The cumulative risk of tuberculin skin test conversion for five years of hospital employment.

We studied tuberculin skin test conversions in a cohort of 550 new employees followed for five years after assignment to adult inpatient services at Charity Hospital at New Orleans, Louisiana. There were 17 known conversions, an overall five-year cumulative probability of converting of 5.2 per cent. Proportional hazards regression analysis found that race and type of job (nursing vs other) were independent explanatory variables. To examine further the job effect, we compared the conversion curves for Blacks in nursing and Blacks in other jobs and found those in nursing to have higher rates.