Data Analysis
Summary statistics were generated for demographic variables. Summary
statistics were also generated for clinical characteristics, such as
whether the participants had been screened for cervical cancer, the
vaginal pH, the severity of the outcome among those who were screened
and tested positive on visual inspection with acetic acid (VIA), and the
cytology result of those who were VIA positive. Additionally, summary
statistics were tabulated for preferences for cervical cancer screening,
including gender preference of the provider, collection type preference
(physician or self), whether the respondents would test with
self-collection again, and whether they would recommend self-collection
to a friend. A 2-by-2 table was generated to compare self-collected
versus physician-collected specimens. From this table, performance
measures and their associated 95% confidence intervals were generated,
including sensitivity and specificity, predictive values positive and
negative, and the proportion of concordant pairs and the proportion of
concordant pairs among those pairs for which the physician-collected
sample was HPV DNA testing.
Acceptability measures included: how well cared for respondents felt;
how well the respondents’ privacy was handled during the tests; the
extent to which respondents felt embarrassed during the test; whether
the test caused the respondents genital discomfort; and whether the test
caused the respondents genital pain.
Data were compared using a paired t-test, or, as appropriate, the
Wilcoxon signed-rank test. Cohen’s kappa, a measure of agreement between
two raters, was also computed. For Cohen’s kappa, a value near zero
represented agreement being due to random chance, 0.01-0.20 represented
slight agreement; 0.21-0.40, fair agreement; 0.41-0.60, moderate
agreement; 0.61-0.80, substantial agreement; and 0.81-1.00 almost
perfect agreement. All tests were carried out using an α=0.05
significance level. Stata version 11.2 (StataCorp, College Station, TX)
was used for all analyses except for Cohen’s Kappa and its associated
confidence interval, for which the ckap command, part of the rel package
in R version 3.6.2 (R Core Team 2019), was used.