Extent of non-publication in cohorts of studies approved by research ethics committees or included in trial registries

BACKGROUND: The synthesis of published research in systematic reviews is essential when providing evidence to inform clinical and health policy decision-making. However, the validity of systematic reviews is threatened if journal publications represent a biased selection of all studies that have been conducted (dissemination bias). To investigate the extent of dissemination bias we conducted a systematic review that determined the proportion of studies published as peer-reviewed journal articles and investigated factors associated with full publication in cohorts of studies (i) approved by research ethics committees (RECs) or (ii) included in trial registries. METHODS AND FINDINGS: Four bibliographic databases were searched for methodological research projects (MRPs) without limitations for publication year, language or study location. The searches were supplemented by handsearching the references of included MRPs. We estimated the proportion of studies published using prediction intervals (PI) and a random effects meta-analysis. Pooled odds ratios (OR) were used to express associations between study characteristics and journal publication. Seventeen MRPs (23 publications) evaluated cohorts of studies approved by RECs; the proportion of published studies had a PI between 22% and 72% and the weighted pooled proportion when combining estimates would be 46.2% (95% CI 40.2%-52.4%, I2 = 94.4%). Twenty-two MRPs (22 publications) evaluated cohorts of studies included in trial registries; the PI of the proportion published ranged from 13% to 90% and the weighted pooled proportion would be 54.2% (95% CI 42.0%-65.9%, I2 = 98.9%). REC-approved studies with statistically significant results (compared with those without statistically significant results) were more likely to be published (pooled OR 2.8; 95% CI 2.2-3.5). Phase-III trials were also more likely to be published than phase II trials (pooled OR 2.0; 95% CI 1.6-2.5). The probability of publication within two years after study completion ranged from 7% to 30%. CONCLUSIONS: A substantial part of the studies approved by RECs or included in trial registries remains unpublished. Due to the large heterogeneity a prediction of the publication probability for a future study is very uncertain. Non-publication of research is not a random process, e.g., it is associated with the direction of study findings. Our findings suggest that the dissemination of research findings is biased

Five insights from the Global Burden of Disease Study 2019

The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a rules-based synthesis of the available evidence on levels and trends in health outcomes, a diverse set of risk factors, and health system responses. GBD 2019 covered 204 countries and territories, as well as first administrative level disaggregations for 22 countries, from 1990 to 2019. Because GBD is highly standardised and comprehensive, spanning both fatal and non-fatal outcomes, and uses a mutually exclusive and collectively exhaustive list of hierarchical disease and injury causes, the study provides a powerful basis for detailed and broad insights on global health trends and emerging challenges. GBD 2019 incorporates data from 281 586 sources and provides more than 3.5 billion estimates of health outcome and health system measures of interest for global, national, and subnational policy dialogue. All GBD estimates are publicly available and adhere to the Guidelines on Accurate and Transparent Health Estimate Reporting. From this vast amount of information, five key insights that are important for health, social, and economic development strategies have been distilled. These insights are subject to the many limitations outlined in each of the component GBD capstone papers.Peer reviewe

Polyorchidism presenting with undescended testis

We report on a case of polyorchidism that presented as undescended testis. Polyorchidism is defined as the presence of more than two testes. As in our case, most cases occur on the left side. The inferior testis is evidently larger than the accessory testis in all of the cases in the literature and, as far as we know, the present case is the first with the small testis located more distally than the larger one. The accessory testis had no reproductive potential due to a lack of attachment to a cord structure; therefore, it was removed because of the high risk of malignancy

Post-traumatic duodenopancreatectomy in a child

We describe a 5-year-old boy who complained of severe abdominal pain after a car accident. He was sitting on the lap of the driver and his abdomen was pressed closely between the pregnant driver and the steering wheel. At operation, associated injuries to the duodenum and pancreas were detected which could not be repaired. The transected pancreas and extensive duodenal injury underwent a Whipple-type reconstruction. On postoperative day six, the patient was re-operated due to extensive liver necrosis which was detected on abdominal computerized tomography and a partial liver resection was performed. He was discharged on day 16 after the second operation and has done well so far

The effect of the genitofemoral nerve division on the contralateral descended testis in the unilateral cryptorchidism model

It is widely accepted that there are degenerative changes and decreased spermatogenesis in the contralateral descended testis (CDT) in unilateral undescended testis (UUDT). While some investigators have postulated that the mechanism may be related to primary (congenital) or secondary (autoimmune, vascular, and neural) events, the exact mechanism of the damage to the CDT is still unknown. The present study was planned to investigate the role of the genitofemoral nerve (GFN) on the changes in the CDT. Forty male Wistar albino rats were divided into four groups of 10 each. During the newborn period a UUDT model was created and at the age of 30 days ipsilateral GFN division was done (group A). In addition, UUDT with intact GFN (group B), divided right GFN with bilateral scrotal testes (group C), and control (group D) groups were formed. When the animals reached early adulthood, they were killed and the testes were removed. Mean seminiferous-tubular diameter (STD) and germinal-ephitelium maturity was determined using modified Johnson testicular biopsy scores (TBS). The mean STD and TBS of the study groups did not show any differences suggesting that ipsilateral division of the GFN has no effect on the CDT in the UUDT model