Costs and healthcare resource use data in mitochondrial diseases associated with seizures: a systematic literature review

Mitochondrial diseases are a diverse group of rare disorders which cause deficiencies in mitochondrial function. Seizures affects between 35% and 60% of those diagnosed. This study was undertaken to review evidence on costs and healthcare resource use in this population. 12 bibliographic databases and information sources were searched in August 2021 to identify studies reporting costs and healthcare resource use data. Two reviewers independently assessed the records against the eligibility criteria reported in the review protocol. One reviewer extracted data from the eligible studies and a second checked each data point. Searches identified 3,333 unique records. Two studies reporting healthcare resource use data were eligible. No studies reported cost data. One study was a retrospective review of hospital medical records of paediatric patients with mitochondrial diseases and early death in Korea (n=31; age: 1.8±2.0 years). The mean number of intensive care unit (ICU) admissions per year was 0.62±0.86 (range: 0 to 3); this was higher for patients younger than six (0.83±1.06) compared with patients aged six or older (0.38±0.52). The mean duration of ICU stay was 15±24 days (range: 0 to 93; 16±23 days for patients younger than six; 14±25 days for patients aged six or older). The second study was a case report of a Japanese woman (24 years) diagnosed with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and admitted to hospital with impaired consciousness and myoclonus. The patient was transferred to ICU after 19 days of hospitalisation and mechanical ventilation in ICU was required for 25 days. This is one of the first systematic literature reviews of costs and healthcare resource use data in mitochondrial diseases associated with seizures. The evidence is sparse, and healthcare resource use data are not widely reported, reflecting the rarity of the disease.