Developing and validating the Earthquake-Related Crush Syndrome Knowledge Scale using tetrachoric and Rasch analyses

A substantial proportion of earthquake-related fatalities result from severe trauma at the time of the event and entrapment under debris. Prolonged compression significantly increases the risk of developing crush syndrome, which is considered a critical determinant of mortality and morbidity. This study aimed to develop and evaluate a scale designed to assess pediatric surgical nurses' knowledge of earthquake-related crush syndrome.

This methodological study was conducted between August and September 2023. The sample consisted of 77 pediatric surgical nurses working in pediatric surgery units of a city hospital who voluntarily participated in the study. Data were collected using a data collection form and a draft 30-item version of the scale. Content and construct validity were assessed to validate the instrument. Tetrachoric factor analysis was used to examine construct validity. Reliability was evaluated using the Kuder-Richardson Formula 20 coefficient and the person reliability coefficient. Rasch analysis was performed to assess item difficulty and discrimination.

The Content Validity Index for the Earthquake-Related Crush Syndrome Knowledge Scale was 0.99. Tetrachoric factor analysis revealed two subdimensions comprising nine items. Goodness-of-fit indices for the confirmatory two-factor model indicated an acceptable to excellent fit. The Kuder-Richardson Formula 20 reliability coefficients were 0.90 for Factor 1 and 0.88 for Factor 2. According to Rasch analysis, the scale demonstrated a two-subdimension structure comprising seven items, with factor loadings ranging from 0.59 to 0.90; the factors were interrelated. In the Rasch model, the person reliability coefficient was 0.433, indicating low reliability. The mean absolute deviation of Q3 residual correlations (MADaQ3), used to assess model fit, was 0.116, while the information-weighted fit (infit) and outlier-sensitive fit (outfit) statistics were within the acceptable range (0.5-1.5).

Preliminary findings suggest that the scale demonstrates acceptable validity and reliability for assessing pediatric surgical nurses' knowledge of earthquake-related crush syndrome.