Valuing comprehensive sequencing to improve diagnosis of rare disorders: a health economic perspective
In the single-centre micro-costing exercise, mean costs of clinical evaluation, local laboratory processing, variant interpretation, result reporting and data storage were around £6,924 per family trio for WGS, compared to £2,452 for trio-based WES. Median costs for standard laboratory testing (including tests performed within and outside Scotland) were £1,478 per singleton patient with intellectual disability and £1,997 per patient with other phenotypes. We are in the process of validating our costings in the three other Scottish genetics centres.
The EQ5D-3L is the current UK standard for assessing the value of health care intervention. However, concern has been raised about its applicability to DNA sequencing due to its focus on health outcomes, thus ignoring wider benefits which have been recognised as important. To understand the EQ5D-3L’s ability to assess the patients’ and families’ valuation of WGS, we interviewed six parents of affected children and three adults with a rare condition. Although the negative effect on wellbeing of the diagnostic odyssey is well documented, participants reported perfect health on all dimensions of EQ5D-3L (mobility, self-care, usual activities, pain/discomfort and anxiety/depression). Thus, any change in wellbeing attributable to WGS would not be detected using EQ-5D. While the chance of obtaining a diagnosis was valued, other important factors include: length of time to get results; secondary findings; health-related information for other family members; and contribution to future research from having the test. Using the economic instrument of willingness to pay, which provides a monetary measure of value, respondents were willing to pay between £200 and £2000 for WGS. Our results support the need to go beyond diagnostic yield and EQ-5D when valuing WGS, and to more appropriately assess the user perspective. This project on 'Should Scotland provide whole genomic sequencing for diagnosis of rare disorders?' will be the focus of our future research.
Outcome and Translation
A key outcome of this project was to develop a grant application to the Scottish Government to take this work forward, conducting a cost-effectiveness and cost-benefit analysis of WGS in Scotland.
External Collaborators: Professor Zofia Miedzybrodzka and Dr Lynne Mennie (Medical Genetics, University of Aberdeen)
Ryan, M., McKenzie, L., Mennie, L. and Miedzybrodzka, Z. (2019) Valuing whole genome sequencing to improve diagnosis of rare disorders: a health economic perspective. Report to Scottish Genomics Partnership.