RESUMO
BACKGROUND: Motivational and behavioural models of adjustment to chronic pain make different predictions about change processes, which can be tested in longitudinal analyses. METHODS: We examined changes in motivation, coping and acceptance among 78 men with chronic haemophilia-related joint pain. Using cross-lagged regression analyses of changes from baseline to 6 months as predictors of changes from 6 to 12 months, with supplementary structural equation modelling, we tested two models in which motivational changes influence behavioural changes, and one in which behavioural changes influence motivational changes. RESULTS: Changes in motivation to self-manage pain influenced later changes in pain coping, consistent with the motivational model of pain self-management, and also influenced later changes in activity engagement, the behavioural component of pain acceptance. Changes in activity engagement influenced later changes in pain willingness, consistent with the behavioural model of pain acceptance. CONCLUSIONS: Based on the findings, a combined model of changes in pain self-management and acceptance is proposed, which could guide combined interventions based on theories of motivation, coping and acceptance in chronic pain. SIGNIFICANCE: This study adds longitudinal evidence about sequential change processes; a test of the motivational model of pain self-management; and tests of behavioural versus motivational models of pain acceptance.