OBJECTIVES: Pathological insatiable hunger (hyperphagia) and early-onset obesity are hallmark characteristics of rare genetic diseases of obesity (RGDOs) and impose a substantial burden on caregivers due to continuous food monitoring, strained family dynamics, and impaired psychological well-being. Inclusion of caregivers’ perspective and quality of life (QoL) into economic evaluations of treatments addressing RGDOs can have a significant impact on incremental cost-effectiveness ratio (ICER). In light of recent discussions by the Swedish HTA agency (TLV), this case study aimed to demonstrate the impact of caregiver QoL on the cost effectiveness of a treatment for RGDOs in patients with Proopiomelanocortin (POMC), Proprotein Convertase Subtilisin/Kexin Type 1 (PCSK1) and Leptin Receptor (LEPR) deficiencies in the Swedish context.

METHODS: A Markov model was developed to assess the cost-effectiveness of setmelanotide, a selective MC4R-agonist. Model health states were based on BMI/BMI-Z-score for adult and paediatric patients. Costs and utilities associated with obesity and obesity-related comorbidities were included. Utilities associated with severity of hyperphagia reflected the direct impact of treatment on hyperphagia and subsequent improvement of patient’s QoL. Caregiver QoL decrements were related to hyperphagia severity and based on literature. The methods used to implement QoL decrement in the model were aligned with previous NICE submissions.

RESULTS: Treatment increased total QALYs eight-fold. The inclusion of one caregiver QoL decrement increased total QALYs by 7.1%, decreasing the ICER by 6.6% compared to the base case. In a scenario analysis, the impact of including the decrement for two caregivers was tested, resulting in a decline of 6.9% in the ICER compared to the base case.

CONCLUSIONS: This case study demonstrates the importance of considering caregiver utility in economic evaluations, especially in conditions like RGDOs that manifest in early childhood and impose substantial caregiver burden. HTA agencies should continue to develop guidance to facilitate methodological rigour in this area.