BACKGROUND Though numbers of Intensive Care Unit (ICU) survivors have been increasing, using data on patient-reported long-term physical and mental functioning post-ICU during ICU admission is rare. Individualised information about long-term quality of life (QoL) supports ICU physicians’ decision making and empowers patients to better manage their disease during ICU admission and recovery and rehabilitation. We aimed to develop a prediction model for ICU survivors’ change in QoL one year after ICU admission. METHODS This is a sub-study of an ongoing multicenter prospective cohort study (MONITOR-IC study), in which long-term outcomes of ICU patients are measured up to five years after ICU admission. Adult patients admitted ≥12hrs to the ICU between July 2016 and January 2019 were included. Moribund patients were excluded. Multivariable linear regression and best subsets regression analysis (SRA) were used for building the prediction model. Change in QoL after one year was quantified using the EuroQol five-dimensional (EQ-5D-5L) questionnaire (Dutch range: -0.446–1), and Short-Form 36 (SF-36, range: 0-100). Models were internally validated RESULTS Data on 1308 ICU survivors was used to build the PREdicting PAtients’ long-term outcome for Recovery, PREPARE, prediction model. The best model contained 33 predictors, using the EQ-5D. Explained variance (R2) was 58.0%. Using SRA, we reduced the number of predictors to 5 (R2=55.3%): QoL before admission; sex; Clinical Frailty Scale; a cerebral embolism, occlusion, bleeding or infarction prevalent at or within one hour of admission; and having been admitted to the ICU from the operating room, from the same hospital’s nursing ward. The prediction model using the EQ-5D to quantify QoL had better predictive performance than the best SF-36 model (R2=40.6%).CONCLUSIONS We developed PREPARE, a prediction model for ICU survivors’ QoL one year after ICU admission that is practically usable due to the small number of predictors, measurable within the first 24 hours of admission. The next step is to test and evaluate the use of this prediction model in conversations between ICU physicians and patients and their families to ultimately improve patient outcomes. TRIAL REGISTRATION ClinicalTrials.gov: NCT03246334 on August 11, 2017.