Cochrane in CORR®: Interventions for Improving Mobility After Hip Fracture Surgery in Adults

Importance of the Topic

One recent estimate found that more than 14 million people experience a hip fracture every year. The fallout of these personally and economically devastating injuries is 2.9 million person-years lived disability [1], and a five- to eightfold increase in the risk of death within 3 months of the fracture [4]. Surgical management, which facilitates early mobilization and faster recovery, is the recommended treatment for hip fractures for patients who are well enough to endure the procedure [2]. However, it is estimated that only 40% to 60% of individuals with hip fracture achieve their previous fracture mobility levels, and the 1-year mortality rate is approximately 30% [2]. Given the severe impact of hip fractures on mobility and the associated negative health consequences, interventions aiming to increase mobility are essential.

Mobility interventions usually are initiated shortly after hip fracture surgery. Some of the postoperative mobility interventions include various types of exercise (such as balance and resistance exercises), gait retraining, electrical stimulation of lower extremity muscles, or general physical activity. The overall objectives of these interventions are to facilitate functional recovery, regain functional independence, and simultaneously limiting adverse events (like refracture or nonunion). These interventions are delivered as a part of in-hospital postoperative care, and they are extended to posthospital settings such as nursing homes, residential care units, and at-home care.

The Cochrane review of interest here analyzed the existing evidence on the effectiveness of interventions aimed to improve mobility after hip fracture surgery [3]. As an update to the previously published review from 2011 [5], the authors screened 3459 records and identified 21 new trials that met the eligibility criteria in addition to the previously included 19 trials on this topic. The authors made recommendations by pooling the interventions’ effects and appraising the risk of bias of the 40 trials, which included more than 4000 participants.

Upon Closer Inspection

The studies they analyzed included all kinds of hip fractures, mainly came from developed countries: North America (n = 8), Europe (n = 15), Australia (n = 9), and Asia (n = 4), and, not surprisingly, enrolled mostly women (80% [3247 of 4059]). The in-hospital treatments that were evaluated varied widely, but they generally consisted of gait training, balance, resistance exercise, and, after discharge, other interventions the authors considered included endurance exercise, telephone and other kinds of coaching, and an activity-enhancing program.

Mobility interventions (including gait, balance, or functional training) delivered in-hospital compared with usual care led to a moderate improvement in mobility (defined as lower extremity functioning such as sit to stand) with moderate certainty of evidence (standardized mean difference 0.57 [95% CI 0.07 to 1.06]; p = 0.02). By contrast, only a small improvement was seen for walking speed, and overall, the aggregate benefits of these interventions were unclear regarding function and quality-of-life outcomes. No substantial differences were found for short-term mortality, adverse events, return to prefracture living residence, and resistance exercise.

After hospital discharge, the review found small improvements in mobility from gait and balance training or functional training; on this endpoint, evidence certainty was high. When multiple types of exercise were combined (multicomponent), this delivered large increases in mobility, and this was supported by moderate-quality evidence. Resistance training appeared to make no difference, the effect of endurance training was unclear, no clinically important differences were seen in terms of functional outcomes scores or quality of life, nor were differences convincingly found in terms of mortality. Interestingly, mobility interventions—particularly gait, balance, or functional tasks—reduced the number of falls, but they did not decrease the number of patients who had more than one fall.

A key point for clinicians is to try to determine whether the patients in the studies we read apply to our own practices. When doing so with respect to this Cochrane review, we note that most of the trials excluded participants with cognitive disorders, which on the surface, appears to limit the applicability of the findings. However, subgroup analyses of trials using this criterion showed no difference in effect, and so we believe that in this instance, the main findings of this Cochrane review probably do apply to the subset of patients with cognitive disorders, provided that they can comply with the interventions in question.

Additionally, adherence to interventions was reported in less than half of the included trials, and trials differed in the constituents of usual care, which also vary across practice settings and over time. For this reason, if there is an intervention from a particular trial that a reader wishes to employ, it’s worth looking carefully at the comparator or control groups in that trial to see how similar they are to the reader’s own practice pattern and whether adherence was reported.

Finally, the main types of bias observed here, which affected studies on in-hospital mobility interventions more than postdischarge interventions, were a lack of blinding of participants and outcome assessors (n = 38 trials) and incomplete data (n =16 trials with high risk of bias). In general, those types of bias will tend to make the intervention being studied look more effective than it is, and readers should consider this when evaluating the effect sizes of individual interventions.

Take-home Messages

Based on this large Cochrane review, we recommend in-hospital exercise interventions targeted to improve gait, balance, and function, but we suggest avoiding resistance exercise, which did not appear to produce a major effect. After hospital discharge, a large effect was seen for multicomponent exercise with moderate certainty of evidence [6, 7]. We recommend against the use of gait, balance, and functional exercises in isolation, as this resulted in small effects, but their combination with other interventions could result in larger effects. The evidence for resistance exercise was only based on one study and, therefore, further studies are needed to make recommendations.

Based on these findings, overall, we recommend focusing on improving mobility outcomes (such as, sit to stand and timed up and go) over endpoints like walking speed. However, the benefits observed for both mobility and walking speed were larger than the minimum clinically important difference for those endpoints, and so these differences may have been perceptible to patients.

Further research is required to identify the impact of mobility interventions on long-term patient-reported and economic outcomes. Also, future studies should compare different timings of mobility interventions on outcomes of mobility and walking speed and interventions in low-income settings.