Economic impact of feeding a phenylalanine-restricted diet to adults with previously untreated phenylketonuria

The aim of the present study was to estimate the direct healthcare cost of managing adults with previously untreated phenylketonuria (PKU) for one yea r before any dietary restrictions and for the first year after a phenylalan ine- (PHE-) restricted diet was introduced. The resource use and correspond ing costs were estimated from medical records and interviews with health ca re professionals experienced in caring for adults with previously untreated PKU. The mean annual cost of caring for a client being fed an unrestricted diet was estimated to be pound 83 996. In the first year after introducing a PHE-restricted diet, the mean annual cost was reduced by pound 20 647 td pound 63 348 as a result of a reduction in nursing time, hospitalizations, outpatient clinic visits and medications. However, the economic benefit of the diet depended on whether the clients were previously high or low users of nursing care. Nursing time was the key cost-driver, accounting for 79% of the cost of managing high users and 3 1% of the management cost for low users. In contrast, the acquisition cost of a PHE-restricted diet accounted for up to 6% of the cost for managing high users and 15% of the management cost for low users. Sensitivity analyses showed that introducing a PHE-res tricted diet reduces the annual cost of care, provided that annual nursing time was reduced by more than 8% or more than 5% of clients respond to the diet. The clients showed Fewer negative behaviours when being fed a PHE-res tricted diet, which may account for the observed reduction in nursing time needed to care for these clients. In conclusion, feeding a PHE-restricted d iet to adults with previously untreated PKU leads to economic benefits to t he UK's National Health Service and society in general.