Background/Purpose: Although measures to assess quality of care in systemic lupus erythematosus (SLE) are available, their relationship to long-term disease outcomes is unknown. Using a prospective, longitudinal cohort study, we examined the associations between high quality care and risks of increased SLE disease activity and damage.

Methods: Data derive from a longitudinal study of individuals with SLE, the UCSF Lupus Outcomes Study (LOS). Participants were followed from 2009 through 2012, responding to yearly telephone surveys. The primary outcomes in this study were clinically meaningful increases (>0.5 standard deviations) in 1) disease activity, defined as greater than or equal to 4 points on the Systemic Lupus Activity Questionnaire (SLAQ) between the 1st and 4th year of observation, and 2) disease damage, defined as greater than or equal to 2 points on the Brief Index of Lupus Damage (BILD) over the same time period. Both SLAQ and BILD have been validated for self-report in telephone surveys. Our primary independent variable was performance on 13 previously validated SLE quality measures, with a pass rate of greater than or equal to 85% (corresponding to the top quintile of performance, with pass rate defined as proportion of eligible recommended services received) considered indicative of high quality care. Using multivariable logistic regression, we examined the relationship between higher performance on quality measures and disease outcomes, adjusting for baseline disease activity and damage, age, gender, race/ethnicity, education, insurance source, health care utilization, specialties of providers seen, number of eligible quality measures, and follow-up time.

Results: Among 737 participants, the mean age at baseline was 50 years (SD 13), 93% were female, 63% were white; 41% had college degrees, and 15% had poverty-level incomes. Respondents were eligible for a mean of 5 quality measures (SD 2, range 2-11). There were 155 participants who had a clinically meaningful increase in SLAQ and 162 with an increase in BILD. In our models, we found no statistically significant relationship between performance on quality measures and changes in SLAQ score. However, receiving higher quality SLE care was significantly protective against increased disease damage (adjusted OR 0.4, 0.2-0.7; Table), even after adjusting for covariates, including baseline damage, disease activity, sociodemographic characteristics, insurance, health care utilization and number of eligible quality measures.

Conclusion: In this community-based cohort of individuals with SLE, 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. This suggests that improving quality of care has the potential to reduce accumulated damage in SLE even in advance of the development of new treatment options.