Randomized Controlled Trials for Geriatric Hip Fracture Are Rare and Underpowered

Abstract

Background: Geriatric hip fracture is a common condition, and there are many open questions regarding patient management. Among the various types of medical evidence, the prospective randomized controlled trial (RCT) is considered the best. Our primary hypothesis was that small sample size would be seen frequently among RCTs involving geriatric patients with hip fracture. A related hypothesis was that studies from the United States would have particularly large deficits in sample size. Therefore, we asked the following research questions: (1) What is the mean sample size of RCTs involving geriatric patients with hip fracture? (2) How do sample sizes for studies from the U.S. differ from those performed elsewhere? Methods: Following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines, a systematic review of hip fracture RCTs was conducted. The Embase and MEDLINE databases were searched. Additional data included the country of origin, the power of the study, and whether sample size calculations were performed. One hundred and forty-seven RCTs were identified. Results: The mean sample size of the 147 RCTs was 134.9. The mean sample size for the 7 American trials was 110.3, and the mean sample size for all trials conducted outside of the United States was 136.1. A sample size that was sufficient to ensure 80% power was used in only 31.3% of the RCTs. Conclusions: RCTs for hip fracture are small and underpowered. Moreover, <5% of the RCT studies have been conducted in the U.S., and they were smaller than those conducted elsewhere. The shortage of American trials may be a feature of the dispersion of geriatric hip fracture care across many hospitals in the United States. If so, better clinical research might require more centralized care (e.g., in specialized geriatric hip fracture centers) or greater collaboration among the many hospitals that provide care.

The Importance of Pragmatic Study Design to the Scholarly Influence of Surgical Hip Fracture Randomized Controlled Trials

“…This finding is in accordance with the call to publish higher quality studies with larger sample size in orthopaedic trauma. 8,16,33 Interestingly, having a more pragmatic study design and reporting a significant primary outcome were not associated with increased scholarly influence. The PRECIS-2 tool was developed to help quantify the level of pragmatism in a given trial.…”

“…18 Measurement of clinical impact of RCTs can be difficult and can only be done adequately using a national fracture registry. The low number of hip fracture RCTs in the United States 33 and the absence of a US national fracture registry 34 increase this difficulty. To circumvent this difficulty, in this study, we chose to assess whether the RCTs were used for scholarly influence and not assess whether this influence was impactful.…”

Is the Revision Rate for Femoral Neck Fracture Lower for Total Hip Arthroplasty Than for Hemiarthroplasty?

“…Our inclusion and exclusion criteria could be applied to future RCTs. However, given the difficulty and expense of performing adequately powered RCTs 67 and the reliability of registry data 53 , these studies may not be necessary before standard practice evolves. Nested RCTs utilizing registry data may be the best study design.…”

Is arthroplaSty bEtter than interNal fixation for undiSplaced femoral nEck fracture? A national pragmatic RCT: the SENSE trial

“…Therefore, we should conduct larger RCTs as hip fracture RCTs, in general, are small and underpowered. 14 In addition, external validity is often a problem in traditional RCTs, because an inclusion rate as little as 7% was seen in the FAITH Study 15 thereby questioning whether hip fracture trials exclude too many patients. 16 A pragmatic RCT design includes a larger proportion of the eligible patients due to fewer exclusion criteria and could, therefore, be a better choice to test an intervention in everyday clinical setting.…”