Measurement equivalence of the paper-based and electronic version of the Integrated Palliative care Outcome Scale (IPOS): A randomised crossover trial

Abstract

Background: The Integrated Palliative Care Outcome Scale (IPOS) validly and reliably measures symptoms and concerns of those receiving palliative care. Aim: To determine the equivalence of the paper version with an electronic version of the IPOS (eIPOS). Design: Multicentre randomised crossover trial (NCT03879668) with a within-subject comparison of the two modes (washout period 30 min). Setting/Participants: Convenience sample of specialist inpatient and palliative home care patients aged over 18 years with cancer and non-cancer conditions was recruited. Scores were compared using intraclass correlation coefficients (ICC), Bland-Altman plots and via a mixed-effects analysis of variance. Results: Fifty patients were randomised to complete paper-electronic (n = 24) and electronic-paper (n = 26) IPOS with median age 69 years (range 24–95), 56% male, 16% non-cancer. The ICCs showed very high concordance for the total score (ICC 0.99, 95% CI 0.98–1.00), lowest ICCs being observed for symptoms ‘Appetite loss’ and ‘Drowsiness’ (ICC 0.95, 95% CI 0.92–0.97). Nine of seventeen items had ICCs above 0.98, as did all subscales. No statistically significant mode, order, age, and interaction effects were observed for IPOS total score and subscales, except for ‘Communication’ (Fmode = 5.9, p = 0.019). Fifty-eight percent preferred the electronic version. In the group 75+ years, 53% preferred the paper version. Only three entries in the free-text main problems differed between the versions. Conclusion: The very high equivalence in scores and free text between the IPOS and the eIPOS demonstrates that eIPOS is feasible and reliable in an older palliative population.