Powerberegnede

Powerberegnede is a Danish term used in statistics to describe study designs, analyses, or estimates for which statistical power has been calculated. The concept stems from power analysis, a set of methods used to determine a study’s ability to detect an effect of a given size under specified assumptions. When a study is described as powerberegnede, it typically indicates that researchers have planned sample size or evaluated whether the study has sufficient power before data collection (a priori) or after data collection (post hoc).

The main purpose of power calculation is to ensure that a study is capable of detecting clinically or scientifically important effects while avoiding unnecessary resource use. A priori power analyses require input of anticipated effect size, significance level, variability, and desired power (commonly 0.8 or 0.9). Powerberegnede planning helps researchers determine the needed sample size and its feasibility in the study design.

Methods for power calculation include standard formulas for comparing means or proportions, regression models, survival analysis, and more complex simulations. Software such as G*Power, R, SAS, and Stata is commonly used. A powerberegnede plan informs decisions about study scope, design choices, and data collection strategies.

Interpretation and limitations: Powerberegning provides a planning target, but actual power depends on true effect sizes and data quality. Post hoc power calculations based on observed results are controversial because they can be misleading and do not replace confidence intervals or p-values.

Language note: Power is an English term widely used in Danish statistical literature, sometimes integrated as a Danish term, with powerberegnede reflecting that usage. See also statistical power, power analysis, and sample size calculation.