PICOTsize is an R package and Shiny app for calculating sample sizes across the study designs covered by the PICOT framework: cross-sectional, case-control, cohort, superiority/non-inferiority/ equivalence clinical trials, and diagnostic test accuracy studies.
It follows the sample size formulas described in Bhardwaj et al. (2024), Determination of sample size for various study designs in medical research: A practical primer, J Family Med Prim Care, using epiR as a validated computational backend rather than reimplementing formulas from scratch. Every calculation is checked against the paper’s own worked examples – see the Validation tab in the app, or the package vignette, for a full comparison and an explanation of the handful of places where this package’s output differs from the paper (and why).
You can install the development version of PICOTsize from GitHub with:
# install.packages("remotes")
remotes::install_github("AtefehRashidi/PICOTsize")Every calculation is available as a plain R function, independent of the Shiny app:
library(PICOTsize)
calc_crosssectional_binary(
p = 0.30,
precision = 0.05,
dropout_rate = 0.10
)library(PICOTsize)
run_app()Bhardwaj R, Agrawal U, Vashist P, Manna S. Determination of sample size for various study designs in medical research: A practical primer. J Family Med Prim Care. 2024;13:2555-61.
Contributions are welcome! If you find a bug, have a suggestion, or would like to request a new feature, please open an issue on the GitHub repository.