Development and psychometric validation of a protection motivation scale for screening following needlestick injuries among Chinese nurses

To develop the Nurses’ Motivation for Screening Protection after Needlestick Injuries Scale (NMSP-NSI) based on protection motivation theory (PMT) and to conduct a preliminary evaluation of its psychometric properties. The scale is intended to assess nurses’ protection motivation toward post-injury screening and inform the development of occupational safety interventions. The initial item pool was generated through a literature review, semi-structured interviews, and two rounds of Delphi expert consultation. A cross-sectional survey was conducted among 431 clinical nurses recruited using purposive sampling. Item analysis was performed using the full sample, which was then randomly divided into subsample A ( n = 215) for exploratory factor analysis and subsample B ( n = 216) for confirmatory factor analysis. Seventy-seven nurses completed a second assessment after two weeks for the evaluation of test–retest reliability. Content validity was assessed using content validity indices. The final NMSP-NSI comprised 24 items across six dimensions: perceived susceptibility, perceived severity, fear arousal, response efficacy, response costs, and self-efficacy. Exploratory factor analysis identified six common factors that explained 75.176% of the total variance. The confirmatory factor analysis produced mixed fit indices, with a CFI and IFI of 0.903, an RMR of 0.038, an SRMR of 0.063, and an RMSEA of 0.105, providing preliminary support for the six-factor structure. Composite reliability ranged from 0.851 to 0.959, and the average variance extracted ranged from 0.590 to 0.855. The Fornell–Larcker criterion supported discriminant validity for most construct pairs, although response efficacy and response costs were at the criterion boundary. Cronbach’s α was 0.955 for the overall scale. The Spearman–Brown and Guttman split-half coefficients were 0.771 and 0.736, respectively, and the two-week test–retest reliability coefficient was 0.936. The item-level content validity index ranged from 0.93 to 1.00, and the scale-level content validity index based on the average method was 0.97. The NMSP-NSI demonstrated stable reliability and generally acceptable preliminary evidence of validity. It may be used to assess nurses’ protection motivation toward screening after needlestick injuries and identify relative weaknesses across its dimensions, thereby informing occupational safety education and screening process optimization. The stability of its factor structure and the distinction between response efficacy and response costs require further examination in independent samples.