Factors that Influence the Prevalence of Latent Tuberculosis Infection among Healthcare Workers in Thailand Open Access

Leisner, Michelle Zippora (2015)

Permanent URL: https://etd.library.emory.edu/concern/etds/9k41zd655?locale=en


Background Healthcare workers (HCWs) are at a higher risk for latent tuberculosis infection than the general population. As individual-level personal protective equipment is regularly not available, environmental factors should be understood to determine mechanisms by which the facility can affect the prevalence of infection among healthcare workers. Therefore, it is important to understand both the individual- and facility-level factors that influence the prevalence of LTBI among HCWs. The present analysis aimed to determine the association between HCW characteristics and facility-level infection control measures and the prevalence of LTBI.

Methods Data were obtained from the "Enhanced Tuberculosis Infection Control Intervention (EnTIC Trial)." 3,835 HCWs from 10 facilities in Thailand were screened for LTBI. At the time of screening, demographic information was obtained on each participant. Facility level information on demographics and infection control measures were also obtained. Bivariate analysis was performed to determine the association of individual level factors with LTBI. Multivariate analysis was utilized, first to create a best-fit individual level model, and then to further evaluate the association between facility-level variables and LTBI. Bonferroni Corrections were utilized to account for multiple-testing. Results of the analysis were reported as prevalence ratios (PRs) accompanied by the corresponding 95% confidence intervals (CIs).

Results The prevalence of LTBI was highest among HCWs aged 40-45, where the prevalence for this age group was over 2 times the prevalence of LTBI among those aged 18-24 (PR=2.13; 95%CI=1.68, 2.70, p<0.05). Duration of exposure, as evaluated by years working in the facility, hours worked per week, and years working in the current occupation were all associated with LTBI in bivariate analysis. Multivariate analysis showed that age, having respiratory hygiene posters in units, working more hours, direct patient contact and position were statistically associated with LTBI at the alpha=.05 level of significance; however, only age was statistically significant when applying Bonferroni corrections (PR=1.04, 95% CI 1.03, 1.05, p<.001).

Conclusion Age is significantly associated with the prevalence of LTBI among HCWs. Further research needs to be done on how environmental factors influence infection; the scope of an intervention that targets facility level change will have broad reach with intervention.

Table of Contents





APPENDIX I: Tables and Figures. 42

Table I: Surveys Used for Analysis to Determine Factors Influencing Prevalence of LTBI among HCWs in 10 Healthcare Facilities in Thailand. 42

Figure 1: Flowchart for recruitment, enrollment and eligibility for analytical sample of HCWs among 10 healthcare Facilities in Thailand. 43

Table II: Characteristics of Healthcare Workers Enrolled in the EnTIC Trial from 10 Healthcare Facilities in Thailand (N=3835). 44

Table III. Characteristics of Healthcare Facilities in the EnTIC Trial, Thailand (n=10). Numbers are facility mean and standard deviation (SD) unless otherwise specified. 47

Table IV. Infection Control Measurement Indicators for the 10 Facilities enrolled in the EnTIC Trial in Thailand. 48

Table V. Prevalence Ratios (PRs) and 95% confidence intervals (95% CIs) Prevalence Ratio for the bivariate association between individual level factors and LTBI for healthcare workers enrolled in the EnTIC Trial at 10 health facilities in Thailand. 50

Table VI. Analysis and Modeling, Evaluating Demographic Variables for Inclusion. 54

Table VII. Prevalence Ratios of LTBI by Duration Worked in Current Occupation, Stratified by Age. 57

Table VIII. Prevalence Ratios of LTBI by Duration Worked in all jobs, Stratified by Age. 59

Table IX. Risk Ratios for Multivariate Model Predicting Outcome of LTBI among HCWs in 10 Healthcare Facilities in Thailand, Individual Risk Factor Risk Ratios Controlling for Other Variables in the Model. 62

APPENDIX II: References. 64

Ethical Approval. 67

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