Progression patterns observed in research cohorts may be representative of those seen in routine care, particularly in the early symptomatic stages of disease. As these stages are a major focus of prognostic modelling, establishing whether trajectories of decline observed after clinical presentation are comparable across research and clinical settings is important for applying biomarker studies and progression models in clinical practice.

We compared ADNI data with BRAIID, a UK-based observational cohort study embedded in routine NHS care.

Progression patterns and cluster characteristics were strikingly similar between the ADNI dementia cohort and the BRAIID clinical cohort, indicating that research cohort data can usefully inform interpretation of progression in clinical populations. Contrasting comparisons with the ADNI MCI cohort highlight limits to generalisation across diagnostic groups.