Validation of Impact of Events Scale in nurses under threat of contagion by severe acute respiratory syndrome

The purpose of the present study was to validate the Impact of Events Scale (IES) in a sample of nurses working under threat of severe acute respiratory syndrome (SARS). The internal consistency, construct validity and convergent validity of the instrument were examined in a sample of 128 nurses during the SARS outbreak in Taiwan. Principal component analysis followed by a quartimax rotation were used to derive a two-factor solution, labeled intrusion (factor 1) and avoidance (factor 2), with both factors accounting for 50.7% of the explained variance. The total Cronbach's alpha of 0.90 reflected the good internal consistency of the instrument. Correlation with the Symptoms Checklist 90-R demonstrated the convergent validity of the IES. In conclusion, the IES can be used as a convenient, reliable and valid instrument for evaluation of the psychological distress of nurses working with the highly contagious disease.