Severe COVID-19 leading to ARDS and ICU admission is associated with high early mortality, yet data on long-term outcomes and societal burden remain limited, particularly in Central and Eastern Europe. To describe 4-year mortality, patient-reported functional status and health-related quality of life (HRQoL) among ICU-treated COVID-19 ARDS patients, and to explore early factors associated with short- and long-term mortality as well as long-term recovery. Single-center retrospective-prospective cohort study with structured 4-year telephone follow-up. 283 adults treated in the Temporary ICU Hospital in Zielona Góra, Poland (December 2020-July 2021). Follow-up interviews were completed in 81 of 157 confirmed 4-year survivors. Associations with 30-day mortality and late mortality (among 30-day survivors) were explored using multivariable logistic regression. Survivors completed a structured interview assessing HRQoL (EQ-5D-5 L/EQ-VAS), dyspnoea severity assessed with the mMRC scale, functional status assessed with PCFS, fatigue, brief cognitive screening items, return to work, rehabilitation use, and financial burden. A cumulative post-ICU impairment score (0-6 domains) was constructed. Cost estimates were exploratory and based on public ICU reimbursement rates and patient-reported rehabilitation burden. Thirty-day mortality was 29.0%, and cumulative 4-year mortality was 45%. In adjusted analyses, older age and higher white blood cell count at ICU admission were associated with mortality endpoints (model discrimination up to AUC 0.86, depending on endpoint). Among 4-year survivors, 27.5% reported clinically relevant fatigue, 46.8% insomnia, and a substantial proportion reported persistent limitations across functional and EQ-5D domains. Rehabilitation was reported by 39% and was associated with lower QALY, likely reflecting greater baseline impairment. Median 4-year QALY was 3.7, varying significantly by fatigue, dyspnoea, return-to-work status, and subjective cognitive complaints. Among ICU-treated COVID-19 ARDS patients, long-term mortality remained high and many survivors reported persistent multidomain impairment years after discharge. These findings support structured post-ICU follow-up pathways and targeted rehabilitation and occupational support for long-COVID survivors.
