The following statements are available in the POWER procedure:
PROC POWER <options>;
COXREG <options>;
CUSTOM <options>;
LOGISTIC <options>;
MULTREG <options>;
ONECORR <options>;
ONESAMPLEFREQ <options>;
ONESAMPLEMEANS <options>;
ONEWAYANOVA <options>;
PAIREDFREQ <options>;
PAIREDMEANS <options>;
PLOT <plot-options> </ graph-options>;
TWOSAMPLEFREQ <options>;
TWOSAMPLEMEANS <options>;
TWOSAMPLESURVIVAL <options>;
TWOSAMPLEWILCOXON <options>;
The statements in the POWER procedure consist of the PROC POWER statement, a set of analysis statements (for requesting specific power and sample size analyses), and the PLOT statement (for producing graphs). The PROC POWER statement and at least one of the analysis statements are required. The analysis statements are COXREG, CUSTOM, LOGISTIC, MULTREG, ONECORR, ONESAMPLEFREQ, ONESAMPLEMEANS, ONEWAYANOVA, PAIREDFREQ, PAIREDMEANS, TWOSAMPLEFREQ, TWOSAMPLEMEANS, TWOSAMPLESURVIVAL, and TWOSAMPLEWILCOXON.
You can use multiple analysis statements and multiple PLOT statements. Each analysis statement produces a separate sample size analysis. Each PLOT statement refers to the previous analysis statement and generates a separate graph (or set of graphs).
The name of an analysis statement describes the framework of the statistical analysis for which sample size calculations are desired. You use options in the analysis statements to identify the result parameter to compute, to specify the statistical test and computational options, and to provide one or more scenarios for the values of relevant analysis parameters.
Table 1 summarizes the basic functions of each statement in PROC POWER. The syntax of each statement in Table 1 is described in the following pages.
Table 1: Statements in the POWER Procedure
| Statement | Description |
|---|---|
| PROC POWER | Invokes the procedure |
| COXREG | Cox proportional hazards regression |
| CUSTOM | extensions of existing analyses that involve the chi-square, F, t, or normal distribution, or the distribution of the correlation coefficient under multivariate normality |
| LOGISTIC | Likelihood ratio chi-square test of a single predictor in logistic regression with binary response |
| MULTREG | Tests of one or more coefficients in multiple linear regression |
| ONECORR | Fisher’s z test and t test of (partial) correlation |
| ONESAMPLEFREQ | Tests, confidence interval precision, and equivalence tests of a single binomial proportion |
| ONESAMPLEMEANS | One-sample t test, confidence interval precision, or equivalence test |
| ONEWAYANOVA | One-way ANOVA including single-degree-of-freedom contrasts |
| PAIREDFREQ | McNemar’s test for paired proportions |
| PAIREDMEANS | Paired t test, confidence interval precision, or equivalence test |
| PLOT | Displays plots for previous sample size analysis |
| TWOSAMPLEFREQ | Chi-square, likelihood ratio, and Fisher’s exact tests for two independent proportions |
| TWOSAMPLEMEANS | Two-sample t test, confidence interval precision, or equivalence test |
| TWOSAMPLESURVIVAL | Log-rank, Gehan, and Tarone-Ware tests for comparing two survival curves |
| TWOSAMPLEWILCOXON | Wilcoxon-Mann-Whitney (rank-sum) test for 2 independent groups |
See the section Summary of Analyses for a summary of the analyses available and the syntax required for them.