Table 3.
Effect of the intervention on outcomes
|
Summary statistics |
Intervention effect* |
|||
|---|---|---|---|---|
| Control (1899 students; 308 staff) | Intervention (1921 students; 283 staff) | Basic model | Adjusted model | |
| Physical violence | ||||
| Student self-reported past week physical violence at school | 48·7% (924/1899) | 31·0% (595/1921) | 0·40 (0·26 to 0·64) p<0·0001 | 0·39 (0·25 to 0·62) p<0·0001 |
| Student self-reported past term physical violence at school | 80·5% (1528/1899) | 60·2% (1157/1921) | 0·32 (0·18 to 0·55) p<0·0001 | 0·31 (0·18 to 0·53) p<0·0001 |
| School staff self-reported past week use of physical violence | 32·5% (100/308) | 15·5% (44/283) | 0·39 (0·20 to 0·73) p=0·0036 | 0·37 (0·20 to 0·69) p=0·0018 |
| Mental health and wellbeing | ||||
| SDQ total difficulties score | 0·44 (0·26) | 0·44 (0·26) | 0·01 (-0·02 to 0·04) 0·6585 | 0·00 (-0·03 to 0·03) 0·8907 |
| School wellbeing | 11·1 (2·5) | 11·7 (2·4) | 0·58 (0·25 to 0·91) 0·0006 | 0·59 (0·24 to 0·93) 0·0008 |
| Educational performance | ||||
| Word recognition in English (words per minute) | 49·7 (27·7) | 48·6 (27·7) | 0·16 (-3·47 to 3·79) 0·9308 | 0·27 (-3·48 to 4·02) 0·8873 |
| Word reading in English | 49·0 (21·3) | 47·8 (21·3) | 1·79 (-1·33 to 4·90) 0·2611 | 1·90 (-1·23 to 5·02) 0·2344 |
| Reading comprehension in English | 1·4 (1·5) | 1·4 (1·6) | 0·13 (-0·18 to 0·44) 0·4115 | 0·12 (-0·20 to 0·44) 0·4593 |
| Word recognition in Luganda (words per minute) | 33·2 (20·7) | 31·2 (20·7) | -1·08 (-3·36 to 1·19) 0·3511 | -0·96 (-3·40 to 1·48) 0·4413 |
| Word reading in Luganda | 37·9 (22·0) | 35·1 (22·4) | -2·01 (-4·66 to 0·65) 0·1385 | -1·89 (-4·67 to 0·90) 0·1844 |
| Reading comprehension in Luganda | 2·8 (1·8) | 2·6 (1·8) | -0·10 (-0·31 to 0·11) 0·3569 | -0·10 (-0·32 to 0·13) 0·3937 |
| Silly sentences test | 9·3 (5·2) | 9·1 (5·1) | -0·63 (-1·61 to 0·35) 0·2106 | -0·55 (-1·58 to 0·48) 0·2963 |
| Spelling in English | 10·8 (6·2) | 10·6 (6·9) | -0·19 (-1·13 to 0·74) 0·6875 | -0·17 (-1·15 to 0·80) 0·7260 |
| Writen numeracy | 24·9 (7·4) | 24·7 (8·1) | -0·87 (-1·87 to 0·14) 0·0904 | -0·91 (-1·99 to 0·17) 0·0972 |
Odds ratio (95% CI), p value for physical violence; difference (95% CI), p value for all other outcomes. The quantity of missing data was extremely low for all measures (<0·5%) and similar in both study arms. The basic model for continuous outcomes (ie, SDQ, school wellbeing, and all educational outcomes) adjusted for baseline by including as a covariate in statistical models the school level mean of the outcome at baseline. The basic model for binary outcomes (ie, the three physical violence measures) made no adjustment for baseline. Adjusted models controlled for school location (uban vs rural) and school-level prevalence of physical violence at baseline. Adjusted models for student-level outcomes controlled additionally for students' sex and disability. The adjusted model for staff self-reported past week use of physical violence controlled additionally for sex. For the educational performance assessments which were administered at class level (silly sentences, spelling in English and written numeracy) data from a total of 5291 students were included in the analysis (control 2833; intervention 2458). Adjusted models for these three outcomes did not control for students' sex and disability, as these measures were not collected for all students in this wider sample. For non-normally distributed continuous outcomes 95% CI were estimated using the bootstrap method. All models accounted for correlations between students within schools. At follow-up, the ICC was 0·105 in the control arm.