Open Access Open Badges Research article

Using an integrated COC index and multilevel measurements to verify the care outcome of patients with multiple chronic conditions

Chien-Lung Chan1, Huey-Jen You12*, Hsin-Tsung Huang12 and Hsien-Wei Ting13

Author affiliations

1 Department of Information Management, College of Informatics, Yuan Ze University, No. 135 Yuan-Tung Road, Zhongli, Taiwan

2 Medical Affairs Division, Bureau of National Health Insurance, No.140, Sec. 3, Hsin-Yi Road, Taipei, Taiwan

3 Department of Health, Taipei Hospital, No. 127, Su-Yuan Rd, Hsin-Chuang District, New Taipei City, Taiwan

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Citation and License

BMC Health Services Research 2012, 12:405  doi:10.1186/1472-6963-12-405

Published: 19 November 2012



The increasing prevalence of multiple chronic conditions has accentuated the importance of coordinating and integrating health care services. Patients with better continuity of care (COC) have a lower utilization rate of emergency department (ED) services, lower hospitalization and better care outcomes. Previous COC studies have focused on the care outcome of patients with a single chronic condition or that of physician-patient relationships; few studies have investigated the care outcome of patients with multiple chronic conditions. Using multi-chronic patients as subjects, this study proposes an integrated continuity of care (ICOC) index to verify the association between COC and care outcomes for two scopes of chronic conditions, at physician and medical facility levels.


This study used a dataset of 280,840 subjects, obtained from the Longitudinal Health Insurance Database (LHID 2005), compiled by the National Health Research Institutes, of the National Health Insurance Bureau of Taiwan. Principal Component Analysis (PCA) was used to integrate the indices of density, dispersion and sequence into ICOC to measure COC outcomes - the utilization rate of ED services and hospitalization. A Generalized Estimating Equations model was used to verify the care outcomes.


We discovered that the higher the COC at medical facility level, the lower the utilization rate of ED services and hospitalization for patients; by contrast, the higher the COC at physician level, the higher the utilization rate of ED services (odds ratio > 1; Exp(β) = 2.116) and hospitalization (odds ratio > 1; Exp(β) = 1.688). When only those patients with major chronic conditions with the highest number of medical visits were considered, it was found that the higher the COC at both medical facility and physician levels, the lower the utilization rate of ED services and hospitalization.


The study shows that ICOC is more stable than single indices and it can be widely used to measure the care outcomes of different chronic conditions to accumulate empirical evidence. Concentrated care of multi-chronic patients by a single physician often results in unsatisfactory care outcomes. This highlights the need for referral mechanisms and integration of specialties inside or outside medical facilities, in order to optimize patient-centered care.