Review for 10.1186/1471-230X-13-101 (2013)

Reviewer's report
Title:Role of Life Events in the Presence of Colon Polyps among African
Americans
Version: 1Date:27 February 2013
Reviewer: Preet Paul Singh
Reviewer's report:
Ashktorab and colleagues have tried to answer an interesting question, by
comparing life event scores in the preceding 12 months in patients who were
found to have polyps vs not among a clinic based cohort of 110 patients
undergoing complete colonoscopy for screening as well as diagnostic purposes.
- Major Compulsory Revisions
1. The comparison of the two groups (polyps vs no polyps) and whether they
were similar, is not provided. Table 1 should have this information for both
groups to rule out confounding.
2. The patient numbers are small and only restricted to African Americans which
limits power and generalizability.
3. Although the authors conclude that patients who experienced more stressful
life events may be at increased risk of colon polyps and adenomas, this is based
on a higher total ‘life event score’ in patients with polyps (Table 2). Interestingly
this includes both negative (bad, stressful) and positive (good, not stressful)
scores and as they are individually not different in two groups, the conclusion
seems premature. As the proposed question is “stressful life events”, only using
the negative score may be more appropriate.
4. The instrument used – the 82 item life event questionnaire (LEQ) –was
developed for adult female respondents of childbearing age and has mostly been
used in teenage mothers or young adults/parents. Although comprehensive, it
appears to be inappropriate to evaluate psychosocial stress in African American
subjects with a mean age of nearly 60 years.
5. Results Section – “Predictors of life event score” – Line 1 - Polyp diagnosis
should not be affecting the life event score as it was measured before the
colonoscopy. It should be the other way round.
6. Details about the regression model are lacking. Also, to answer the study
question, regression model should include life event score as a variable
alongwith other factors (age, gender, education, smoking status etc) that can
affect polyp incidence. But instead, the authors are reporting predictors of life
event score – which fails to answer the proposed question. This data is not very
useful.
7. Discussion – para 2 – The authors state that as positive events may effect
colon polyps. As there was no difference in the positive score in the 2 groups –
this is incorrect. Also it’s incorrect to equate perceived positive life events to
“general stress”.
8. Also there is evidence that recall of life events is subject to telescoping (i.e.,
remote events are reported to have occurred more recently) and to mood
(patients with lower mental health scores report more life events, especially
perceived rather than factual events). Information about Baseline/known
psychiatric diagnosis and its distribution among patients with polyps and no
polyps would be helpful.
- Minor Essential Revisions
1. The introduction is quite long and there is repetition in discussion. Some of this
can be consolidated.
2. Few grammatical mistakes in para 3 of discussion need correction.
Level of interest: An article of limited interest
Quality of written English: Acceptable
Statistical review: Yes, and I have assessed the statistics in my report.
Declaration of competing interests:
I declare that I have no competing interests.