. 2015 Jul 1;18(17):3108–3124. doi: 10.1017/S1368980015001937

Table 2.

Characteristics of the study population by country: nationally representative samples of 6–9-year-olds, WHO European Childhood Obesity Surveillance Initiative, school year 2007/2008

Characteristic	Bulgaria	Czech Republic	Lithuania	Portugal	Sweden
Children who were present on the day of the anthropometric measurements: total (n)	3914	1695	4955	3592	5338
Children who participated in the anthropometric measurements: total (n)^‡	3392	1695	4948	3590	4708
Children with complete data on age, sex, weight and height measures: total (n)	3381	1692	4939	3590	4581
Children who returned a filled out family form: total (n)^§	3427	1660	4436	3063	3711
Total study group of children: total (n)^\|\|	3267	1633	4084	3026	3633
Age (years)
Mean	7·7	7·0	7·8	7·5	8·4
sd	0·3	0·3	0·3	0·6	0·6
Boys
n	1619	815	2064	1509	1874
%	49·6	49·9	50·5	49·9	51·6
Prevalence of overweight (%)^¶	28·8^b	20·9^c	23·1^c	37·6^a	23·2^c
Prevalence of obesity (%)^¶	12·4^a	7·3^b	8·3^b	14·6^a	6·5^b
Prevalence of normal weight (%)^¶	68·4^b	76·3^a	74·9^a	61·5^c	75·6^a
Prevalence of thinness (%)^¶	2·9^a	2·8^a	2·0^a	0·9^b	1·1^b
BMI-for-age Z-score
Mean	0·35	0·13	0·27	0·71	0·27
sd	1·36	1·21	1·18	1·20	1·07
Subgroup of children: total (n)^‡‡	2373	1107	2874	1818	2345
Age (years)
Mean	7·7	7·0	7·8	7·5	8·4
sd	0·3	0·3	0·3	0·6	0·6
Boys
n	1189	543	1475	901	1247
%	50·1	49·1	51·3	49·6	53·2
Prevalence of overweight (%)^¶	29·3^b	20·1^c	24·5^c	37·7^a	22·6^c
Prevalence of obesity (%)^¶	12·6^a	7·4^b,c	8·9^b	13·8^a	5·8^c
Prevalence of normal weight (%)^¶	68·1^b	77·2^a	73·5^a	61·6^c	76·1^a
Prevalence of thinness (%)^¶	2·6^a	2·7^a,b	2·0^a,b	0·7^c	1·3^b,c
BMI-for-age Z-score
Mean	0·38	0·13	0·30	0·70	0·25
sd	1·36	1·22	1·20	1·19	1·07

^a,b,cProportions within a row with unlike superscript letters were significantly different (Marascuilo procedure). Superscripts are ranked by decreasing prevalence, whereby the highest prevalence was indicated with superscript a.

^‡

All children who agreed to have their weight and height measured, including children with missing information on age or sex.

^§

Out of the children who returned a filled out family form, 3285 Bulgarian, 1649 Czech, 4089 Lithuanian, 3032 Portuguese and 3637 Swedish children had complete information on age, sex, weight and height measures.

^||

Children with complete information on sex, whose age was between 6 and 9 years old, whose weight and height were measured, whose BMI-for-age Z-score was within the normal range (≥–5 and ≤+5) and who returned a filled out family record form.

^¶

Overweight is defined as the proportion of children with a BMI-for-age value >+1 Z-score (i.e. BMI-for-age above +1 sd relative to the median BMI-for-age of the 2007 WHO growth reference)⁽ ²⁵ ⁾, obesity as the proportion of children with a BMI-for-age value >+2 Z-score, normal weight as the proportion of children with a BMI-for-age value ≥–2 and ≤+1 Z-score, and thinness as the proportion of children with a BMI-for-age value <–2 Z-score. Statistically significant difference in proportions across the countries (χ ² test; P<0·001).

^‡‡

All criteria for the total study group of children, as well as no missing values for the thirteen health-risk behaviours, children’s residential urbanization grade, parental education and parental occupation.