Outpatient healthcare utilization among incident cases of systemic sclerosis: results from a population-based US cohort (1988–2016)

Objective: Systemic sclerosis (SSc) is a complex, heterogeneous connective tissue disease with multiorgan dysfunction. This study aimed to compare healthcare utilization among incident cases of SSc versus age- and gender-matched comparators. Method: A population-based cohort of physician-diagnosed patients with SSc in Olmsted County, MN, USA, from 1 January 1988 to 31 December 2016 was assembled. A 2:1 cohort of age- and gender-matched non-SSc subjects was randomly selected for comparison. Patients were followed until death, migration from Olmsted County, or 31 December 2017. Outpatient utilization data were obtained beginning 12 months before the SSc incidence/index date and compared using negative binomial and multinomial models. Services were summarized as visit-days to avoid overestimation of services provided. Results: The study included 69 incident SSc cases and 138 non-SSc comparators (mean ± sd age 57 ± 16 years at diagnosis/index, 90% female). Patients with SSc had higher utilization of outpatient physician, laboratory, and combined radiology visit-days annually for the year before and for each of the first 5 years after diagnosis than comparators. Among patients with SSc, healthcare utilization was highest during the year of SSc diagnosis. Rate ratios comparing utilization in patients with and without SSc ranged from 1.8 to 3.0 for all comparisons. Conclusion: Higher utilization of outpatient physician, laboratory, and radiology visit-days was observed among patients with SSc compared to non-SSc subjects throughout 5 years of disease duration, indicating high and continued care needs in this patient population. The highest utilization of services among SSc patients occurred during the year of SSc diagnosis.