Background It has been hypothesized (i) that pain and low vitality lead to an increase in avoidance of activities in persons with early symptomatic knee osteoarthritis (OA), and (ii) that avoidance of activities leads to an increase in activity limitations.
Objectives The present study aimed to evaluate these hypotheses in a cross-sectional and longitudinal design.
Methods Baseline, 2-year and 5-year follow-up data of 828 participants from the Cohort Hip and Cohort Knee (CHECK) study with early symptomatic knee OA were used. Knee pain, vitality, avoidance of activities and activity limitations were measured with reliable and validated instruments. Regression and autoregressive generalized estimating equations (GEE) models analyzed the cross-sectional and longitudinal associations between pain, vitality, avoidance of activities and activity limitations. The models were adjusted for age, gender, education level, body-mass index, comorbidity, and radiographic severity.
Results (i) In cross-sectional analyses, greater knee pain and lower vitality were associated with higher levels of avoidance of activities. In longitudinal analyses, pain and vitality predicted a subsequent increase in avoidance of activities. (ii) In cross-sectional analyses, a higher level of avoidance of activities was associated with greater activity limitations. In longitudinal analyses, this relationship was marginally significant.
Conclusions Knee pain and low vitality lead to a subsequent increase in avoidance of activities, already at an early stage of knee OA. Avoidance of activities is related to activity limitations: alternative measurement instruments and a longer follow-up may be required to establish the longitudinal relationship.
Disclosure of Interest None declared