SELF-ASSESSMENT OF TUBERCULIN SKIN-TEST REACTIONS BY NEW-YORK-CITY FIREFIGHTERS - RELIABILITY AND COST-EFFECTIVENESS IN AN OCCUPATIONAL-HEALTH CARE SETTING

Objective: To determine whether self-assessment of purified protein de rivative of tuberculin (PPD) skin test reactions, done using a simple two-choice approach, is an effective screening method for tuberculosis . Design: Double-blind comparison between self-assessments and trained professional readings of PPD skin test reactions, done 72 hours after test administration. Setting: The New York City Fire Department's Bur eau of Health Services Participants: 2011 New York City firefighters a nd fire officers were given PPD skin tests during a mandatory retraini ng course. Thirty-seven persons were excluded because of a history of a positive PPD skin test result or a bacille Calmette-Guerin vaccinati on. All others agreed to participate in testing and self-assessment do ne using simple written instructions, Self-assessment results were sub mitted lust before trained professional readings were done. Measuremen ts: Self-assessments and trained professional readings of PPD skin tes t reactions. Results: 1833 participants (98%) interpreted their-test r eactions as flat. Of these interpretations, 1824 (99.5%) matched the p rofessional reading and 9 (0.5%) did nor. One hundred seventy-eight pa rticipants (9%) interpreted their test reactions as not flat; 136 of t hese interpretations (76.4%) matched the professional reading and 42 ( 23.6%) did not (k = 0.828; lower 95% confidence limit = 0.790). The pr edictive value of a negative self-assessment reading was 99.5%, and th e specificity was 97.7%. Conclusion: In this occupational health care setting, we follow (and recommend to others with similar populations) a tuberculin screening program based on self-assessment. Repeated test s with follow-up are required for all persons who do not report their results. All persons with self-assessments of ''not flat'' should retu rn for readings by trained professionals, counseling, and treatment.