The Patient Reported Outcomes in Lupus (PATROL) study: role of depression in health-related quality of life in a Southern California lupus cohort

Abstract

This study examines the relationship between psychosocial factors, ethnicity, disease activity and quality of life in systemic lupus erythematosus. One hundred and twenty-five adult Caucasian and Hispanic lupus patients were recruited from four Southern California medical centers. Linear regression analysis was performed to assess the correlation of ethnicity, socioeconomic factors (age, income), and disease activity (patient and physician reported), as well as psychological (depression, internality, helplessness) variables with quality of life (QOL) as measured by the Short Form (SF)-36. Hierarchical multiple regression analysis was then used to determine the stepwise contribution of the above determinants on the eight domains of the SF-36 questionnaire. Depression negatively correlated with QOL in both Caucasians (r -0.488 to -0.660) and Hispanics (r -0.456 to -0.723). Patient-reported disease activity was moderately related (r -0.456 to -0.698) to seven of the eight SF-36 domains in Hispanics, and none in Caucasians. Physician-reported disease activity, measured by SLEDAI, did not correlate with QOL among Hispanics or Caucasians. When linear and hierarchical regression was used, depression significantly correlated (p < 0.0001) with the majority of the SF-36 domains, except general health, while age had a significant effect in only one domain of the SF-36, physical functioning (p < 0.0001). Depression, and not disease activity, appears to have a major influence on quality of life in both Hispanic and Caucasian patients in this lupus cohort.