Validation of the Bluebelle Wound Healing Questionnaire for assessment of surgical-site infection in closed primary wounds after hospital discharge

Background: Accurate assessment of surgical-site infection (SSI) is crucial for surveillance and research. Self-reporting patient measures are needed because current SSI tools are limited for assessing patients after leaving hospital. The Bluebelle Wound Healing Questionnaire (WHQ) was developed for patient or observer completion; this study tested its acceptability, scale structure, reliability and validity in patients with closed primary wounds after abdominal surgery. Methods: Patients completed the WHQ (self-assessment) within 30 days after leaving hospital and returned it by post. Healthcare professionals completed the WHQ (observer assessment) by telephone or face-to-face. Questionnaire response rates and patient acceptability were assessed. Factor analysis and Cronbach's α examined scale structure and internal consistency. Test–retest and self- versus observer reliability assessments were performed. Sensitivity and specificity for SSI discrimination against a face-to-face reference diagnosis (using Centers for Disease Control and Prevention criteria) were examined. Results: Some 561 of 792 self-assessments (70·8 per cent) and 597 of 791 observer assessments (75·5 per cent) were completed, with few missing data or problems reported. Data supported a single-scale structure with strong internal consistency (α greater than 0·8). Reliability between test–retest and self- versus observer assessments was good (κ 0·6 or above for the majority of items). Sensitivity and specificity for SSI discrimination was high (area under the receiver operating characteristic (ROC) curve 0·91). Conclusion: The Bluebelle WHQ is acceptable, reliable and valid with a single-scale structure for postdischarge patient or observer assessment of SSI in closed primary wounds.