Previous studies of tuberculosis screening using skin testing (TST) or interferon-gamma release assays (IGRA) suggested cost-effectiveness, but they were relying on outdated (inflated) pretest probability estimates from 1950s prevalence studies.
In fact, using a Markov model with true population prevalence of TB plugged-in, Linas et al suggest that screening for TB is not very cost-effective overall — about $100,000 per quality-adjusted life-year gained, or more ($50,000 is generally accepted as cost-effective).
In high-risk groups (HIV+, recent immigrant adults), QALYs were $50,000 or less, and authors advocate resources be dedicated toward identifying TB there. IGRA performed slightly better than TST.
The peace of mind from living in a society in which we can safely assume that very few people coughing on us have tuberculosis (which I value highly) was not included in the model.
Linas BP et al. Priorities for Screening and Treatment of Latent Tuberculosis Infection in the United States. Am J Resp Crit Care Med 2011;184:590-601.