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Table 1 Critical appraisal tool for study validity assessment

From: The effectiveness of spawning habitat creation or enhancement for substrate-spawning temperate fish: a systematic review

Category Bias and generic data quality features Specific data quality features Validity Design of assessed study
1 Selection bias: study design Design (i.e., well-controlled) High BACI
Medium BA or CI
Replication High Replication at level of intervention (n > 5)
Medium Replication at level of intervention (true n = 1 with pseudoreplication) or n = 2–5
Low Unreplicated (i.e. no variance, or variance across years only)
Control matching High Control and treatment samples well-matched or likely well-matched at baseline
Medium Control and treatment samples moderately matched
Low Control and treatment samples poorly matched
2 Assessment bias: measurement of outcome Measured outcome High Quantitative
Medium Quantitative approximations or semi-quantitative
Low Qualitative
3 Performance bias: baseline comparison Other confounding environmental factors High Intervention and comparator sites homogenous
Medium Intervention and comparator sites moderately comparable with respect to confounding factors
Low Intervention and comparator sites hardly comparable with respect to confounding factors or lacking sufficient information to judge
N/A if BA design and before measurement taken immediately prior to restoration
  1. Reviewers provided a rating of high, medium, or low for each of the specific data quality features. Reviewers also had the opportunity to provide comments for each study based on external validity (generalizability)