title: The Association between Continuity of Care and All-Cause Mortality in Patients with Newly Diagnosed Obstructive Pulmonary Disease: A Population-Based Retrospective Cohort Study, 2005-2012.
abstract: BACKGROUND
  The disease burden is increasing for chronic obstructive pulmonary disease (COPD) due to increasing of the growth rate of prevalence and mortality. But the empirical researches are a little for COPD that studied the association between continuity of care and death and about predictors effect on mortality.
  
  
  OBJECTIVE
  To investigate the association between continuity of care (COC) and chronic obstructive pulmonary disease (COPD) mortality and to identify other mortality-related factors in COPD patients.
  
  
  METHODS
  We conducted a longitudinal, population-based retrospective cohort study in adult patients with COPD from 2002 to 2012 using a nationwide health insurance claims database. The study sample included individuals aged 40 years and over who developed COPD in 2005 and survived until 2006. We performed a Cox proportional hazard regression analysis with COC analyzed as a time-dependent covariate.
  
  
  RESULTS
  Of the 3,090 participants, 60.8% died before the end of study (N = 1,879). The median years of survival for individuals with high COC (COC index≥0.75) was 3.92, and that for patients with low COC (COC index<0.75) was 2.58 in a Kaplan Meier analysis. In a multivariate, time-dependent analysis, low COC was associated with a 22% increased risk of all-cause mortality (HR, 1.22; 95% CI, 1.09-1.36). Not receiving oxygen therapy at home was associated with a 23% increased risk of all-cause mortality (HR, 1.23; 95% CI, 1.01-1.49). Moreover, the risk of all-cause mortality for individuals who admitted one time increased 38% (HR, 1.38; 95% CI, 1.21-1.59), two times was 63% (HR, 1.63; 95% CI, 1.34-1.99) and 3+ times was 96% (HR, 1.96; 95% CI, 1.63-2.36) relative to the reference group (no admission).
  
  
  CONCLUSIONS
  High COC was associated with a decreased risk of all-cause mortality. In addition, home oxygen therapy and number of hospital admissions may predict mortality in patients with COPD.
authors.affiliation: Department of Public Health, Graduate School, Yonsei University, Seoul, Korea; Institute of Health Services Research, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Kyoung Hee
authors.initials: KH
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Young Sam
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Biostatistics, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Chung Mo
authors.initials: CM
authors.lastname: Nam
authors.affiliation: Institute of Health Services Research, College of Medicine, Yonsei University, Seoul, Korea; Graduate School of Public Health, Yonsei University, Seoul, Korea.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Public Health, Graduate School, Yonsei University, Seoul, Korea; Institute of Health Services Research, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Sun Jung
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Public Health, Graduate School, Yonsei University, Seoul, Korea; Institute of Health Services Research, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Kyu-Tae
authors.initials: KT
authors.lastname: Han
authors.affiliation: Institute of Health Services Research, College of Medicine, Yonsei University, Seoul, Korea; Department of Preventive Medicine, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Eun-Cheol
authors.initials: EC
authors.lastname: Park
mesh_terms: D002908:Chronic Disease; D003266:Continuity of Patient Care; D005260:Female; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy*; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors