Appropriateness of Tuberculin Skin Testing (TST) at Yale New Haven Hospital (YNHH): The Good, the Bad, and the Ugly

Background: Identifying persons with latent TB (LTB) who may benefit from prophylaxis is an important part of TB control. TST is usually done in outpatient area, but hospital admissions may be an important venue in urban hospitals that are likely to see patients in the CDC’s TB risk groups. In 2009, 18 patients at YNHH were diagnosed with TB disease; the New Haven TB case rate is more than double that of the US (8.7/100,000 population vs. 3.8/100,000 respectively). Objective: Determine what proportion of adult medical, surgical YNHH admissions are candidates for TST, TST placed, TST results, prophylaxis started. Methods: Prospective 3-month chart review of patients >18yo admitted to non-ICU medicine and surgery units. Patient demographics, presence of TB risk factors as per CDC, time to TST placement, TST results and interventions were collected. Chi square analysis was used to determine if patients with certain risk factors were more likely to get a TST. Results: Patients fell into 4 groups: 1) TST indicated by CDC guidelines and done; 2) TST indicated and not done; 3) TST not indicated but done and 4) TST not indicated and not done. Of 760 patients in the study, 545 were eligible for TST placement: 112 patients had only 1 risk factor, 215 patients had 2 risk factors, and 218 patients > 2 risk factors. Patients with the following risk factors were significantly more likely to have a TST placed: HIV/AIDS, contact with MTB, IDU, incarceration, rapid weight loss. Patients without the following risk factors were significantly more likely to have a TST placed compared to patients with these risk factors: age greater than 35, malignancy, poorly controlled diabetes, and connective tissue disorders. Of the 545 patients eligible for TST placement, only 78 (14%) underwent TST and 39 (18%) patients did not meet criteria for TST but had one placed. TST frequency p-value between both groups was 1.73. Of the 117 TSTs placed, 30 were positive (22 in patients who met TST criteria). 10 patients started treatment (8 among TST eligible patients). Conclusions: Screening patients on admission for LTB risk factors finds many who should be considered for TST (71% in our study) particularly if their admission is expected to be at least 48 hours. This approach offers multiple advantages:1) identify persons with LTB who are eligible for prophylaxis and decrease the risk of future TB disease and transmission; 2) lessens the chance of non-compliance with TST; 3) standardizes the TST process and documentation; 4) allows multi-disciplinary care and patient education. Integration of TB prevention into basic patient assessment requires: 1) increased provider awareness of TB risk factors and prophylactic measures; 2) prompts, preferably automated, for TB risk factor screening and ordering TST at hospital admission; 3) monitoring appropriateness of TSTs with clinician feedback to clinicians. ?? ?? ?? ?? 1