Skip to main content

Table 3 Factors associated with positive IGRA results

From: Decreased annual risk of tuberculosis infection in South Korean healthcare workers using interferon-gamma release assay between 1986 and 2005

  IGRA Total Univariable Multivariable
  Negative Positive OR 95% CI p OR 95% CI p
Age N (%) N (%)   1.096 1.086 1.107  < 0.001     
 20–29 780 (93.4) 55 (6.6) 835 1     1    
 30–39 774 (85.6) 130 (14.4) 904 2.259 1.612 3.166  < 0.001 2.25 1.593 3.18  < 0.001
 40–49 656 (65.7) 343 (34.3) 999 7.031 5.165 9.570  < 0.001 5.95 4.282 8.268 0.0028
 50–59 220 (49.0) 229 (51.0) 449 14.013 10.023 19.591  < 0.001 10.24 7.136 14.692  < 0.001
 ≥ 60 23 (50.0) 23 (50.0) 46 13.340 7.021 25.345  < 0.001 13.3 6.637 26.655  < 0.001
Gender, male 576/2453 (23.5) 308/779 (39.5) 884 (27.4) 2.299 1.931 2.737  < 0.001 1.56 1.243 1.968  < 0.001
Finding of CXR           
 No active lung 2319 (75.0) 774 (25.0) 3093 1     1    
 Healed TB 14 (33.3) 28 (66.7) 42 6.240 3.268 11.915  < 0.001 4.39 2.175 8.86  < 0.001
Occupation           
 Administrative 212 (53.0) 188 (47.0) 400 1     1    
 Techniciana 155 (70.1) 66 (29.9) 221 0.473 0.334 0.671 0.6059 0.703 0.482 1.024 0.8625
 Health-Aidsb 642 (73.9) 227 (26.1) 869 0.447 0.348 0.575 0.9207 0.858 0.648 1.135 0.0454
 Physician 212 (73.6) 76 (26.4) 288 0.403 0.290 0.561 0.4081 0.485 0.334 0.703 0.0040
 Nurse 1232 (84.7) 223 (15.3) 1455 0.202 0.158 0.258  < 0.001 0.66 0.484 0.899 0.3822
Department           
 High-riskc 521 (85.7) 87 (14.3) 608 0.443 0.348 0.566  < .0001 0.895 0.676 1.184 0.436
 Others 1932 (73.6) 693 (26.4) 2625 1     1    
Working duration, months            
 < 12 months 326 (90.6) 34 (9.4) 360 1        
 12 to < 60 months 655 (90.7) 67 (9.3) 722 0.956 0.612 1.493  < .0001     
 60 to < 120 months 236 (84.6) 43 (15.4) 279 1.675 1.027 2.733 0.0127     
 120 to < 240 months 531 (79.6) 136 (20.4) 667 2.342 1.551 3.535 0.7556     
 240 to < 360 months 583 (60.0) 389 (40.0) 972 6.116 4.152 9.010  < 0.001     
 > 360 months 119 (51.7) 111 (48.3) 230 8.612 5.500 13.485  < 0.001     
  1. Data are presented as numbers (percentages) unless otherwise indicated
  2. HCW health care worker; LTBI latent tuberculous infection; BMI body mass index; TB tuberculosis; CXR chest X-ray; IGRA IFN-γ release assay; IQR interquartile range; CI confidence interval
  3. aTechnicians who perform radiological, laboratory and pathology testing
  4. bEmployees who provide physiotherapy and patient transfer services
  5. chigh risk department defined as those who are working at TB-related departments, such as respiratory department of ward and outpatient clinic, medical intensive care unit, emergency department, microbiology laboratory, and radiology department