Table 1 Checklist for reporting methods used for performing TSAs

RIS

• Type I error rate

• Type II error rate (or statistical power)

• Diversity (if heterogeneity is present)

• Minimally relevant differences and variances for continuous outcomes

• Relative risk reductions and assumed event rates in control groups for binary outcomes

Decision boundaries

• Data used for deriving information fractions (typically the cumulative sample sizes of individual studies divided by the RIS)

• Spending functions for deriving adjusted type I and type II error rates for decision boundaries (optional, as they are typically used as the functions suggested by Lan and DeMets [7])

Z-curve

• Sample means, sample standard deviations, and sample sizes from individual studies for continuous outcomes

• 2 × 2 tables (event counts and sample sizes) from individual studies for binary outcomes

• Meta-analytical model types, such as the common-effect model (also known as the fixed-effect model) and random-effects model

• Estimation methods, particularly for between-study variances, such as the DerSimonian–Laird approach or restricted maximum-likelihood approach

• Methods for handling zero events, such as continuity correction, removal, and use of exact models (e.g., generalized linear mixed models)