530. Risk Factors for Missed Study Visits Among Patients with a Positive Screening Test for Latent Tuberculosis Infection (LTBI)
Session: Poster Abstract Session: Latent Tuberculosis Diagnosis and Management
Thursday, October 27, 2016
Room: Poster Hall
Background: Ascertainment of active TB disease endpoints in studies of latent tuberculosis infection (LTBI) is critical. Identification of groups at risk for missed follow-up visits is important for targeting interventions to improve visit attendance.

Methods: The Tuberculosis Epidemiologic Studies Consortium is conducting a multicenter study evaluating the tuberculin skin test (TST) and 2 interferon gamma release assays (IGRAs), QuantiFERON Gold in-tube and T-SPOT TB. Patients with a positive TST or IGRA (using standard United States cut-points) enrolled in Nashville, Tennessee April 2012- June 2015 were included. Study follow-up visits were conducted in-person or by phone every 6 months for 2 years to ascertain active TB endpoints; compensation was provided. Modified Poisson Regression estimated the adjusted relative risk (aRR) of any one of 4 possible missed study visits. Generalized estimating equations accounted for multiple outcomes per individual. Variables with p<0.10 in univariate analysis were included in adjusted analyses; age, sex, and study visit number were also included. Interactions were assessed; none were significant.

Results: Among 185 persons and 597 study visits, 99 visits (17%) were missed. Those reporting Bacillus Calmette–Guérin (BCG) vaccination and current smoking were at increased risk for missed study visits; there was a trend toward increased risk of missed study visits among non-English speakers (32% Nepali, 31% Burmese, 10% Arabic) (Table 1).

Conclusion: In this population, BCG vaccination and current smoking may be predictors of missed study visits; linguistic barriers may also contribute. Interventions, such as enhanced LTBI education, targeted toward these groups may improve follow-up for future LTBI studies.

Table 1. Adjusted Model

Characteristic

N (%) or Median (Interquartile Range)

aRR (95% Confidence Interval)

Age

31 (25-43)

1.01 (0.99-1.03)

Male Sex

105 (57%)

1.33 (0.79-2.23)

Non-English Speaking

120 (65%)

2.06 (0.85-5.01)

High School/GED Education

77 (42%)

0.78 (0.36-1.67)

BCG vaccination

99 (54%)

1.80 (1.10-2.95)

Current smoker

32 (17%)

2.25 (1.29-3.92)

HIV-infection

14 (8%)

0.18 (0.02-1.42)

LTBI Treatment Offered

114 (62%)

1.17 (0.60-2.28)

Both TST and IGRA positive

119 (64%)

1.32 (0.69-2.53)

Marian Lacy, MD1, Fernanda Maruri, MPH2,3, Kristian Atchley, RN, BSN3,4, Timothy R. Sterling, MD, FIDSA2,3 and April Pettit, MD, MPH2,3, (1)Department of Internal Medicine/Pediatrics, Vanderbilt University, Nashville, TN, (2)Department of Medicine, Division of Infectious Diseases, Vanderbilt University, Nashville, TN, (3)Vanderbilt Tuberculosis Center, Vanderbilt University, Nashville, TN, (4)Nashville Metropolitan Public Health Department, Nashville, TN

Disclosures:

M. Lacy, None

F. Maruri, None

K. Atchley, None

T. R. Sterling, None

A. Pettit, None

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