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.