An Evaluation of ICU Follow-Up Clinic Attendance and Subsequent Healthcare Resource Utilization in Wales, United Kingdom: A Retrospective, Population-Level Data-Linkage Study.

IMPORTANCE: Postintensive care syndrome encapsulates the long-term physical, psychologic, and cognitive impairments often seen among ICU survivors. Post-ICU follow-up clinics may support recovery and reduce avoidable healthcare utilization, but population-level evidence remains limited. OBJECTIVES: To identify patient characteristics associated with follow-up clinic attendance and evaluate differences in healthcare resource utilization (HRU) across three groups: invited and attended, invited but did not attend, and not invited. DESIGN SETTING AND PARTICIPANTS: A retrospective cohort study using anonymised, linked administrative data from the Secure Anonymised Information Linkage Databank in Wales, United Kingdom. Adults (≥ 18 yr) with ICU admissions between 2016 and 2023 who survived to discharge were included. Follow-up clinic data were obtained from three regional health boards (healthcare organizations responsible for delivering National Health Services in Wales) with follow-up clinic availability. MAIN OUTCOMES AND MEASURES: HRU outcomes included ICU readmissions, emergency department attendances, hospital admissions (elective and emergency), hospital bed days, outpatient appointments, and general practitioner (GP) events. Multivariable models assessed associations between clinic attendance and HRU. RESULTS: Of 6491 eligible patients, 761 attended a follow-up clinic, 1473 were invited but did not attend, and 4257 were not invited. Among invited patients, attendance was associated with increasing age, comorbidity, deprivation, and ICU length of stay. Compared with attendees, nonattendees and those not invited had higher adjusted odds of ICU readmission (odds ratio [OR] = 2.81 and 2.22, respectively), elective admissions, and hospital bed days. No significant differences were observed for emergency admissions or GP events. Attendees were more likely to have 4 or more (non-follow-up clinic) outpatient appointments. CONCLUSIONS AND RELEVANCE: Clinic attendance was associated with differences in several HRU domains. Variability in access and engagement suggests potential inequalities in post‑ICU recovery pathways. Standardizing referral practices and expanding clinic availability may improve outcomes for ICU survivors.