Reaching detection targets in familial hypercholesterolaemia: Comparison of identification strategies

Background and aims: Familial hypercholesterolaemia (FH) is a common and preventable cause of premature heart attack but in most nations only a small proportion of FH-positive individuals have been identified. The aim of this study was to estimate the time to close this FH detection gap. Methods: We developed a model to estimate the time to identify different proportions of FH in the population for three identification strategies (i) Cascade Testing (FH-mutation testing in relatives of someone with an FH mutation) (ii) Child-parent Screening (testing children for cholesterol and FH mutations during 1-year immunisation and parents of FH-positive children) and (iii) Child-parent Cascade Screening (integrating the first two methods). We used publicly available data to compare the strategies in terms of the time to identify 25%, 50% and 75% of all FH cases in the UK (current target is 25% in 5 years). For Child-parent Cascade Screening, we applied the model to other populations that have reported FH identification levels. Results: In the UK, 25% of FH individuals would be identified after 47 years for Cascade Testing, 12 years for Child-parent Screening and 8 years for Child-parent Cascade Screening; 50% identification after 146, 33 and 19 years and 75% after 334, 99 and 41 years respectively. For Child-parent Cascade Screening, the times to identify 50% FH were, for Netherlands, Norway, Japan, Canada, USA, Australia/NZ, South Africa and Russia, 0, 5, 13, 15, 16, 18, 21, and 30 years respectively. Conclusions: Child-parent Cascade Screening is the fastest strategy for identifying FH in the population. The model is applicable to any country to estimate the time to close the FH detection gap.