Table 2

Meta-regression of quality of life based on countries, continents, WHO regions

Subgroups	Mixed-effects analysis	Effect size and 95% CI						Test of null (2-tail)
Subgroups	Mixed-effects analysis	Number of studies	Point estimate	SE	Variance	Lower limit	Upper limit	Z value	P value
Countries	Brazil	18	58.03	2.34	5.45	53.45	62.60	24.85	<0.001
	China	9	47.16	1.81	3.26	43.62	50.69	26.12	<0.001
	Egypt	4	41.82	8.66	75.01	24.84	58.79	4.83	<0.001
	Iran	9	41.88	5.42	29.41	31.25	52.51	7.72	<0.001
	Japan	4	66.96	1.69	2.86	63.65	70.28	39.61	<0.001
	The Netherlands	6	46.68	2.08	4.35	42.59	50.76	22.39	<0.001
	Spain	5	56.42	4.68	21.94	47.24	65.60	12.04	<0.001
	Turkey	15	47.67	1.37	1.89	44.98	50.36	34.69	<0.001
	USA	16	47.59	0.94	0.89	45.74	49.43	50.54	<0.001
	Multi	12	52.01	1.79	3.20	48.51	55.52	29.07	<0.001
	Other	49	51.16	1.55	2.41	48.12	54.20	32.95	<0.001
Continents	Africa	4	50.65	1.02	1.47	31.01	70.30	5.05	<0.001
	Asia	44	49.50	1.73	3.01	46.10	52.90	28.54	<0.001
	Europe	48	50.12	1.24	1.54	47.69	52.54	40.44	<0.001
	North America	18	48.62	0.91	0.82	46.85	50.40	53.65	<0.001
	South America	22	56.37	2.19	4.79	52.08	60.65	25.76	<0.001
	Multi	11	49.51	1.81	3.28	45.95	53.06	27.32	<0.001
WHO regions	AFRO	1	65.20	1.28	1.65	62.69	67.71	50.82	<0.001
	EMRO	18	46.81	3.75	14.04	39.47	54.16	12.49	<0.001
	EURO	48	50.12	1.24	1.54	47.69	52.54	40.44	<0.001
	PAHO	40	52.63	0.85	0.72	50.97	54.30	62.01	<0.001
	SEARO	7	47.95	3.28	10.76	41.52	54.38	14.62	<0.001
	WPRO	23	51.32	1.81	3.28	47.77	54.87	28.34	<0.001
	Multi	10	50.23	1.90	3.60	46.51	53.96	26.46	<0.001

Multi: the studies which were investigated on some countries in the same time.
AFRO, African Region Organization; EMRO, Eastern Mediterranean Region Organization; EURO, European Region Organization; PAHO, Pan American Health Organization; SEARO, South-East Asian Region Organization; WPRO, Western Pacific Region Organization.