AimThe implementation of newborn screening programs for inborn errors of metabolism has advanced the diagnosis and management of affected infants and undoubtedly improved their outcomes. We aimed to determine out-of-pocket health expenditures of patients with inborn errors of metabolism during follow-up and treatment processes and to determine the economic burden on the families.Materials and methodsA total of 232 patients who voluntarily agreed to participate in the study and were regularly followed up in the Department of Pediatric Metabolism with the diagnosis of Inborn Errors of Metabolism between April 2022 and July 2022 were included. Questionnaires were asked about the demographic characteristics of patients, use of health services, follow-up, treatment procedures, frequency of controls and health expenditures.ResultsThe average out-of-pocket expenditure of the households in the last month was 1039.22 ± 1030.08 (minimum: 20, maximum: 5000) Turkish Liras. When we consider the catastrophic health expenditure rate as expenditure exceeding 40% of household income, we found that 9.9% (23 people) of parents included in the study made catastrophic health expenditures. The rate of catastrophic expenditure of patients with a diagnosis of Amino Acid Metabolism Disorders was found to be higher than that of patients with a diagnosis of Vitamin and Cofactor Metabolism Disorders. Similarly, patients with a diagnosis of lysosomal storage diseases had more expenditures than patients with a diagnosis of vitamin and cofactor metabolism disorders. When we compared the rate of catastrophic health expenditure of the patients with urea cycle disorders and the patients with a diagnosis of vitamin and cofactor metabolism disorders, the former had more expenditure than the latter (p< 0.05). There was no significant difference between other disease groups in terms of catastrophic expenditure. The rate of catastrophic expenditures of the households living as large family type were higher than the families living as nuclear family type (p< 0.01). A statistically significant difference was found between the rates of catastrophic expenditures of the families living in Ankara and those who were admitted from other provinces for follow-up and treatment (p< 0.001). However, there was no difference between the rates of catastrophic expenditure of the patients who received any treatment and those who were followed up without treatment (p> 0.05).ConclusionDue to the high rate of consanguineous marriages in our country, the development of newborn screening programs, the increase in awareness about metabolic diseases and the improvement in diagnostic methods, the frequency of metabolic diseases is increasing, and mortality and morbidity rates are significantly reduced with early diagnosis and treatment opportunities. It is necessary to carry out more comprehensive studies to determine and prevent the socioeconomic effects of out-of-pocket health expenditures of patients living with Inborn Errors of Metabolism.