Quality of life measures in Italian neurosurgical patients: validity of the EUROHIS-QOL 8-item index

Purpose: To assess the validity, reliability and factor structure of the Italian version of the EUROHIS-QOL (European Health Interview Survey-Quality of Life) 8-item index in patients who are potential candidates for neurosurgical procedures. Methods: Cross-sectional study. Patients completed the EUROHIS-QOL 8-item index, a disability and general well-being questionnaire; the Karnofsky performance status scale (KPS) was used as a general measure of functional status. Factor analysis was used to confirm the one-factor structure of the EUROHIS-QOL 8-item index. Reliability was measured using Cronbach’s alpha coefficient, item-total correlation and inter-item correlation. Construct validity was assessed with Pearson’s coefficient (expected to be below 0.70) and known-group analysis, dividing patients between those KPS >90 and KPS ≤90 (the latter expected to report lower QoL). Results: The one-factor structure was partly confirmed, with two items having low loadings. Cronbach’s alpha was 0.78; item-total correlations were below 0.70; and average inter-item correlation was 0.309. Correlations were all significant and moderate; known-group analysis shows that QoL scores were lower in patients with active symptoms (KPS ≤90). Conclusions: Our findings partly confirm the factor structure and reliability of the EUROHIS-QOL 8-item index, which suggests that it may be a useful and straightforward quality of life measurement technique in neurosurgical departments.