TABLE 2

Re-analysis stratified by altitude, age and duration of high-altitude climatic therapy

	Subjects	Sets of results	SMD (95% CI)	Heterogeneity
	Subjects	Sets of results	SMD (95% CI)	I²	p-value^#
Overall	907	28	0.53 (0.43–0.62)	85	<0.001
Altitude MASL
≤2000	717	22	0.53 (0.42–0.64)	85	<0.001
>2000	190	6	0.53 (0.32–0.74)	88	0.02
Age group
Children	371	14	0.24 (0.09–0.38)	4	0.41
Adults	536	14	0.75 (0.63–0.88)	90	<0.001
Treatment duration weeks
≤4	437	16	0.42 (0.28–0.55)	74	<0.001
>4	470	12	0.63 (0.50–0.77)	90	<0.001

Data are presented as n or %, unless otherwise stated. SMD: standardised mean difference; MASL: metres above sea level. ^#: p-value is for heterogeneity Chi-squared.