Table 7. Unadjusted and adjusted hierarchical regression model-pH effect vs die-off rate, n = 30.
| Covariates | pH_code | V | Day | Metal*pH level | Day*pH level | Constant |
| A | −2.546 (−3.009–−2.083) | 81.64(69.28–94.00) | ||||
| B | −2.546 (−3.009–−2.083) | −12.03(−16.03– −8.029) | 87.66(82.99–92.32) | |||
| C | −2.546 (−2.814–−2.278) | 22.18(19.86–24.49) | 70.55(58.51–82.59) | |||
| D | −2.546(−2.814–−2.278) | −12.03(−14.35– −9.713) | 22.18(19.86–24.49) | 76.57(73.63–79.51) | ||
| E | −2.968(−3.338–−2.598) | −18.79(−23.54– −14.03) | 22.18(19.92–24.44) | 0.844(0.321–1.368) | 79.95(76.40–83.49) | |
| F | −1.769(−2.113–−1.425) | −12.03(−14.13– −9.930) | 34.60(30.18–39.03) | −1.554(−2.040– −1.067) | 70.35(67.06–73.65) | |
| G | −2.191(−2.599–−1.783) | −18.79(−23.07– −14.50) | 34.60(30.32–38.89) | 0.844(0.373–1.316) | −1.554(−2.025– −1.082) | 73.73(70.02–77.44) |
Confidence Interval in parentheses; Note: p value for all the parameters was less than 0.01.
A: Model Main effect, B: Adjusting for metal, C: Adjusting for incubation period (Time), D: Adjusting for metal and time, E: Adjusting for metal, time and metal*pH interaction, F: Adjusting for metal, time and time* pH interaction, G: adjusting for metal, time, metal*pH interaction and and time* pH interaction.
Note: Each model includes the coefficient and their confidence interval in bracket.