Power Trip: A Road Map of PROC POWER

Sample size and power analyses are extremely important components to consider when designing, planning and recruiting for prospective clinical research projects. Unfortunately, these are often considered to be scary and complicated calculations for research clinicians. PROC POWER offers a systematic solution to finding the balance between efficiency and conclusive results, while remaining simple enough for non-statisticians to use. More power is universally considered to be advantageous, even outside of the domain of statistics. It is especially important in statistics, as more power results in a higher probability that the null hypothesis will be rejected when it is false. Additionally, sample size is directly related to power. In general, a larger sample size will result in more accuracy, precision, and higher power. An important aspect of study design is maximizing power while remaining within the bounds of financial feasibility. This is where PROC POWER comes in, providing methods of determining sample sizes and power calculations. Throughout this paper, we will construct a road map of the POWER procedure to assist both statisticians and non-statisticians with the implementation of this POWERful SAS tool.