Power analysis for longitudinal data with dropout
This app calculates statistical power for a linear mixed-effects model, comparing the rate of change between two groups over time. It supports standard null hypothesis testing, as well as non-inferiority and equivalence tests. The model accommodates random slopes and accounts for participant dropout. Adjust the parameters using the inputs on the left.
Power Curve
Power for varying sample sizes. The dashed line represents power without any dropout. You can adjust the maximum value and step size using the settings button.
Power (complete data)
Power (with dropout)
Explore the Model
Use the buttons bellow to explore model implied parameters.
Proportion Remaining
This plot shows the proportion of participants remaining at each time point. The dropout process is monotonic, with no intermittent missing data.
Power Summary (WIP)
About
Created by Kristoffer Magnusson. This app is currently under active development and is not yet ready for use in planning real studies. Please contact me with any ideas or suggestions.