Secular trends in osteoporosis prevalence at first presentation over 26 years in a regional Irish DEXA registry: a retrospective repeated cross-sectional analysis.

UNLABELLED: Declining osteoporosis prevalence at first DEXA presentation over 26 years in a regional Irish registry suggests improving baseline skeletal health independent of demographic shifts. If sustained, these trends may temper projected fracture burden, with implications for prevention strategies and health-system planning.

PURPOSE: Despite decades of investment in fracture prevention and growing clinical awareness of osteoporosis, whether the skeletal health of individuals presenting for assessment has actually improved remains unknown. We investigated secular trends in osteoporosis prevalence at first presentation using a regional Irish DEXA registry spanning 26 years.

METHODS

In a retrospective repeated cross-sectional analysis, we examined all DEXA scans performed between January 1998 and December 2024 at two hospitals serving the Midwest region of Ireland, restricting analyses to each individual's first scan to minimise treatment and surveillance bias. Osteoporosis was defined as a T-score of - 2.5 or lower at the total hip or lumbar spine. Logistic regression assessed calendar year as the exposure and osteoporosis as the outcome, adjusted for age and sex. Direct age standardisation and 3-year moving averages were used to stabilise annual estimates.

RESULTS

Among 66,681 individuals undergoing a first DEXA scan (80.7% female), osteoporosis prevalence declined substantially. Hip osteoporosis fell from 19 to 7% and lumbar spine osteoporosis from 30 to 8% between 1998 and 2024. Each calendar year was associated with a 4.0% reduction in odds of hip osteoporosis (OR 0.960, 95% CI 0.957-0.964) and a 4.8% reduction in lumbar spine osteoporosis (OR 0.952, 0.949-0.955). These findings persisted after age standardisation and adjustment for scan volume.

CONCLUSION

Osteoporosis prevalence at first presentation declined by approximately two-thirds over nearly three decades, pointing to a meaningful improvement in skeletal health at the point of clinical assessment, with potential implications for future fracture burden projections.