A systematic review of utility values in children with cerebral palsy

Utsana Tonmukayakul, Long Khanh-Dao Le, Shalika Bohingamu Mudiyanselage, Lidia Engel, Jessica Bucholc, Brendan Mulhern, Rob Carter, Cathrine Mihalopoulos

Project aims include the following: (i) to identify reported utility values associated with CP in children aged ≤ 18 years; (ii) to explore utility value elicitation techniques in published studies; and (iii) to examine performance of the measures and/or elicitation approaches. Peer-reviewed studies published prior to March 2017 were identified from six electronic databases. Construct validity, convergent validity, responsiveness, and reliability of instruments were assessed. Five studies met the inclusion criteria. Utility values of hypothetical general CP states obtained from a general population of parents ranged from 0.55 to 0.88 using time trade off (TTO) and 0.60-0.87 using standard gamble (SG) techniques. Utility values reported by clinicians of three hypothetical spastic quadriplegic CP states, using the Health Utility Index Mark 2 (HUI-2), ranged from 0.40 to 0.13. Other sources of utilities identified were based on both proxy and child ratings using Health Utility Index Mark 3 (HUI-3) (values ranged from - 0.013 to 0.84 depending on the valuation source) and the Assessment of Quality of Life 4 Dimension instrument, with values ranging from 0.01 to 0.58. Construct validity of the HUI-3 varied from moderate to strong, whereas mixed results were found for convergent validity. Responsiveness and reliability were not reported. There was substantial variation in reported utilities. Indirect techniques (i.e. via multi-attribute utility instruments) were more frequently used than direct techniques (e.g. TTO, SG). Further research is required to improve the robustness of utility valuation of health-related quality of life in children with CP for use in economic evaluation.