Table 5.
Frequency of positive UDS cases for drug type combinations of one to four drugs rank ordered from most to least prevalent
| Number of Drugsa | Rank Orderb | |||||
|---|---|---|---|---|---|---|
| 1st | 2nd | 3rd | 4th | 5th | 6th | |
|
One Drug n = 16,651 (51.1%) |
Cannabis | Stimulants | Opiates | Sedatives | ||
| n | 10,541 | 4261 | 1266 | 583 | ||
| % | 63.3 | 25.6 | 7.6 | 3.5 | ||
|
Two Drugs n = 11,137 (34.2%) |
Cannabis, Stimulants | Opiates, Stimulants | Cannabis, Opiates | Cannabis, Sedatives | Sedatives, Stimulants | Opiates, Sedatives |
| n | 5897 | 2798 | 1157 | 627 | 398 | 260 |
| % | 53.0 | 25.1 | 10.4 | 5.6 | 3.6 | 2.3 |
|
Three Drugs n = 4,042 (12.4%) |
Cannabis, Opiates, Stimulants | Cannabis, Sedatives, Stimulants | Opiates, Sedatives, Stimulants | Cannabis, Opiates, Sedatives | ||
| n | 2612 | 622 | 531 | 277 | ||
| % | 64.6 | 15.4 | 13.1 | 6.9 | ||
|
Four Drugs n = 731 (2.3%) |
Cannabis, Opiates, Sedatives, Stimulants | |||||
| n | 731 | |||||
| % | 100 | |||||
a Percentages for combination groups were calculated by dividing the number of UDS cases positive for a given number of drugs by the total number of positive UDS cases (n = 32561). For example, the following formula was used to calculate the percentage of UDS cases positive for only one drug: 
b Percentages for each specific drug type combination in each row (one, two, three, or four drugs) were calculated by dividing the number of UDS cases positive for a given drug combination by the total number of cases producing UDS results positive for the corresponding number of drugs. For example, the following formula was used to calculate the percentage of UDS cases positive for only cannabis: 