Avoidance Learning Across the Menstrual Cycle: A Conceptual Replication.

Hormonal transitions across the menstrual cycle may modulate human reward processing and reinforcement learning, but previous results were contradictory. Studies assessed relatively small samples (n < 30) and exclusively used within-subject designs to compare women in hormonally distinct menstrual cycle phases. This increased the risk of sporadic findings and results may have been disproportionally affected by expectancy effects. Also, replication studies are widely missing, which currently precludes any reliable inferences. The present study was intended as a conceptual replication of a previous study [(1), Neuropsychologia 84; n = 15]. There, we had observed a reduction in avoidance learning capacity when women were in the high estradiol state of the late follicular phase as compared to the mid luteal phase with enhanced progesterone influence. These results conformed to the idea that estradiol and progesterone may antagonistically modulate dopaminergic transmission as a dopamine agonist and antagonist, respectively. Heightened progesterone in the luteal phase thereby supported the ability to learn from the negative outcomes of one's actions, while the follicular rise in estradiol interfered with this capacity. Here, we re-examined the above described within-subject difference between the follicular and the luteal phase in a between-subjects design. Seventy-five women were tested once with a probabilistic feedback learning task, while being either in the follicular (36 women) or luteal phase (39 women), and were compared for phase-related differences in behavior. Secondly, we combined the new data with data from three previous studies from our laboratory that used the same task and menstrual cycle phases. This meta-analysis included only data from the first test day, free of any biasing expectancy effects. Both analyses demonstrated the consistency of the decline in avoidance learning in the follicular relative to the luteal phase. We also showed that this decline reliably occurred in all of the included samples. Altogether, these results provide evidence for the consistency of a behavioral difference and its apparent association with a transient change in hormonal state that occurs in the natural menstrual cycle. Our findings may also open new avenues for the development of reliable between-subjects test protocols in menstrual cycle research.

Completeness of reporting in randomized controlled trials of 3 vaccines: a review of adherence to the CONSORT checklist.

BACKGROUND: Clear reporting of randomized controlled trials (RCTs) of vaccines is important for understanding results and assessing their validity. The CONsolidated Standards of Reporting Trials (CONSORT) statement provides guidance to help authors reporting RCTs. The objective was to assess the completeness of reporting of RCTs of vaccines based on the CONSORT 2010 checklist. METHODS: We collected data about items required by the CONSORT checklist or specific to trials of vaccines. We used publications of RCTs identified in 3 systematic reviews of pneumococcal polysaccharide, pneumococcal conjugate and rotavirus vaccines. We included the first journal publication that reported clinical, carriage or immunological data for each trial and summarized results descriptively. RESULTS: We included 70 publications from 19 journals. Of these, 14 publications (20%) stated in the title that the trial was randomized and 26 publications (37%) nominated at least 1 primary outcome. The method for generating the random allocation sequence was fully reported in 24 publications (34%), the method of allocation concealment in 9 publications (13%) and 30 publications (43%) included a flow diagram. Trial registration numbers were reported in all articles published in 2010 to 2011. Actual age at vaccination was reported in 20% of trials of childhood schedules. Eleven of 19 journals endorsed the CONSORT statement. CONCLUSIONS: The reporting of RCTs of vaccines is incomplete, with important methodological details missing from most reports. Journals could play a leading role in implementing changes. Improved reporting would make publications of vaccine trials easier to find, the findings easier to interpret and aid the incorporation of findings into policy.