To determine the test-retest reliability, sensitivity and specificity, and criterion-related validity of the Risk Behavior Assessment (RBA) syphilis questions. The RBA is a standardized instrument that has been used in several studies of STDs in drug users.
For the test-retest reliability study, 219 injection drug users completed the RBA twice within a 48-hour period. To determine criterion-related validity, 207 individuals, who also completed the RBA, were tested with the rapid plasma reagin test (RPR), and 206 individuals were also tested with the Serodia Treponema pallidum particle agglutination test (TP-PA).
The test-retest reliability for the question “How many times have you been told by a doctor or a nurse that you had syphilis?” was 0.78. The test-retest reliability for the question “In what year were you last treated for syphilis?” was 0.89. For the comparison of self-report with the RPR test, the sensitivity of self-report was 46.2% and the specificity was 95.7%. For the comparison of self-report with the TP-PA test, the sensitivity of self-report was 37% and the specificity was 97.7%.
Self-reports of syphilis infection history were found to have good reliability, excellent specificity, and moderate sensitivity. These characteristics need to be taken into account in any study using these self-report items.
Reliability and validity of syphilis infection self-report was assessed in samples of injection drug users and others at high-risk. Reliability was very good, specificity was excellent, but sensitivity was moderate as compared with laboratory testing.
From the *Center for Behavioral Research and Services, California State University, Long Beach, California; †Behavioral Health Research and Services, University of Alaska, Anchorage, Alaska; and the ‡Department of Health and Human Services, City of Long Beach, Long Beach, California
This research was supported in part by contract number H-700939-1 from the County of Los Angeles, Office of AIDS Programs and Policy. Further support was provided in part by contract 28569 from the City of Long Beach, California, Department of Health.
Correspondence: Dennis G. Fisher, PhD, Center for Behavioral Research and Services, 1090 Atlantic Avenue, Long Beach, CA 90813. E-mail: firstname.lastname@example.org.
Received for publication March 11, 2006, and accepted August 14, 2006.