OBJECTIVES: Rare diseases (RD) patients face health challenges and limited treatments, and their impact within Brazilian healthcare unknown. This study investigated healthcare resource utilization (HCRU) to provide a better understanding of economic impacts of RD.

METHODS: Data from January/2019 to December/2023 were used to extract HCRU and costs of 793 ICD-10 codes linked as RDs, which was primarily provided by Orphanet. Common conditions (CCs) were defined as any condition not included in the RD/ICD-10 list. Direct medical costs were calculated annually for patients with costs independent of the stage of diagnosis. Data were aggregated by prevalence, costs, and demography. Chi-square and Fisher’s exact and Student’s t tests for categorical/continuous measures were used. Statistical significance for p<0.05.

RESULTS: A total of 60,012 individuals (average age 53 years) were analyzed. When combined, RD are not rare, as they collectively affect 5.9% (n=3,564, 63 years old, female 61.4%). Of $367 million expenses in the health plan, 21.9% corresponded to RD. Overall, total aggregate charges were $80 million for RDs and $358 million CCs, a despite RD patients accounting for a small percentage of the overall population. Observed significant differences in HCRU between RD and CCs, with higher rates for visits, emergency services, tests, therapies, and hospitalizations when compared to CCs (p<0.0001), and nearly quadruple the average total charges per patient ($6,816) compared to CCs ($1,960) (p<0.0001).

CONCLUSIONS: RD patients are difficult to quantify in healthcare systems using ICD coding search criteria, which likely results in under-counting and under-estimation of their true impact to healthcare systems. Direct medical costs of RD are high, estimated to be around three–four higher than CCs group. The diagnostic journeys are likely prolonged and may result in progressive, irreversible, and costly complications of their disease. That is why they are an extraordinary financial and organizational challenge for payers.