Burden of Sickle Cell Disease: A Brazilian Societal Perspective Analysis

Introduction: Sickle cell disease (SCD) is a group of inherited disorders that shorten life expectancy. It is estimated that 300,000 children are born with the disease worldwide each year [1,2]. In Brazil is it estimated that 3,500 children are born with SCD each year [3]. The SCD is a multisystem disorder that leads to several complications (acute and chronic) including vaso-occlusive crisis [1,4]. SCD patients experience increase morbidity and mortality, the implications of which are known to impacts the whole society [2]. Although there is some knowledge about the clinical impacts of SCD, little is known about the societal costs. Due to the limited available, to the best of our knowledge there are no similar studies which have been conducted and published. The aim of this study is to estimate SCD societal costs based on a burden of disease model, utilizing the Brazilian societal perspective.

Material and Methods: A burden of disease model (Figure 1) was built considering direct medical costs to adults and children and indirect costs, taking into account lost wages due to SCD related morbidity and death. Direct costs were estimated using a bottom-up strategy and micro-costing method, and indirect costs were estimated using a prevalence method. Disability-adjusted life years (DALYs) were calculated from the sum of years of life lost and disability. The rate and duration of SCD related complications (including death) was calculated using information from a Brazilian governmental healthcare public database (DATASUS). The prevalence of each complication was determined by literature data or medical experts. It is important to point that there is some uncertainty around the prevalence estimates. Direct costs for complications were captured from the Brazilian public healthcare system table of procedures and medications (SIGTAP). Indirect costs attributed to productivity loss were calculated using the human capital method. All values were reported in 2020 Brazilian real (BRL).

Results: Considering a prevalence of 23.9 cases per 100,000 (50,000 patients in 2018) and a probability of death of 1.11% (560 deaths in 2018), the annual total SCD cost in Brazil was estimated at 1,519,473,501 BRL. Table 1 shows the contribution of the direct and indirect costs to the total cost for the SCD population in Brazil. Further, results were stratified by children and adults (56% and 44%, respectively).

Indirect cost was the main driver of disease burden, estimated at 1,128,355,824 BRL. Approximately 40,829 DALYs were lost by SCD patients in 2018 (22,750 and 18,079 among adults and children, respectively). Direct medical costs represented 25.7% of total costs and were estimated at 391,117,677 BRL. Provision of standard of care was the main driver of direct costs in both populations (157,521,597 BRL for adults and 100,133,575 BRL for children).

Chronic complication management was shown to be more expensive than acute complication management among adults, while the opposite was observed for children. Vaso-occlusive crisis was the acute complication most frequently observed in available literature and according to medical experts (75.0% among adults and 59.5% among children). Acute chest syndrome had the highest disability weight (0.33). Considering chronic complications, calculous chronic cholecystitis was considered the most frequent among adults (62.0%) and renal abnormalities (without failure) among children (20.0%).

Conclusion: SCD patients generate a high economic burden for the Brazilian society greater than one point five billion BRL per year. Most of the cost is related to indirect burden due to increased mortality and morbidity. Investments in technologies and therapies that can decrease the impact of SCD on patients’ lives by reducing morbidity and/or mortality are necessary.

References:

1. Kato GJ, Piel FB, Reid CD, Gaston MH, Ohene-Frempong K, Krishnamurti L, et al. Sickle cell disease. Nat Rev. 2018 Jun 15;4(1):18010.
2. Mburu J, Odame I. Sickle cell disease : Reducing the global disease burden. 2019;41(February):82–8.
3. Carneiro-Proietti ABF, Kelly S, Miranda Teixeira C, Sabino EC, Alencar CS, Capuani L, et al. Clinical and genetic ancestry profile of a large multi-centre sickle cell disease cohort in Brazil. Br J Haematol. 2018 Sep;182(6):895–908.
4. Piel FB, Steinberg MH, Rees DC. Sickle Cell Disease. Longo DL, editor. N Engl J Med. 2017 Apr 20;376(16):1561–73.