Background/Purpose:

Patients with systemic sclerosis (SSc) have considerable morbidity which may be associated with high health resource utilization.  Studies on health use and costs are scarce and the few available have short follow-up from clinic-based samples.  To address this knowledge gap, we have estimated the longitudinal health care costs of cases with SSc.  We measured physician visits, hospitalizations, and dispensed medication data that cover the entire SSc population of our province.

Methods:

Data Source: Universal coverage is a feature of our healthcare system and administrative data captures all funded health services (outpatient visits, tests and hospitalizations) and all dispensed medications from 1996 through 2010 (regardless of funding source).

Cases: A population-based cohort of SSc was identified using the following algorithm: a) diagnosis of SSc on at least two visits within a two-year period between Jan 1990 and Dec 2010 by a non-rheumatologist physician; b) diagnosis of SSc on at least one visit by a rheumatologist or from hospitalization. To increase specificity we excluded cases that were not confirmed by a rheumatologist if they were seen at a later point.  

Cost Calculation: Costs for outpatient services and prescriptions were summed directly from paid claims.  Case-mix methodology was used to cost hospitalizations.  Costs are reported in 2010 Canadian dollars.

Results:

We identified 1,456 SSc cases (82% female, mean (SD) age of 55.3 (±14.9) years) contributing 7,824 total patient-years (PY).  Over 15 calendar years the cumulative costs for SSc cases totalled $83,507,123 and averaged $10,673 per-PY with $2,475 (23%) from outpatient services, $5,360 (50%) from hospitalizations, and $2,837 (27%) from prescription medications.  Cases who were hospitalized at least once over the period averaged 1.9 (±3.0) admissions per-PY. 

After adjustment to 2010 dollars, annual mean per-PY costs increased by 8%, from $9,513 in 1996 to $10,261 in 2010.  Mean per-PY outpatient costs decreased by 14% and hospital costs by 15% (see table).  In contrast, mean per-PY prescription costs increased by 109% (from $1,740 in 1996 to $3,641 in 2010), and the mean number of prescriptions per-PY increased by 56% (from 29 to 46).

92% of the cohort’s cumulative healthcare costs came from the 67% of SSc cases (n=977) that were hospitalized at least once.  These cases had a substantially larger increase in prescription drug costs over the 15 years (by 193%, $1,791 to $5,253 per-PY) than never-hospitalized cases (by 42%, $1,283 to $1,824). 

Conclusion:

This is the first longitudinal and population-based study assessing the direct medical costs of patients with SSc.  As outpatient and hospital costs decrease, medication use and costs continue to rise.  Given there are no specific disease modifying anti-rheumatic drugs for SSc, our results suggest the long-term costs of SSc cases may be driven by ongoing complications and comorbidities of this disease.