In total, 12,455 subjects with at least one prescription for a synthetic or biologic DMARD was identified in the period 2007–2010. Of these, 2895 subjects were excluded because they did not meet any of the conditions required for a confirmed RD. The category of indistinct RD was defined to include those cases in which, despite the certainty of the presence of RD, it was not possible to assign the condition to one of the three rheumatic diseases of interest. This category included patients with a discordant definition of more than one disease of interest (n = 584; 4.7%), those who were identified as RD patients only on the basis of a prescription for methotrexate (n = 710; 5.7%), and those with juvenile idiopathic arthritis (n = 6; ≈0.0%). Following exclusion of those who did not meet the inclusion criteria, the overall study population consisted of 9560 patients, among whom 1855 had psoriatic arthritis (19%), 5989 had rheumatoid arthritis (63%), and 416 had ankylosing spondylitis (4%). The majority of patients were women (58.1%), and the mean [±standard deviation (SD)] age of the study population was 55.3 (±17.4) years. The analysis of presence of comorbidity in the study population (N = 9560) is shown in Table 1.
Table 1 Comorbidities in the study population (n = 9560)
Of the 9560 patients entered into the study, 4153 (43%) reported at least one hospitalization between the index date and the end of the 3-year observation period, among whom were 2655 of the 5989 patients with rheumatoid arthritis (44%), 149 of the 416 patients with ankylosing spondylitis (36%), and 651 of the 1885 patients with psoriatic arthritis (35%). Of the 1300 patients diagnosed with indistinct RD, 698 (54%) reported at least one hospitalization during the index date and the end of the 3-year observation period.
On the index date 12.9% of the study population were receiving a biologic DMARD. The distribution of all prescriptions on the index date is shown in Table 2. The total study population of 9560 patients received 9963 prescriptions in the first year (some patients received more >1 biologic DMARD). The highest number of prescriptions were written for methotrexate (46.6%) and hydroxychloroquine (30.7%); the mostly highly prescribed biologic DMARDs were adalimumab (4.7%) and etanercept (4.4%). Tocilizumab, certolizumab, golimumab, and ustekinumab were not available in Italy on the index date and therefore not prescribed at that time.
Table 2 Number of prescriptions on the index date in the study population (n = 9560) according to drug
The prescription of concomitant medications during the 3 years of follow-up was also analyzed, revealing that concomitant medications were used by 92.5% of the study population in follow-up year 1, 97.2% in follow-up year 2, and 97.5% in follow-up year 3 (Table 3). The highest number of prescriptions was for non-steroidal anti-inflammatory drugs (60.4–59.6%) and corticosteroids (58.3–57.7%).
Table 3 Prevalence of prescriptions for concomitant drugs in the study population (n = 9560) during the 3-year follow-up
The total monthly healthcare expenditure for hospitalizations, emergency care, outpatient care, and pharmacological therapy (synthetic and biologic DMARDs, concomitant drugs) was assessed for the study population during the 3 years of follow-up. The total expenditure was €377.98 per patient per month (patient-month), attributable to the costs of synthetic DMARDs (€17.03), biologic DMARDs (€149.75), concomitant medications (€61.07), emergency care (€4.55), hospitalization (€92.61), and visits (€52.96) (Table 4).
Table 4 Mean total monthly costs in the study population (n = 9560)
The mean cost per patient per month was analyzed in the subgroups of patients who received or did not receive at least one prescription of biologic DMARD in a specific year. During years 1, 2, and 3 of the follow-up 17.7%, 17.5%, and 19.4% of patients, respectively, had at least one prescription for a biologic DMARD. The mean total cost per patient per month including the cost of biologics was €1037.97 (€1061.20, €1002.23 and €1050.48 in years 1, 2, and 3, respectively, of the follow-up) (Fig. 1). The cost of biologic DMARDs was the most important component of this total expenditure, totaling €821.54 (€829.17, €798.27. and €837.17 in years 1, 2, and 3, respectively, of the follow-up). The mean total cost per patient per month in the subgroup of patients who did not have prescriptions for biologic DMARDS was €230.86 (€241.25, €222.58 and €228.74 in years 1, 2, and 3, respectively, of the follow-up). In this subgroup the cost for hospitalization was the most important component of the healthcare expenditure, totaling €94.64 (€99.42, €90.40 and €94.10 in years 1, 2, and 3, respectively, of the follow-up).
The average monthly total cost per patient was also analyzed by stratifying the cohort on the basis of the specific biologic DMARD received. In this subgroup analysis, the total cost per patient per month ranged from a low of €657.61 (golimumab) to a high of €1384.15 (rituximab) (Table 5).
Table 5 Mean total monthly costs during the 3 years of follow-up stratified by the type of biologic disease-modifying antirheumatic drug