Table 2.
Methodological characteristics and geographical location of 50 studies included for review.
| Variable | No. of studies (%) |
|---|---|
| Geographical location | |
| Africa | 17 (34) |
| Middle East | 2 (4) |
| Asia | 12 (24) |
| South and Central America | 14 (28) |
| Europe | 5 (10) |
| UNICEF definitions of street children for inclusion criteria | 8 (16) |
| Defined drug use | 15 (30) |
| Defined life-time drug usea | 5 (19) |
| Defined current drug useb | 8 (89) |
| Used a validated questionnaire | 8 (16) |
| Ethics approval reported | 23 (46) |
| Sampling origin | |
| Temporary home/institution | 9 (18) |
| Drop-in centres | 10 (20) |
| Streets | 26 (52) |
| Mixed (streets, institutions) | 2 (4) |
| Unknown | 1 (2) |
| Otherc | 2 (4) |
| Sampling methodology | |
| Non-probability | 34 (68) |
| Probability | 12 (24) |
| Unknown | 4 (8) |
| Analysis | |
| Descriptive only | 26 (52) |
| Bivariate only | 14 (28) |
| Multivariate only | 2 (4) |
| Bivariate and multivariate | 8 (16) |
| Study design | |
| Cross-sectional | 41 (82) |
| Case–control | 2 (4) |
| Cohort | 1 (2) |
| Mixed methods | 3 (6) |
| Conference abstracts | 3 (6) |
a
Of those who reported life-time use (n = 27).
b
Of those who reported current use (n = 9).
c
Aljamiri schools, hospital records.