Validation of CARE Scale-7 in treatment-seeking patients with chronic pain: measurement of sex invariance.

OBJECTIVES

Social and interpersonal factors impact the trajectory of chronic pain. We previously developed and validated a 2-factor, 7-item measure to assess interpersonal factors, including relationship guilt and worry and difficulty prioritizing self-care in chronic pain. Here, we confirm the factor structure and examine the sex invariance of the two-factor structure of the CARE Scale-7.

METHODS

Data were collected as part of routine clinical care at a tertiary pain clinic using the Collaborative Health Outcomes Information Registry. Patient participants (67% women) were predominantly middle-aged (M = 50.9 years, SD = 17.8), married (55.2%), and White/non-Hispanic (55.7%). Data included demographics, pain characteristics, CARE Scale-7, pain catastrophizing, and Patient-Reported Outcomes Measurement Information System psychological and physical function measures. Confirmatory factor analysis was conducted to validate the factor structure of the CARE Scale, and a stepwise approach to measurement invariances by sex examined configural, metric, and scalar invariance.

RESULTS

Internal consistency of the scale items ensured suitability for factor analyses. Confirmatory factor analysis findings revealed an overall good fit of the 2-factor model among males and females and that CARE Scale-7 is in fact sex invariant. Finally, CARE Scale-7 showed convergent validity with pain-related outcomes.

DISCUSSION

The CARE Scale is the first validated instrument to assess self-care in both sexes among patients with chronic pain. The subscale of difficulty prioritizing self-care emerged as a potentially unique factor that should be integrated in clinical assessment. CARE Scale may facilitate standardized measurement in research and clinical contexts, which may inform a comprehensive treatment focus that integrates individualized self-care planning.