Comparing two pre-operative anxiety scales for predicting postoperative pain in ambulatory surgery: Data from a multicentre observational study.

BACKGROUND

Pre-operative anxiety is present in most day surgery patients and is associated with increased postoperative pain. However, most anaesthetists do not objectively evaluate pre-operative anxiety. Both Surgical Fear Questionnaire (SFQ) and Anxiety Numeric Rating Scale (ANRS) are tools that can be used for standardised anxiety assessment.

OBJECTIVE

To compare the SFQ and ANRS in assessing pre-operative anxiety and predicting postoperative pain; to identify predictive factors for high pre-operative anxiety.

STUDY

DESIGN

Secondary analysis of a multicentre prospective observational study.

SETTING

Three Portuguese ambulatory surgery units.PATIENTS Two hundred and ninety-six patients underwent open inguinal hernia repair between September 2018 and March 2020.

INTERVENTION: Patients were assessed for pre-operative anxiety using the SFQ and ANRS before surgery. Postoperative evaluations were conducted at 24 h, 7 days, 3 months and 1 year.

MAIN OUTCOME MEASURES: Pre-operative anxiety and postoperative pain, Global Surgery Recovery Index and patient satisfaction.

RESULTS

Two hundred and fifty-four patients completed the 12-month follow-up, with 260 men and 31 women analysed. The mean pre-operative SFQ score was 21.6 ± 15.8, with cutoffs of 20/24 for predicting acute/chronic pain. The mean pre-operative ANRS score was 3.7 ± 2.5, with an optimal cutoff of 4. Patients with SFQ at least 21 had worse postoperative outcomes at all time points (P < 0.03). The SFQ could predict pain at least 4 at all analysed time points while the ANRS could only predict pain 1 year after surgery. Independent predictors of high pre-operative anxiety included younger age, female sex, BMI less than 30 and pre-operative pain score at least 4.

CONCLUSION

Pre-operative anxiety evaluation allows for the identification of patients at a high risk for postoperative complications. Both instruments demonstrated some ability to predict postoperative pain and might be valuable in the pre-operative setting, with the SFQ showing better performance.

TRIAL REGISTRATION: NCT03499730.