Table 2 Risk-of-bias assessment tool for case-control methodology
Item | Scoring |
|---|---|
Selection: | |
 1. Is the control group representative for normal adolescents? | 1 = Community control; 0 = Hospital controls; 0 = No description of source |
 2. Was other pathology excluded that possibly influences the outcome? | 1 = Yes; 0 = No or no description |
Comparability: | |
 3. Were the same in- and exclusion criteria (except for the spinal deformity) used for AIS and healthy adolescents? | 1 = Yes; 0 = No or no description |
Exposure/outcome: | |
 4. Were the observers blinded to AIS/healthy adolescent status? | 1 = Yes; 0 = No or not documented |
 5. Was the data collection performed in the same standardised way for AIS cases and healthy adolescents? | 1 = Yes; 0 = No or not documented |
 6.a Was the primary outcome parameter for AIS cases and healthy adolescents available? | 1 = Available for > 90% of AIS and healthy adolescents; 0 = Available for < 90% of AIS or healthy adolescents |