Prevalence of low back pain in children and adolescents: a meta-analysis

BMC Pediatrics

Table 2 Results of the weighted ANOVAs of qualitative moderator variables on the lifetime prevalence estimates

Moderator variable	k	p ₊	95%	C. I.	ANOVA results
			p _l	p _u
Continent:
Europe	21	0.390	0.314	0.472	Q _B(4) = 1.95, p = .745; R ² = 0.0
North America	3	0.455	0.255	0.670	Q _W(25) = 4227.25, p < .001
Oceania	1	0.403	0.128	0.757
Africa	2	0.277	0.114	0.532
Asia	3	0.490	0.285	0.698
Origin of the sample:
School	25	0.398	0.333	0.467	Q _B(3) = 0.87, p = .833; R ² = 0.0
Community	2	0.396	0.197	0.638	Q _W(26) = 3833.03, p < .001
University	2	0.470	0.249	0.703
School + sport	1	0.280	0.085	0.619
Data extraction method:
Questionnaire	23	0.411	0.354	0.471	Q _B(1) = 0.36, p = .546; R ² = 0.143
Interview	4	0.365	0.243	0.507	Q _W(25) = 2345.19, p < .001

k: number of studies. p ₊: mean prevalence. p _l and p _u: lower and upper confidence limits of the 95% confidence interval around the mean prevalence. Q _B: between-categories statistic to test the influence of the moderator variable on the prevalence rates. Q _W: within-categories statistic to test the model misspecification. R ²: proportion of variance accounted for by the moderator variable.

ISSN: 1471-2431