The Fragility Index in a Cohort of HIV/AIDS Randomized Controlled Trials.

HIV/AIDS is associated with significant morbidity, mortality, and financial burden. For these reasons, robust clinical evidence is critical. We aim to investigate the fragility index, fragility quotient, and risk of bias of clinical trial endpoints in HIV medicine. The fragility index represents the minimum amount of trial endpoint "nonevents" changed to "events" in one trial arm required to nullify statistical significance. The fragility quotient contextualized the fragility index by dividing the index by the total trial sample size. We selected eligible trials from the Department of Health and Human Services guideline for the use of antiretroviral agents in HIV-1-infected adults and adolescents. We calculated the fragility index and fragility quotient for all included trials. The Cochrane "risk of bias" Tool 2.0 was used to evaluate the likelihood and sources of bias in the included trials. Thirty-nine RCTs were included for our analysis of fragility. Thirty-six were included for our analysis of the risk of bias. The median fragility index was 5. Three RCTs were at high risk of bias, all due to the selection of the endpoint or statistical test. Twenty had some concerns for risk of bias. The analyzed HIV medicine RCT endpoints were fragile, overall. This indicates that a median of 5 patients across all included studies would nullify the statistical significance of the endpoints. Furthermore, we found evidence that concerns for bias are present at a high rate.

Estrogen and voluntary exercise interact to attenuate stress-induced corticosterone release but not anxiety-like behaviors in female rats.

The beneficial effects of physical exercise to reduce anxiety and depression and to alleviate stress are increasingly supported in research studies. The role of ovarian hormones in interactions between exercise and anxiety/stress has important implications for women's health, given that women are at increased risk of developing anxiety-related disorders, particularly during and after the menopausal transition. In these experiments, we tested the hypothesis that estrogen enhances the positive impact of exercise on stress responses by investigating the combined effects of exercise and estrogen on anxiety-like behaviors and stress hormone levels in female rats after an acute stressor. Ovariectomized female rats with or without estrogen were given access to running wheels for one or three days of voluntary running immediately after or two days prior to being subjected to restraint stress. We found that voluntary running was not effective at reducing anxiety-like behaviors, whether or not rats were subjected to restraint stress. In contrast, stress-induced elevations of stress hormone levels were attenuated by exercise experience in estrogen-treated rats, but were increased in rats without estrogen. These results suggest that voluntary exercise may be more effective at reducing stress hormone levels if estrogen is present. Additionally, exercise experience, or the distance run, may be important in reducing stress.