Response to Letter to the Editor Regarding the Article Entitled ‘The Safety of Spinal Surgery in Patients over 80 Years of Age: Propensity Score Matching Study’ by Bang C et al

I would like to thank Yabin liu, BS et al for their interest in my research. Firstly, as the author mentioned, many studies have reported that spinal anesthesia is superior to general anesthesia,^1,2 but since all the surgeries analyzed in this study were performed under general anesthesia, anesthetic technique cannot be considered as a confounding variable. Secondly, we did not analyze the anesthetic agent. However, this study was conducted at a single institution, and we do not think there will be a big difference in anesthesia methods, given the relatively short period (January 2016 to December 2021) and the elderly (over 65 years old) who underwent spinal surgery in common. Nevertheless, if we focus on postoperative delirium, it would be good to add this item to future studies. Lastly, we wanted to emphasize the safety of spinal surgery in patients over 80 years of age. In this regard, although postoperative delirium was more common in the older patient group, it was all a transient symptom and we did not consider it a dangerous complication, so we did not analyze the drugs or indicators that caused postoperative delirium. In addition, although it is known that postoperative delirium is more dangerous with age,^3-5 we think there are limitations in analyzing it in the complex pathophysiology of elderly patients. In fact, the paper cited by the author only targeted patients over 75 years of age and acknowledged that there are limitations in diagnosis due to the complexity of delirium. ⁶ Of course, we think it would be more interesting if these items were included in future studies.

In conclusion, I do not think that further research in terms of anesthesia and the thoughts on delirium-related drugs are very relevant to the message that this study is trying to convey. However, I think that if future research considers these items, it will be a meaningful study in many ways.