title: Reliability and validity of the Nurse Practitioners' Roles and Competencies Scale.
abstract: OBJECTIVE
  The objective of this study was to test the reliability and construct validity of the Nurse Practitioners' Roles and Competencies Scale.
  
  
  BACKGROUND
  The role of nurse practitioners has attracted international attention. The advanced nursing role played by nurse practitioners varies with national conditions and medical environments. To date, no suitable measurement tool has been available for assessing the roles and competencies of nurse practitioners in Asian countries.
  
  
  METHODS
  Secondary analysis of data from three studies related to nurse practitioners' role competencies.
  
  
  METHODS
  We analysed data from 563 valid questionnaires completed in three studies to identify the factor structure of the Nurse Practitioners' Roles and Competencies Scale. To this end, we performed exploratory factor analysis using principal component analysis extraction with varimax orthogonal rotation. The internal consistency reliabilities of the overall scale and its subscales were examined using Cronbach's alpha coefficient.
  
  
  RESULTS
  The scale had six factors: professionalism, direct care, clinical research, practical guidance, medical assistance, as well as leadership and reform. These factors explained 67·5% of the total variance in nurse practitioners' role competencies. Cronbach's alpha coefficient for the overall scale was 0·98, and those of its subscales ranged from 0·83-0·97.
  
  
  CONCLUSIONS
  The internal consistency reliability and construct validity of the Nurse Practitioners' Roles and Competencies Scale were good. The high internal consistency reliabilities suggest item redundancy, which should be minimised by using item response theory to enhance the applicability of this questionnaire for future academic and clinical studies.
  
  
  CONCLUSIONS
  The Nurse Practitioners' Roles and Competencies Scale can be used as a tool for assessing the roles and competencies of nurse practitioners in Taiwan. Our findings can also serve as a reference for other Asian countries to develop the nurse practitioner role.
authors.affiliation: Graduate Institute of Clinical Medical Sciences, Chang Gung University, Tao-Yuan, Taiwan.|Department of Nursing, Kuang Tien General Hospital, Taichung, Taiwan.
authors.forename: Li-Chun
authors.initials: LC
authors.lastname: Lin
authors.affiliation: Examination Yuan, R.O.C, Taichung, Taiwan.|College of Nursing, Chung-Shan Medical University, Taichung, Taiwan.
authors.forename: Sheuan
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Medicine, Chang Gung University, Taipei, Taiwan.|Chang Gung Memorial Hospital, Linkou Branch, Taipei, Taiwan.
authors.forename: Steve Wen-Neng
authors.initials: SW
authors.lastname: Ueng
authors.affiliation: Graduate Institute of Nursing, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Woung-Ru
authors.initials: WR
authors.lastname: Tang
mesh_terms: D000328:Adult; D002983:Clinical Competence; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007857:Leadership; D008297:Male; D008875:Middle Aged; D009722:Nurse Practitioners; D024802:Nurse's Role; D000068616:Professionalism; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D013624:Taiwan; D055815:Young Adult
keywords: factor analysis; nurse practitioners; reliability; role competencies; validity