Psychometric properties of a generic health measure in patients with neck pain

Objective: To examine the reliability, validity and responsiveness of the generic Current Perceived Health 42 (CPH42) Profile in Chinese patients with neck pain in Hong Kong. Design: A prospective observational study. Setting: Physiotherapy outpatient departments. Subjects: Two samples with 472 consecutive adult patients with neck pain from seven physiotherapy outpatient departments in Hong Kong. Methods: Subjects were requested to complete the CPH42 Profile, and their pain intensity was measured using the 11-point numerical rating scale (NRS). They were observed and measured at the beginning of physiotherapy, at seven days, at week 3 and at week 6 after treatment began. Results: The CPH42 Profile had very good test-retest reliability and internal consistency (intraclass correlation coefficient 0.91, Cronbach's alpha 0.90). Validity was confirmed by a moderate correlation with the NRS at the beginning of treatment and week 6 (rank correlation 0.41-0.53). Moreover, a significant difference in scores was found between those who had sought medical consultation and/or had taken medication because of neck pain than those who did not. The responsiveness measured from the beginning of treatment to week 3 and week 6 (standard response means of 0.33 and 0.36) was comparable to the respective changes in pain intensity. Conclusion: The CPH42 Profile has been shown to demonstrate good reliability and validity, and it is sensitive to changes in severity over time. It is suitable for use as an outcome measure for evaluation of patients with neck pain.