Strengths and Limitations
anxiety
RECRUITMENT
There are several strengths of this study. First, it adopted an RCT design, which is considered the criterion standard for evaluating the cause-and-effect relationships between interventions and outcomes. Second, to our knowledge, it was the first study to investigate VR-based interventions in a preanesthetic assessment clinic setting, providing valuable insights into its potential as a nonpharmacological approach to reducing preoperative anxiety and improving outcomes in adult patients undergoing elective surgery.There are also some limitations to be considered. First, because the 0.64 effect estimator corresponded to the standardized mean difference for different scales to measure preoperative anxiety in the previous meta-analysis and although it was adopted for sample size calculation, this could not precisely imply that a score reduction of at least 0.64 on the APAIS indicates a relevant reduction in anxiety. Furthermore, the study was conducted during the COVID-19 pandemic, and up to 50% of elective surgical procedures had been canceled or deferred. Therefore, only 74 participants were recruited, and the power of the intervention may be limited. Second, this study was conducted in a single preanesthetic assessment clinic, and the standard of care and provision of service may vary among different clinics. Also, the recruitment of mostly young participants with ASA grade I status for relatively low-risk, short duration, or less-pain-induced surgical procedures may limit the generalizability of the findings to patients aged more than 80 and 90 years or patients with higher ASA risk. Patients in different assessment clinics for different types of surgical procedures should be investigated in future studies. Third, owing to the nature of the intervention, the allocation of intervention was unable to be concealed from the participants, and those in the intervention group may have been more susceptible to performance bias by subjectively providing more positive self-reports that aligned with the perceived goals of their assigned intervention during the outcome measurement.