Table 5.

Agreement between control indexes and proxies about frequency of surrogate consumption among 1564 control households with complete information for both respondents

	Control
Control proxy	Every day or more often	Nearly every day	3–4 times per week	Once or twice a week	1–3 times per month	A few times per year	Never or almost never	Total
Every day or more often	2	0	1	2	1	1	0	7
Nearly every day	1	11	8	12	8	4	0	44
Three or four times a week	0	2	14	39	15	3	3	76
Once or twice a week	0	5	17	159	103	15	3	302
1–3 times a month	1	4	7	100	284	66	12	474
A few times per year	1	4	0	22	100	187	21	335
Never or almost never	0	3	1	8	13	32	269	326
Total	5	29	48	342	524	308	308	1,564

Weighted Cohen's kappa coefficient for agreement between 1564 index-proxy pairs = 0.61