Table 1.

Characteristics of the participants included in the validation study of the mother–child ‘Rhea’ birth cohort, Heraklion, Crete, Greece, 2011–2012 and comparison with the total population of the Rhea study

	Validation study		Rhea
	(n 99)		(n 1008)
	n	%	n	%	P value
Maternal education					0·353
Low	13	13·1	169	17·7
Medium	50	50·5	495	51·8
High	36	36·4	292	30·5
Mother’s origin					0·301
Greek	95	96·0	929	93·3
Other	4	4·0	67	6·7
Marital status					0·748
Married/engaged	87	87·9	853	88·9
Other	12	12·1	106	11·1
Residence					0·982
Urban	63	71·6	555	71·7
Rural	25	28·4	219	28·3
Smoking status					0·003*
Smoker	19	21·6	292	12·5
Non-smoker	69	78·4	484	87·5
Parity					0·268
Multiparous	50	51·5	543	57·4
Primiparous	47	48·5	403	42·6
Child gender					0·894
Male	51	51·5	526	52·2
Female	48	48·5	482	47·8
	Mean	sd	Mean	sd	P value
Maternal age (years)	33·64	5·37	33·50	4·92	0·910
Maternal BMI (kg/m2)	25·59	5·44	25·43	4·92	0·973
Child age (years)	3·65	0·11	3·69	0·39	0·639
Child BMI (kg/m2)	16·48	1·87	16·43	1·98	0·845

Missing values have been excluded (pair-wise: validation study, Rhea): maternal education (n 0, n 52); Greek origin (n 0, n 12); marital status (n 0, n 49); residence (n 11, n 234); smoking status (n 11, n 232); parity (n 2, n 62); child gender (n 0, n 0).

^*Statistically significant difference (P<0·05) based on Mann–Whitney U test for two independent samples and Pearson’s χ ² test for independence.