Comparability of telephone and face-to-face interviews in assessing patients with posttraumatic stress disorder
Mohamed A Aziz1, Susan Kenford
1University of Cincinnati and Cincinnati VA Medical Center, OH, USA.
Introduction:
Structured clinical interviews are very important in the area of mental health research and services. Prior research comparing the reliability and validity of face-to-face and phone interviews has found high levels of agreement. This project compared the results of face-to-face and phone interviews for two widely used measures: The Clinician-Administered PTSD Scale (CAPS) for assessing posttraumatic stress disorder diagnostic status and symptom severity and the Hamilton Rating Scale for Depression (Ham-D) to determine the severity of major depressive disorder.
Method:
Subjects were 34 veterans recruited from applicants to the PTSD Assessment and Intervention program at the Cincinnati VA Medical Center. Order of interview (in-person or phone) was determined using random assignment within a counterbalanced framework. After attaining satisfactory levels of interrater reliability, four clinicians independently and blindly evaluated the subjects.
Results:
Pearson correlation coefficients between face-to-face and phone interviews revealed high consistency (CAPS r = 0.745, HAM-D r = 0.748). The level of agreement between the two methods was 82% for the CAPS and 85% for the HAM-D. Diagnostic thresholds for the CAPS and HAM-D, after adjusting for the interview order and time elapsed between interviews, did not differ between the two groups (p = 0.31 for the CAPS and p = 0.96 for the HAM-D). High levels of agreement were achieved between the two methods (kappa = 0.75 for the CAPS using a cutoff of 65 and 0.70 for the HAM-D). The high sensitivity, specificity, and predictive values support the reliability of the phone-interview method.
Conclusion:
Phone interviews are a reliable method of interviewing for use in assessing patients for posttraumatic stress disorder and major depressive disorder.
