Reviewer's report
Title:Analysis of 3 strategies to increase screening coverage for cervical cancer
in the general population of women from 60 to 70 years of age: A randomized
controlled trial. The CRICERVA Study
Version:6Date:22 April 2014
Reviewer: Catherine Crespi
Reviewer's report:
Major compulsory revisions
1. General comments: I am in agreement with Dr. Rossi regarding the concerns
with randomizing 4 groups to 4 intervention arms. This does not guarantee
balance on prognostic variables between groups and these data cannot be
validly analyzed as a randomized trial, i.e., it is not valid to make direct
comparisons between arms, especially when it is not possible to control for
potential confounders. I agree with Dr. Rossi’s suggestion to report confidence
intervals for the change in coverage within each group. Tests and p-values
comparing groups should not be presented. This includes the logistic
regressions; these ORs should be deleted.
2. Page 1, abstract: Remove the p-value from the Results in the abstract. Rather,
provide the coverage at pre and post in the control group as is done for the
intervention groups.
3. Abstract refers to “actively setting a date” but this was not mentioned as part of
the interventions when they were described earlier.
4. Page 4: “we analysed the results and factors conditioning screening
adherence and
coverage (population finally screened)”: do the authors mean, “we analysed the
factors associated with screening adherence and coverage”? There actually isn’t
any such analysis in the paper. Delete this.
5. It seems to be implied that the invitation letter included an appointment date,
but this is not explicitly mentioned in the description of IG1.
6. Page 8: It is not completely clear, but I gather from the response to comments
that the logistic regressions did not control for potential confounders because
these were not collected in all women. These direct comparisons between the
intervention and control groups, with no control for confounding, are simply
misleading and should be deleted. Delete “We compared the coverage in the
control group with the intervention arms by means of logistic regression. Odds
Ratio (OR) and 95% CI are provided.” And delete the ORs from Table 2.
7. Page 9: “distributed into one of the intervention arms” makes it seem as
though women were individually distributed into arms, which is not true. Delete
“and distributed into one of the intervention arms”
8. Discussion. It should be noted as a limitation that the NIG group had a much
lower coverage levels at baseline, which makes it less comparable to the
intervention groups.
9. Discussion, page 11, 4th paragraph: this finally provides details of the
invitation letters. This is critically important information to have in the Methods. It
should not be introduced for the first time in the Discussion.
Minor essential revisions
10. Page 2, introduction: First line: change “frequent” to “frequently diagnosed”
11. “morbimortality” is not a proper English word; change to “morbidity and
mortality”
12. Bottom of page 2: “impact of screening among women with invasive cervical
cancer”: this is misphrased; the authors do not mean to refer to screening among
women who have cancer, do they?
13. Page 3: ethnic, not ethinic
14. Delete “However” so the sentence reads, “The recommendations of the
Spanish Consensus…
15. Page 5: first line: do not capitalize “community”; there is a comma at the end
of the paragraph
16. Page 6, line 8: misspelled “appropriately”, missing a period at end of
sentence
17. Middle of page: so not capitalize “socio-economic”; replace “plannification”
with “planning”
18. IG1: delete “in” so it reads “was sent to the participants signed by”
19. Page 7: should be “The secondary outcome measures were…”
20. “lesions” not “lessions”
21. Page 8: rephrase to: ”The effect size of each study arm was quantified as the
difference in coverage before and after intervention and its 95% confidence
interval (CI).”
22. Figure 1: “Population assigned” is not a correct label. Is this “eligible sample
size”? Also, should “responding to citation” be “responding to invitation”?
23. Page 9: the text says “The screening situation of 3616 women in the
intervention groups and 665 in the NIG was unknown” but Figure 1 says these
women were not appropriately screened. Revise the text.
24. Page 9, middle of page: replace “Globally” with “Overall”; fix “children (%?)”;
replace “gynaecological control” with “gynaecological care”
25. Page 10: Change :”the initial coverage was found to be of 47.4 % (Table 2)”
to “the initial coverage was estimated to be 47.4% in the 3 intervention groups
overall (Table 2)”
26. Page 10: another “(%?)” about 10 lines down
27. Page 10: the change in coverage in the control arm should also be
mentioned in the text.
28. Discussion, page 11: This is not a “population study”
29. Page 12, first paragraph: REF missing
30. Page 12: unfinished sentence: “Our recommendation would be to…”
31. Table 2: delete the odds ratios
Level of interest: An article whose findings are important to those with closely
related research interests
Quality of written English: Not suitable for publication unless extensively edited
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests.