Measuring the Latent Tuberculosis Infection Care Cascade Using Electronic Health Record Data from Primary Care Clinics in the Tuberculosis Epidemiologic Studies Consortium-III

ImportanceTuberculosis (TB) was the leading infectious cause of death worldwide in 2023. Most US TB cases represent reactivation of latent TB infection (LTBI). Because LTBI treatment is approximately 90% effective for preventing TB disease, LTBI screening and treatment are primary strategies for US TB elimination. The Tuberculosis Epidemiologic Studies Consortium-III (TBESC-III) supports US TB elimination efforts by addressing LTBI among individuals at higher risk of infection seeking care in US primary care clinics. ObjectiveTo characterize and measure outcomes across a longitudinal LTBI care cascade, from proportion of persons at higher risk through testing, diagnosis, and treatment. DesignLongitudinal study using patient-level electronic health record (EHR) data. SettingPrimary care clinics serving at least 10,000 non-US-born individuals annually from countries with high TB disease incidence rates (defined as [≥]10 cases per 100,000 persons among expatriates living in the US). ParticipantsPersons at higher risk of TB infection, defined as non-US birth or, if unknown, a non-English language preference, who had a visit during the study period at a participating clinic. Intervention(s) (for clinical trials) or Exposure(s) (for observational studies)Not relevant Main Outcome(s) and Measure(s)Among participants without prior TB or LTBI testing, diagnosis, or treatment documented (ie, cascade eligible), we determined proportions: tested for TB infection, with available test results, with positive results, chest imaging ordered, LTBI diagnoses, and with LTBI treatment prescribed, started, and completed. Percentages were averaged across four sites representing multiple clinics. ResultsOf 3.5 million persons seeking care, on average, 48% were at higher risk of TB infection, and 69% of these were cascade eligible. Among cascade eligible individuals, 14% were tested; 92% of those tested had available results, with 17% testing positive. Of those testing positive, 82% underwent chest imaging; 70% met LTBI diagnostic criteria. Among those diagnosed, 61% were prescribed treatment; 87% started treatment, with 56% completing treatment. Conclusions and RelevanceAlthough an average of 17% of participants tested had TB infection, most (average, 86%) higher-risk individuals were not tested; an average of 39% of those diagnosed were not prescribed treatment, and nearly half (average, 44%) did not complete treatment. Targeted interventions to increase LTBI testing and treatment completion among higher-risk individuals could facilitate more preventive treatment and reductions in TB-associated morbidity.