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Table 1 Comparison of paired EMS-spot samples collected pre- and post-treatment

From: Spot sputum samples are at least as good as early morning samples for identifying Mycobacterium tuberculosis

  Paired pre-treatment samples (n = 1115)   Paired post-treatment samples (n = 2995)
Smear microscopy    Spot      Spot   
Negative Positive Total Negative Positive Total
EMS Negative 1 (0.1%) 33 (3.0%) 34 (3.0%)   EMS Negative 2853 (95.3%) 15 (0.5%) 2868 (95.8%)  
Positive 17 (1.5%) 1064 (95.4%) 1081 (97.0%) Positive 24 (0.8%) 103 (3.4%) 127 (4.2%)
  Total 18 (1.6%) 1097 (98.4%) 1115    Total 2887 (96.4%) 118 (3.9%) 2995
     P = 0.02       P = 0.15  
Smear grading   Agreement (both positive) 506 (47.6%)    Agreement (both positive) 71 (68.9%)  
Grading higher on EMS 409 (38.4%)   Grading higher on EMS 24 (23.3%)  
Grading higher on spot 149 (14.0%) χ2 P < 0.001 Grading higher on spot 8 (7.8%) χ2 P = 0.002
Total (where both positive) 1064   Total (where both positive) 103  
LJ culture    Spot     Spot  
Negative Positive Contaminated Total Negative Positive Contaminated Total
EMS Negative 18 (1.6%) 48 (4.3%) 10 (0.9%) 76 (6.8%) EMS Negative 2129 (71.1%) 52 (1.7%) 247 (8.2%) 2428 (81.1%)
Positive 30 (2.7%) 826 (74.1%) 61 (5.5%) 917 (82.2%) Positive 31 (1.0%) 85 (2.8%) 11 (0.4%) 127 (4.2%)
Contaminated 8 (0.7%) 91 (8.2%) 23 (2.1%) 122 (10.9%) Contaminated 268 (8.9%) 10 (0.3%) 162 (5.4%) 440 (14.7%)
  Total 56 (5.0%) 965 (86.5%) 94 (8.4%) 1115   Total 2428 (81.1%) 147 (4.9%) 420 (14.0%) 2995
      P = 0.006       P = 0.11
MGIT culture    Spot     Spot  
Negative Positive Contaminated/false positive Total Negative Positive Contaminated/false positive Total
EMS Negative 2 (0.2%) 12 (1.1%) 1 (0.1%) 15 (1.3%) EMS Negative 1979 (66.1%) 67 (2.2%) 227 (7.6%) 2273 (75.9%)
Positive 9 (0.8%) 998 (89.5%) 34 (3.0%) 1041 (93.4%) Positive 73 (2.4%) 119 (4.0%) 36 (1.2%) 228 (7.6%)
Contaminated/false positive 3 (0.3%) 49 (4.4%) 7 (0.6%) 59 (5.5%) Contaminated/false positive 288 (9.6%) 46 (1.5%) 160 (5.3%) 494 (16.5%)
  Total 14 (1.3%) 1059 (95.0%) 42 (3.8%) 1115   Total 2340 (78.1%) 232 (7.7%) 423 (14.1%) 2995
      P = 0.18       P = 0.01
  1. EMS early morning sputum sample, LJ Lowenstein–Jensen, MGIT mycobacteria growth indicator tube