Patient-reported questionnaires to preoperatively identify high-risk surgical patients.

Purpose: Low cardiorespiratory fitness (CRF) increases the risk of postoperative morbidity and mortality following major surgery. Assessing CRF preoperatively, by measuring peak oxygen uptake (VO) during cardiopulmonary exercise testing (CPET), is valuable yet not widely available. This study aimed to assess whether questionnaires could be used preoperatively to identify high-risk surgical patients.

Methods: Healthy participants and patients who underwent CPET completed the FitMáx, Duke Activity Status Index (DASI), the modified 4-questions DASI (M-DASI-4Q), Veterans-Specific Activity Questionnaire (VSAQ), and Metabolic Equivalents of Task (MET) questionnaire. Questionnaire-VO was compared with CPET-VO. Overall performance of the questionnaires was assessed by the area under the curve (AUC) of receiver operating characteristic (ROC) curves. Furthermore, corresponding to the Youden index or pre-specified levels, sensitivity, specificity, and predictive values were determined.

Results: In total, 361 participants were included. All questionnaires showed high AUC values to identify high-risk patients, defined on the basis of CPET-VO thresholds. FitMáx and VSAQ demonstrated superior results compared to the other questionnaires. Based on the Youden index, the optimal questionnaire-VO cut-off values were 20.6, 21.3, and 26.1 ml·kg·min for the FitMáx and 16.3, 18.2, and 20.4 ml·kg·min for the VSAQ corresponding to the VO thresholds 16.0, 18.2 and 24.5 ml·kg·min respectively.

Conclusion: The ability to identify high-risk surgical patients preoperatively (defined by the CPET-VO thresholds) by the FitMáx and the VSAQ indicates that they could be used to identify high-risk surgical patients. Patients with a poor predicted VO ≤ 21.3 and ≤ 18.2 ml·kg·min, respectively for FitMáx and VSAQ, should be referred to formal preoperative (cardiopulmonary) exercise testing.

Trial Registration: The study was registered as NL-OMON23304 in the Overview of Medical Research in the Netherlands, retrospectively at 28-04-2020.