In medical research, latent subgroups often emerge with characteristics or trends distinct from the general population, yet identifying them directly remain challenging. The latent variable mixture modeling, grounded in the idea that a population consists of a limited mixture of subgroups, assigns latent categories to individuals based on posterior probabilities. This model is suitable for both cross-sectional and longitudinal datasets. Approaching from a statistical perspective, this paper thoroughly explicates the foundational principles of four prevalent methods within the latent variable mixture modeling realm, outlining the essential modeling workflow. By integrating insights from previous cases and real-world data, we review the rational applications of these methods. The latent variable mixture modeling stands as a flexible classification tool for identifying and analyzing latent categories within research populations, further facilitating the in-depth exploration of predictors influencing these latent categories and their consequent effects on outcome variables.
ObjectiveTo review the characteristics of registered industry-sponsored clinical trials of pediatric drugs and vaccines in China and to provide references for promoting the development of new pediatric drugs. MethodsWe searched ClinicalTrials.gov and the Chinese Clinical Trial Registry for completed registered industry-sponsored clinical trials of pediatric drugs and vaccines from the database inception to September 11, 2022. Data including the date the trial was first posted, product type (drug or vaccine), sample size, and other information to describe the general characteristics of pediatric clinical trials were collected. The studies were divided into 2 phases based on the trial posted date, 2005―2010 and 2011―2022, reflecting the enactment of pediatric drug clinical trial policies in recent years. The quality of trial registration and the main characteristics of interventional trials in the 2 phases were then compared. Exploring the results attached to industry and non-industry sponsored clinical trials. ResultsData for 145 trials were collected, and the largest proportion (63.4%) involved vaccines. Randomized control trial (RCT) was the study type with the highest percentage (68.3%). The average report completion rate for registered interventional trials was 81.0%. Compared with 2005―2010, the percentage of average report completions, pediatric drug clinical studies, multicenter, RCTs, and double-blinded registered trials increased in 2011―2022. The proportion of positive outcomes in pediatric clinical trials sponsored by industries was higher than those sponsored by non-industry. ConclusionThe majority of completed pediatric clinical trials sponsored by industries are for vaccines, in line with the promotion of pediatric policies. The quality of trial registration has improved, but not significantly, and some characteristics of trial design have changed. The proportion of positive outcomes in pediatric clinical trials sponsored by industries is higher. And further promotion of pediatric clinical trials is needed.