2025/05/12 by Elnè Noppè, Aoife Lavelle · 1 voice · 1 citation
Medicine · #Cardiac, Anesthesia and Surgical Outcomes #Frailty in Older Adults #Hip and Femur Fractures
paper · pdf · doi:10.1111/anae.16639
We read with interest the article by Takahashi et al., who conducted the first systematic review and meta-analysis evaluating the association between subjective functional capacity and postoperative outcomes in non-cardiac surgery [1]. While cardiopulmonary exercise testing is the gold standard for objective functional capacity assessment, funding for staff and equipment limits its availability and, thus, necessitates subjective assessments, especially in resource-limited settings. This meta-analysis offers valuable insights into peri-operative risk stratification based on subjective functional capacity, supporting existing recommendations. The authors acknowledge limitations in generalisability for mortality outcomes given high heterogeneity (I2 = 81%). However, the moderate heterogeneity in postoperative complications (I2 = 42%) also warrants cautious interpretation, especially considering the difficulty in assessing publication bias based on asymmetrical funnel plots. We were interested in the reason for not performing a subgroup analysis, as this might have helped clarify these differences. Could the authors comment on any limitations or considerations that led to this decision? The meta-analysis included studies using various subjective functional capacity assessment methods, with five studies not having a defined assessment method. Not all subjective measures of functional capacity accurately correlate with metabolic equivalents (METs), and not all predict postoperative complications. The METS study showed that only the Duke Activity Status Index correlated with the primary outcome of death or myocardial infarction [2]. The authors report that METs were estimated using guidelines in the absence of quantitative methods and that “the ability to climb stairs was considered ≥ 4 METs”. However, this assumption is flawed, as climbing two flights of stairs without stopping or experiencing limiting symptoms is equated to approximately 4 METs but supporting data for this are limited. This approach also does not account for the speed of ascension, the number of stairs in a ‘flight’ and stair width, all of which may impact the predictive value of this assessment [3]. The threshold of 4 METs is used traditionally to distinguish between poor and good functional capacity. However, continuing advances in surgical and anaesthetic techniques may see risk thresholds decrease over time [4]. Takahashi et al. highlight the importance of other risk predictors, especially frailty, in addition to oxygen supply–demand matching. Tools like the FRAIL (fatigue, resistance, ambulation, illness and weight loss) and Clinical Frailty Scale have shown predictive value in assessing peri-operative risk independent of traditional cardiopulmonary measures. Studies have shown that frailty is linked to higher rates of postoperative complications, longer hospital stays and increased mortality [5]. This indicates the need for a more detailed risk assessment approach and additional research on other established factors influencing outcomes. The meta-analysis by Takahashi et al. strengthens the case for subjective functional capacity assessment. High variability in the incidence of mortality and postoperative complications, the lowering risk threshold for defining poor functional capacity and the recognition of other important predictors of peri-operative outcomes highlight the need for further research and validated risk-scoring tools that consider more than just functional capacity.