Improving Recognition of Fracture Risk in People with Human Immunodeficiency Virus: Performance and Model Contribution of Two Common Risk Assessment Tools

Abstract
Current guidelines recommend screening people with HIV (PWH) for bone disease using predictive tools developed for the general population, although data on PWH are scarce. In this study, we assessed the performance of FRAX and QFracture scoring systems to predict the occurrence of fragility fractures in a prospective cohort of 17,671 adults with human immunodeficiency virus (HIV) included in the HIV/AIDS research network (CoRIS) in Spain. The survival estimates of fragility fractures during follow-up were calculated and FRAX and QFracture scores were computed at cohort inclusion. For both tools, discriminatory measures and the observed-to-expected (O/E) ratios were assessed. During a follow-up time of 42,411.55 person-years, 113 fragility fractures were recorded. Areas under the curve were 0.66 [95% confidence interval (95% CI) 0.61–0.71] for FRAX and 0.67 (95% CI 0.62–0.73) for QFracture for major osteoporotic fractures, and 0.72 (95% CI 0.57–0.88) and 0.81 (95% CI 0.68–0.95) for hip fracture, respectively. The O/E was 1.67 for FRAX and 5.49 for QFracture for major osteoporotic fractures, and 11.23 for FRAX and 4.87 for QFracture for hip fractures. Moreover, O/E raised as the risk increased for both tools and in almost all age groups. When using the recommended assessment thresholds, <6% and 10% of major osteoporotic and hip fractures would have been identified, respectively. In conclusion, FRAX and QFracture displayed acceptable discrimination, although both tools significantly underestimated the risk of fragility fractures in PWH. The recommended assessment thresholds may not be appropriate for this population as they were unable to identify individuals with fragility fractures during follow-up.