Determinants of Cervical Cancer Screening Accuracy for Visual Inspection with Acetic Acid (VIA) and Lugol's Iodine (VILI) Performed by Nurse and Physician

PLoS One. 2017 Jan 20;12(1):e0170631. doi: 10.1371/journal.pone.0170631. eCollection 2017.


Background: Visual inspection with acetic acid (VIA) and Lugol's iodine (VILI) are used to screen women for cervical cancer in low-resource settings. Little is known about correlates of their diagnostic accuracy by healthcare provider. We examined determinants of VIA and VILI screening accuracy by examiner in a cross-sectional screening study of 1528 women aged 30 years or older in a suburb of Kinshasa, Democratic Republic of Congo.

Methods: We used a logistic regression model for sensitivity and specificity to estimate the diagnostic accuracy of VIA and VILI, independently performed by nurse and physician, as a function of sociodemographic and reproductive health characteristics.

Results: Nurses rated tests as positive more often than physicians (36.3% vs 30.2% for VIA, 26.2% vs 25.2% for VILI). Women's age was the most important determinant of performance. It was inversely associated with sensitivity (nurse's VIA: p<0.001, nurse's VILI: p = 0.018, physician's VIA: p = 0.005, physician's VILI: p = 0.006) but positively associated with specificity (all four combinations: p<0.001). Increasing parity adversely affected sensitivity and specificity, but the effects on sensitivity were significant for nurses only. The screening performance of physician's assessment was significantly better than the nurse's (difference in sensitivity: VIA = 13%, VILI = 16%; difference in specificity: VIA = 6%, VILI = 1%).

Conclusions: Age and parity influence the performance of visual tests for cervical cancer screening. Proper training of local healthcare providers in the conduct of these tests should take into account these factors for improved performance of VIA and VILI in detecting cervical precancerous lesions among women in limited-resource settings.

MeSH terms

  • Acetic Acid / therapeutic use*
  • Adult
  • Democratic Republic of the Congo
  • Early Detection of Cancer / methods*
  • Female
  • Humans
  • Iodides / therapeutic use*
  • Middle Aged
  • Nurses / statistics & numerical data
  • Physicians / statistics & numerical data
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Uterine Cervical Neoplasms / diagnosis*
  • Vaginal Smears / methods*


  • Iodides
  • Acetic Acid
  • Lugol's solution

Grants and funding

Financial support for the Congo Cervical Screening Study was provided by the Program for Appropriate Technology in Health (PATH) (Grant to Ghislain Sangwa-Lugoma), an International Agency for Research on Cancer Postdoctoral Fellowship (to Ghislain Sangwa-Lugoma), and by the Cancer Research Society Division of Epidemiology.