The economic burden of tuberous sclerosis complex in UK patients with renal manifestations: a retrospective cohort study in the clinical practice research datalink (CPRD)

Background: Tuberous sclerosis complex (TSC) is a multi-system genetic disorder in which renal manifestations occur in similar to 50% of children and 80% of adults. Since these often present alongside other manifestations, renal TSC is likely to incur significant costs. This study aims to quantify healthcare resource use (HCRU) and costs for renal TSC patients in the UK. Methods: TSC patients in the Clinical Practice Research Datalink (CPRD) linked to Hospital Episodes Statistics were identified from January 1987-June 2013. Clinical data were extracted over the entire history and costs were reported over the most recent 3-year period. HCRU was compared with a matched comparator cohort. Incremental costs were reported and the key cost drivers by primary manifestation category were identified by regression modeling. Results: A total of 79 renal TSC patients were identified with manifestations including chronic kidney disease stage 3-5 (with prevalence increasing with age) and renal angiomyolipoma. Renal TSC patients consistently reported greater HCRU than the comparator. Inpatient hospitalizations were more frequent for renal TSC patients (3.2 vs 1.6), but length of stay was comparable; however, 70.9% of renal TSC patients recorded no kidney-related procedures ever and averaged <1 test per year in the 3-year period. Average costs for renal TSC patients were nearly 3-fold greater than the comparator (15,162 pound vs 5672) pound. Costs increased with additional manifestation categories (3600 pound: only renal; 27,531 pound: renal with >= 4 additional manifestation categories [25% of patients]). Additional nervous system and dermatology/psychiatric manifestations significantly (p<0.028) affected costs. Conclusions: Renal TSC patients have greater HCRU than the general CPRD population, likely to result from progression of renal disease and additional manifestations; however, surveillance for disease progression appears to be deficient. Inadequate monitoring may contribute to a lack of co-ordinated care and increased healthcare-associated costs. Efforts should be made to follow the TSC guidelines to effectively monitor and treat patients.