Minnesota Colon Cancer Control Study: Difference between revisions

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=The effect of fecal occult-blood screening on the incidence of colorectal cancer=
=The effect of fecal occult-blood screening on the incidence of colorectal cancer=
This is a structured summary of a research study originally published in 1993 in the New England Journal of Medicine <ref name="pmid8474513">{{cite journal | author = Mandel J, Bond J, Church T, Snover D, Bradley G, Schuman L, Ederer F | title = Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study | journal = N Engl J Med | volume = 328 | issue = 19 | pages = 1365-71 | year = 1993 | id = PMID 8474513}}"</ref>.
This is a structured summary of a research study originally published in 1993 in the New England Journal of Medicine <ref name="pmid8474513">{{cite journal | author = Mandel J, Bond J, Church T, Snover D, Bradley G, Schuman L, Ederer F | title = Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study | journal = N Engl J Med | volume = 328 | issue = 19 | pages = 1365-71 | year = 1993 | id = PMID 8474513 | url = http://content.nejm.org/cgi/content/full/328/19/1365}}"</ref>.
''This page is under development; please see the discussion of this page for details''
''This page is under development; please see the [[http://pilot.citizendium.org/wiki?title=Talk:PMID_8474513&action=edit discussion]] of this page for details''


The results of the is study after 18 years of follow-up have been published <ref name="pmid11096167">{{cite journal | author = Mandel J, Church T, Bond J, Ederer F, Geisser M, Mongin S, Snover D, Schuman L | title = The effect of fecal occult-blood screening on the incidence of colorectal cancer | journal = N Engl J Med | volume = 343 | issue = 22 | pages = 1603-7 | year = 2000 | id = PMID 11096167}}</ref>.
===Summary===
46,551 participants aged 50 to 80 years were randomized to one of:
*screening for colorectal cancer once a year with 'six guaiac-impregnated paper slides with two smears from each of three consecutive stools'
*screening every two years  with 'six guaiac-impregnated paper slides with two smears from each of three consecutive stools'
*control group.
 
===Results===
{| class="wikitable" style="width:33%"
|+Cross tabulation
|-
!
! Deaths from<br>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 [http://content.nejm.org/cgi/content/full/328/19/1365/T1 Table 1] of the article and using the outcomes in [http://content.nejm.org/cgi/content/full/328/19/1365/T4 Table 4] of the article)
 
According to the article, the 13-year cumulative rates of mortality from colorectal cancer were:
*0.588% in the annually screened group (95 percent confidence interval, 4.61 to 7.15)
*0.833% in the biennially screened group (95 percent confidence interval, 6.82 to 9.84)
*0.883% in the control group (95 percent confidence interval, 7.26 to 10.40)
 
These numbers lead to the following measures of efficacy:
{| class="wikitable" style="width:33%"
|+Measures of Efficacy
|-
| [[Absolute risk reduction]]
| 0.3%
|-
| [[Number needed to treat]]
| 339
|-
| [[Relative risk]]
| 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?===
To assess whether the results are [[statistically significant]], not only the p-value is important, but factors that might influence the p-value are important. For example, (''text needed''). To alter the a priori estimate of the null hypothese, click here. ('this paragraph needs to be much more user friendly')
 
===How will these result be changed in patients with higher or lower risk?===
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 [[http://medinformatics.uthscsa.edu/cgi-bin/calc-rx.pl?eer=0.588&cer=0.883&outcome=- this link]] to adjust the baseline risk.
 
===Follow-up===
The results of the is study after 18 years of follow-up have been published <ref name="pmid11096167">{{cite journal | author = Mandel J, Church T, Bond J, Ederer F, Geisser M, Mongin S, Snover D, Schuman L | title = The effect of fecal occult-blood screening on the incidence of colorectal cancer | journal = N Engl J Med | volume = 343 | issue = 22 | pages = 1603-7 | year = 2000 | id = PMID 11096167 | url = http://content.nejm.org/cgi/content/full/343/22/1603}}</ref>.


==References==
==References==

Revision as of 00:32, 11 January 2007

The effect of fecal occult-blood screening on the incidence of colorectal cancer

This is a structured summary of a research study originally published in 1993 in the New England Journal of Medicine [1]. This page is under development; please see the [discussion] of this page for details

Summary

46,551 participants aged 50 to 80 years were randomized to one of:

  • screening for colorectal cancer once a year with 'six guaiac-impregnated paper slides with two smears from each of three consecutive stools'
  • screening every two years with 'six guaiac-impregnated paper slides with two smears from each of three consecutive stools'
  • control group.

Results

Cross tabulation
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)

According to the article, the 13-year cumulative rates of mortality from colorectal cancer were:

  • 0.588% in the annually screened group (95 percent confidence interval, 4.61 to 7.15)
  • 0.833% in the biennially screened group (95 percent confidence interval, 6.82 to 9.84)
  • 0.883% in the control group (95 percent confidence interval, 7.26 to 10.40)

These numbers lead to the following measures of efficacy:

Measures of Efficacy
Absolute risk reduction 0.3%
Number needed to treat 339
Relative risk 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?

To assess whether the results are statistically significant, not only the p-value is important, but factors that might influence the p-value are important. For example, (text needed). To alter the a priori estimate of the null hypothese, click here. ('this paragraph needs to be much more user friendly')

How will these result be changed in patients with higher or lower risk?

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

The results of the is study after 18 years of follow-up have been published [2].

References

  1. ↑ 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. "
  2. ↑ 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.
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