Skip to main content

Table 4 Comparative values: conventional versus LCA model results

From: Visual inspection with acetic acid as a cervical cancer test: accuracy validated using latent class analysis

Reference standard Disease prevalence (± SE) Test positive Sensitivity (± SE) (*) Specificity (± SE)
1. Colposcopy/Biopsy LGSIL+ 0.233
(0.009)
VIA Abnormal, CA 0.640 (0.022) 0.671 (0.012)
   Pap LGSIL + 0.298 (0.021) 0.923 (0.007)
   HPV >= 1.0 RLU 0.649 (0.022) 0.638 (0.012)
2. Colposcopy/Biopsy HGSIL+ 0.096
(0.006)
VIA Abnormal, CA 0.775 (0.030) 0.639 (0.011)
   Pap LGSIL + 0.445 (0.035) 0.905 (0.007)
   HPV >= 1.0 RLU 0.800 (0.028) 0.613 (0.011)
3. LCA disease derived from Trichotomous (†) VIA, Pap, HPV, including colposcopy/biopsy: 2 class solution 0.302
(0.028)
VIA Abnormal, CA 0.637 0.701
   Pap LGSIL + 0.417 0.997
   HPV >= 1.0 RLU 0.973 0.807
   Colposcopy/Biopsy LGSIL+ (‡) 0.442 0.857
   Colposcopy/Biopsy HGSIL+ 0.251 0.970
4. LCA disease derived from Trichotomous (†) VIA, Pap, HPV, including colposcopy/biopsy: 3 class solution 0.118 (§)
(0.022)
VIA Abnormal, CA 0.744 0.568
   Pap LGSIL+ 0.560 0.820
   HPV >= 1.0 RLU 0.972 0.568
   Colposcopy/Biopsy LGSIL+ 0.926 0.758
   Colposcopy/Biopsy HGSIL+ 0.632 0.860
  1. (*) Standard errors (SE) are not given for the LCA-derived sensitivity and specificity estimates because some of these estimates are themselves calculated from combinations of conditional probabilities, which have individual maximum-likelihood estimated (MLE) standard errors. The MLE standard errors for these component conditional probabilities are given in Figures 1 and 2, in parentheses.
  2. (†) Trichotomous response codes are used to define the latent classes, but results are re-interpreted dichotomously in order to calculate sensitivity and specificity estimates.
  3. (‡) Results are given for Colposcopy/Biopsy with a low threshold (LGSIL+ is test positive, as it would be for Pap smears), and also with a high threshold (HGSIL+) as the latter is the threshold at which the gold standard for VIA testing is usually set when using the traditional formula.
  4. (§) Prevalence of class 3 (disease) in a 3-class model; all other LCA prevalence estimates are from 2-class models.