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

Background

People with intellectual disabilities (ID) suffer higher rates of major osteoporotic fracture (MOF), including hip fracture (HF), at younger ages than the general population. We compared the cost-effectiveness of alternative fracture risk assessment strategies for people with ID aged ≥40 years from a UK National Health Services perspective over a lifetime horizon.

Methods

Three strategies were assessed: (S1) Risk assessment using the standard (QFracture) score at current policy thresholds; (S2) Use of a novel, tailored IDFracture risk score for all; and (S3) Conducting a one-time dual-energy X-ray absorptiometry (DXA) scan in all. S1 and S2 were followed by DXA scan for those at risk. At-risk individuals received recommended interventions. A decision-analytical model incorporated data from literature and national databases to calculate discounted direct healthcare costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). Sensitivity and subgroup analyses were conducted.

Results

In the base-case, S2 (ICER: −£2,568/QALY) was dominant (i.e. less costly and more effective) and S3 (ICER: £1,678/QALY) was cost-effective relative to S1 for MOF. For HF, S2 (ICER: £32,116/QALY) and S3 (ICER: £49,536/QALY) were not cost-effective relative to S1 under the NICE-recommended cost-effectiveness thresholds. Findings from the sensitivity analyses were predominantly consistent with the base-case results. Subgroup analyses showed that age- and gender-specific strategies could be used.

Conclusions

For people with ID aged ≥40 years, a proactive approach to risk assessment for MOF is not only clinically beneficial, but also cost-effective.

PLAIN ENGLISH SUMMARY

People with intellectual disabilities (ID) are at higher risk of fracture, particularly hip fracture, due at least partly to thinning of the bones (osteoporosis). These fractures carry huge costs in human terms, and to the NHS. Finding better ways of preventing them is essential. In this study, we aimed to determine which of three risk assessment strategies is the most cost-effective at preventing fractures in these individuals.

The first strategy was the currently recommended approach, involving risk assessment in all women from age 65 and men from 75 years, or younger in those with a risk factor for osteoporosis. ID itself is not recognised as a risk factor in current guidelines. The second involved using IDFracture in people with ID at or above 40 years, followed by a bone density (DXA) scan for those found to be at risk. The third strategy involved a single DXA in those aged 40 years or over. In each strategy, preventive treatment would be offered if needed, based on the DXA result.

We found that the most cost-effective way of identifying people with risk above the intervention threshold of 10% over ten years for major osteoporotic fracture at age 40-79 years is to perform a DXA. The most cost-effective way of identifying people with risk above the intervention thresholds of 3% over ten years for hip fracture at age 40-79 years is to use QFracture and perform a DXA in those at risk. However, different strategies may be needed for different age and gender subgroups.