Parameter | Estimate | Standard error | Chi-square* | P value |
---|
P0 | 5.3754 | 0.6836 | 61.84 |  < 0.0001 |
P1 | − 0.1271 | 0.0253 | 25.31 |  < 0.0001 |
P2 | 0.00106 | 0.000292 | 13.24 | 0.0003 |
P3 | − 3.24E−06 | 1.05E−06 | 9.47 | 0.0021 |
- P0, P1, P2, and P3 are the maximum likelihood estimates of the intercept, linear, quadratic, and cubic coefficients, respectively. *Chi-square is the value of the likelihood ratio test to determine whether equation coefficients differed significantly from zero