This Wiki article provides a structured summary a previously published research study. There are two purposes for summarizing previously published research articles in a standard format:
- Increase the reader's ability to understand the contents of the article. Research has shown that physicians have difficulty reading medical research articles. Physicians and patients have trouble quantifying benefits of treatments and diagnostic tests [1][2][3]. A specific example of this difficulty is that physicians have difficulty interpreting relative versus absolute effects [4]
- Provide building blocks that Wiki authors can reference to when writing about this topic (in this case, screening for colorectal cancer). The format below is based on prior work about "critically appraised topics"[5][6][7][8].
This page is under development; for discussion please see:
- The discussion page for this article
- Discussion at Wikipedia about why an earlier version of this article was deleted from WikiPedia. This discussion includes debate on whether summarizing research should be a purpose of a Wiki and also includes debate on deciding notability of topics.
"Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study" edit
This is a structured summary of a research study entitled "Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study"[9] originally published in 1993 in the New England Journal of Medicine. Click here to see the original abstract.
Summary of the original article edit
A randomized controlled trial of 46,551 participants aged 50 to 80 years were randomized to one of:
- screening for colorectal cancer once a year using the stool guaiac test. Per the text of the paper, 'six guaiac-impregnated paper slides with two smears from each of three consecutive stools'.
- screening every two years using the stool guaiac test. Per the text of the paper, 'six guaiac-impregnated paper slides with two smears from each of three consecutive stools'.
- control group.
Results edit
These results are limited to the annually screened group versus the control group as the effect of biennial screening was not significant.
| Deaths from colorectal cancer |
Alive | Totals | |
|---|---|---|---|
| Annual screening | 82 | 15488 | 15570 |
| Control | 117 | 15277 | 15394 |
| Totals | 199 | 30765 | |
| (this table was reconstructed by using the totals in Table 1 of the article and using the outcomes in Table 4 of the article) | |||
The numbers in the cross tabulation lead to the following event rates:
| Group | Rate | Confidence interval |
|---|---|---|
| Annual screening | 0.588% | (4.61 to 7.15) |
| Control | 0.883% | 7.26 to 10.40) |
These event rates lead to the following measures of efficacy:
| Absolute risk reduction | 0.3% |
| Number needed to treat | 339 |
| Relative risk reduction | 33.4% |
Per the authors, 'the rate in the annually screened group, but not in the biennially screened group, was significantly lower than that in the control group'. The p-value is not in the article.
Are the results significant? edit
- To assess whether the results are statistically significant, not only the p-value is important, but factors such as publication bias that might influence the p-value are important. To alter the a priori estimate of the null hypothesis, click here. (this paragraph needs to be much more user friendly)
- Clinical significance must also be considered. For example, the results may be statistically significant, but the number needed to treat may reveal that too few patients will benefit for patients to be willing to accept expense and effort of the treatment.
How will these result be changed in patients at higher or lower risk of the outcome? edit
The risk of death from colorectal cancer in this study is 0.883% in the unscreened group. For patients who have risk factors that make their risk higher or lower than this number, their benefit will be higher or lower. Use [this link] to adjust the baseline risk.
Follow-up edit
The results of the is study after 18 years of follow-up have been published.[10]
References edit
- ^ Bergman D, Pantell R (1986). "The impact of reading a clinical study on treatment decisions of physicians and residents". J Med Educ. 61 (5): 380–6. PMID 3701813.
- ^ Beasley B, Woolley D (2002). "Evidence-based medicine knowledge, attitudes, and skills of community faculty". J Gen Intern Med. 17 (8): 632–9. PMID 12213145.
- ^ Berwick D, Fineberg H, Weinstein M (1981). "When doctors meet numbers". Am J Med. 71 (6): 991–8. PMID 7315859.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Bucher H, Weinbacher M, Gyr K (1994). "Influence of method of reporting study results on decision of physicians to prescribe drugs to lower cholesterol concentration". BMJ. 309 (6957): 761–4. PMID 7950558.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Oosterhuis WP, Bruns DE, Watine J, Sandberg S, Horvath AR (2004). "Evidence-based guidelines in laboratory medicine: principles and methods". Clin. Chem. 50 (5): 806–18. doi:10.1373/clinchem.2003.025528. PMID 15105349.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Castro J, Wolf F, Karras B, Tolentino H, Marcelo A, Maramba I (2003). "Critically Appraised Topics (CAT) peer-to-peer network". AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium: 806. PMID 14728311.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Shannon S (2001). "Critically appraised topics (CATs)". Canadian Association of Radiologists journal = Journal l'Association canadienne des radiologistes. 52 (5): 286–7. PMID 11702349.
{{cite journal}}: Missing pipe in:|journal=(help) - ^ Ismach RB (2004). "Teaching evidence-based medicine to medical students". Academic emergency medicine : official journal of the Society for Academic Emergency Medicine. 11 (12): e6-10. doi:10.1197/j.aem.2004.08.037. PMID 15579428.
- ^ Mandel J, Bond J, Church T, Snover D, Bradley G, Schuman L, Ederer F (1993). "Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study". N Engl J Med. 328 (19): 1365–71. PMID 8474513.
{{cite journal}}: CS1 maint: multiple names: authors list (link)" - ^ Mandel J, Church T, Bond J, Ederer F, Geisser M, Mongin S, Snover D, Schuman L (2000). "The effect of fecal occult-blood screening on the incidence of colorectal cancer". N Engl J Med. 343 (22): 1603–7. PMID 11096167.
{{cite journal}}: CS1 maint: multiple names: authors list (link)