Table 5 AQI growth model for all classrooms, and stratified by centre type; with intraclass correlations on age group and classroom levels

Fixed effects

 Slope

0.041***

0.026

0.083***

0.050***

0.027**

0.039*

(0.007)

(0.023)

(0.019)

(0.012)

(0.010)

(0.019)

 Intercept

4.052***

3.982***

4.083***

3.975***

4.063***

4.375***

(0.015)

(0.041)

(0.048)

(0.027)

(0.023)

(0.029)

Random effects

 var(Age group—Intercept)

0.073***

0.045***

0.072

0.068***

0.071***

0.014***

(0.006)

(0.012)

(.)

(0.010)

(0.009)

(0.006)

 var(Classroom—Slope)

0.008***

0.008***

0.000

0.013***

0.007***

0.005***

(0.003)

(0.008)

(.)

(0.005)

(0.004)

(0.005)

 Intercept

0.010***

0.004**

0.000

0.026***

0.005***

0.000

(0.005)

(0.008)

(.)

(0.010)

(0.008)

(0.009)

 Cov(Slope|Intercept)

− 0.008*

− 0.005

0.000

− 0.019

− 0.005

− 0.001

(0.003)

(0.008)

(.)

(0.006)

(0.005)

(0.006)

var(Residual)

0.077***

0.074***

0.067

0.084***

0.077***

0.037***

(0.003)

(0.009)

(.)

(0.005)

(0.005)

(0.007)

N

3057

264

282

1074

1242

195

Age group

0.457

0.363

0.518

0.382

0.465

0.275

Age group|Classroom

0.518

0.393

0.518

0.528

0.498

0.279