topic Re: 95% confidence intervals in Statistical Procedures

95% confidence intervals

GS2 — Thu, 06 Sep 2018 17:43:10 GMT

Using SAS 9.4

I did a proc freq: to return my descriptive and pvalue statistics. When I run it, it returns:

SAS Output

Statistic DF Value ProbChi-SquareLikelihood Ratio Chi-SquareMantel-Haenszel Chi-SquarePhi CoefficientContingency CoefficientCramer's VWARNING: 100% of the cells have expected counts lessthan 5. Chi-Square may not be a valid test.

SAS Output

336	519.2845	<.0001
336	204.4836	1.0000
1	.	.
	1.6532
	0.8556
	0.8266

Fisher's Exact TestTable Probability (P)

<.0001

Monte Carlo Estimate for the Exact TestPr <= P99% Lower Conf Limit99% Upper Conf Limit Number of SamplesInitial Seed

0.0338

0.0291

0.0385

10000

30061001

Sample Size = 190

For my confidence intervals, they are default at 95%. Does SAS automatically convert my CIs to 99% if the pvalue is less than that level? If so, is their any way to return it at the 95% CI level as the rest of my results are at the 95% CI level? Thank you

code for my proc freq:

proc freq data = RAW.PRESENTS_04SEPT2018 (where=(used_recommendation ne 'N/A'));
tables insurance_status_at_testing*hh_inc_med/list missing nocum;
title 'Insurance status at testing pvalue';
exact fisher /mc;
run;

Re: 95% confidence intervals

ballardw — Thu, 06 Sep 2018 17:49:17 GMT

Default is Alpha=0.05 (95% confidence interval)

use the ALPHA= option to set the desired level on the TABLES statement. If you want a 99% interval use ALPHA=0.01.

Re: 95% confidence intervals

GS2 — Thu, 06 Sep 2018 17:51:16 GMT

What if alpha=0.05 does not work I guess should have been my question. I tried to set that and it still report it as a 99% CI

Re: 95% confidence intervals

Reeza — Thu, 06 Sep 2018 17:58:52 GMT

You probably didn't set it in the right place.

Try this:

proc freq data = sashelp.heart ;
tables status*chol_status/list missing nocum;
exact fisher /mc alpha=0.05;
run;

@GS2 wrote:

What if alpha=0.05 does not work I guess should have been my question. I tried to set that and it still report it as a 99% CI