LAUSR

A meta‐analysis by Guan et al. compared the surgical outcomes of patients with hip fracture between surgery done during daytime and after-hours [1]. The study found that outcomes of after‐hours surgery for hip fracture were favorable, and were even better when considering outcomes such as surgical complications and length of hospitalization. However, we have the following concerns: First, Guan and his colleagues did not sufficiently clarify the potential influence of heterogeneous adjusted confounders in the included cohort studies. Several studies did not adjust for such confounding factors [2, 3]. Furthermore, the authors failed to account for the influence of different types of surgery on the overall result. Though little statistical heterogeneity was found in the synthesis results, quality and certainty of the produced evidence should be further evaluated since some level of heterogeneity in clinical or methodological characteristics existed in included studies. Second, the findings of the study may not apply in other countries. In their meta‐analysis, only one study originated from developing country if Hong Kong was excluded. It is likely that they did not search for published studies in the local databases of developing countries. Actually, doctors from Chinese mainland commonly undertake heavy medical tasks especially in tertiary hospitals. Sudden deaths among Chinese physicians have escalated in the past few years which might be associated with high workload [4]. Thus, after‐hours surgery might be common in Chinese hospitals, as well as some other developing countries. However, the authors did not discuss whether such a conclusion was appropriate for developing countries, although they pointed out that after‐hours operation had a positive impact on the financial burden in developing countries. Lastly, though Guan and his colleagues concluded that after-hours surgery was safe and recommended for expedited treatment of patients with hip fracture, actually, there were some difficulties when solving the research question about the difference in surgical outcomes between daytime and after-hours surgery. One is the uncertainty of time from injury to surgery [5]. Though operations performed in the early period after onset of injury could be beneficial to patients, neglect or misestimation of the time from injury to admission made the estimated effect of after-hours surgery blurry. Additionally, confounders like surgeon fatigue, emotional factors, and level of medical care in hospitals were hard to measure especially in retrospective studies which may also influence the interpretation of the research question. Based on these concerns, the results of Guan and his colleagues should be interpreted more cautiously.