Utilization of Ambulatory Physician Encounters, Emergency Room Visits, and Hospitalizations by Systemic Lupus Erythematosus Patients: A 13-Year Population Health Study

Objective. To determine total physician encounters, emergency room (ER) visits, and hospitalizations in an incident cohort of systemic lupus erythematosus (SLE) cases and matched control patients over 13 years. Methods. A retrospective cohort study was performed utilizing administrative health care data from approximately 1 million people with access to universal health care. Using International Classification of Diseases, Ninth and Tenth Revisions diagnostic codes, 7 SLE case definitions were used. Each case was matched by age and sex to 4 randomly selected controls. Data included physician billings, ER visits, and hospital discharges over 13 years. Results. The number of incident SLE cases varied from 564 to 4,494 depending on the case definition used. The mean age varied from 47.7 to 50.6 years and the proportion of females from 78.0% to 85.1%. SLE utilization of physicians was highest in the index year, and declined significantly thereafter for all case definitions. By the fourth year, encounters with sub-specialty physicians fell by 60% (rheumatologists), 50% (internists), and 31% (other physicians). In contrast, visits to family physicians fell by only 9%. Visits to the ER and hospital admissions for SLE cases were also more frequent early in the disease course and fell significantly over the study for both ER visits (all case definitions) and hospitalizations (2 of 7 case definitions). Conclusion. In SLE patients, health care utilization is highest in the first few years following the diagnosis, which is also the time of maximal involvement by rheumatologists. Utilization declines over time, and encounters with patients' family physicians predominate over those of other physician groups.