Analysis

All aspects of development in Analysis (which does not fit in another project)
Tasklist

FS#122 - significance tests for an adjusted odds ratio (options /t and /ex)

Attached to Project: Analysis
Opened by Tom Nichols (tom.nichols) - Tuesday, 10 December 2013, 17:43 GMT
Task Type Bug Report
Category Statistics
Status Assigned
Assigned To Torsten Bonde Christiansen (torstenchr)
Operating System Windows
Severity High
Priority Normal
Reported Version 2.2
Due in Version Undecided
Due Date Undecided
Percent Complete 0%
Votes 0
Private No

Details

* EPIDATA ANALYSIS PROGRAM

logopen "H:\Teaching Courses\Outbreak Course\bugTN_06122013\bugTN_06122013.htm" /close /replace

cd "H:\Teaching Courses\Outbreak Course\bugTN_06122013"
read "H:\Teaching Courses\Outbreak Course\bugTN_06122013\wedd" /close

set random simulations=10000

***********************************************
* EpiData Analysis 2.2.1.171
* tables ill redsauce gheerchick /o /nt /nc /ex /t /obs
* Using 2.2.1.171: OR = 1.08 [95% CI 0.22 to 5.66]; p(M-H)=0.916; p(exact)=0.0414

* EpiData Analysis 2.2.2.182
tables ill redsauce gheerchick /o /nt /nc /ex /t /obs /oex
* Using 2.2.2.182: OR(Exact) = 1.08 [95% CI 0.22 to 5.66]; p(M-H)=0.046; p(exact)=0.0414
* Using 2.2.2.182: OR = 1.07 [95% CI 0.11 to 10.06]



* Epi Info for DOS v6.04d
* tables redsauce ill gheerchick
* Using Epi Info for DOS v6.04d: OR (MLE) = 1.08 [95% CI 0.22 to 5.66]; p(M-H uncorrected)=0.91644269; p(M-H corrected)=0.81105112

* Stata/SE 12.1 for Windows (32 bit) Revision 20 Mar 2013
* logit ill redsauce gheerchick
* P-value for coefficient of redsauce = 0.916

* The estimate is close to 1 and the confidence interval is wide, so a test for the adjusted OR being significantly different to 1 should have a p-value close to 1
* Both Epi Info for DOS and Stata give a p-value of 0.916
* So I have a lot of confidence in this being the correct p-value.

* EpiData Analysis (build 171)
* The chi-squared test statistic and the p-value for a M-H weighted odds ratio using the option /t is 0.01 and 0.916
* This p-value using the option /t appears to be correct.
* The p-value using the option /ex appears to be incorrect.
* The chi-squared test statistic and the p-value using the option /ex is 6.147 and 0.0414.
* If the test statistic is correct a comparison to a chi-squared distribution of 1 degree of freedom should give a p-value equal to 0.0132?
* Possibly the correct p-value should be calculated as 1-2*(0.0414) = 0.917?

* EpiData Analysis (build 182)
* The chi-squared test statistic and the p-value for a M-H weighted odds ratio using the option /t is 6.15 and 0.046
* This p-value using the option /t appears to be incorrect.
* The p-value using the option /ex appears to be incorrect.
* The chi-squared test statistic and p-value using the option /ex is 6.147 and 0.0414.
* If the test statistic is correct a comparison to a chi-squared distribution of 1 degree of freedom should give a p-value equal to 0.0132?
* Possibly the correct p-value should be calculated as 1-2*(0.0414) = 0.917?


***********************************************
logclose
This task depends upon

Loading...