Background: Identifying moderators of the effects of self-efficacy enhancing interventions could facilitate their refinement and more targeted, cost-effective delivery. Current theories and data concerning the potential moderating effect of depressive symptoms on interventions to enhance patient chronic illness self-management self-efficacy are conflicting.
Objectives: To explore the moderating effect of depressive symptoms on the effect of an intervention to enhance patient self-efficacy for self-managing chronic illness.
Research design: Regression analyses using baseline and postintervention (6 weeks) data from an ongoing randomized controlled trial.
Subjects: Patients (N = 415) aged >or=40 years recruited from a primary care network in Northern California with arthritis, asthma, chronic obstructive pulmonary disease, congestive heart failure, depression, and/or diabetes mellitus, plus impairment in >or=1 basic activity, and/or a score of >or=4 on the 10-item Center for Epidemiologic Studies Depression Scale (CES-D).
Measures: Stanford self-efficacy scale, self-reported depression, CES-D, and Medical Outcomes Study Short Form health status questionnaire (SF-36) Mental Component Summary score.
Results: Regression analyses revealed the intervention was effective primarily in those with self-reported depression (interaction effect F = 8.24, P = 0.0003), highest CES-D score category (F = 5.68, P = 0.0037), and lowest (most depressed) Mental Component Summary-36 tercile (F = 4.36, P = 0.0135).
Conclusions: Individuals with more depressive symptoms seem more likely to experience self-efficacy gains from chronic illness self-management training than individuals with less depressive symptoms. Future self-management training studies should stratify subjects within study groups by depressive symptom level to further explore its potential moderating effect.