Table 5.

The associations of education with high plasma vitamin C concentration in Pitkäranta, the Republic of Karelia, Russia in 1997 and 2002 and in North Karelia, Finland in 1992, 1997 and 2002. The reference category comprised the middle and lowest vitamin C tertiles

		Unadjusted		Adjusted for age
	Education tertile	OR	95 % CI	OR	95 % CI	P value*
Pitkäranta
Men†
1997	High	1·00	–	1·00	–
	Intermediate	0·53	0·29, 0·96	0·49	0·27, 0·90	0·02
	Low	0·58	0·28, 1·19	0·59	0·28, 1·23	0·16
2002	High	1·00	–	1·00	–
	Intermediate	0·35	0·18, 0·67	0·31	0·16, 0·61	0·001
	Low	0·10	0·04, 0·26	0·09	0·03, 0·25	<0·001
1997 and 2002	High	1·00	–	1·00	–
	Intermediate	0·44	0·28, 0·68	0·40	0·26, 0·63	<0·001
	Low	0·27	0·15, 0·47	0·27	0·15, 0·47	<0·001
Women
1997	High	1·00	–	1·00	–
	Intermediate	0·83	0·49, 1·39	0·86	0·51, 1·45	0·57
	Low	0·28	0·15, 0·52	0·27	0·14, 0·51	<0·001
2002	High	1·00	–	1·00	–
	Intermediate	0·79	0·43, 1·44	0·85	0·46, 1·57	0·61
	Low	0·46	0·25, 0·87	0·46	0·24, 0·86	0·02
1997 and 2002	High	1·00	–	1·00	–
	Intermediate	0·81	0·55, 1·20	0·86	0·58, 1·27	0·44
	Low	0·36	0·23, 0·56	0·35	0·23, 0·55	<0·001
North Karelia
Men
1992	High	1·00	–	1·00	–
	Intermediate	0·64	0·31, 1·29	0·65	0·32, 1·34	0·24
	Low	0·54	0·28, 1·05	0·51	0·26, 1·01	0·054
1997	High	1·00	–	1·00	–
	Intermediate	0·63	0·29, 1·36	0·62	0·28, 1·36	0·23
	Low	0·50	0·24, 1·05	0·49	0·23, 1·02	0·06
2002	High	1·00	–	1·00	–
	Intermediate	0·67	0·43, 1·04	0·67	0·43, 1·04	0·07
	Low	0·94	0·61, 1·43	0·94	0·62, 1·44	0·81
1992, 1997 and 2002	High	1·00	–	1·00	–
	Intermediate	0·65	0·46, 0·91	0·65	0·47, 0·92	0·01
	Low	0·73	0·53, 1·00	0·72	0·53, 1·00	0·05
Women
2002	High	1·00	–	1·00	–
	Intermediate	1·03	0·68, 1·54	1·04	0·69, 1·56	0·85
	Low	0·75	0·51, 1·13	0·76	0·51, 1·13	0·17

*P value for age-adjusted figures.

†The data from Pitkäranta in 1992 were omitted from the logistic regression analyses because of the skewed distribution in plasma vitamin C concentration.