Psychometric validation of the Coronary Revascularisation Outcome Questionnaire (CROQv2) in the context of the NHS Coronary Revascularisation PROMs Pilot

OBJECTIVES The Coronary Revascularisation Outcome Questionnaire (CROQ) is a patient-reported outcome measure (PROM) for coronary artery bypass surgery (CABG) and percutaneous coronary intervention (PCI). We tested the psychometric properties of a modified version (CROQv2) when administered in a National Health Service (NHS)/Department of Health (DH) funded pilot of PROMs for coronary revascularisation. DESIGN Psychometric validation study. SETTING 11 English hospitals in the UK taking part in the NHS/DH funded pilot of PROMs for coronary revascularisation. PARTICIPANTS Comprehensive analyses of acceptability, reliability, validity and responsiveness were conducted independently for each of the prerevascularisation (n=2685 and n=3711) and postrevascularisation (n=869 and n=837) versions of the CROQ-CABG and CROQ-PCI, respectively. RESULTS All versions met prespecified stringent criteria for (1) acceptability of items (missing data) and scales (missing data, floor and ceiling effects, skewness); (2) tests of scaling assumptions; (3) reliability: internal consistency (Cronbach's α, item-total correlations); (4) construct validity based on within-scale analyses (internal consistency, intercorrelations between scales, factor analysis and hypothesis testing); (5) construct validity based on comparisons with external measures (convergent and discriminant validity and hypothesis testing) and (6) responsiveness. Results were also confirmed when tests were repeated on subsamples of CABG (n=639) and PCI (n=615) patients who reported receiving help completing prerevascularisation questionnaires. CONCLUSIONS The availability of a psychometrically robust procedure-specific tool that could be used as part of a large-scale coronary revascularisation PROMs programme to capture the patients' perspective of coronary revascularisation will enable outcomes important to patients to be routinely collected alongside clinical outcomes. The CROQ is suitable for administration by postal survey or the prerevascularisation versions can be administered in the clinical setting as in the Coronary Revascularisation PROMs Pilot.