The Patient-reported Genetic testing Utility InDEx (P-GUIDE): A novel measure of personal utility

Consensus is lacking on how to define and measure the concept of personal utility in genomic medicine. The study objective was to develop and assess the validity of the Patient-reported Genetic testing Utility InDEx (P-GUIDE) for pediatric genetics.

Informed by the literature, experts, and patient partners, a 55-item first draft of P-GUIDE was developed. Interviews were conducted with parents of children who had genetic testing to assess item clarity and relevance. Clinical experts assessed content validity. Two independent sequential samples of parents completed questionnaires. Item reduction was achieved using exploratory factor analysis and confirmatory factor analysis. Performance characteristics were assessed on the final tool.

Interviewees (n=22) found most items relevant but requiring modifications. Clinical experts (n=11) recommended further revisions. Exploratory factor analysis (n=103) removed 9 items. Confirmatory factor analysis (n=103) generated a final tool consisting of 19 items across three factors: understanding and decision-making, psychosocial benefit, and psychosocial concern. P-GUIDE scores were positively correlated with published measures of utility, knowledge, empowerment, and emotion, establishing construct validity. P-GUIDE demonstrated strong test-retest reliability.

P-GUIDE is available for use with pediatric populations. Emerging adaptations of P-GUIDE contribute to a novel utility measurement system for genetic testing.