Table 1

Mean prevalences, 95% confidence intervals, and heterogeneity statistics
Type of prevalence k N Min. Max. p+ 95% C. I. Q df I2
pl pu
Point prevalence 10 49,124 0.032 0.350 0.120 0.090 0.159 546.87* 9 98.3
 Period prevalence:
 1 week 6 9,812 0.097 0.350 0.177 0.124 0.247 156.56* 5 96.8
 2 weeks 1 1,193 0.246 0.246 0.246 0.222 0.271 -- -- --
 1 month 14 23,191 0.025 0.398 0.183 0.128 0.255 1618.85* 13 99.2
 3 months 2 4,126 0.224 0.513 0.355 0.134 0.662 187.49* 1 99.5
 6 months 7 25,037 0.008 0.420 0.177 0.088 0.324 2197.00* 6 99.7
 12 months 13 19,673 0.174 0.603 0.336 0.269 0.410 997.00* 12 98.8
Lifetime prevalence 30 61,732 0.086 0.648 0.399 0.342 0.459 4957.79* 29 99.4

* p < .001. k: number of studies. N: total sample size. Min. and Max.: minimum and maximum prevalence rates. p+: mean prevalence. pl and pu: lower and upper confidence limits of the 95% confidence interval around the mean prevalence. Q: heterogeneity statistic to test the homogeneity hypothesis of the prevalence rates. df: degrees of freedom of the Q statistic. I2: heterogeneity index.

Calvo-Muñoz et al.

Calvo-Muñoz et al. BMC Pediatrics 2013 13:14   doi:10.1186/1471-2431-13-14

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