Measurement Invariance and Latent Mean Differences in the Nurses' Emotional Labour Scale.

Background: The measurement invariance and latent mean differences in emotional labor across different hospital and monthly salary levels among registered nurses have never been confirmed for the Emotional Labour Scale. These issues may influence the application and efficacy of this scale in practice.

Purpose: This study was developed to evaluate the factor structure of the nurses' Emotional Labour Scale and to examine the measurement invariance and latent mean differences for this scale across different hospital and monthly salary levels.

Methods: Data were collected from 461 registered nurses working in four general hospitals and 12 long-term care hospitals. Confirmatory factor analysis and a multigroup confirmatory factor analysis were performed to determine the internal structure and measurement invariance of the Emotional Labour Scale.

Results: The results of the confirmatory factor analysis indicate that the factor structure model proposed by the original scale fits well with our data as well as configural invariance, factor loading invariance, intercept invariance, and uniqueness invariance. Moreover, factor variance/covariance invariance across two hospital levels as well as configural invariance, factor loading invariance, and intercept invariance across two monthly salary levels were supported. The mean score for emotional control effort in the profession of general hospital nurses was lower than that for long-term care hospital nurses. No statistically significant latent mean differences were found across monthly salary levels.

Conclusions/implications for practice: The findings show the Emotional Labour Scale to be a valid and reliable tool for assessing registered nurses and also comparing the mean score for emotional labor across hospital and monthly salary levels to be feasible. The scale may contribute to the development of human resource strategies.