Assessing clinically meaningful change following a programme for managing chronic pain.

OBJECTIVES: (1) To identify criteria for clinically meaningful change scores in commonly used measures of pain and related disability, using Goal Attainment Scaling as an external indicator of success. (2) To investigate the chances of achieving these scores following a pain management programme versus remaining on the waiting list.
DESIGN: Participants were assessed on entry to waiting list, on admission and at follow-up from the pain management programme. Three groups of Goal Attainment Scaling scores (-1.0, +1) were created from final Goal Attainment Scaling achievements. Mean scores on other measures were analysed in relation to Goal Attainment Scaling score groups by ANOVA. Differences in numbers achieving clinically meaningful changes when on the pain management programme or waiting list were compared.
SUBJECTS: Chronic musculoskeletal pain participants (N = 73) attending a rehabilitation centre, mean age (range) 44.8 (24-70) years, mean age (range) 44.8 (24-70), mean pain duration 7.7 (1-32) years. INTERVENTION: Three-week (15-day) pain management programme based on cognitive behavioural principles. MEASURES: McGill Pain Questionnaire, 0-10 Pain Intensity Numerical Rating Scale (NRS), Oswestry Disability Questionnaire (ODQ), General Health Questionnaire (GHQ), 5 minute walk, 1 minute sit/stand, 1 minute stair-climbing, and Goal Attainment Scaling (GAS).
RESULTS: Mean change scores differed significantly for three GAS groups and were highest in the most successful (+1) group. These scores were used to define clinically meaningful changes on the NRS (-3), ODQ (-12), walk (+87) and stairs (+14). Significantly more participants on the pain management programme achieved these scores than those on the waiting list.
CONCLUSION: Using GAS as a criterion of patient-perceived improvement enabled identification of clinically meaningful changes on some other common measures. These successfully differentiated achievement between patients on the pain management programme and those on the waiting list.