Source: National Cancer Institute \ Winship Cancer Institute of Emory University
Creator: Scott Wilkinson, Adam Marcus
We will be discussing Accuracy of combinations of visual inspection using acetic acid or Iugol Iodine to detect cervical precancer: A meta-analysis. Catarino et al. BJOG 2017 on Wednesday 27 September, 8pm BST.
You have been asked to develop a screening system for cervical cancer in a low income country. What method do you recommend?
Description of research
|Participants||101,273 women participating in 23 studies in India (11 studies), Africa (9 studies), Oceania (one study) and Latin America (two studies)|
|Interventions||Four strategies of cervical screening:
(1) visual inspection of the cervix with acetic acid (VIA);
(2) visual inspection with Iugol’s iodine (VILI);
(4) VILI as a triage test of a positive VIA result.
|Comparison||Histology if a cervical biopsy was performed; colposcopy when no sample was taken|
|Outcomes||Sensitivity and specificity of testing strategy|
|Study Design||Diagnostic test accuracy meta-analysis|
- What are the described screening strategies? Do they differ from what you do in clinical practice?
- What are the properties of an ideal screening test?
- What is the relationship between sensitivity and specificity, and positive predictive value?
- Most of the studies included were cross-sectional and prone to bias. What kinds of bias are discussed in this meta-analysis? Are there others you can think of? (1)
- What other information would you like in order to answer the question in the scenario?
- Imagine that a funder, hearing of the need for cancer screening in this country and the paucity of evidence, offers research funding for a trial to evaluate different methods. How would you design such a trial?
Leeflang MMG, Deeks JJ, Gatsonis C, Bossuyt PMM, Cochrane Diagnostic Test Accuracy Working Group. Systematic reviews of diagnostic test accuracy. Ann Intern Med. NIH Public Access; 2008 Dec 16;149(12):889–97.