Age and sex effects on 5-HT(4) receptors in the human brain: a [(11)C]SB207145 PET study.

Experimental studies indicate that the 5-HT(4) receptor activation influence cognitive function, affective symptoms, and the development of Alzheimer's disease (AD). The prevalence of AD increases with aging, and women have a higher predisposition to both AD and affective disorders than men. This study aimed to investigate sex and age effects on 5-HT(4) receptor-binding potentials in striatum, the limbic system, and neocortex. Positron-emission tomographic scans were conducted using the radioligand [(11)C]SB207145 in a cohort of 30 healthy subjects (mean age 44 years; range 20 to 86 years; 14 men and 16 women). The output parameter, BP(ND), was modeled using the simplified reference tissue model, and partial volume correction was performed with the Muller-Gartner method. A decline with age of 1% per decade was found only in striatum. Women had a 13% lower 5-HT(4) receptor binding in the limbic system. The lower limbic 5-HT(4) receptor binding in women supports a role for 5-HT(4) receptors in the sex-specific differences in emotional control and might contribute to the higher prevalence of affective diseases and AD in women. The relatively stable 5-HT(4) receptor binding with aging contrasts others in subtypes of receptors, which generally decrease with aging.

Reporting on blinding in trial protocols and corresponding publications was often inadequate but rarely contradictory.

OBJECTIVE: To compare the reporting on blinding in protocols and articles describing randomized controlled trials. STUDY DESIGN AND SETTING: We studied 73 protocols of trials approved by the scientific/ethical committees for Copenhagen and Frederiksberg, 1994 and 1995, and their corresponding publications. RESULTS: Three out of 73 trials (4%) reported blinding in the protocol that contradicted that in the publication (e.g., "open" vs. "double blind"). The proportion of "double-blind" trials with a clear description of the blinding of participants increased from 11 out of 58 (19%) when based on publications alone to 39 (67%) when adding the information in the protocol. The similar proportions for the blinding of health care providers were 2 (3%) and 22 (38%); and for the blinding of data collectors, they were 8 (14%) and 14 (24%). In 52 of 58 publications (90%), it was unclear whether all patients, health care providers, and data collectors had been blinded. In 4 of the 52 trials (7%), the protocols clarified that all three key trial persons had been blinded. CONCLUSIONS: The reporting on blinding in both trial protocols and publications is often inadequate. We suggest developing international guidelines for the reporting of trial protocols and public access to protocols.

Ghost authorship in industry-initiated randomised trials.

BACKGROUND: Ghost authorship, the failure to name, as an author, an individual who has made substantial contributions to an article, may result in lack of accountability. The prevalence and nature of ghost authorship in industry-initiated randomised trials is not known. METHODS AND FINDINGS: We conducted a cohort study comparing protocols and corresponding publications for industry-initiated trials approved by the Scientific-Ethical Committees for Copenhagen and Frederiksberg in 1994-1995. We defined ghost authorship as present if individuals who wrote the trial protocol, performed the statistical analyses, or wrote the manuscript, were not listed as authors of the publication, or as members of a study group or writing committee, or in an acknowledgment. We identified 44 industry-initiated trials. We did not find any trial protocol or publication that stated explicitly that the clinical study report or the manuscript was to be written or was written by the clinical investigators, and none of the protocols stated that clinical investigators were to be involved with data analysis. We found evidence of ghost authorship for 33 trials (75%; 95% confidence interval 60%-87%). The prevalence of ghost authorship was increased to 91% (40 of 44 articles; 95% confidence interval 78%-98%) when we included cases where a person qualifying for authorship was acknowledged rather than appearing as an author. In 31 trials, the ghost authors we identified were statisticians. It is likely that we have overlooked some ghost authors, as we had very limited information to identify the possible omission of other individuals who would have qualified as authors. CONCLUSIONS: Ghost authorship in industry-initiated trials is very common. Its prevalence could be considerably reduced, and transparency improved, if existing guidelines were followed, and if protocols were publicly available.

[Constraints on publication rights in industry-initiated clinical trials--secondary publication]. / Begraensninger i publikationsrettighederne i industriinitierede kliniske forsøg - sekundaerpublikation.

In 22 of 44 industry-initiated clinical trial protocols from 1994-95, it was noted that the sponsor either owned the data or needed to approve the manuscript; another 18 protocols had other constraints. Furthermore, in 16 trials, the sponsor had access to accumulating data, and in an additional 16 trials the sponsor could stop the trial at any time, for any reason. These facts were not noted in any of the trial reports. We found similar constraints on publication rights in 44 protocols from 2004. This tight sponsor control over industry-initiated trials should be changed.

[Selective reporting of positive outcomes in randomised trials--secondary publication.. A comparison of protocols with published reports]. / Selektiv rapportering af effektmål i randomiserede forsøg--sekundaerpublikation. En sammenligning af protokoller med publicerede artikler.

INTRODUCTION: Selective reporting of positive outcomes is associated with bias. MATERIALS AND METHODS: We conducted a cohort study of 102 protocols of randomised trials approved by the Scientific Ethics Committees for Copenhagen and Frederiksberg in 1994-1995 and the corresponding 122 reports. RESULTS: The median proportion of incompletely reported outcomes per trial was 50%. Statistically significant outcomes were more often fully reported, odds ratio 2.4. In 62% of trials, at least one primary outcome was changed. DISCUSSION: Outcomes in randomised trials are often reported selectively.

Empirical evidence for selective reporting of outcomes in randomized trials: comparison of protocols to published articles.

CONTEXT: Selective reporting of outcomes within published studies based on the nature or direction of their results has been widely suspected, but direct evidence of such bias is currently limited to case reports. OBJECTIVE: To study empirically the extent and nature of outcome reporting bias in a cohort of randomized trials. DESIGN: Cohort study using protocols and published reports of randomized trials approved by the Scientific-Ethical Committees for Copenhagen and Frederiksberg, Denmark, in 1994-1995. The number and characteristics of reported and unreported trial outcomes were recorded from protocols, journal articles, and a survey of trialists. An outcome was considered incompletely reported if insufficient data were presented in the published articles for meta-analysis. Odds ratios relating the completeness of outcome reporting to statistical significance were calculated for each trial and then pooled to provide an overall estimate of bias. Protocols and published articles were also compared to identify discrepancies in primary outcomes. MAIN OUTCOME MEASURES: Completeness of reporting of efficacy and harm outcomes and of statistically significant vs nonsignificant outcomes; consistency between primary outcomes defined in the most recent protocols and those defined in published articles. RESULTS: One hundred two trials with 122 published journal articles and 3736 outcomes were identified. Overall, 50% of efficacy and 65% of harm outcomes per trial were incompletely reported. Statistically significant outcomes had a higher odds of being fully reported compared with nonsignificant outcomes for both efficacy (pooled odds ratio, 2.4; 95% confidence interval [CI], 1.4-4.0) and harm (pooled odds ratio, 4.7; 95% CI, 1.8-12.0) data. In comparing published articles with protocols, 62% of trials had at least 1 primary outcome that was changed, introduced, or omitted. Eighty-six percent of survey responders (42/49) denied the existence of unreported outcomes despite clear evidence to the contrary. CONCLUSIONS: The reporting of trial outcomes is not only frequently incomplete but also biased and inconsistent with protocols. Published articles, as well as reviews that incorporate them, may therefore be unreliable and overestimate the benefits of an intervention. To ensure transparency, planned trials should be registered and protocols should be made publicly available prior to trial completion.