topic How to get percentages? in Statistical Procedures

How to get percentages?

VNS0 — Tue, 22 Nov 2011 17:16:51 GMT

I have this variable tobhrd3 (stands for: How many of you have heard of electronic cigarettes?). I want to find the % and 95% CI of each category (sex, age groups, race, income, education, region, etc) that has heard of electronic cigarettes. How do I do that? Not PROC FREQ or PROC UNIVARIATE. PROC TABULATE?

How to get percentages?

Doc_Duke — Tue, 22 Nov 2011 18:00:51 GMT

Actually, you can get that from PROC FREQ; -- look at the TABLES option BINOMIAL.

Re: How to get percentages?

Rick_SAS — Tue, 22 Nov 2011 18:04:42 GMT

I might be confused, but can't you use PROC FREQ with a BY statement? Here's what I'm thinking (data for SEX):

data a;

input tobhrd3 sex;

datalines;

1 0

0 0

1 0

0 0

1 1

0 1

;

proc format;

value MF 1='Male' 0='Female';

run;

proc freq data=a;

by sex;

format sex MF.;

tables tobhrd3 / binomial(level=1);

run;

The BINOMIAL option is described at http://support.sas.com/documentation/cdl/en/procstat/63963/HTML/default/viewer.htm#procstat_freq_a0000000563.htm

It can be used only for one-way tables. Is that why you say "not PROC FREQ"?

How to get percentages?

VNS0 — Tue, 22 Nov 2011 18:47:34 GMT

I tried your way but I'm seeing output for just male and not female and 2 observations only. When I ran proc freq for tobhrd3 there are total of 2433 people that heard of electronic cigarettes. Something is not right..

How to get percentages?

Rick_SAS — Tue, 22 Nov 2011 18:50:01 GMT

What do you get if you run PROC FREQ on the SEX variable? Do you correctly get k males and 2433-k females?

How to get percentages?

VNS0 — Tue, 22 Nov 2011 18:54:51 GMT

When I do proc freq on sex, I find 1971 males and 2079 females.

How to get percentages?

Rick_SAS — Tue, 22 Nov 2011 18:58:18 GMT

It's not feasible to debug your code long distance, but

1) make sure your data are sorted by the BY group var

2) try

TABLES sex*tobhrd3;

Do you correctly get the cross tab?

How to get percentages?

VNS0 — Tue, 22 Nov 2011 19:05:06 GMT

it worked. it gave me the correct numbers in the table. how do I get 95% CI?

proc freq data=merged;

tables sex*tobhrd3;

run;

How to get percentages?

Rick_SAS — Tue, 22 Nov 2011 19:07:37 GMT

I already gave you the answer. I don't have any further suggestions. Anybody else?

How to get percentages?

Reeza — Tue, 22 Nov 2011 19:53:46 GMT

Calculate the % in a datastep if you're not using the default sas output from binomial as mentioned by Rick.

http://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval

For results similar to Ricks that might be more useful you could consider doing the following:

ods table binomialprop=sample;

proc freq data=merged;

by sex;

tables tobhrd3/binomial(level=1);

run;

data sample2;

set sample;

where name1 in ("_BIN_", "L_BIN", "U_BIN");

run;

proc transpose data=sample2 out=answer;

by sex;

var nvalue1;

id name1;

run;