Psychometric Properties of Scales Assessing Psychosocial Determinants of Staff Compliance with Surgical Site Infection Prevention: The WACH-Study

Purpose: Psychosocial determinants influence healthcare workers' compliance with surgical site infection (SSI) preventive interventions. In order to design needs-based interventions promoting compliance, such determinants must first be assessed using valid and reliable questionnaire scales. To compare professional groups without bias, the scales must also be measurement-equivalent. We examine the validity/reliability and measurement equivalence of four scales using data from physicians and nurses from outside the university sector. Additionally, we explore associations with self-reported SSI preventive compliance. Participants and Methods: N = 90 physicians and N = 193 nurses (response rate: 31.5%) from nine general/visceral or orthopedic/ trauma surgery departments in six non-university hospitals in Germany participated. A written questionnaire was used to assess the compliance with SSI preventive interventions and the determinants of compliance based on the Capability-Opportunity-Motivation- Behavior-Model. Psychometric testing involved single- and multiple-group confirmatory factor analyses, and explorative analyses used t-tests and multiple linear regression. Results: The scales assessing individual determinants of compliance (capability, motivation, and planning) were found to be reliable (each Cronbach's alpha >= 0.85) and valid (each Root-Mean-Square-Error of Approximation <= 0.065, each Comparative-Fit-Index = 0.95) and revealed measurement equivalence for physicians and nurses. The scale assessing external determinants (opportunity) did not demonstrate validity, reliability, or measurement equivalence. Group differences were found neither in compliance (p = 0.627) nor determinants (p = 0.192; p = 0.866; p = 0.964). Capability ((3 = 0.301) and planning ((3 = 0.201) showed associations with compliance for nurses only. Conclusion: The scales assessing motivation, capability, and planning regarding SSI preventive compliance provided reliable and valid scores for physicians and nurses in surgery. Measurement equivalence allows group comparisons of scale means to be interpreted without bias.