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

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≥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, timedependent 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.