A new study revealed that less than one-third of older adults filled prescriptions for antiosteoporosis medications within 1 year of experiencing a fragility fracture.
In the population-based, retrospective cohort study, published in JAMA Network Open, investigators analyzed data from 37,874 patients aged 66 years and older in Ontario, Canada, who were hospitalized for initial hip, vertebral, or pelvic fragility fractures between 2017 and 2021.
They used data from the Ontario Ministry of Health to identify patients with an initial fragility fracture admitted to an Ontario hospital from January 1, 2017, to December 31, 2021, and employed a validated algorithm to identify fragility fractures and linked datasets using unique identifiers.
The primary outcome of the study was time to filling a prescription for an antiosteoporosis medication (alendronate, risedronate, etidronate, zoledronic acid, denosumab, raloxifene, or teriparatide) in the 365 days following hospital discharge. Outcomes were censored at 365 days following discharge or at death. The investigators used multivariable Cox proportional hazards regression to model time to prescription fill. Analyses were performed using SAS, version 9.4 (SAS Institute). The study followed the STROBE reporting guideline and was approved by Sunnybrook Health Sciences Centre's Research Ethics Board, with informed consent waived because of the use of de-identified data.
The study cohort (N = 37,874) had a median age of 84 years (interquartile range = 77–90) and was predominantly female (69.1%, n = 26,169). Nearly half (48.0%, n = 18,170) of the patients were aged 85 years or older.
Fracture types included:
- Hip and/or femur: 80.3% (n = 30,427)
- Pelvis: 14.0% (n = 5,290)
- Vertebrae: 5.7% (n = 2,157).
Among the key findings were:
- Only 31.3% (n = 11,853) of the patients filled an antiosteoporosis drug prescription within 1 year of hospital discharge.
- Risedronate was the most commonly prescribed medication (n = 5,677).
- Factors associated with higher likelihood of filling a prescription included: female sex (hazard ratio [HR] = 1.23, 95% confidence interval [CI] = 1.17–1.28), vertebral fracture (HR = 1.30, 95% CI = 1.21–1.41), and discharge to a rehabilitation hospital (HR = 1.64, 95% CI = 1.56–1.72).
Discharge destinations varied:
- Rehabilitation hospital: 31.9% (n = 12,082)
- Home: 28.0% (n = 10,594)
- Complex continuing care: 16.8% (n = 6,354)
- Nursing home: 16.5% (n = 6,244)
- Other (including retirement homes and transitional care units): 6.9% (n = 2,600)
Additional factors associated with filling an antiosteoporosis medication prescription:
- Age 75 to 84 years (HR = 1.06, 95% CI = 1.01–1.12)
- Drug holiday (HR = 1.15, 95% CI = 1.10–1.22)
- Internal or geriatric medicine consultation during hospitalization (HR = 1.11, 95% CI = 1.06–1.15)
- 25-Hydroxyvitamin D3 level measured during hospitalization (HR = 1.40, 95% CI = 1.33–1.47)
- Bone mineral density test within 5 years of hospitalization (HR = 1.28, 95% CI = 1.23–1.34)
- Rostered to a primary care clinician (HR = 1.08, 95% CI = 1.02–1.14).
Factors associated with lower likelihood of filling a prescription:
- Age ≥ 85 years (HR = 0.84, 95% CI = 0.80–0.89)
- Rural residence (HR = 0.89, 95% CI = 0.84–0.96)
- Lower neighborhood income quintiles
- Charlson Comorbidity Index Score ≥ 2 (HR = 0.80, 95% CI = 0.70–0.91)
- Diabetes (HR = 0.95, 95% CI = 0.91–0.99)
- Pelvic fracture compared to hip/femur (HR = 0.94, 95% CI = 0.89–0.997).
The investigators noted that annual prescription rates remained stable during the study period. Admission during the COVID-19 pandemic (March 2020 to December 2021) was associated with a slightly lower likelihood of filling a prescription (HR = 0.94, 95% CI = 0.91–0.98).
Additional cohort characteristics:
- 86.4% (n = 32,585) resided in urban areas
- 86.2% (n = 32,643) were rostered to a primary care clinician
- 89.0% (n = 33,712) had a Charlson Comorbidity Index Score of 0
- 27.8% (n = 10,547) had diabetes
- 2.1% (n = 812) used glucocorticoids within 1 year of hospitalization
- 15.5% (n = 5,856) were on a drug holiday.
Prehospitalization and in-hospital care:
- 11.0% (n = 4,163) had an outpatient visit for osteoporosis within 5 years before hospitalization
- 25.0% (n = 9,466) had a bone mineral density test within 5 years of hospitalization
- 52.6% (n = 19,939) received an internal or geriatric medicine consultation during index hospitalization
- 13.1% (n = 4,980) had their 25-hydroxyvitamin D3 level measured during hospitalization.
Limitations of the study included the inability to evaluate the appropriateness of antiosteoporosis medication prescribing, confirm medication adherence beyond dispensation, and generalize findings beyond the Canadian health care system.
Conflict of interest disclosures can be found in the study.