Excess mortality following a first and subsequent osteoporotic fracture: a Danish nationwide register-based cohort study on the mediating effects of comorbidities

Prediction of imminent osteoporotic fracture risk in Danish postmenopausal women-can the addition of self-reported clinical risk factors improve the prediction of the register-based FREM algorithm?

Obtaining accurate self-reports on clinical risk factors, such as parental hip fracture or alcohol and tobacco use, limits the utility of conventional risk scores for fracture risk. We demonstrate that fracture-risk prediction based on administrative health data alone performs equally to prediction based on self-reported clinical risk factors.

BACKGROUND

Accurate assessment of fracture risk is crucial. Unlike established risk prediction tools that rely on patient recall, the Fracture Risk Evaluation Model (FREM) utilises register data to estimate the risk of major osteoporotic fracture (MOF). We investigated whether adding self-reported clinical risk factors for osteoporosis to the FREM algorithm improved the prediction of 1-year fracture risk by comparing three approaches: the FREM algorithm (FREMorig), clinical risk factors (CRFonly), and FREM combined with clinical risk factors (FREM-CRF).

METHOD

Clinical risk factor information was obtained through questionnaires sent to women aged 65-80 years living in the Region of Southern Denmark in 2010, who participated in the Risk-stratified Osteoporosis Strategy Evaluation study. Register data was obtained through national health registers and linked to the survey data. Positive and negative predictive values and concordance statistics were calculated for the performance of each approach using logistic regression and Cox proportional hazards models.

RESULTS

Of the 18,605 women included, 280 sustained a MOF within 1 year. All three approaches performed similarly in 1-year fracture risk prediction for low- and high-risk individuals. However, the FREMorig and FREM-CRF approach slightly overestimated fracture risk for medium-risk individuals.

CONCLUSION

Adding self-reported clinical data to FREM did not increase precision in predicting 1-year MOF risk. The discrimination of FREMorig was similar to that of CRFonly, suggesting it may be possible to estimate fracture risk with the same precision by using register data instead of self-reported risk information. Register-based prediction models may be applicable in individualised risk monitoring or large-scale osteoporosis screening programmes.

Increased Mortality After Lower Extremity Amputation in a Danish Nationwide Cohort: The Mediating Role of Postoperative Complications

Objective

Patients who undergo major lower extremity amputation (MLEA) have the highest postoperative mortality among orthopedic patient groups. The comorbidity profile for MLEA patients is often extensive and associated with elevated postoperative mortality. This study primarily aimed to investigate the increased short- and long-term mortality following first and subsequent major lower extremity amputation. Secondarily, to examine the mediation role of post-amputation complications.

Study Design and Setting

With data from the Danish National Patient Registry, 11,695 first-time MLEAs in patients aged ≥50 years were identified between January 1, 2010, and December 31, 2021, along with 58,466 unamputated persons matched 1:5 by year of birth, sex, and region of residence. Mediators were identified through diagnosis codes (ICD-10) present in 6 months following MLEA.

Results

The increased mortality following MLEA was highest in the month following MLEA, hazard ratio (HR) 38.7 (95% confidence interval (CI) 30.5-48.9) in women and HR 55.7 (CI 44.3-70.2) in men compared to a matched unamputated cohort. Subsequent amputation resulted in an increased mortality the month after a subsequent amputation (overall HR 3.2 (CI 2.8-3.7) in women and HR 3.2 (CI 2.8-3.6) in men) and almost normalized after the first year. The proportion of the mortality risk that potentially could be reduced by preventing sepsis was 16% (CI 11.7-20.3) for women and 17% (CI 13.4-20.4) for men. For pneumonia, it was 10.5% (CI 7.1-13.9) in women and 14.9% (11.6-18.2) in men.

Conclusion

We observed an increased mortality in the month following MLEA, which remained elevated for years compared to the matched unamputated cohort. A subsequent amputation results in increased mortality in the following year, but declined and normalized after the first year. Sepsis and pneumonia arising after the amputation appeared to be important factors that contributed to the increased postoperative mortality.

Association of systemic inflammation response index with mortality risk in older patients with hip fracture: a 10-year retrospective cohort study

Objective

With a rapidly aging global population, the assessment of mortality risk following hip fracture in older adults has received increasing attention. Recently, the system inflammation response index (SIRI) has been identified as a novel prognostic marker to reflect both systemic inflammation and immune status. However, it is not yet known whether SIRI is a potential predictor of subsequent death in hip fracture patients. Therefore, this study aimed to investigate the association between SIRI and mortality in older patients with hip fracture.

Methods

A total of 1,206 older hip fracture patients undergoing surgery between January 2013 and December 2022 were consecutively derived from our longitudinal database. Patients were divided into three groups according to SIRI tertiles, calculated as neutrophil × monocyte / lymphocyte. Survival status was obtained from medical records or telephone interviews, and the study outcome was all-cause mortality after hip fracture at the longest follow-up. Multivariate Cox proportional hazard model and restricted cubic spline (RCS) regression model were used to evaluate the association between SIRI and mortality. Moreover, a series of sensitivity analyses were conducted to further validate the robustness of the association.

Results

During a median follow-up of 43.85 months, 337 patients (27.94%) died. After full adjustment, each unit increase in SIRI was significantly associated with a 2.2% increase in overall mortality (95% confidence interval [CI]: 1.001-1.042, p = 0.029). Similarly, compared with the first tertile of SIRI, the second and third tertile showed a 1.335-fold (95% CI: 1.011-1.762, p = 0.042) and 1.447-fold (95% CI, 1.093-1.917, p = 0.010) higher risk of death. Sensitivity analyses confirmed the stability of the association. Moreover, RCS analysis revealed a positive non-linear relationship between SIRI and mortality (P for nonlinearity = 0.021).

Conclusion

High SIRI level at admission was significantly and positively associated with an increased risk of death, suggesting that SIRI may be an independent predictor of mortality in older patients with hip fracture.

Ten-year follow-up of fracture risk in a systematic population-based screening program: the risk-stratified osteoporosis strategy evaluation (ROSE) randomised trial

Background

Osteoporotic fractures pose a growing public health concern. Osteoporosis is underdiagnosed and undertreated, highlighting the necessity of systematic screening programs. We aimed to evaluate the effectiveness of a two-step population-based osteoporotic screening program.

Methods

This ten-year follow-up of the Risk-stratified Osteoporosis Strategy Evaluation (ROSE) randomized trial tested the effectiveness of a screening program utilizing the Fracture Risk Assessment Tool (FRAX) for major osteoporotic fractures (MOF) to select women for dual-energy x-ray absorptiometry (DXA) scan following standard osteoporosis treatment. Women residing in the Region of Southern Denmark, aged 65-80, were randomised (single masked) into a screening or a control group by a computer program prior to inclusion and subsequently approached with a mailed questionnaire. Based on the questionnaire data, women in the screening group with a FRAX value ≥15% were invited for DXA scanning. The primary outcome was MOF derived from nationwide registers. ClinicalTrials.gov: NCT01388244, status: Completed.

Findings

All randomised women were included February 4, 2010-January 8, 2011, the same day as approached to participate. During follow-up, 7355 MOFs were observed. No differences in incidences of MOF were identified, comparing the 17,072 women in the screening group with the 17,157 controls in the intention-to-treat analysis (IRR 1.01, 0.95; 1.06). However, per-protocol, women DXA-scanned exhibited a 14% lower incidence of MOF (IRR 0.86, 0.78; 0.94) than controls with a FRAX value ≥15%. Similar trends were observed for hip fractures, all fractures, and mortality.

Interpretation

While the ROSE program had no overall effect on osteoporotic fracture incidence or mortality it showed a preventive effect for women at moderate to high risk who underwent DXA scans. Hence the overall effect might have been diluted by those who were not at an intervention level threshold risk or those who did not show up for DXA. Using self-administered questionnaires as screening tools may be inefficient for systematic screening due to the low and differential screening uptake.

Funding

INTERREG and the Region of Southern Denmark.