Main Outcome Measures Sensitivity, specificity, positive and negative predictive values of the questionnaire, and odds ratio (OR) of reactive skin test results.
Results The NYCDOH questionnaire identified 413 children (14%) as having at least 1 risk factor. Of these, 23 (5.6%) had a positive skin test result; 4 (0.16%) of the 2507 without risk factors had a positive result. Results for the full NYCDOH questionnaire were sensitivity, 85.2%; specificity, 86.0%; negative predictive value, 99.8%; positive predictive value, 5.4%; and OR, 35.2 (95% confidence interval, 12.1-102.4).
Conclusion The NYCDOH questionnaire is a valid instrument for identifying children for tuberculin skin testing.
Surveillance strategies for the prevention of tuberculosis (TB) in children have alternated between universal screening and targeted screening based on epidemiological risk. Between 1985 and 1992, there was a reported recrudescence of TB that accounted for a 35% increase in the number of cases involving children.1- 5 In response, universal Mantoux skin testing using purified protein derivative (PPD) of tuberculin of all children was advocated by several authorities, including the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP).6- 8
A decline in the prevalence of TB in the mid-1990s coincided with published reports indicating that universal tuberculin screening of all children was a costly and inefficient use of limited health care resources.9,10 In February 1996, the AAP's Committee on Infectious Diseases issued updated guidelines that supported focusing tuberculin skin testing on children who are at increased risk of acquiring TB.11 In July 1996, the New York City Department of Health (NYCDOH) also revised its TB screening policy to allow for targeted screening.12 Both the AAP and NYCDOH identified similar epidemiological risk factors for TB infection in the pediatric population, including (1) close contact with an active case of TB; (2) birth in or travel to an endemic region; (3) close contact with high-risk adults, including those with prolonged incarceration, human immunodeficiency virus (HIV) infection, homelessness, and intravenous drug use; and (4) HIV infection. Recently, targeted tuberculin screening based on similar risk categories has been endorsed by a joint statement of the American Thoracic Society, the CDC, and the Infectious Diseases Society of America.13 Although the risk categories were based on current knowledge, no formal analysis of the validity of this approach has been reported. To our knowledge, no other risk assessment categories have been developed and validated.
When any strategy is adopted for targeted screening, an essential question emerges: Are the risk assessment questions used to identify the need for a test both sensitive and specific? The present study was designed to determine the sensitivity, specificity, and predictive validity of the NYCDOH risk assessment questions used to assess the need for a tuberculin skin test.