Cost-effectiveness of osteoporotic fracture risk assessment in people with intellectual disabilities

Research question: What is the most cost-effective method for osteoporotic fracture risk assessment in people with intellectual disabilities?

Background Our originating study “Fractures in people with intellectual disabilities: comparison with the general population and development of a fracture risk calculator specific to these patients” (PB-PG-1216-20017), included all patients with intellectual disabilities [ID] (n= 43,176) and five age and gender matched controls without ID per patient in the Clinical Practice Research Datalink (CPRD) linked to the Hospital Episode Statistics (HES) database (1998-2017).

It included the largest cohort of people with Down s syndrome ever studied (n= 4,119).

Unpublished results showed a higher incidence rate of major osteoporotic (MOP) fractures (vertebra, shoulder, wrist, hip) and of hip fracture in adults with ID.

The difference is outstanding for hip fracture, for which incidence rate ratios (95%CI), between subjects with and without ID varied between 2.3 (1.9-2.7) and 7.8 (4.1-14.6) according to age and gender.

We developed a fracture risk score (IDFracture) estimating the 10-year risk of hip, MOP or any fracture for adults with ID 30-79-years old. Aim To determine the most cost-effective risk assessment method for osteoporotic fractures. Short-term objective To reach a policy change in assessing osteoporotic fracture risk.

Long-term objective To reduce the risk of osteoporotic fractures.

Methods We will validate the IDFracture risk scores on the Aurum database (from 23 million people) with full linkage to the HES dataset. For the cost-effectiveness analyses we will use the subset of people aged 40-79-years from the Aurum cohort. We will use a Markov model with an annual transition cycle projecting life-long incidence of fractures and death.

To estimate cost-effectiveness, the model will be run assuming several strategies: Current strategy, i.e.

NICE and National Osteoporosis Guidelines Group, using QFracture for risk score calculation Risk assessment by IDFracture in all patients at age 40-years at their yearly review, with bone mineral density scan (DXA) in those between predefined age-related risk thresholds. To perform DXA in all patients at age 40 (follow up according to result).

For each of these strategies, total lifetime costs and outcomes plus incremental cost-effectiveness ratio (ICER) will be calculated against the next most effective strategy. The main analyses will be done from the NHS perspective. The impact of fracture on health-related quality of life will be taken from the literature.

Timeline Months 1-5: regulatory approval, data management, model validation, calculation of risk score algorithms Months 3-11 Cost effectiveness analyses Months 11-12 Final report/ manuscripts writing Anticipated Impact and Dissemination We will use our links to national bodies: the National Institute for Health and Care Excellence (NICE), the Royal Colleges of Physicians, of Psychiatrists, of General Practitioners, the British Medical Association, the Society for Academic Primary Care, the Royal Mencap Society, the Down s Syndrome Association, the Royal Osteoporosis Society, the Society for Endocrinology, the Bone Research Society.

The latter three societies are part of the NICE accredited National Osteoporosis Guideline Group. All this will guarantee widespread dissemination of results, and lead to rapid clinical impact.