Regular Learner
Posts: 1

# Power calculation in cohort study

Hi, I am trying to calculate power for a hypothetical cohort study, I have run in multiple times this code but I still receive the same error 180-322.

groupweights=(1 9)/*Divide ntotal 9 to 1 between the groups => n2=9*n1, where n1 = exposed sample size & n2 = unexposed sample size*/
ntotal=120000 /*120,000 total participants in the study*/
power=.; /*Calculate power*/

OPTIONS NONOTES NOSTIMER NOSOURCE NOSYNTAXCHECK;
72
73 proc groupweights=(1|9)/*Divide ntotal 9 to 1 between the groups => n2=9*n1, where n1 = exposed sample size & n2 =
73 ! unexposed sample size*/
74 ntotal=120000 /*120,000 total participants in the study*/
75 power=.; /*Calculate power*/
76
77 OPTIONS NONOTES NOSTIMER NOSOURCE NOSYNTAXCHECK;
Super User
Posts: 23,724

## Re: Power calculation in cohort study

WHere's the rest of the code? The PROC POWER statement for starters?

73 proc groupweights=

And the rest of that code doesn't look close to correct.

See the documentation reference here:

http://documentation.sas.com/?docsetId=statug&docsetTarget=statug_power_toc.htm&docsetVersion=14.3&l...

See the examples section for various full examples.

emma19901 wrote:

Hi, I am trying to calculate power for a hypothetical cohort study, I have run in multiple times this code but I still receive the same error 180-322.

groupweights=(1 9)/*Divide ntotal 9 to 1 between the groups => n2=9*n1, where n1 = exposed sample size & n2 = unexposed sample size*/
ntotal=120000 /*120,000 total participants in the study*/
power=.; /*Calculate power*/

OPTIONS NONOTES NOSTIMER NOSOURCE NOSYNTAXCHECK;
72
73 proc groupweights=(1|9)/*Divide ntotal 9 to 1 between the groups => n2=9*n1, where n1 = exposed sample size & n2 =
73 ! unexposed sample size*/