Table 5.

Effect of the degree of freedom of the smoothing function use to adjust for seasonality on the association between NO₂ and CVD.

Degree of freedom per year	ERR [IC 95%]	Sum of the absolute values of PACF
1	3.6 [2.5; 4.8]	1.495
2	3.6 [2.5; 4.8]	1.468
3	3.6 [2.5; 4.8]	1.441
4	3.1 [1.9; 4.3]	1.455
5	2.3 [1.1; 3.5]	1.469
6	2.5 [1.3; 3.7]	1.555
7	2.4 [1.1; 3.6]	1.711

ERR: excess of relative risk; PACF: partial autocorrelation function.