Psychometric properties of the Patient Activation Measure among individuals presenting for elective lumbar spine surgery

Background: An individual's propensity to engage in adaptive health and rehabilitation behaviors may account for variation in postsurgical outcome. Purpose: To determine the psychometric properties and construct validity of the recently developed Patient Activation Measure (PAM) (previously unused in spine research) in persons undergoing elective lumbar spine surgery. Methods: We prospectively used the PAM to assess activation in 283 patients undergoing elective lumbar spine surgery. Reliability statistics were computed using repeated assessment (baseline and 1-week follow-up) before surgery. Additional psychological attributes were assessed at baseline and correlated with patient activation. Factor analysis was used to confirm the theoretical structure of patient activation. Results: Repeat PAM administrations had an intraclass correlation coefficient of 0.85. The PAM showed positive correlation with optimism (r = 0.75), hope (r = 0.73), self-efficacy (r = 0.65), and internal locus of control (r = 0.65) but no correlation with comorbidity (r = 0.01). Confirmatory factor analysis of the PAM items indicated reasonable fit between observed data and a three-factor patient activation model. Conclusions: The PAM is a reliable, valid measure of patient activation for individuals undergoing elective lumbar spine surgery and may have clinical utility in identifying those at risk for poor engagement in postsurgical rehabilitation.