Table 2: QATQS assessment and grading criteria.

Quality Component Assessment Criteria
Selection Bias Degree to which participants are representative of target population
Percentage of study candidates who agreed to participate
Design Study design
Description of randomization process
Appropriate randomization sequence
Confounders Controlling of confounders via design
Baseline balance as to confounders
Blinding Outcome assessors
Participants
Data Collection Reliability and validity of assessment tools/methods
Withdrawals and Drop-Outs Reporting of withdrawal numbers and reasons
Percentage of participants completing the study
Intervention Integrity Percentage of participants receiving intended intervention
Measurement of consistency of intervention administration
Contamination/unintended intervention
Analysis Appropriate to Question Level of allocation and analyses
Appropriateness of statistical methods to study design
Analyses for intention-to-treat
Global Quality Rating Strong = 4 strong ratings and 0 weak ratings
Moderate = less than 4 strong ratings and 1 weak rating
Weak = 2+ weak ratings