[Complex care, high cost, and loss of income: frequent issues for families of children and adolescents with rare health conditions].

Estimates point to more than seven thousand rare diseases already identified, representing 6 to 10% of all diseases. In Brazil, a rare disease is defined as one that affects up to 65 persons per 100,000. The quantification of costs for the families of patients with such conditions and their impact on income provides information capable of supporting public policies for these youngsters. The study aimed to estimate the cost and loss of earnings, viewed from the perspective of families of children and adolescents with cystic fibrosis, mucopolysaccharidosis, and osteogenesis imperfecta. The study included 99 families of patients treated at a national referral hospital for rare diseases in Rio de Janeiro, based on the principal caregiver's report. The descriptive data analysis showed that the median direct nonmedical cost for families was BRL 2,156.56 (USD 570) for cystic fibrosis, BRL 1,060.00 (USD 280) for mucopolysaccharidosis, and BRL 1,908.00 (USD 505) for osteogenesis imperfecta. Loss of earnings exceeded 100% for all three diseases. A total of 54% of families fail to receive any social benefits. The estimate of coping costs indicated that 69% of the families had incurred loans and that 22.5% had sold household assets to cope with the treatment costs. Catastrophic expenditures were observed in families dealing with the three diseases. The results unveil costs that are rarely estimated, and not only in the field of rare diseases. The findings point to a major burden on the families' income. It is important to incorporate such studies in the discussion of financing, the incorporation of new technologies, and the supply of health services.