Women’s involvement in clinical trials: historical perspective and future implications

The importance of considering the differences between the male and female sex in clinical decision-making is crucial. However, it has been acknowledged in recent decades that clinical trials have not always adequately enrolled women or analyzed sex-specific differences in the data. As these deficiencies have hindered the progress of understanding women’s response to medications, agencies in the United States have worked towards the inclusion of women in clinical trials and appropriate analysis of sex-specific data from clinical trials. This review outlines the history and progress of women’s inclusion in clinical trials for prescription drugs and presents considerations for researchers, clinicians, and academicians on this issue.

Effectiveness of inulin intake on indicators of chronic constipation; a meta-analysis of controlled randomized clinical trials

Background: Constipation is an intestinal dysfunction. Prebiotics, such as inulin, can improve bowel function by positively influencing intestinal biota. Aim: To analyze the scientific evidence for the role of inulin in improving bowel function in patients with chronic constipation. Methods: A meta-analysis of randomized controlled clinical trials was conducted, grounded on a literature search for the period 1995-2013 (descriptors: inulin & constipation) on PubMed, ScieLo and Central Trials Register Cochrane databases. A total of 24 articles were found, 5 of them were selected for this meta-analysis, involving 252 subjects (experimental group: n = 144, control group: n = 108). The quality of the studies was assessed using the Jadad scale. Results: We found a significant overall effect of inulin on stool frequency (DEM = 0.69, 95%CI: 0.04, 1.34), stool consistency (Bristol scale) (DEM = 1.07, 95% CI: 0.70, 1.45), transit time (DEM = -0.57, 95% CI: -0.99, -0.15) and hardness of stool (RR = 0.42, 95% CI: 0.26, 0.70). Pain and bloating do not improve with inulin intake. Conclusions: inulin intake has a positive effect on bowel function.

Assessment of the quality of sample labelling for clinical research

Objective: To assess the quality of the labels for clinical trial samples through current regulations, and to analyze its potential correlation with the specific characteristics of each sample. Method: A transversal multicenter study where the clinical trial samples from two third level hospitals were analyzed. The eleven items from Directive 2003/94/EC, as well as the name of the clinical trial and the dose on the label cover, were considered variables for labelling quality. The influence of the characteristics of each sample on labelling quality was also analyzed. Outcome: The study included 503 samples from 220 clinical trials. The mean quality of labelling, understood as the proportion of items from Appendix 13, was of 91.9%. Out of these, 6.6% did not include the name of the sample in the outer face of the label, while in 9.7% the dose was missing. The samples with clinical trial-type samples presented a higher quality (p < 0.049), blinding reduced their quality (p = 0.017), and identification by kit number or by patient increased it (p < 0.01). The promoter was the variable which introduced the highest variability into the analysis. Conclusions: The mean quality of labelling is adequate in the majority of clinical trial samples. The lack of essential information in some samples, such as the clinical trial code and the period of validity, is alarming and might be the potential source for dispensing or administration errors.

Informed consent in clinical research: do patients understand what they have signed?

Informed consent is an essential element of research, and signing this document is required to conduct most clinical trials. Its aim is to inform patients what their participation in the study will involve. However, increasingly, their complexity and length are making them difficult to understand, which might lead patients to give their authorization without having read them previously or without having understood what is stated. In this sense, the Ethics Committees for Clinical Research, and Pharmacists specialized in Hospital Pharmacy and Primary Care in their capacity as members of said committees, play an important and difficult role in defending the rights of patients. These Committees will review thoroughly these documents to guarantee that all legal requirements have been met and, at the same time, that they are easy to understand by the potential participants in a clinical trial.

Chromium supplementation in patients with type 2 diabetes and high risk of type 2 diabetes: a meta-analysis of randomized controlled trials

Introduction: Chromium is an essential trace mineral for carbohydrate and lipid metabolism, which is currently prescribed to control diabetes mellitus. Results of previous systematic reviews and meta-analyses of chromium supplementation and metabolic profiles in diabetes have been inconsistent. Aim: The objective of this meta-analysis was to assess the effects on metabolic profiles and safety of chromium supplementation in type 2 diabetes mellitus and cholesterol. Methods: Literature searches in PubMed, Scopus and Web of Science were made by use of related terms-keywords and randomized clinical trials during the period of 2000-2014. Results: Thirteen trials fulfilled the inclusion criteria and were included in this systematic review. Total doses of Cr supplementation and brewer's yeast ranged from 42 to 1,000 µg/day, and duration of supplementation ranged from 30 to 120 days. The analysis indicated that there was a significant effect of chromium supplementation in diabetics on fasting plasma glucose with a weighted average effect size of -29.26 mg/dL, p = 0.01, CI 95% = -52.4 to -6.09; and on total cholesterol with a weighted average effect size of -6.7 mg/dL, p = 0.01, CI 95% = -11.88 to -1.53. Conclusions: The available evidence suggests favourable effects of chromium supplementation on glycaemic control in patients with diabetes. Chromium supplementation may additionally improve total cholesterol levels.