Validation of days at home as an outcome measure after surgery: a prospective cohort study in Australia

Objective To evaluate 'days at home up to 30 days after surgery' (DAH(30)) as a patient-centred outcome measure. Design Prospective cohort study. Data source Using clinical trial data (seven trials, 2109 patients) we calculated DAH(30) from length of stay, readmission, discharge destination and death up to 30 days after surgery. Main outcome The association between DAH(30) and serious complications after surgery. Results One or more complications occurred in 263 of 1846 (14.2%) patients, including 19 (1.0%) deaths within 30 days of surgery; 245 (11.6%) patients were discharged to a rehabilitation facility and 150 (7.1%) were readmitted to hospital within 30 days of surgery. The median DAH 30 was significantly less in older patients (p<0.001), those with poorer physical functioning (p<0.001) and in those undergoing longer operations (p<0.001). Patients with serious complications had less days at home than patients without serious complications (20.5 (95% CI 19.1 to 21.9) vs 23.9 (95% CI 23.8 to 23.9) p<0.001), and had higher rates of readmission (16.0% vs 5.9%; p<0.001). After adjusting for patient age, sex, physical status and duration of surgery, the occurrence of postoperative complications was associated with fewer days at home after surgery (difference 3.0(95% CI 2.1 to 4.0) days; p<0.001). Conclusions DAH(30) has construct validity and is a readily obtainable generic patient-centred outcome measure. It is a pragmatic outcome measure for perioperative clinical trials.