Enhanced Statistical Reporting Guidelines

| update: January 19, 2024 |

1. Core COPE Principles for Statistical Reporting
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1.1 Transparency
- Full disclosure of statistical methods
- Clear documentation of analysis decisions
- Complete reporting of all outcomes
- Open access to data and code (where applicable)

1.2 Reproducibility
- Detailed methodology documentation
- Version control for analysis software
- Availability of analysis scripts
- Clear documentation of data preprocessing

2. Study Design and Planning
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2.1 Sample Size and Power
Required Elements:
□ Power calculation with justification
□ Effect size assumptions
□ Sample size determination method
□ Interim analysis plans (if applicable)

Example:
"Sample size was calculated using G*Power 3.1, assuming α=0.05, power=0.80, and effect size d=0.5, requiring 128 participants."

2.2 Hypotheses
Required Elements:
□ Primary hypothesis clearly stated
□ Secondary hypotheses listed
□ Directional vs. non-directional tests specified
□ Multiple testing adjustment methods

3. Data Analysis Requirements
---------------------------
3.1 Descriptive Statistics
Required Reporting:
□ Measures of central tendency
- Mean ± SD for normal distributions
- Median (IQR) for non-normal distributions
□ Sample sizes for all groups
□ Missing data frequencies
□ Data distribution assessment

Example Table Format:
| Variable | Group A (n=50) | Group B (n=50) | P-value |
|----------|---------------|---------------|---------|
| Age | 45.2 ± 8.4 | 46.1 ± 7.9 | 0.56 |
| BMI | 24.5 (22-27) | 25.1 (23-28) | 0.48 |

3.2 Inferential Statistics
Required Elements:
□ Test selection justification
□ Assumption checking results
□ Effect sizes with confidence intervals
□ Exact p-values (unless p < 0.001)

4. Specific Analysis Guidelines
-----------------------------
4.1 Regression Analyses
Required Reporting:
□ Model specification
□ Variable selection method
□ Assumption checks
□ Goodness-of-fit measures
□ Parameter estimates with CIs

Example:
"Multiple linear regression was performed with backward selection (criterion: p < 0.10). Model assumptions were verified using residual plots and variance inflation factors."

4.2 Survival Analyses
Required Elements:
□ Censoring definition
□ Survival time calculation method
□ Competing risks handling
□ Proportional hazards testing

5. Data Visualization Standards
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5.1 Figure Requirements
□ Clear labeling of axes
□ Appropriate error bars
□ Sample size indication
□ Statistical test annotation

Example Annotation:
"Error bars represent 95% CIs. *p < 0.05, **p < 0.01, ***p < 0.001"

5.2 Table Requirements
□ Clear variable definitions
□ Appropriate precision level
□ Missing data notation
□ Statistical test specification

6. Special Considerations
------------------------
6.1 Missing Data
Required Documentation:
□ Missing data patterns
□ Handling method justification
□ Sensitivity analysis results
□ Impact on conclusions

6.2 Multiple Testing
Required Elements:
□ Family-wise error rate control
□ False discovery rate methods
□ Adjusted and unadjusted results
□ Hierarchical testing procedures

7. Reporting by Study Type
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7.1 Randomized Controlled Trials
□ CONSORT checklist compliance
□ Randomization method
□ Allocation concealment
□ Intention-to-treat analysis

7.2 Observational Studies
□ STROBE checklist compliance
□ Confounding assessment
□ Selection bias evaluation
□ Exposure-outcome modeling

8. Quality Control Procedures
---------------------------
8.1 Data Quality
Required Elements:
□ Data cleaning procedures
□ Outlier detection methods
□ Quality control checks
□ Data validation steps

8.2 Analysis Quality
Required Documentation:
□ Code review process
□ Reproducibility checks
□ Version control methods
□ Independent verification

9. Practical Examples
--------------------
9.1 Sample Size Calculation
"For detecting a difference in means of 5 units (SD=10) between two groups with 80% power at α=0.05, 64 participants per group are required."

9.2 Results Reporting
"Treatment effect was 5.2 units (95% CI: 3.1 to 7.3, p=0.002) after adjusting for age and sex."

10. Implementation Checklist
--------------------------
Pre-Submission:
□ Statistical methods fully described
□ All primary outcomes reported
□ Effect sizes and CIs included
□ Data sharing statement provided
□ Code availability documented

Post-Review:
□ Reviewer statistical concerns addressed
□ Additional analyses documented
□ Methods updates included
□ Results verification completed

11. COPE-Specific Requirements
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11.1 Ethical Considerations
□ Data privacy protection
□ Participant confidentiality
□ Informed consent documentation
□ Ethical approval details

11.2 Transparency Measures
□ Protocol registration
□ Analysis plan documentation
□ Deviations reporting
□ Conflicts of interest

12. Contact and Support
----------------------
Statistical Editor: stats.editor@ajbm.org
Methods Support: methods@ajbm.org
Technical Help: support@ajbm.org

Note: These guidelines align with COPE standards and current best practices in biomedical research. Authors must adhere to these guidelines for manuscript submission and revision.