Gout Linked to Higher Fracture Rates, Less Bone-Protective Therapy
Key Takeaways
- Among patients with gout in American College of Rheumatology registry–Medicare matched comparisons, nonvertebral osteoporotic fracture incidence was higher than among patients with either osteoarthritis or soft-tissue rheumatism.
- For the gout–osteoarthritis comparison, the authors report baseline fracture prevalence of 1.4% versus 2.6% and osteoporosis-diagnosis prevalence of 7.1% versus 15.4%, respectively.
- Baseline bone-protective therapy use was lower among patients with gout in both matched comparisons.
- During follow-up, bone-protective therapy use remained lower among patients with gout in both comparisons.
In a recent study, investigators retrospectively linked the American College of Rheumatology's Rheumatology Informatics System for Effectiveness (RISE) registry to Medicare claims from 2015–2021. They matched patients with gout separately 1:1 to patients with osteoarthritis or soft-tissue rheumatism by age within two years, sex, race, and enrollment quarter. Investigators assessed fracture incidence, baseline osteoporosis diagnoses, bone-protective therapy, and medication and laboratory information. They calculated crude and adjusted fracture incidence rates and incidence-rate ratios (IRRs), reporting confidence intervals (CIs) for the ratios. Matching did not allocate patients to an intervention.
Incident nonvertebral osteoporotic fracture rates were higher among patients with gout in both matched comparisons. The gout-versus-osteoarthritis IRR was 1.4 (95% CI 1.1–1.8); the gout-versus-soft-tissue-rheumatism IRR was 2.0 (95% CI 1.3–3.1). These estimates compare incidence rates rather than giving an individual's absolute fracture risk. In the separately matched gout–osteoarthritis groups, baseline bone-protective therapy use was 5% versus 11.8%, respectively.
In the gout–soft-tissue-rheumatism match, baseline bone-protective therapy use was 9% versus 23.2%, respectively. During follow-up, therapy use was 2% versus 4.5% in the gout–osteoarthritis groups and 3.4% versus 10.3% in the gout–soft-tissue-rheumatism groups. Each pair refers to its own matched comparison, with the gout group listed first. The follow-up figures describe therapy use during that period, rather than treatment in response to a fracture.
Retrospective, separately matched comparisons cannot establish that gout caused the higher fracture incidence. The authors also identified more chronic kidney disease and glucocorticoid use among patients with gout; those observed risk-factor differences are not proven explanations for the fracture-rate differences. Likewise, less frequent bone-protective therapy use does not establish that treatment was appropriate for every untreated individual. The comparisons describe group-level patterns, not the clinical basis for each treatment decision.
Researchers concluded that patients with gout had greater osteoporotic fracture rates and a greater burden of fracture risk factors than the comparator groups, yet received bone-protective therapy less often. Their conclusion concerns the observed differences between matched groups.
Clinician Questions
Which patients were excluded from the gout fracture comparisons with osteoarthritis and soft-tissue rheumatism?
Investigators included eligible people in the registry–Medicare gout comparisons after exclusions; examples included inconsistent age or sex information and immunomodulation during the baseline period.
Was DXA utilization quantified for patients with gout in the Medicare-linked comparisons?
The gout-versus-osteoarthritis and gout-versus-soft-tissue-rheumatism comparisons included dual-energy x-ray absorptiometry (DXA) utilization as an objective. Although 74.4% of both gout and OA cohorts met recommendations for DXA screening, only 10.5% of gout patients vs 14.1% with OA underwent DXA at the index date.