Association of polydoctoring and mortality among very old persons with multimorbidity: a prospective cohort study in Japan.

BACKGROUND: Polydoctoring is a crucial aspect of care fragmentation among patients with multimorbidity, but its impact on health outcomes remains unclear.

AIM: To determine the effects of polydoctoring, as measured by the Regularly Visited Facility (RVF) indicator, on patient outcomes among older individuals with multimorbidity.

DESIGN & SETTING: Data from the ongoing prospective cohort study, Kawasaki Aging and Wellbeing Project (KAWP), was utilized in this study. Among the 1,026 KAWP participants aged 85-89 years, those with two or more chronic conditions were enrolled in this study.

METHOD: Care fragmentation or polydoctoring, was evaluated using the RVF, a new indicator that measures the number of medical facilities consistently involved in a patient's care. Based on RVF, mortality was analysed using the Cox-hazards model, with adjustments for age, sex, frailty, and number of comorbidities.

RESULTS: A significant reduction in mortality rates was observed in participants with an RVF of ≥3 and 2-4 comorbidities (hazard ratio [HR] 0.46, 95% confidence interval [CI]: 0.18-0.99). However, no significant difference in mortality based on RVF was observed for those with ≥5 comorbidities. Notably, individuals with ≥5 comorbidities and an RVF of 0 had a significantly higher HR for death (HR 2.68, 95% CI 1.05-6.84).

CONCLUSIONS: In older patients with multimorbidity, polydoctoring reduces mortality in patients with ≤4 coexisting conditions, but it does not significantly impact mortality in those with ≥5 conditions. These findings provide insights for healthcare decision-making in managing older patients with multimorbidity.