Background/Purpose: Resource utilization has been examined
in various geographic locations and utilizing different research methodologies
including secondary use of heath care administrative data. Our objective was to determine total physician
encounters, emergency room visits and hospitalizations in an incident cohort of
systemic lupus erythematosus (SLE) cases and matched controls over 13 years.

Methods: A retrospective cohort study was
performed utilizing administrative health care data from approximately 1
million people with access to universal healthcare. Using ICD-9 and ICD-10
diagnostic codes, 7 SLE case definitions were used and each SLE case was
matched by age and gender to four randomly selected controls. Information on physician
billings, emergency room visits and hospital discharges over 13 years was
obtained. Analysis included descriptive statistics, linear regression and negative binomial models to examine differences in
utilization between cases and controls. Models were also adjusted for the index
year of utilization.

Results: The number
of incident SLE cases varied from 564 to 4,494 depending upon the case
definition. The mean ± SD age was 50.4 ± 16.4 with 77.9% females. For all case
definitions there was significantly higher utilization of all physician groups by
SLE cases compared to controls (p<0.001). For SLE cases the utilization was
highest in the index year and fell thereafter, although never to the level of
utilization in the matched controls. By the fourth year, encounters with
subspecialty physicians fell by 60% (Rheumatologists), 50% (Internal medicine)
and 31% (other physicians). In contrast, visits to family physicians fell by
only 9%. Regardless of which case definition for SLE that was used, visits to
the emergency room were significantly more frequent for SLE cases (P<0.001).
This was most apparent early in the disease and fell to within the range seen
in the controls by the end of the study. Likewise, the hospital admission rate
for SLE cases was significantly higher (P<0.001) than controls, especially
early in the disease course.

Conclusion: In SLE patients, health care
utilization is highest in the first few years following the diagnosis, which
coincides with the highest frequency of visits to rheumatologists. Utilization
declines over time and encounters with patient’s family physicians predominate
over other physician groups.