Table 2.

Estimated parameter coefficients explaining age of onset with 2414 patients in 180 clusters^a

Parameter	Coefficient estimate	95% Wald confidence interval		Coefficient significance
		Lower	Upper	Wald Chi-square	p
Demographics
Latitude	−0.040	−0.170	0.090	0.367	0.545
Gender (female)	−0.406	−1.199	0.387	1.009	0.315
Monthly insolation values
Maximum monthly insolation	−1.268	−2.304	−0.231	5.743	0.017b
Minimum monthly insolation	−0.227	−1.645	1.191	0.098	0.754
Monthly insolation range	−1.168	−2.117	−0.218	5.811	0.016b
Cumulative insolation for year	−0.085	−0.199	0.029	2.126	0.145
Mean monthly isolation	−1.017	−2.385	0.350	2.126	0.145
Mean winter insolation	−0.067	−1.405	1.270	0.010	0.921
Mean spring insolation	−1.181	−2.395	0.033	3.633	0.057
Mean summer insolation	−1.125	−2.265	0.016	3.737	0.053
Mean fall insolation	−0.844	−2.131	0.444	1.649	0.199
Insolation range mean summer - mean winter	−1.265	−2.333	−0.197	5.393	0.020b
Monthly insolation changes
Maximum monthly insolation increase	−4.724	−8.124	−1.323	7.413	0.006b
Maximum monthly insolation decrease	0.412	−4.360	5.183	0.029	0.866
Percent maximum monthly insolation increase	−0.048	−0.099	0.002	3.560	0.059

^aGEE model estimated age of onset using a constant, each country’s median age, and the listed parameter with an exchangeable correlation structure in each cluster. There was one degree of freedom for all models.

^bSignificance < 0.05%.