Table 1 Study quality criteria and scores

1). Study Design: Was there a comparison group and were treatments randomized?

1.22 (0.42)

1–2

2.53 (0.61)

1–3

2.67 (0.47)

2–3

2.14 (0.82)

1–3

2). Sampling Methods: Were schools and participants selected randomly or through convenience sampling?

2.00 (0)

2

2.00 (0)

2

2.00 (0)

2

2.00 (0)

2

3). Data Collection Methods/Measurement Techniques: Were valid and reliable methods used to collect outcome data?

2.56 (0.50)

2–3

2.53 (0.50)

2–3

3.00 (0)

3

2.59 (0.49)

2–3

4). Intervention Integrity Checks: Did the study include any announced or unannounced intervention integrity checks?

1 (0)

1

1.35 (0.48)

1–2

2.33 (0.94)

1–3

1.34 (0.60)

1–3

5). Demographic Confounders Controlled for: Were relevant demographic confounders (gender, SES, race/ethnicity) controlled for in study design or analysis?

1 (0)

1

2.12 (0.83)

1–3

3.00 (0)

3

1.86 (0.90)

1–3

6). Environmental/Systems Confounders: Were environmental/systems confounders controlled for in study design or the analysis?

1.44 (0.50)

1–2

1.76 (0.73)

1–3

2.00 (0.82)

1–3

1.69 (0.70)

1–3

Total Study Quality Score

(sum of items 1–6)

9.22 (0.63)

8–10

12.29 (1.02)

11–14

15.00 (0)

15

11.62 (1.99)

8–15