Table 1 Operationalisation of the study groups
Group 1: currently ATS dependent (CDU) | Group 2: formerly ATS dependent users (FDU) | Group 3: currently frequent, non-dependent ATS users (CFU) | Group 4: formerly frequent, non-ATS dependent users (FFU) | Group 5: non-frequent ATS users (currently and formerly) (NFU) | Group 6: exposed non-ATS users (ENU) |
|---|---|---|---|---|---|
SDS positive (last 12 months) | SDS positive (any time except last 12 months) | SDS negative lifetime | SDS negative lifetime | SDS negative lifetime | SDS not applicable |
≥ 10 ATS consumption days within past 12 months | ≥ 10 ATS consumption days within a year except past 12 months | ≥ 10 ATS consumption days within past 12 months | ≥ 10 ATS consumption days within a year except past 12 months | < 10 ATS consumption days within any given 12 months | Exposed to ATS without ATS consumption |