Development and Psychometric Properties of the Occupational Health Service Competency Scale of Nurses Working at Thai Primary Care Units

The purposes of this study were to develop and examine the psychometric properties of the Occupational Health Service Competency Scale for nurses working at Thai primary care units. The conceptual definition and content domains of the instrument were developed through a comprehensive literature review and in-depth interviews. Spencer's competency concept and the Basic Occupational Health Service activity model were used to guide the research. Content validity was examined by a panel of five experts, and pre-testing of internal consistency was determined by 30 nurses working at primary care units. After a pilot test, the psychometric properties of the instrument were examined by distributing a mailed questionnaire to 750 nurses working in randomly selected Thai primary care units; 68.1% of these were returned. The Occupational Health Service Competency Scale is composed of three dimensions: occupational health service knowledge, occupational health service skills, and occupational health service traits. Exploratory factor analysis identified 14 subscales distributed among 120 items using a five-point Likert scale. Each subscale accounted for greater than 60% of the total variance. Cronbach's alpha coefficients for the subscales ranged from 0.81 to 0.96. Test-retest analysis of the overall scale was relatively stable over a two week period (r = 0.76, p =.01). Based on these analyses, the newly-developed Scale demonstrates sound psychometric properties and can be used to assess the occupational health service competencies of nurses working at primary care units. Results can be used to plan professional development and human resources management related to occupational health services.