withincohort
Withincohort is a term used in epidemiology and biostatistics to describe analyses conducted within a defined cohort. It refers to methods and metrics that focus on variation observed inside the cohort over time, rather than comparisons between different cohorts. In a withincohort analysis, researchers examine how changes in exposures or outcomes within the same individuals relate to each other, leveraging longitudinal data to control for confounding by fixed, unobserved characteristics.
Common approaches include fixed-effects models that estimate within-individual associations by removing all time-invariant between-individual differences, and
Applications span longitudinal cohort studies, clinical cohorts, and social epidemiology, where the goal is to understand
Limitations include reliance on repeated measures, potential bias from time-varying confounders, measurement error, and reduced generalizability