Longitudinal analysis of impulse control disorders in Parkinson’s disease

Objective: To investigate the longitudinal dose-effect relationship between dopamine replacement therapy and impulse control disorders (ICDs) in Parkinson’s disease (PD). Methods: We used data from a multicentre longitudinal cohort of consecutive PD patients with ≤5y disease duration at baseline followed annually up to 5y. ICDs were evaluated during face-to-face semi-structured interviews with movement disorder specialists. Generalized estimating equations Poisson models with robust variance were used to study the association between several time-dependent definitions of dopamine agonist (DA) use, taking dose and duration of treatment into account, and ICDs at each visit; other antiparkinsonian drugs were also examined. Results: Among 411 patients (40.6% women; mean age=62.3y, average follow-up=3.3y, SD=1.7y), 356 (86.6%) took DA at least once since disease onset. In 306 patients without ICDs at baseline, the 5y cumulative incidence of ICDs was 46.1% (95% CI=37.4-55.7; DA ever-use...