Psychometric properties of a generic health measure in Chinese patients with low back pain in Hong Kong

In Hong Kong, the measurement of perceived health status in patients with low back pain (LBP) can be facilitated by the availability of a health profile specifically designed for the Chinese culture. This prospective observational study investigated the psychometric properties of the generic Current Perceived Health 42 (CPH42) Profile in four separate samples (totalling 473) of Chinese patients with LBP in Hong Kong. The patients completed the CPH42 Profile and the Roland LBP Disability Scale at various points in the course of physiotherapy. Their pain intensity was measured using the 11-point pain numerical rating scale (NRS). The test-retest reliability and internal consistency of the CPH42 Profile demonstrated high intra-class correlation coefficient of 0.92 and Cronbach's alpha of 0.90. Validity was confirmed by a moderate correlation with the Chinese adaptations of the Roland LBP Disability Scale and the NRS at the commencement of physiotherapy (Spearman's correlation coefficients were 0.48 and 0.42, respectively). The responsiveness, measured from the commencement of physiotherapy to weeks 3 and 6 (standard response means of 0.33 and 0.58, respectively), were commensurate with the respective changes in pain intensity. The psychometric properties of the CPH42 Profile suggest its suitability for use as an outcome instrument in future efficacy studies on LBP intervention.