Statistical planning
Define the quantities to estimate, comparisons, assumptions and analysis methods before interpreting results. Plan sample size or precision, missing data, multiplicity and sensitivity as appropriate to the question.
Flows for this purpose
- Endpoint hypothesis and method
Endpoint and estimand → objective → hypotheses or estimation target → method → assumptions
- Sample size and power
Endpoint and method → effect and variability assumptions → scenarios → selected design → rationale
- Multiple-endpoint testing
Endpoint family → success criteria → testing strategy → decision rules
- Interim monitoring and stopping
Information schedule → efficacy, futility or safety review → continue, modify or stop decision
- Confounding adjustment strategy
Causal question → covariates → adjustment method → diagnostics → analysis strategy
- Missing-data strategy
Expected missingness → reasons and assumptions → handling method → sensitivity plan
- Subgroup and effect-modification plan
Scientific rationale → subgroup definitions → interaction approach → precision and interpretation plan
- Adaptive design decision plan
Planned looks → adaptation criteria → permissible changes → subsequent analysis
- Estimation and sensitivity plan
Specify estimates and robustness checks
- Analysis and missingness plan
Specify estimates and attrition handling
- Confounding adjustment plan
Specify covariates adjustment and diagnostics
- Estimation and sensitivity plan
Specify effects and bias analyses
- Sampling and analysis plan
Account for matching and sampling
- Bias and sensitivity plan
Assess selection and measurement errors
- Estimation and sensitivity plan
Account for sampling and uncertainty
- Accuracy and precision plan
Specify paired measures and uncertainty
- Bias and applicability assessment
Assess verification and spectrum effects
- Sample size and testing
Specify scenarios hypotheses and multiplicity
- Statistical analysis plan
Specify estimation missingness and sensitivity
- Sample size and decision rules
Specify precision thresholds and stopping
- Data and analysis plan
Define populations methods and sensitivity
- Sample size and precision
Justify information needed for decisions
- Feasibility analysis and refinement
Summarize findings and required changes
- Emulation adjustment and estimation
Specify identification and estimation methods
- Emulation sensitivity and feasibility
Evaluate deviations and identifying assumptions
- Matched risk-set analysis and sensitivity
Respect sampled sets and assumptions
- Within-person incidence analysis
Specify incidence contrasts and adjustments
- Self-controlled assumptions and sensitivity
Assess event-dependent exposure and observation
- Interrupted time-series impact estimation
Model level slope and correlation
- Time-series diagnostics and sensitivity
Assess seasonality shocks and specifications
- Difference-in-differences identification and estimation
Specify comparison assumptions and estimands
- Comparative change diagnostics and sensitivity
Assess trends anticipation and spillovers
- Prediction model development specification
Specify fitting tuning and complexity
- Prediction internal validation
Estimate optimism using appropriate resampling
- Prediction performance and usefulness
Assess calibration discrimination and utility
- External performance and precision
Estimate validation metrics and uncertainty
- Transportability and model updating decisions
Separate evaluation from model modification
- Nonrandomized sample size and confounding
Plan precision adjustment and overlap
- Nonrandomized intervention data and analysis
Specify populations estimation and sensitivity
- Crossover sample size and paired precision
Model within-participant variation and precision
- Crossover analysis specification
Specify period sequence and sensitivity
- Factorial sample size and multiplicity
Plan effect precision and testing
- Factorial analysis specification
Specify interactions contrasts and sensitivity
- Cluster sample size and testing
Specify correlation sizes and power
- Clustered trial analysis specification
Specify multilevel estimation and sensitivity
- Stepped-wedge design scenarios and power
Account for time and clustering
- Stepped-wedge time-adjusted analysis
Separate intervention effects from trends
- Dose escalation and stopping decisions
Define permitted decisions and safeguards
- Dose-design simulations and assumptions
Evaluate operating characteristics across scenarios
- Safety review and dose selection
Integrate evidence into dose recommendations
- Adaptation and interim decisions
Specify triggers actions and boundaries
- Adaptive design simulations and sample size
Evaluate power error and feasibility
- Adaptive final analysis specification
Account for adaptations in inference
- Platform interim decisions and governance
Prespecify adaptations and review responsibilities
- Platform simulations and sample-size scenarios
Evaluate changing platform operating characteristics
- Platform comparison analysis specification
Specify comparisons across calendar epochs