problems of both types of bias and efforts should be concentrated on improving the reporting of trials.     

Can We Depend on Investigators to Identify and Register Randomized Controlled Trials?

Purpose

To reduce publication bias, systematic reviewers are advised to search conference abstracts to identify randomized controlled trials (RCTs) conducted in humans and not published in full. We assessed the information provided by authors to aid identification of RCTs for reviews.

Methods

We handsearched the Association for Research in Vision and Ophthalmology (ARVO) meeting abstracts for 2004 to 2009 to identify reports of RCTs. We compared our classification with that of authors (requested by ARVO 2004–2006), and authors’ report of trial registration (required by ARVO 2007–2009).

Results

Authors identified their study as a clinical trial for 169/191 (88%; 95% CI, 84–93) RCTs we identified for 2004, 174/212 (82%; 95% CI, 77–87) for 2005 and 162/215 (75%; 95% CI, 70–81) for 2006. Authors provided registration information for 107/172 (62%; 95% CI, 55–69) RCTs for 2007, 103/153 (67%; 95% CI, 60–75) for 2008, and 126/171 (74%; 95% CI, 67–80) for 2009. Most RCT authors providing a trial register name specified ClinicalTrials.gov (276/312; 88%; 95% CI, 85–92) and provided a valid ClinicalTrials.gov registration number (261/276; 95%; 95% CI, 92–97). Based on information provided by authors, trial registration information would be accessible for 48% (83/172) (95% CI, 41–56) of all ARVO abstracts describing RCTs in 2007, 63% (96/153) (95% CI, 55–70) in 2008, and 70% in 2009 (118/171) (95% CI, 62–76).

Conclusions

Authors of abstracts describing RCTs frequently did not classify them as clinical trials nor comply with reporting trial registration information, as required by the conference organizers. Systematic reviewers cannot rely on authors to identify relevant unpublished trials or report trial registration, if present.     

Participant informed consent in cluster randomized trials: review

Background

The Nuremberg code defines the general ethical framework of medical research with participant consent as its cornerstone. In cluster randomized trials (CRT), obtaining participant informed consent raises logistic and methodologic concerns. First, with randomization of large clusters such as geographical areas, obtaining individual informed consent may be impossible. Second, participants in randomized clusters cannot avoid certain interventions, which implies that participant informed consent refers only to data collection, not administration of an intervention. Third, complete participant information may be a source of selection bias, which then raises methodological concerns. We assessed whether participant informed consent was required in such trials, which type of consent was required, and whether the trial was at risk of selection bias because of the very nature of participant information.

Methods and Findings

We systematically reviewed all reports of CRT published in MEDLINE in 2008 and surveyed corresponding authors regarding the nature of the informed consent and the process of participant inclusion. We identified 173 reports and obtained an answer from 113 authors (65.3%). In total, 23.7% of the reports lacked information on ethics committee approval or participant consent, 53.1% of authors declared that participant consent was for data collection only and 58.5% that the group allocation was not specified for participants. The process of recruitment (chronology of participant recruitment with regard to cluster randomization) was rarely reported, and we estimated that only 56.6% of the trials were free of potential selection bias.

Conclusions

For CRTs, the reporting of ethics committee approval and participant informed consent is less than optimal. Reports should describe whether participants consented for administration of an intervention and/or data collection. Finally, the process of participant recruitment should be fully described (namely, whether participants were informed of the allocation group before being recruited) for a better appraisal of the risk of selection bias.     

Quality of reporting of bioequivalence trials comparing generic to brand name drugs: a methodological systematic review

Background

Generic drugs are used by millions of patients for economic reasons, so their evaluation must be highly transparent.

Objective

To assess the quality of reporting of bioequivalence trials comparing generic to brand-name drugs.

Methodology/Principal Findings

PubMed was searched for reports of bioequivalence trials comparing generic to brand-name drugs between January 2005 and December 2008. Articles were included if the aim of the study was to assess the bioequivalency of generic and brand-name drugs. We excluded case studies, pharmaco-economic evaluations, and validation dosage assays of drugs. We evaluated whether important information about funding, methodology, location of trials, and participants were reported. We also assessed whether the criteria required by the Food and Drug Administration (FDA) and the European Medicine Agency (EMA) to conclude bioequivalence were reported and that the conclusions were in agreement with the results. We identified 134 potentially relevant articles but eliminated 55 because the brand-name or generic drug status of the reference drug was unknown. Thus, we evaluated 79 articles. The funding source and location of the trial were reported in 41% and 56% of articles, respectively. The type of statistical analysis was reported in 94% of articles, but the methods to generate the randomization sequence and to conceal allocation were reported in only 15% and 5%, respectively. In total, 65 articles of single-dose trials (89%) concluded bioequivalence. Of these, 20 (31%) did not report the 3 criteria within the limits required by the FDA and 11 (17%) did not report the 2 criteria within the limits required by the EMA.

Conclusions/Significance

Important information to judge the validity and relevance of results are frequently missing in published reports of trials assessing generic drugs. The quality of reporting of such trials is in need of improvement.     

Acceptability of Carraguard vaginal microbicide gel among HIV-infected women in Chiang Rai, Thailand

Background

Few studies of microbicide acceptability among HIV-infected women have been done. We assessed Carraguard® vaginal gel acceptability among participants in a randomized, controlled, crossover safety trial in HIV-infected women in Thailand.

Methodology/Principal Findings

Participants used each of 3 treatments (Carraguard gel, methylcellulose placebo gel, and no product) for 7 days, were randomized to one of six treatment sequences, and were blinded to the type of gel they received in the two gel-use periods. After both gel-use periods, acceptability was assessed by face-to-face interview. Responses were compared to those of women participating in two previous Carraguard safety studies at the same study site. Sixty women enrolled with a median age of 34 years; 25% were sexually active. Self-reported adherence (98%) and overall satisfaction rating of the gels (87% liked “somewhat” or “very much”) were high, and most (77%) considered the volume of gel “just right.” For most characteristics, crossover trial participants evaluated the gels more favorably than women in the other two trials, but there were few differences in the desired characteristics of a hypothetical microbicide. Almost half (48%) of crossover trial participants noticed a difference between Carraguard and placebo gels; 33% preferred Carraguard while 12% preferred placebo (p = 0.01).

Conclusions/Significance

Daily Carraguard vaginal gel use was highly acceptable in this population of HIV-infected women, who assessed the gels more positively than women in two other trials at the site. This may be attributable to higher perceived need for protection among HIV-infected women, as well as to study design differences. This trial was registered in the U.S. National Institutes of Health clinical trials registry under registration number {"type":"clinical-trial","attrs":{"text":"NCT00213044","term_id":"NCT00213044"}}NCT00213044.