Trajectories of chronic illnesses depend on patient socioeconomic status (SES). This study examines main and equity effects (age, gender, education, region of residence) of a brief telephone self-management intervention on self-rated health and depressive symptoms of health insurance clients with chronic illnesses. Randomized invitation design (n = 2628) with predominantly male (82%) older individuals (modal age = 65–74) with one or more chronic illnesses. Primary outcomes: Self-rated health and depressive symptoms. Intervention: Brief CBT-based telephone counseling. Propensity score matching was used to equate intervention and control groups (n = 1314 pairs). Change score models were used to analyze changes in health-related outcome measures. The intervention resulted in improvements in self-rated health (d = .37) and fewer depressive symptoms (d = .17) over 4 and 6 months. There were comparable effects across education and regions, but younger and female participants profited more from the intervention compared with older and male participants. A brief telephone-based intervention led to improved self-rated health and well-being in a large sample of participants with chronic health conditions. This effect was observed over and above regular medical care. The intervention was equitable with respect to education and region, but not age and gender
