Daily Low-Dose Aspirin and Risk of Serious Falls and Fractures in Healthy Older People:
A Substudy of the ASPREE Randomized Clinical Trial
Strengths
Barker et al. (2022) performed a longitudinal study over four years to determine whether fracture risk decreased in patients placed on 100mg daily aspirin. This allowed them to capture meaningful differences in risk over time (as any treatment-induced bone density loss would have to accumulate over time to increase fracture risk; further, fall risks can increase at certain times of the year – such as the wet season in Australia).
The large sample of 16,703 subjects provided more than enough statistical power while minimising outlier impact.
The narrow sample (White Australians) can be seen as a strength because it likely reduced overall confounding and more clearly captured differences due to treatment rather than potentially impactful ethnic differences in bone remodeling or renal function (Jorgetti, dos Reis and Ott, 2014; Kuipers et al., 2015), or even socioeconomic status and associated behaviour.
General Weaknesses
For measuring the effect of aspirin on bone fracture risk, the failure of the researchers to measure bone density is a significant weakness, regardless of the narrowness of the sample.
In regard to identifying increased risk of ‘serious’ falls (incidence rate ratio: 1.17; 95% CI: 1.031.33; P = 0.01), the authors fail to investigate further or discuss how this did not increase the incidence of bone fractures. Curiously, Barker et al. pool the data into one category, ‘with/without fracture’ (2022, p. E3).
Critical Weakness
Crucially, Barker et al. define ‘serious’ falls as those resulting in ‘fall-related hospital presentations’ (2022, p. E1). Evidently, the authors failed to consider that elderly patients
(median age 74) on antiplatelets versus placebo would be more likely to bleed/bruise and thus present more to the hospital. Indeed, low-dose aspirin users have been observed seeking medical advice over bruising (Bhatt, 2021). This is the only coherent explanation for how ‘serious’ falls could have increased without impacting bone fracture rates.
References
Barker, A.L. et al. (2022) ‘Daily Low-Dose Aspirin and Risk of Serious Falls and Fractures in Healthy Older People: A Substudy of the ASPREE Randomized Clinical Trial.’ JAMA Internal Medicine. doi: 10.1001/jamainternmed.2022.5028.
Bhatt, D.L. (2021) Aspirin and bruising, Harvard Health https://www.health.harvard.edu/heart-health/aspirin-and-bruising (Accessed: 17 November 2022).
Jorgetti, V., dos Reis, L.M. and Ott, S.M. (2014) ‘Ethnic differences in bone and mineral metabolism in healthy people and patients with CKD’, Kidney International, 85(6), pp. 1283–1289. doi: 10.1038/ki.2013.443.
Kuipers, A.L. et al. (2015) ‘Renal Function and Bone Loss in a Cohort of Afro-Caribbean Men’, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research, 30(12), pp. 2215–2220. doi: 10.1002/jbmr.2562.
End of Assignment