Measuring professional competency of public health nurses: development of a scale and psychometric evaluation

AIMS AND OBJECTIVES: To develop an instrument to measure public health nurse competencies in Taiwan and to test its psychometric properties. BACKGROUND: Core competencies for public health nursing practice have been established in the USA and elsewhere but no equivalent studies have been undertaken in Taiwan. DESIGN: Postal survey of self-administered questionnaire to 1534 full-time public health nurses (response rate 67.3%). METHODS: The Public Health Nurse Professional Competency Scale was based on a literature review, the six key competencies identified by the Taiwan Nurses Association and the 'typical' tasks reported by nursing researchers. The scale comprised four domains and 38 items using a four-point Likert scale. Validity and reliability of the scale were determined by a seven-member professional panel and the content validity calculated for each domain. Discriminatory power and the item-total correlation index were used to analyse and eliminate items. Convergent and discriminant validity were assessed and factor analysis to test the dimensions of the scale--stability was determined by interscale correlations, internal and test-retest reliability. RESULTS: The mean age of respondents was 40.6 years (SD 8.54) with the majority holding an associate degree (67.0%). Participants had worked for an average of 11.7 years (SD 9.20) and 74.4% held a registered nurse license. The scale had strong content validity (Indices > 0.8) and good test-retest reliability (Cronbach's α = 0.93-0.97). Nine items were excluded during factor analysis and three factors accounted for 46-82% of the total variance: (1) basic-care, (2) community health management and (3) combined teaching and self-development competencies. The scale had high discriminant validity. CONCLUSIONS: A Public Health Nurse Professional Competency Scale has been developed and shown to have good reliability and validity. RELEVANCE TO CLINICAL PRACTICE: The scale can be used to assess the competencies of Public Health Nurses in Taiwan and improve the quality of clinical services provided.