Cost-of-illness in systemic sclerosis: a retrospective study of an italian cohort of 106 patients

Aims: It is increasingly important to determine the economic consequences of diseases considering the policy of limited health–care budgets. In this study we evaluated the annual direct and indirect costs of Systemic Sclerosis (SSc) and we tried also to identify any cost predictors. Methods: We studied 106 patients (103 female, 3 male), 57 affected by Limited Systemic Sclerosis (LSSc) and 49 affected by Diffuse Systemic Sclerosis (DSSc). Mean age was 57 years (SD±13,8) and mean disease duration was 8,9 years (SD±7,2). Direct costs: data were calculated referring to DRG (Disease Related Group) expenses for the in-patients. We referred to national pharmacopoeia to calculate the pharmaceutical cost for the out-patients. Indirect costs: we estimated the expense comparing our cases to literature data. Intangible costs: these are attributable to pain and psychological suffering. It is very difficult to express the intangible costs in monetary terms and they are often conveyed as disability and poorer quality-of-life. We used the Health Assessment Questionnaire “HAQ” and the Short Form-36 “SF-36” to evaluate this issues. Results: Our study confirms, the extremely high costs caused by Systemic Sclerosis (total cost’s 2001 year is € 1.173.842,93, and average yearly patient cost is € 11.073,99). Considering an estimated prevalence of 375 cases/106, the total yearly economic impact of SSc in Italy should be € 249.000.000,00. Intangible costs were calculated as modifications of the health status. Average value of the HAQ was significantly higher than the control population (0,94±0,72), average values in the SF-36 were significantly lower than the control population (49,99±19,16 for physical dimension and 58,42±27,71 for mental dimension). The diffuse form of SSc, positivity for anti-Scl 70 antibodies, high skin score and a poor health status (HAQ and SF-36) were found to be cost predictors. Conclusions: As reported in the literature, our study confirms, the extremely high costs for total and single patients caused by Systemic Sclerosis. The DSSc are more expensive than the LSSc approximately 11% (p=0,0067). The direct costs are 30% higher in the DSSc than the LSSc (p<0.001). The indirect and intangible costs are not significantly different. Moreover, our study shows also the possibility of identifying different cost predictors.