Economic impact of juvenile idiopathic arthritis and familial Mediterranean fever

In this study, the mean annual total cost of JIA in Turkey was estimated as €3,994 ± 4,101. Cost of medications (85%), especially that of anti-TNF agents (76%), made the largest contribution to the total cost. Among the subtypes of JIA, polyarthritis type had the highest cost. Meanwhile, the control group FMF was found to have a modest total annual cost (€162 ± 77).

The main results of the 5 JIA costing studies published within the last 6 years are summarized in Table 6 [2, 4‐7]. As there are great variances with regard to the health care systems, methodologies, patient characteristics, frequency of DMARDs and anti-TNF use, caution is required while comparing each other. Minden et al. in their first study assessed costs of JIA patients in the adulthood and found that 55% of the patients had still active disease after 17 years of disease onset [2]. The costs due to loss of productivity made 45% of the total costs in contrast to other studies including ours [4‐7]. In their second study, Minden et al. assessed the costs in a younger JIA cohort [7]. They observed that health care costs accounted for 89% of total costs and medications contributed to half of this value [7]. The Finnish study evaluated especially the costs of etanercept addition to the prevailing drug therapy for a 1-year period [4]. While total median costs amounted to $7,732 by the end of the year, the median direct costs per patient was increased by about $2,700. However, authors observed a 50% drop in the indirect costs [4]. Bernatsky et al. showed that direct costs for children with JIA ($3002 Canadian dollars) were higher than that for children without chronic disease ($1,686 Canadian dollars), particularly due to medication costs [5]. Thornthon et al. observed direct costs of JIA patients specifically in the first year of their diagnosis and found that the highest cost component was appointments with pediatric rheumatologists [6]. There is also another study that was done in the United States by Allaire et al. about two decades ago when biologics were not introduced and therapy with DMARDs was a new notion [3]. The mean annual direct cost per child was estimated as $7,905, annual family costs averaged $1,524 and medications contributed to only 7% of the health care costs [3].

Drugs are currently the main cost driver in rheumatoid arthritis [17, 18] and in most JIA costing studies including ours [4, 5, 7] as shown in Table 6. However, data about the use of DMARDs and biologics were not sufficient in these studies, despite the fact that most of them dated relatively to a recent period. Of the 5 studies, 3 did not determine DMARD use and 2 did not specify biologics use [2, 4, 6]. Moreover, of the remaining studies, in one, only about 1/3rd of the patients used DMARDs [5] and in 2, biological use was present in the minority of patients [5, 7]. The rate of DMARD use (61% vs. 68%) was similar, however, that of biological use was substantially higher in our study compared to the recent German study (49% vs. 6%, respectively) [7]. This is most probably due to the great variance in the use of biologics according to the center’s therapeutic approaches. Reimbursement by the health insurance systems may also play role. It is also to be noted that, although patients are included in a consecutive manner in the study, those who use anti-TNFs may tend to attend the outpatient clinic more frequently than those who do not use. Therefore, the current study may not represent the actual anti-TNF use in our center.

While medication was the major contributor to the health care cost, its share was almost 50% in most of the JIA costing studies [4, 5, 7]. However, in our study, this was 90%. Similarly, contribution of medications was calculated as 78% in another cost of illness study done for Behçet’s syndrome again in our institution [19]. In fact, when the costs for laboratory tests and devices were excluded, costs for inpatient and outpatient care, which also included physician visits, rheumatology consultations, physiotherapy, and nurse care, altogether made only 3% of the health care costs in JIA. This negligible share is the result of the low cost of health care system in Turkey. Prominent changes in the health care policies for the last 5 years as part of a health reform program helped more in the minimization of this share [14, 15]. The reform program, which had aimed making health care available to a larger share of the population, caused much controversy. Decrease in the quality of the health care is one of its drawbacks.

Similar to what was reported in previous studies [2‐7], we also showed that JIA causes considerable economic burden for the health care system in Turkey. However, with such a high rate of anti-TNF use at hand, one might have expected much increased total costs if the study had been done in Finland or Germany. This is, as mentioned earlier, due to low priced health care system in our country.

FMF is one of the most common disease in Turkey with a prevalence rate amounting to 0.9% [20, 21]. Our study is the first to assess socioeconomic status and economic impact of juvenile patients with FMF. While socioeconomic status was found to be more favorable, total costs were significantly lower in patients with FMF compared to those with JIA. Certain diseases such as asthma, coronary atherosclerosis, systemic lupus erythematosus, and Behçet’s syndrome have been reported to be more frequent in lower socioeconomic classes [22‐25]. Furthermore, socioeconomic status and education may have impact on disease outcome [26]. On the other hand, this issue seems to be controversial for JIA, since one study from Denmark reported that children whose parents had a high income had a 2 times greater risk of developing JIA compared to age and sex matched controls [27]. It is also to be noted that, our study may not be conclusive, since parents of FMF patients may not represent general population in Turkey. Moreover, high wealth score was a predictor of high costs for JIA patients in our study, a fact supporting the Danish study.

This study has some limitations. Sample size of JIA subgroups was small and we did multiple comparisons; therefore, caution is needed in interpretation the results. Our findings are subject to recall bias because of the methodology used; similar to most cost of illness studies, our study was retrospective taking into account preceding 3 months. We did not evaluate missed school days of the patients. As part of out-of-pocket expenses we assessed only transportation and lodging expenses during the hospital visits and cost for any domestic help. Finally, since our study was done in Turkey and in a tertiary referral center, our results must not be generalized.