Table 4.

Ultraviolet Radiation determining dementia incidence rate in different country groupings.

Country groupings	Pearson r	p	Nonparametric	p	n
Worldwide	−0.764	<0.001	−0.704	< 0.001	191
World Bank income classifications
High income	−0.733	< 0.001	−0.654	< 0.001	63
Upper middle income	−0.596	< 0.001	−0.519	< 0.001	51
Low middle income	−0.610	< 0.001	−0.384	< 0.010	49
Low income	−0.479	< 0.010	−0.312	0.106	28
Low‐ and middle‐income countries (LMIC)	−0.620	< 0.001	−.524	< 0.001	128
Fisher r‐to‐z transformation (LMIC vs. High‐income)	z = 1.34, p = 0.090		z = 1.28, p = 0.100
United Nations (common practice)
Developed	0.200	0.193	0.190	0.217	44
Developing	−0.448	< 0.001	−0.405	< 0.001	147
Fisher r‐to‐z transformation (Developing vs. developed)	z = −3.87, p < 0.001		z = −3.51, p < 0.001
WHO regions
Africa	−0.289	0.052	−0.056	< 0.001	47
Americas	−0.682	< 0.001	−0.224	0.197	35
Eastern Mediterranean	−0.748	< 0.001	−0.738	< 0.001	21
Europe	−0.504	< 0.001	−0.322	< 0.050	51
South‐East Asia	−0.281	0.403	−0.209	0.537	11
Western Pacific	−0.575	0.002	−0.446	0.020	27
Countries grouped with various factors
Asia Cooperation Dialog	−0.459	< 0.050	−0.392	< 0.050	30
Asia‐Pacific Economic Cooperation	−0.739	< 0.001	−0.868	< 0.001	19
Arab World	−0.798	< 0.001	−0.748	< 0.001	21
European Economic Area	0.146	0.449	0.398	< 0.033	29
English as Official Language	−0.756	< 0.001	−0.474	< 0.001	56
Latin America	−0.633	< 0.001	−0.400	0.058	23
Latin America and Caribbean	−0.388	< 0.050	−0.074	0.684	33
Organization for Economic Co‐operation and Development	−0.416	< 0.010	−0.141	0.406	37
Southern African Development Community	0.120	0.658	0.129	0.633	16
Shanghai Cooperation Organization	−0.484	0.012	−0.561	0.003	26

Note: Ultraviolet Radiation (UVR), expressed as the average daily ambient ultraviolet radiation level (in J/m²), the World Health Organization; Dementia incidence rate (DIR), the number of new cases per 100,000 people diagnosed in 2019 Institute for Health Metrics and Evaluation of the University of Washington.