Table II.

Analysis of deviance table for comparison of various specification of the two-dimensional log-linear model for exposure and latency.

Latency model (knots [years])*	Exposure model (knots [WL])*	Model DF	Deviance	LRT† statistic (DF)	p-Value	AIC
Cumulative exposure		1	1878.7	—	—	1880.7
Piecewise constant	Piecewise constant	16	1791.7	87.0 (15)	<0.001‡	1823.7
Cubic (none)	Linear (none)	4	1840.0	38.7 (3)	<0.001‡	1848.0
	Linear (63)	8	1778.4	61.6 (4)	<0.001§	1794.4
	Linear [42,92]	12	1771.9	68.1 (8)	<0.001	1795.9
	Quadratic (None)	8	1799.0	41.0 (4)	<0.001	1815.0
	Quadratic (63)	12	1774.0	66.0 (4)	<0.001	1798.0
	Quadratic [42,92]	16	1768.5	71.5 (8)	<0.001	1800.5
	Cubic (None)	12	1770.7	69.3 (8)	<0.001	1794.7
	Cubic (63)	16	1759.0	81.0 (12)	<0.001	1791.0
	Cubic [42,92]	20	1757.7	82.3 (16)	<0.001	1797.7

^*Degree of the polynomial in each dimension of the tensor product spline, along with the position of the knots (in brackets).

^†Likelihood ratio test.

^‡Compared with a cumulative exposure model.

^§This and subsequent models compared with a tensor-product spline model with cubic and linear polynomials (no knots) for latency and exposure, respectively.