Inadequate reporting of trials compromises the applicability of systematic reviews.

BACKGROUND: Uncertainty about the applicability of controlled trial findings is an increasing concern for clinicians and policy decision makers. This study aimed to determine whether information reported in studies included in systematic reviews was adequate enough to assess their applicability. METHODS: We used the databases of four recently conducted systematic reviews on the comparative efficacy and safety of second-generation antidepressants, inhaled corticosteroids, Alzheimer's drugs, and targeted immune modulators. We developed and pilot-tested a questionnaire to assess the adequacy of reporting with respect to seven previously validated criteria of study design that distinguish explanatory from pragmatic studies. For each of the 137 included studies, two reviewers independently assessed the adequacy of reporting. RESULTS: Overall, only 12 percent of the included studies provided sufficient information to reliably distinguish explanatory from pragmatic studies. The areas with the greatest lack of reporting were the setting of the study, methods of adverse event assessment, and sample size considerations to determine a minimally important difference from a patient perspective. CONCLUSIONS: Substantial shortcomings in reporting exist in aspects of study design important to determine whether a study is applicable to specific populations of interest.

MicroRNA-208a is a regulator of cardiac hypertrophy and conduction in mice.

MicroRNAs (miRNAs) are a class of small noncoding RNAs that have gained status as important regulators of gene expression. Here, we investigated the function and molecular mechanisms of the miR-208 family of miRNAs in adult mouse heart physiology. We found that miR-208a, which is encoded within an intron of alpha-cardiac muscle myosin heavy chain gene (Myh6), was actually a member of a miRNA family that also included miR-208b, which was determined to be encoded within an intron of beta-cardiac muscle myosin heavy chain gene (Myh7). These miRNAs were differentially expressed in the mouse heart, paralleling the expression of their host genes. Transgenic overexpression of miR-208a in the heart was sufficient to induce hypertrophic growth in mice, which resulted in pronounced repression of the miR-208 regulatory targets thyroid hormone-associated protein 1 and myostatin, 2 negative regulators of muscle growth and hypertrophy. Studies of the miR-208a Tg mice indicated that miR-208a expression was sufficient to induce arrhythmias. Furthermore, analysis of mice lacking miR-208a indicated that miR-208a was required for proper cardiac conduction and expression of the cardiac transcription factors homeodomain-only protein and GATA4 and the gap junction protein connexin 40. Together, our studies uncover what we believe are novel miRNA-dependent mechanisms that modulate cardiac hypertrophy and electrical conduction.