Characteristics of drug use when subjects in the HC group reported using only 1 drug in a given month and when the same subjects reported using both drugs in the same month In different questionnaires
| No. of subjects | Either drug used in the month; mean no. (and SD) | Both drugs used in the same month; mean no. (and SD) | |||
|---|---|---|---|---|---|
| Days of use | Injections/d | Days of use | Injections/d | ||
| Heroin | 9 | 15.7 (12.9) | 2.5 (1.5) | 14.6 (10.2) | 2.6 (1.8) |
| Cocaine | 36 | 16.1 (12.0) | 10.7 (9.6) | 16.3 (10.8) | 11.0 (12.0) |