Care of patients with Phenylketonuria (PKU) in Germany – a claims data analysis from 2013 to 2023

BACKGROUND: Phenylketonuria (PKU) is a rare inherited metabolic disorder requiring lifelong management to prevent neurological, psychiatric, and physical complications. Although early detection through newborn screening has improved outcomes, real-world evidence on long-term care and healthcare utilisation remains limited. This study assessed the epidemiology, comorbidities, treatment practices, rehabilitation and healthcare resource utilisation (HCRU) of individuals with PKU in Germany, using nationwide statutory health insurance (SHI) claims data over ten years. RESULTS: Based on anonymised claims data of 16 SHI funds (~ 4.4 million insured; 5% representative sample), 4,949-6,105 PKU patients were identified annually from 2013 to 2023, yielding a prevalence of 0.007%-0.008%. The five-year cumulative prevalence (2019-2023) was 0.010%, with a slight female predominance (52%). Compared to matched controls (1:10), PKU patients had higher odds of comorbidities, including intellectual disability (OR 16.0), other metabolic disorders (OR 9.2), osteoporosis (OR 3.4), hyperkinetic disorders (OR 2.1), and recurrent depressive disorders (OR 1.6), with the severity of cognitive impairment increasing with age. Less than 20% of the individuals received pharmacological treatment, with low incidences in patients older than 54 years. Nutritional therapy was common during childhood, adolescence and young adulthood (average 49% in ages 0-24) but declined with increasing age. Pregnancy terminations were documented in more than 15% of the 34 women with recorded pregnancy in the cohort. Rehabilitation care was overall higher than in the healthy population, especially among children aged 2-12 years (5.6% vs. 0.3% in controls), primarily for developmental disorders. Healthcare costs were considerably higher in the PKU cohort. CONCLUSIONS: PKU care in Germany exhibits age-dependent differences in documented treatment patterns and a high burden of comorbidities, highlighting a substantial unmet medical need and the importance of structured lifelong management strategies.