Patterns of sick leave and unemployment prior to a diagnosis of young onset Alzheimer's disease

INTRODUCTION: Early symptoms in young onset Alzheimer's disease (YOAD) may be misinterpreted, causing delayed diagnosis. This population-based study aimed to map adverse occupational events preceding YOAD diagnosis as potential prodromal signs.

METHODS: In a register-based, incidence density matched nested case-control study, we examined unemployment and long-term sick leave among individuals diagnosed with YOAD in Danish memory clinics between 2016 and 2022 compared to controls over a 13-year period. Conditional logistic regression produced incidence rate ratios (IRRs).

RESULTS: The study included 2434 cases and 12,170 controls. YOAD patients had higher rates of adverse occupational events, particularly long-term sick leave, starting from 8 years before diagnosis (IRR 1.40, 95% confidence interval [CI] 1.07-1.84) and increasing to an IRR of 29.59 (95% CI 18.97-46.13) in the year before diagnosis.

DISCUSSION: Adverse occupational events may serve as warning signs of YOAD. Timely diagnosis could facilitate restructuring the remaining working life to accommodate cognitive deficits or in seeking a disability pension.

HIGHLIGHTS: This is a retrospective, nested case-control study of young onset Alzheimer's disease (YOAD). Unemployment rates rise significantly 5 years before the YOAD diagnosis. Long-term sick leave rates rise significantly 8 years before the YOAD diagnosis. This emphasizes the importance of occupational history in the timely diagnosis of YOAD. Findings suggest the need for earlier YOAD diagnosis for work-life management.