Scientometric measures of prospectively registered clinical trials over time: A comparison of IRCT and ClinicalTrials.gov.

Background: Iranian Registry of Clinical Trials (IRCT) started as a primary registry in 2008. We examined the characteristics and scientometric measures of prospectively registered clinical trials in IRCT over time and compared them with that of ClinicalTrials.gov. Methods: We selected eligible trial records between 2008 and 2016 from the IRCT database. We assessed their characteristics and the journal metrics of ensuing outputs over the study period and compared our findings with the corresponding information from ClinicalTrials.gov reported by Magdalena Zwierzyna et al. and a random sample of trials registered with this registry. We used the chi-square test for comparison of proportions and Mann-Whitney U test for comparison of medians. P-value <0.05 was considered statistically significant. Statistical analyses were performed using IBM SPSS Statistics V.22. Results: 1751 prospectively registered clinical trials were eligible for analysis, of which 1526 (87%) had parallel-group design, 1541 (88%) reported to be randomized, 753 (43%) used double-blinding design, 485 (%27.7) had sample size more than 100, 1313 (75%) completed within a year, 1539 (87.9%) were single centered and 1529 (87.3%) exclusively used public money. Comparison with ClinicalTrials.gov showed that they are less likely to have multiple centers, funded by private sectors, continue beyond one year; and more likely to be randomized, double-blind and get published as a paper. The sample sizes were similar. Journal scientometric measures remained constant over the study period for both databases but were higher in ClinicalTrials.gov (median SJR=1.67, IQR=1.1-3.23) compared with IRCT (median SJR=0.58, IQR=0.34-0.91). Conclusion: Our findings suggest that clinical trials registered in IRCT are predominantly investigator-initiated studies with acceptable methodological features and high publication rate albeit in journals with substantially lower scientometric measures compared with that of ClinicalTrials.gov. Journal metric indices remained constant despite an increase in the number of registrations in IRCT.

Impact of body mass index on immunogenicity of hepatitis B vaccine in bariatric surgery candidates: A retrospective study.

AIMS: Hepatitis B virus (HBV) immunization is regarded as the most effective method for the prevention of HBV infection. Various factors, including body mass index (BMI), may contribute to decreased immunization responses. This study aimed to investigate the relationship between BMI at the time of vaccination with anti-HBs levels over the following years. METHODS: In this retrospective study, 790 vaccinated participants were recruited. Of these, individuals were selected whose hepatitis B antibody (HBsAb) information was available in 2017. The researchers contacted participants by phone to gather data regarding vaccination history, and weight at the time of vaccination. All data analysis was performed by SPSS. RESULTS: This study included 165 eligible adults (28 males and 137 females). Among them, 79% participants were obese. Additionally, 46 (27.88%) and 119 (72.12%) had negative and positive HBsAb, respectively. There were no statistically significant differences seen across all characteristics, except for the number of HBV vaccinations between the positive and negative HBsAb groups. Multiple logistic regression also indicated no meaningful relationship between BMI and positive antibodies. CONCLUSION: There was no relationship observed between BMI and immune response to HBV vaccine in bariatric candidates. Known risk factors (age, sex, diabetes, and the number of HBV vaccinations) were not independent predictors of the antibody response to the HBV vaccine.

Investigation on factors associated with ovarian cancer: an umbrella review of systematic review and meta-analyses.

Following cervical and uterine cancer, ovarian cancer (OC) has the third rank in gynecologic cancers. It often remains non-diagnosed until it spreads throughout the pelvis and abdomen. Identification of the most effective risk factors can help take prevention measures concerning OC. Therefore, the presented review aims to summarize the available studies on OC risk factors. A comprehensive systematic literature search was performed to identify all published systematic reviews and meta-analysis on associated factors with ovarian cancer. Web of Science, Cochrane Library databases, and Google Scholar were searched up to 17th January 2020. This study was performed according to Smith et al. methodology for conducting a systematic review of systematic reviews. Twenty-eight thousand sixty-two papers were initially retrieved from the electronic databases, among which 20,104 studies were screened. Two hundred seventy-seven articles met our inclusion criteria, 226 of which included in the meta-analysis. Most commonly reported genetic factors were MTHFR C677T (OR=1.077; 95 % CI (1.032, 1.124); P-value<0.001), BSML rs1544410 (OR=1.078; 95 %CI (1.024, 1.153); P-value=0.004), and Fokl rs2228570 (OR=1.123; 95 % CI (1.089, 1.157); P-value<0.001), which were significantly associated with increasing risk of ovarian cancer. Among the other factors, coffee intake (OR=1.106; 95 % CI (1.009, 1.211); P-value=0.030), hormone therapy (RR=1.057; 95 % CI (1.030, 1.400); P-value<0.001), hysterectomy (OR=0.863; 95 % CI (0.745, 0.999); P-value=0.049), and breast feeding (OR=0.719, 95 % CI (0.679, 0.762) and P-value<0.001) were mostly reported in studies. Among nutritional factors, coffee, egg, and fat intake significantly increase the risk of ovarian cancer. Estrogen, estrogen-progesterone, and overall hormone therapies also are related to the higher incidence of ovarian cancer. Some diseases, such as diabetes, endometriosis, and polycystic ovarian syndrome, as well as several genetic polymorphisms, cause a significant increase in ovarian cancer occurrence. Moreover, other factors, for instance, obesity, overweight, smoking, and perineal talc use, significantly increase the risk of ovarian cancer.