Environmental health knowledge of healthcare professionals: Instrument development and validation using the Rasch model

Introduction: environmental risk factors constitute a major public health issue, calling for preventive actions and interventions at multiple levels. An important step in this direction is increasing the environmental health (EH) knowledge of the healthcare professionals. In this context, tools designed to measure such knowledge are of imperative importance. The aim of the present study was to develop an EH knowledge tool for healthcare professionals. Methods: a group of experts defined the knowledge areas of the EH tool and their corresponding items. An online pilot and a validation study were performed. Internal consistency reliability was measured with the KuderRichardson 20 (KR-20) estimate, the construct validity and uni-dimensionality of the tool were assessed with the Rasch model. Known-groups validity was analysed with the two-sample t-test. Results: a total of n = 151 and n = 444 healthcare professionals and end-year medical and nursing students, participated in the pilot and the validation study, respectively. The resulting 33-item EH knowledge questionnaire for healthcare professionals (EHKQ-HP) obtained a KR-20 = 0.82. The scale is uni-dimensional. Its construct validity was verified, and its items cover a wide range of difficulties. Separation statistics were adequate and known-groups behaved as hypothesized. Conclusions: the EHKQ-HP is a valuable resource for measuring the EH knowledge of the healthcare professionals. As such it will be useful in detecting EH knowledge gaps, and helping public health agents in making informed decisions when developing interventions for increasing this very knowledge. This would consequently help in improving the health of the general population.