Table 3c.

Output of the univariate regression on the COVID-19 affected cases per swabs by region SE = standard error. Significant level at 0.05 (The variables with p-value <0,05 are marked in bold) CI = confidence interval.

Variable	Regression coefficient	SE	P-value	% of variation explained	Effect size (%)a	95% CI
Vitamin D UV exposure	−1.89	0.53	2.2 × 10−3	41.4	−4.2	−6.6	−1.7
PM10	0.02	0.01	1.9 × 10−1	9.5	1.1	−0.6	2.8
RH	0.03	0.03	2.1 × 10−1	8.7	5.6	−3.3	15.3
T	−0.05	0.03	8.9 × 10−2	15.2	−1.3	−2.8	0.2
Mean age	0.06	0.04	1.9 × 10−1	9.3	6.1	−3.2	16.4
NHR/population %	50.21	17.90	1.2 × 10−2	30.4	0.8	0.2	1.4
Mortality rate	0.07	0.05	1.5 × 10−1	11.4	1.8	−0.7	4.4
Ischemic heart diseases	−14.00	8.69	1.2 × 10−1	12.6	−1.6	−3.7	0.5
Circulatory system diseases	−7.17	2.85	2.1 × 10−2	26.1	−2.4	−4.4	−0.4
Cerebrovascular diseases	−14.26	8.73	1.2 × 10−1	12.9	−1.2	−2.7	0.3
Diabetes mellitus	−7.11	2.77	2.0 × 10−2	26.8	−1.0	−1.8	−0.2

RH = relative humidity.

NHR = nursing home residents.

T= air temperature.

^aThe effect size is the estimated mortality change due to a 1% increase of the relative variable average.