Designing and psychometric evaluation of safe nursing care instrument in intensive care units

Providing safe care in a sensitive and high-risk unit such as the ICU is one of the most crucial tasks for nurses. One way to establish the criteria for safe care is by creating a instrument to assess it. Therefore, this study was conducted with the aim of designing and psychometrically evaluating an instrument for safe nursing care in the ICU.

The current study employed a sequential-exploratory mixed-method approach with two qualitative and quantitative phases. Based on the results of qualitative phase and the literature review, the primary instrument was designed. In the quantitative phase, the designed instrument underwent psychometric evaluation. Face, content and construct validity were assessed. Face validity was assessed by 20 nurses, and content validity was assessed by 26 experts. In the construct validity stage, the sample size for the exploratory factor analysis (EFA) included 300 nurses, and for the confirmatory factor analysis (CFA) included 200 nurses who work full-time in the ICUs of hospitals affiliated with Kermanshah University of Medical Sciences in western Iran. EFA sampling was conducted in three hospitals, encompassing six ICUs, while CFA sampling was carried out in two hospitals, covering four ICUs. Sampling was done using the convenience method. The reliability of the instrument was also assessed. Finally, the interpretability, feasibility, weighting, and scoring of the instrument were evaluated.

The qualitative phase identified three themes, including professional behavior (with categories: Implementation of policies, organizing communication, professional ethics), holistic care (with categories: systematic care, comprehensive care of all systems), and safety-oriented organization (with categories: human resource management and safe environment). The primary instrument was designed with 107 items rated on a five-point Likert scale. In the quantitative phase, the psychometrics of the instrument were conducted. First, the face and content validity were assessed, and the average scale content validity index (S-CVI) was 0.94. Then, a preliminary test was conducted to assess the initial reliability (α = 0.92) and the correlation of each item with the total score. After completing these steps, the number of items in the instrument was reduced to 52. The results of the EFA explained 58% of the total variance, with 4 factors identified: professional behavior by following guidelines, comprehensive care, accurate documentation, and pressure ulcer care. At the CFA stage, the results of the calculation of indices and goodness of fit showed that the model had a good fit. The reliability of the relative stability by examining the intraclass correlation coefficient (ICC) for the whole instrument in 20 samples was 0.92 with a confidence interval of 0.97 - 0.81. To measure absolute stability and determine the responsiveness of the instrument, the standard error of measurement (SEM) was 4.39 and the minimum detectable change (MDC) was 12.13.

The instrument for safe nursing care in the ICU has favorable psychometric properties.