COPD Continuity of Care Linked to Fewer Hospitalizations

Key Takeaways

• Among older adults with newly diagnosed COPD in South Korea’s national insurance cohort, lower outpatient continuity was associated with higher COPD-related hospitalization and all-cause mortality.
• Risk increased stepwise as continuity worsened from high to intermediate to low categories.
• Fragmented follow-up was also associated with more COPD hospitalization by both general-admission and emergency-entry routes during follow-up.
• Alternative continuity measures reproduced the hospitalization pattern more consistently than the mortality pattern.

Chronic obstructive pulmonary disease (COPD) is often managed across repeated outpatient visits, inhaler adjustments, and intermittent worsening, so the pattern of follow-up can become part of the clinical trajectory itself in health systems where patients can move easily between providers. In older adults, fragmented ambulatory care may affect how quickly exacerbations are recognized and how consistently longitudinal treatment plans are carried forward. That clinical question is especially relevant in a free-access system, where continuity after diagnosis can vary widely during the first year of care.

The Ko et al. nationwide cohort study of continuity of care in COPD used South Korea’s National Health Insurance Service (NHIS)-Senior data from 2002-2019 to assemble a retrospective nationwide cohort of 29,316 older adults with newly diagnosed COPD after a 2-year washout period.

Incident COPD required International Classification of Diseases 10th Revision (ICD-10) code J44 with at least 1 hospitalization or 3 outpatient visits.

Continuity of care (CoC) was measured with the Bice-Boxerman index during the 1-year period after diagnosis, with low continuity defined as less than 0.7 and high continuity as 0.7 or greater.

Patients with fewer than 3 outpatient visits and those who died or had the primary outcome before the landmark window ended were excluded. In the source’s full-text methods and results, COPD exacerbation-related hospitalization and all-cause mortality were then assessed for up to 3 years after the 1-year landmark period. Analyses were adjusted for grouped demographic, comorbidity, disease-severity, utilization, and care-site factors.

Compared with high continuity, low continuity was associated with a higher adjusted risk of COPD exacerbation-related hospitalization at HR 1.63 (95% CI 1.45-1.83) and a higher adjusted risk of all-cause mortality at HR 1.25 (95% CI 1.11-1.40). The hospitalization signal remained essentially unchanged in a competing-risk analysis that accounted for death, at HR 1.64 (95% CI 1.52-1.78).

Lower continuity was also associated with COPD hospitalization by general-admission route at HR 1.70 (95% CI 1.47-1.95) and by emergency-entry route at HR 1.48 (95% CI 1.19-1.83). Hospitalization and mortality increased in a graded pattern as continuity worsened, and analyses using usual provider continuity (UPC), sequential continuity (SECON), and modified modified continuity index (MMCI) more consistently reproduced the hospitalization signal than the mortality signal. Subgroup analyses pointed in the same direction, with the hospitalization association most pronounced among clinic-managed patients and the mortality association stronger among metropolitan residents.

Because the analysis relied on administrative claims, it could not account for spirometry, smoking status, symptom burden, health behaviors, provider-switching behavior, care coordination, or social support, and mortality was available only as all-cause rather than cause-specific death. The outpatient-visit requirement may also have selected away from patients with very limited utilization or very early severe trajectories, while claims-based continuity indices reflect visit patterns more directly than trust or communication quality. The cohort reflects older adults in South Korea’s open-access system with limited gatekeeping, so applicability is most direct to settings with similar access patterns.

Lower continuity after COPD diagnosis was consistently associated with higher hospitalization risk and a more modest increase in all-cause mortality, with the hospitalization pattern holding across graded and alternative continuity analyses. These findings describe an observational relationship rather than a proven causal effect of improving continuity.

Clinician Questions

What counted as COPD exacerbation-related hospitalization in this cohort?

COPD exacerbation-related hospitalization in this cohort meant an inpatient admission carrying ICD-10 code J44, and investigators also separated those admissions by route as emergency department versus general admission.

Which patients with COPD were excluded from the continuity analysis?

The continuity analysis excluded patients with fewer than 3 outpatient visits during the 1-year continuity-measurement window, as well as patients who died or experienced the primary hospitalization outcome before that window ended, so the findings do not fully represent people with very limited utilization or very early severe trajectories after diagnosis.

Did any subgroups show a stronger association between low continuity and worse COPD outcomes?

Within subgroup analyses, the association between lower continuity and hospitalization was most pronounced among patients primarily managed in clinics, while the association with all-cause mortality appeared stronger among metropolitan residents. These subgroup patterns came from an observational analysis with multiple comparisons, so they should be read as signals that may still reflect chance.

How much do these COPD continuity findings depend on South Korea’s healthcare system?

These findings came from older adults with COPD in South Korea’s single-payer system, where patients have relatively unrestricted access to providers and limited primary care gatekeeping. That makes the observed continuity signal most directly relevant to systems with similar care-access patterns rather than a universal estimate that can be transferred unchanged to every health system.