Latent structure of the Davis Interpersonal Reactivity Index in methadone maintenance patients

The latent structure of Davis's 28-item Interpersonal Reactivity Index (IRI) measure of empathy was examined in 241 methadone maintenance (MM) patients using factor analytic procedures and the divergent and convergent reliability of the derived structure was determined. Contrary to the four-factor structure determined for the IRI previously, three factors, comprised of 18 items, were found to best represent the construct of empathy in MM patients-an Empathy factor (nine items) combining the Empathic Concern and Perspective Taking factors originally described by Davis, and Fantasy (four items) and Personal Distress (five) factors. Canonical correlation analysis undertaken to determine concurrent validity of the IRI's revealed latent structure supported the validity of the derived Empathy factor as a measure of empathy, but indicated that Personal Distress appeared to be associated with neuroticism. These findings are consistent with more recent factor analytic and validity findings for the IRI.