Quality of care in systemic lupus erythematosus: the association between process and outcome measures in the Lupus Outcomes Study

Objectives Although process measures to assess quality of care in systemic lupus erythematosus (SLE) are available, their relationship to long-term outcomes has not been studied. Using a prospective, longitudinal cohort study, we examined the associations between high-quality care and two important SLE outcomes, disease activity and damage. Methods Data were derived from the University of California, San Francisco Lupus Outcomes Study. Participants were followed from 2009 through 2013, responding to yearly surveys. Primary outcomes in this study were clinically meaningful increases in disease activity and damage, assessed by the Systemic Lupus Activity Questionnaire (SLAQ) and the Brief Index of Lupus Damage (BILD), respectively. Using multivariable regression, we examined the relationship between high performance on 13 validated quality measures (receipt of >= 85% of quality measures), and disease outcomes, adjusting for disease status, sociodemographic characteristics, healthcare services and follow-up time. Results The 737 participants were eligible for a mean of five quality measures (SD 2, range 2-12). There were 155 and 162 participants who had clinically meaningful increases in SLAQ and BILD, respectively. In our models, we found no statistically significant relationship between performance on quality measures and changes in SLAQ. However, receiving higher-quality SLE care was significantly protective against increased disease damage (adjusted OR 0.4, 95% CI 0.4 to 0.7), even after adjusting for covariates. Discussion In this community-based cohort, we illustrate for the first time a strong link between processes of care, defined by SLE quality measures, and the subsequent accumulation of disease damage, an important outcome.