Clinical manifestations, healthcare resource utilization, and costs among patients with long-chain fatty acid oxidation disorders: a retrospective claims database analysis.

OBJECTIVE Long-chain fatty acid oxidation disorders (LC-FAOD) are a group of rare genetic inborn errors of metabolism. Clinical manifestations may result in frequent healthcare visits, hospitalizations, and early death. This retrospective cohort study assessed manifestations, healthcare resource use (HRU), direct medical costs, and the impact of COVID-19 on HRU among patients with LC-FAOD. METHODS The IQVIA PharMetrics Plus database was searched for pediatric (0-17 years) and adult (≥18 years) patients with confirmed LC-FAOD (ICD-10-CM Diagnosis Code E71.310) and ≥12 months continuous enrollment (CE) between January 2016-February 2020. A non-LC-FAOD general population cohort was randomly selected and matched using 1:20 exact matching on age, gender, payer type, and CE start year. Manifestations were identified via ICD-10 diagnosis codes (any billing position). Overall HRU and attributable costs were stratified by care setting. Pre-COVID-19 (March 2019-February 2020) and during COVID-19 (March 2020-February 2021) HRU was assessed among a subgroup of patients and the general population. Outcomes were evaluated among children and adults, respectively. RESULTS 423 patients with LC-FAOD (47% female; 79.7% children) were included. Mean enrollment duration was 2.6 ± 1.2 years. 22.6% of children with LC-FAOD had at least one major clinical event (MCE), consisting of rhabdomyolysis (10.1%), hypoglycemia (9.8%), or cardiomyopathy (8.6%) versus 1.5% overall occurrence in the general population. Adults with LC-FAOD had higher incidence of MCEs (37.2%) than children with LC-FAOD. Annualized all-cause HRU in all care settings and mean total annualized medical costs (children: $17,082 vs $4,144; adults: $43,602 vs $3,949) were higher in patients with LC-FAOD versus the general population. Patients with LC-FAOD had substantially fewer healthcare visits during COVID-19 across care settings than during the pre-COVID-19 period. CONCLUSIONS LC-FAOD impart a high burden on patients. Extended hospital stays and increased outpatient management were especially pronounced for adults and for patients with ≥1 MCE, resulting in substantially higher medical costs than the general population.