Background
Despite the high prevalence of atrial fibrillation (AF), the incidence and impact of care fragmentation (CF) following hospitalization for this condition remain unstudied.

Objectives
The present study used a national database to determine the incidence of and risk factors associated with CF. Outcomes following CF were also examined.

Methods
All adults who were discharged alive following hospitalization for AF (index facility) were identified within the 2016 to 2019 Nationwide Readmissions Database. Patients requiring nonelective rehospitalization within 30 days of discharge were categorized into 2 groups. The CF cohort included those readmitted to a nonindex facility, while others were classified as noncare fragmentation. Multivariable regression was used to evaluate factors associated with CF, as well as its impact on in-hospital mortality, length of stay, and costs at rehospitalization.

Results
Of an estimated 686,942 patients who met study criteria and survived to discharge, 13.6% (n = 93,376) experienced unplanned readmission within 30 days. Among those readmitted, 21.3% (n = 19,906) were readmitted to a nonindex facility. Patients who experienced CF were younger, more commonly male and less frequently readmitted for AF. Upon multivariable adjustment, male sex, Medicaid insurance (ref: private), and transfer status were associated with increased odds of CF. Upon readmission, CF was associated with a 18% increment in relative odds of in-hospital mortality, a 0.3-day increment in length of stay, and an additional $1,500 in hospitalization costs.

Conclusions
CF was associated with significant clinical and financial burden. Further studies are needed to address factors which contribute to increased mortality and resource use following CF.