Treatment patterns of long-dose-interval medication for persistent management of osteoporosis in Taiwan

Treatment Persistence and Medication Switch Associated With Subsequent Fractures After Osteoporotic Fractures

CONTEXT

Despite prevalent anti-osteoporosis medication (AOM) switching in real-world osteoporosis management, few studies have evaluated the impact of persistent AOM treatment, allowing for AOM switching, on the risk of subsequent fracture.

OBJECTIVE

We examined the association between persistence in AOM and subsequent fractures, allowing for medication switching among patients with osteoporotic fractures.

METHODS

This retrospective cohort study used Taiwan National Health Insurance claims data to select patients who initiated AOM between 2013 and 2016. Treatment persistence was defined as use of any AOM on a given day of interest with a 45-day grace period. Medication switch was allowed for persistence if remaining on treatment. AOMs with long-lasting inhibition of bone resorption (zoledronate and denosumab) were categorized as high-potency; others as low-potency. Multivariate Cox models were used to evaluate risk of subsequent fractures ≥3 months after initiating AOM.

RESULTS

A total of 119 473 patients were included (mean [SD] follow-up 46.4 [15.6] months), and 26.8% switched from the index AOM. Within 1 year, 52% remained persistent with AOM. Compared to patients with persistent AOM, those not persistent had higher risk of subsequent hip (adjusted hazard ratio [aHR] = 1.31; 95% CI, 1.21-1.42), vertebral (aHR = 1.17; 95% CI, 1.13-1.22), and radius fractures (aHR = 1.16; 95% CI, 1.08-1.25). Patients with persistent AOM who switched from high- to low-potency AOM had higher risk of subsequent vertebral fractures than those with persistent AOM and no potency switch (aHR = 1.28; 95% CI, 1.02-1.60).

CONCLUSION

Patients with non-persistent AOM had higher risk of subsequent fractures than persistent users when allowing AOM switch. Switching AOM potency may influence the risk of subsequent vertebral fractures and warrants further investigation.

The real-world adherence of the first-line anti-osteoporosis medications in Taiwan: Visualize the gap between reality and expectations

BACKGROUND

Adherence to anti-osteoporosis medications (AOMs) is crucial. National Health Insurance (NHI) in Taiwan has its own rules of reimbursement rule for AOMs. The midterm adherence remained inconclusive. Here we investigated the adherence according to the initially used AOMs, for three consecutive years.

METHODS

The nationwide cohort study from 2008 to 2018, based on Taiwan's National Health Insurance Research Database, included 336,229 patients. Their adherence, indicated by medication possession ratio (MPR), to the initial AOMs was investigated yearly for three consecutive years. The overall MPRs (OMPR), including the switched AOMs, were also calculated in the first year. The Sankey diagram further visualized the patient flows toward different adherence according to the initial AOMs.

RESULTS

The OMPR in the first year improved if the patients used AOMs with longer dosing intervals. 100%, 68.9%, 40.7%, and 34.0% of the patients started the treatment with zoledronate, denosumab, alendronate, and raloxifene, respectively, had OMPR ≥75% in the first year. In the 3rd year, only 20.89%, 24.13%, and 12.83% of the patients continuously treated with zoledronate, denosumab, and alendronate, respectively, had MPR ≥75%. From the Sankey diagram, we also observed that patients who had poor adherence at one year were inclined to have poor adherence or discontinue antiosteoporosis treatment in the next year.

CONCLUSION

The initial AOMs and the observed adherence may provide clues for optimizing patient treatment. The real-world adherence in Taiwan was far from satisfactory in our study.

Denosumab versus zoledronic acid in elderly patients after hip fracture

BACKGROUND

Two injectable anti-osteoporosis medications, denosumab and zoledronic acid, have been widely used to treat patients with severe osteoporosis. The purpose of this study was to evaluate the real-world effectiveness and adherence of denosumab compared to zoledronic acid in geriatric patients after a hip fracture.

METHODS

A total of 282 patients treated with osteoporotic hip fracture between March 2014 and Aug 2022 were retrospectively reviewed. The patients were asked to select the anti-osteoporosis medication after surgery. Treatment persistence was monitored by follow-up visit to the outpatient clinic at postoperative 2 years.

RESULTS

Of 282 individuals with baseline data, 162 patients took subcutaneous denosumab and 120 patients took intravenous zoledronic acid. At postoperative 2 years, the change in bone mineral density (BMD) from baseline was greater in the denosumab group compared with the zoledronic acid group (p < 0.001). The rate of persistence to denosumab was significantly higher than that for 12-months zoledronic acid (p = 0.01). Serious adverse events were similar in the two groups.

CONCLUSIONS

Our study revealed the effectiveness and patients' persistence for two commonly used anti-osteoporosis agents after hip fracture. In this frail, elderly population, half-yearly denosumab was superior to yearly zoledronic acid in BMD and demonstrated significant higher persistence rate, indicating a potential therapeutic advantage that warrants further validation.