title: Using an integrated COC index and multilevel measurements to verify the care outcome of patients with multiple chronic conditions.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Information Management, College of Informatics, Yuan Ze University, No, 135 Yuan-Tung Road, Zhongli, Taiwan.
authors.forename: Chien-Lung
authors.initials: CL
authors.lastname: Chan
authors.forename: Huey-Jen
authors.initials: HJ
authors.lastname: You
authors.forename: Hsin-Tsung
authors.initials: HT
authors.lastname: Huang
authors.forename: Hsien-Wei
authors.initials: HW
authors.lastname: Ting
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease / Q000628:therapy*; D003266:Continuity of Patient Care / Q000592:standards*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D010043:Outcome and Process Assessment, Health Care / Q000592:standards; D019984:Quality Indicators, Health Care / Q000592:standards; D011787:Quality of Health Care / Q000592:standards; D013624:Taiwan; D055815:Young Adult