Impact of day-to-day variation in FEV1 on measures of change: A conceptual description.

Clinical trials often demonstrate treatment efficacy through change in forced expiratory volume in one second (FEV), comparing single FEV measurements from post- versus pre-treatment timepoints. Day-to-day variation in measured FEV is common for reasons such as diurnal variation and intermittent health changes, relative to a stable, monthly average. This variation can alter estimation of associations between change in FEV and baseline in predictable ways, through a phenomenon called regression to the mean.

Clinical Effectiveness of Elexacaftor/Tezacaftor/Ivacaftor in People with Cystic Fibrosis: A Clinical Trial.

The cystic fibrosis (CF) modulator drug, elexacaftor/tezacaftor/ivacaftor (ETI), proved highly effective in controlled clinical trials for individuals with at least one F508del allele, which occurs in at least 85% of people with CF. PROMISE is a postapproval study to understand the broad effects of ETI through 30 months' clinical use in a more diverse U.S.

Tuning parameter selection for a penalized estimator of species richness.

Our goal is to estimate the true number of classes in a population, called the species richness. We consider the case where multiple frequency count tables have been collected from a homogeneous population, and investigate a penalized maximum likelihood estimator under a negative binomial model. Because high probabilities of unobserved classes increase the variance of species richness estimates, our method penalizes the probability of a class being unobserved.