Abstract

LOPEZ ALONSO, Sergio R. et al. Validity, reliability and convergence of COOP/WONCA and EUROQoL, via telephone, on people suffering from hip and knee osteoarthritis. Index Enferm [online]. 2009, vol.18, n.3, pp.195-200. ISSN 1699-5988.

Objectives: To determine the metric properties of EUROQoL and to optimize the metric properties of COOP/WONCA on people suffering from hip and knee osteoarthritis, via telephone. Also to identify the convergence validity between them. Methods: A descriptive study design is performed at "La Merced" (Osuna-Sevilla) and "Torrecárdenas" (Almería) Hospitals, via telephone interview since October 2004 to November 2006. The study included all people suffering from hip and knee osteoarthritis and awaiting for a surgical intervention. Results: COOP/WONCA obtained a maximum value of 79,9% on endorsement frequency. Main components factorial analysis resulted on two items with a value below 0,5; and the greatest explained total variance -71,09%- of Health Related Quality of Life (HRQoL) with two components of 50,70% and 20,38%, respectively. A Promax rotation was performed, once determined the correlation between factors (0,36). Reliability analysis obtained a Cronbach a value of 0,75. EUROQoL presented an endorsement frequency of 96,8% for the item related to mobility. Main component factor analysis found an explained total variance of 59,46%, with two factors of 36,77% and 22,68%. Factors correlations was below 0,2 and determined Varimax rotation. Reliability analysis found a Cronbach a value of 0,53. Convergence analysis between both questionnaires showed a low correlation. Conclusion: The 5 items COOP/WONCA showed appropriate metric properties, which convert the instrument on the first choice to measure the HRQoL on people suffering from hip and knee osteoarthritis, while metric properties of EUROQoL are clearly deficient. Both questionnaires do not show a sufficient content parallelism for COOP/WONCA to use Quality-Adjusted Life Years tables of EUROQoL.

Keywords : Questionnaires; Osteoarthritis Hip; Osteoarthritis Knee; Quality of life; Quality-Adjusted Life Years.