Searching for unpublished data for Cochrane reviews:cross sectional study

Objective To describe the experiences of authors of Cochrane reviews in searching for, getting access to, and using unpublished data. Design Cross sectional study. Setting Cochrane reviews. Participants 2184 corresponding authors of Cochrane reviews as of May 2012. Main outcome measure Frequencies of responses to open ended and closed questions in an online survey. Results Of 5915 authors contacted by email, 2184 replied (36.9% response rate). Of those, 1656 (75.8%) had searched for unpublished data. In 913 cases (55.1% of 1656), new data were obtained and we received details about these data for 794 data sources. The most common data source was “trialists/investigators,” accounting for 73.9% (n=587) of the 794 data sources. Most of the data were used in the review (82.0%, 651/794) and in 53.4% (424/794) of cases data were provided in less than a month. Summary data were most common, provided by 50.8% (403/794) of the data sources, whereas 20.5% (163/794) provided individual patient data. In only 6.3% (50/794) of cases were data reported to have been obtained from the manufacturers, and this group waited longer and had to make more contacts to get the data. The data from manufacturers were less likely to be for individual patients and less likely to be used in the review. Data from regulatory agencies accounted for 3.0% (24/794) of the obtained data. Conclusions Most authors of Cochrane reviews who searched for unpublished data received useful information, primarily from trialists. Our response rate was low and the authors who did not respond were probably less likely to have searched for unpublished data. Manufacturers and regulatory agencies were uncommon sources of unpublished data

Human Papillomavirus Testing in the Last Cervical Screening Round at Age 60-64 Years

OBJECTIVE: To compare the real-life screening outcomes after cytology was replaced by human papillomavirus (HPV) testing for women aged 60–64 years. METHODS: Using the Danish national pathology register, we compared screening outcomes during two consecutive calendar periods, one where women were screened with cytology and one where most women were screened with HPV testing. Our primary outcomes were the proportions of women with positive test results, high-grade cervical intraepithelial neoplasia (CIN 2 or worse), and cervical cancer. RESULTS: Women screened during the HPV testing period were more likely to have a positive screening test result than were women screened during the cytology period (relative proportion 2.80, 95% CI 2.65–2.96). The detection of CIN 2 or worse was also increased (relative proportion 1.54, 95% CI 1.31–1.80), whereas there was no increase in screen-detected cervical cancer diagnoses (relative proportion 1.27, 95% CI 0.76–2.12). Within the first 4 years after a negative screening test result, including 168,477 woman-years at risk after a negative screen result in the HPV period and 451,421 woman-years after a negative screen result in the cytology period, the risk of a cervical cancer diagnosis was approximately 4 per 100,000 woman-years and was similar for both screening tests (relative risk 0.99, 95% CI 0.41–2.35). CONCLUSION: Human papillomavirus testing led to more positive screening test results and diagnoses of high-grade CIN lesions. Few women were diagnosed with cervical cancer after a negative screening test result

Assessment of Adverse Events in Protocols, Clinical Study Reports, and Published Papers of Trials of Orlistat:A Document Analysis

Little is known about how adverse events are summarised and reported in trials, as detailed information is usually considered confidential. We have acquired clinical study reports (CSRs) from the European Medicines Agency through the Freedom of Information Act. The CSRs describe the results of studies conducted as part of the application for marketing authorisation for the slimming pill orlistat. The purpose of this study was to study how adverse events were summarised and reported in study protocols, CSRs, and published papers of orlistat trials.We received the CSRs from seven randomised placebo controlled orlistat trials (4,225 participants) submitted by Roche. The CSRs consisted of 8,716 pages and included protocols. Two researchers independently extracted data on adverse events from protocols and CSRs. Corresponding published papers were identified on PubMed and adverse event data were extracted from this source as well. All three sources were compared. Individual adverse events from one trial were summed and compared to the totals in the summary report. None of the protocols or CSRs contained instructions for investigators on how to question participants about adverse events. In CSRs, gastrointestinal adverse events were only coded if the participant reported that they were "bothersome," a condition that was not specified in the protocol for two of the trials. Serious adverse events were assessed for relationship to the drug by the sponsor, and all adverse events were coded by the sponsor using a glossary that could be updated by the sponsor. The criteria for withdrawal due to adverse events were in one case related to efficacy (high fasting glucose led to withdrawal), which meant that one trial had more withdrawals due to adverse events in the placebo group. Finally, only between 3% and 33% of the total number of investigator-reported adverse events from the trials were reported in the publications because of post hoc filters, though six of seven papers stated that "all adverse events were recorded." For one trial, we identified an additional 1,318 adverse events that were not listed or mentioned in the CSR itself but could be identified through manually counting individual adverse events reported in an appendix. We discovered that the majority of patients had multiple episodes of the same adverse event that were only counted once, though this was not described in the CSRs. We also discovered that participants treated with orlistat experienced twice as many days with adverse events as participants treated with placebo (22.7 d versus 14.9 d, p-value < 0.0001, Student's t test). Furthermore, compared with the placebo group, adverse events in the orlistat group were more severe. None of this was stated in the CSR or in the published paper. Our analysis was restricted to one drug tested in the mid-1990s; our results might therefore not be applicable for newer drugs.In the orlistat trials, we identified important disparities in the reporting of adverse events between protocols, clinical study reports, and published papers. Reports of these trials seemed to have systematically understated adverse events. Based on these findings, systematic reviews of drugs might be improved by including protocols and CSRs in addition to published articles

Human papillomavirus vaccination in women undergoing excisional treatment for cervical intraepithelial neoplasia and subsequent risk of recurrence:A systematic review and meta-analysis

INTRODUCTION: In this review and meta‐analysis we aimed to investigate whether human papilloma virus (HPV) vaccination administered after excisional treatment of cervical intraepithelial neoplasia (CIN) is associated with a reduced risk of recurrence of CIN grade 2 or worse (CIN2+). MATERIAL AND METHODS: We performed a systematic literature search in three online databases through June 2021. Observational studies and randomized controlled trials (RCTs) were eligible for inclusion if the prophylactic HPV vaccine was administered after excisional treatment for histologically verified CIN. Only English language literature was included. The primary outcome measure was recurrence of CIN2+ after treatment. A meta‐analysis was performed using fixed and random‐effects models, and results were reported as pooled odds ratios (OR) with 95% confidence intervals (95% CI). Quality assessment was performed using ROB2‐tool for RCTs and ROBINS‐I for observational studies. The protocol was registered in PROSPERO (CRD42021238257). RESULTS: A total of 1561 studies were identified, of which nine, including 19 971 women, were included. Two studies were RCTs and seven were observational studies. Using the fixed‐effect model on the two RCTs, the OR for recurrence of CIN2+ was 0.29 (95% CI 0.16–0.53). Due to considerable heterogeneity in observational studies, the random‐effects model was used to estimate pooled OR for CIN2+ recurrence in these studies. Thus, using unadjusted data from observational studies, the OR for CIN2+ recurrence was 0.35 (95% CI 0.18–0.67), whereas when using adjusted data, the OR for CIN2+ recurrence was 0.54 (95% CI 0.21–1.35). However, quality assessment revealed a serious risk of bias for the majority of the studies included. CONCLUSIONS: HPV vaccination post‐treatment was associated with a significantly reduced risk of CIN2+ recurrence when using unadjusted estimates from observational studies and RCTs. We found no significant effect of HPV vaccination on risk of CIN2+ recurrence when using the outcome measure from observational studies with the least risk of bias. Large, well‐designed randomized placebo‐controlled trials are needed to determine whether post‐treatment HPV vaccination should be recommended to all women undergoing excisional treatment for CIN

Challenges in Coding Adverse Events in Clinical Trials: A Systematic Review

<div><h3>Background</h3><p>Misclassification of adverse events in clinical trials can sometimes have serious consequences. Therefore, each of the many steps involved, from a patient's adverse experience to presentation in tables in publications, should be as standardised as possible, minimising the scope for interpretation. Adverse events are categorised by a predefined dictionary, e.g. MedDRA, which is updated biannually with many new categories. The objective of this paper is to study interobserver variation and other challenges of coding.</p> <h3>Methods</h3><p>Systematic review using PRISMA. We searched PubMed, EMBASE and The Cochrane Library. All studies were screened for eligibility by two authors.</p> <h3>Results</h3><p>Our search returned 520 unique studies of which 12 were included. Only one study investigated interobserver variation. It reported that 12% of the codes were evaluated differently by two coders. Independent physicians found that 8% of all the codes deviated from the original description. Other studies found that product summaries could be greatly affected by the choice of dictionary. With the introduction of MedDRA, it seems to have become harder to identify adverse events statistically because each code is divided in subgroups. To account for this, lumping techniques have been developed but are rarely used, and guidance on when to use them is vague. An additional challenge is that adverse events are censored if they already occurred in the run-in period of a trial. As there are more than 26 ways of determining whether an event has already occurred, this can lead to bias, particularly because data analysis is rarely performed blindly.</p> <h3>Conclusion</h3><p>There is a lack of evidence that coding of adverse events is a reliable, unbiased and reproducible process. The increase in categories has made detecting adverse events harder, potentially compromising safety. It is crucial that readers of medical publications are aware of these challenges. Comprehensive interobserver studies are needed.</p> </div

Description of included studies.

<p>Description of included studies.</p

The MedDRA 5-level hierarchy demonstrated by using ‘common cold’ as an example.

<p>The MedDRA 5-level hierarchy demonstrated by using ‘common cold’ as an example.</p

Flow chart of the process of identifying studies.

<p>Flow chart of the process of identifying studies.</p