TNF and tuberculosis: Although many factors are associated with increased risk of progression to active TB disease in the literature (eg, use of tumor necrosis factor alpha inhibitors),2,28 we were only able to include variables that could be extracted from our EHR databases and have high enough prevalence to be meaningfully included in this analysis; for example, we did not include persons who have been exposed to tumor necrosis factor alpha inhibitors, as in the 20-year period included in this analysis, we found only 24 persons with active TB who had been prescribed a tumor necrosis factor alpha inhibitor.