Highly frequent utilization of outpatient services in a national health insurance system - analysis of associated factors and underlying co-morbidity

Objective We aimed to identify associated factors of highly frequent use of outpatient services and explore how they were impacted to provide policy references for government and medical institutes in their efforts to seek provision of reasonable medical services, continuous care and integrated outpatient services. Methods The Taiwanese national health insurance database was used and 661,125 patients were identified in 2009. The patients with >= 100 internal medicine outpatient (IMO) visits were defined as the highly frequent group and they were matched at a ratio of 1:4 with patients of 1-99 IMO visits based on demographic characteristics. Multivariate logistic regression was used to estimate adjusted odds ratios with 95% confidence intervals. Results Among 1 million patients in the outpatient department, 0.05% had at least 100 visits. These patients with highly frequent IMO visits had significantly higher rates of emergency department (ED) visits, hospitalization, psychiatric disorders and possession of a catastrophic illness card as well as a significantly lower level of continuity of care index (COCI). Multivariate analysis showed that ED visits (adjusted OR [AOR] = 1.63), psychiatric disorders (AOR = 7.13), low COCI (AOR = 1.69), and several comorbidities including peripheral vascular diseases (AOR = 4.33), dementia (AOR = 0.04), chronic pulmonary disease (AOR = 3.02), peptic ulcer diseases (AOR = 3.70), diabetes mellitus (AOR = 3.45) and renal disease (AOR = 2.43) were significant associated factors. Conclusions To rationalize use and distribution of medical resources, we suggest proper regular care and health education to those with mental disabilities and multiple chronic conditions, which may not only improve the situation of highly frequent hospital visits but also effectively control incidence of acute conditions and reduce their ED visits. In addition, improving the continuity of care is vital, and the best way to do this is to promote family medicine as the primary form of healthcare.