Course of pain and fluctuations in pain related to suspected early hip osteoarthritis: the CHECK study

OBJECTIVES: To evaluate the prevalence during a 10-year follow-up of clinically relevant fluctuations in pain and the course of hip pain in participants with hip complaints suspected to be early stage hip osteoarthritis (OA). To distinguish between participants with relevant fluctuations in pain and those without based on baseline characteristics.

METHODS: Data were collected at baseline and after 2, 5, 8, and 10 years on 495 participants from the Cohort Hip and Cohort Knee Study (CHECK) with hip pain at baseline. Baseline demographic, anamnestic, and physical-examination characteristics were assessed. The primary outcome was levels of pain in the past week (scored using 0-10 Numeric Rating Scale) at follow-up assessments. Relevant fluctuation was defined as average absolute residuals greater than 1 after fitting a straight line to the participant's pain scores over time.

RESULTS: The majority of the participants (76%) had stable or decreasing pain. Relevant fluctuations were found in 37% of the participants. The following baseline variables were positively associated with the presence of relevant fluctuations: higher levels of pain in the past week, use of pain transformation as a coping style, higher number of comorbidities, use of pain medication, and higher levels of high-sensitivity C-reactive protein. No associations were found for baseline radiographic hip OA or clinical hip OA.

CONCLUSION: During a 10-year follow-up, the majority of participants had stable or decreasing pain levels. In those participants with relevant fluctuation (37%), a limited number of baseline variables were associated with increased odds of having relevant fluctuations in pain.