Association between interhospital care fragmentation, readmission diagnosis, and outcomes.

Objectives: To assess in-hospital mortality, length of stay, and costs associated with interhospital fragmentation in 30-day readmissions and to determine whether these associations were more or less pronounced for patients with specific high-prevalence conditions.

Study Design: Cross-sectional analysis using the Agency for Healthcare Research and Quality's National Readmissions Database for 2013 and 2014.

Methods: All patients 18 years and older with a 30-day readmission in 2014 were included. We assessed if readmission to a hospital different from that of the index admission was associated with in-hospital mortality, length of stay, and costs of readmission, separately by whether the readmission occurred for the same or different major diagnostic category. Patients with 1 of 3 common diagnoses (congestive heart failure [CHF], chronic obstructive pulmonary disease [COPD], or myocardial infarction) were studied for disease-specific trends. The same analyses were performed on 2013 data as a sensitivity analysis.

Results: In 2014, among 792,596 patients with a 30-day readmission, 22.2% experienced fragmentation. Compared with patients whose readmission occurred at the index hospital, patients readmitted to a different hospital experienced 20% higher odds of dying in hospital (P = .02 for same diagnosis readmission; P = .03 for different diagnosis readmission), a half-a-day longer length of stay (P < .001 for both same and different diagnosis readmissions), and more than $1000 higher costs (P < .001 for both same and different diagnosis readmissions). For patients with a CHF or COPD index admission, mortality was consistently higher for fragmented readmissions for a different condition.

Conclusions: Fragmented readmissions were associated with higher in-hospital mortality and cost. Clinical variation across conditions warrants further investigation to optimize pre- and postdischarge operations and policy.