Designing Stepped Wedge Cluster Randomized Trials With a Baseline Measurement of the Outcome
Bibliographic record
Abstract
Stepped wedge cluster randomized trials (SW-CRTs) are a type of uni-directional crossover designs and are increasingly common in prevention and implementation research. Although sample size formulas have been developed to support the planning of SW-CRTs, almost no prior methods incorporated the baseline measurement of the outcome-a common feature in many randomized trials and, increasingly, in cross-sectional SW-CRTs. In this article, we systematically investigate the possibility of addressing a baseline outcome measurement in designing cross-sectional SW-CRTs. We provide three linear mixed modeling approaches to adjust for the baseline outcome and derive the corresponding variance formula of the treatment effect estimator under each. The derived formulas reveal the efficiency implications of including a baseline outcome measurement, and provide a natural vehicle for the efficiency comparisons across adjustment approaches to generate practical recommendations. We validate the power and sample size methods under each baseline adjustment approach using simulations and provide an illustrative sample size calculation with a baseline outcome using the context of a real SW-CRT.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.100 | 0.210 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.002 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.003 | 0.002 |
| Research integrity | 0.002 | 0.003 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".