Table 3.
Type of combination effect observed in vitro
| Group no.a | Treatmentb | O/E ratiosc | Mean O/E ratio ± SDd | Type of interactione | |
|---|---|---|---|---|---|
| 1 | A | MTA 0.04→GEM 0.04 | 0.75 | 0.73±0.04 | More than additive |
| B | MTA 0.04→GEM 0.16 | 0.66 | |||
| C | MTA 0.04→GEM 0.64 | 0.73 | |||
| D | MTA 0.04→GEM 2.56 | 0.73 | |||
| E | MTA 0.04→GEM 10.24 | 0.77 | |||
| 2 | A | GEM 0.02→MTA 0.02 | 1.15 | 1.08±0.13 | Additive |
| B | GEM 0.02→MTA 0.08 | 1.27 | |||
| C | GEM 0.02→MTA 0.34 | 1.04 | |||
| D | GEM 0.02→MTA 1.36 | 0.94 | |||
| E | GEM 0.02→MTA 5.43 | 1.01 | |||
| 3 | A | MTA 0.02 + GEM 0.04 | 1.29 | 1.29±0.03 | Less than additive |
| B | MTA 0.02 + GEM 0.16 | 1.28 | |||
| C | MTA0.02 + GEM 0.64 | 1.26 | |||
| D | MTA 0.02 + GEM 2.56 | 1.33 | |||
| E | MTA 0.02 + GEM 10.24 | 1.31 | |||
| 4 | A | GEM 0.04 + MTA 0.02 | 1.29 | 1.25±0.05 | Less than additive |
| B | GEM 0.04 + MTA 0.08 | 1.32 | |||
| C | GEM 0.04 + MTA 0.34 | 1.23 | |||
| D | GEM 0.04 + MTA 1.36 | 1.18 | |||
| E | GEM 0.04 + MTA 5.43 | 1.24 | |||
aGroup numbers correspond to Table 1
bDetails of treatment are given in Table 1
cO/E = ratio of observed versus expected treatment effect
dMean O/E ratio with standard deviation
eAn O/E ratio equal to unity (±0.14) was considered an additive combination effect, an O/E ratio <0.86 was considered a more than additive combination effect, and an O/E ratio >1.14 was considered a less than additive combination effect