Misclassification of smoking habits: An updated review of the literature

Table 2 Misclassification rates from Palmier et al[26] and from the other studies combined by meta-analysis (based on weighted analysis, avoiding double-counting)

Rate		Other studies combined				Palmier
		Cut 1a		Cut 2b		Cut 2b
		n	Rate (95%CI)	n	Rate (95%CI)	Rate
M1	% of self-reported non-smokers whose cotinine implies current smoking	209	4.96 (4.32 to 5.60)	65	3.66 (2.68 to 4.65)	2.01
M2	% of self-reported never smokers whose cotinine implies current smoking	86	3.00 (2.45 to 3.54)	22	2.34 (1.28 to 3.41)	-
M3	% of self-reported ex-smokers whose cotinine implies current smoking	88	10.92 (9.23 to 12.61)	24	6.79 (4.60 to 8.98)	-
M4	% of self-reported current smokers whose cotinine implies non-smoking	142	9.67 (7.73 to 11.61)	44	18.48 (14.46 to 22.50)	53.08
M5	% of true current smokers who report being non-smokers	136	14.50 (12.36 to 16.65)	43	10.42 (5.91 to 14.92)	19.31
M6	% of true current smokers who report being never smokers	52	5.70 (3.20 to 8.20)	13	4.34 (0.19 to 8.49)	-
M7	% of true current smokers who report being ex-smokers	52	8.93 (6.57 to 11.29)	13	7.89 (4.07 to 11.71)	-
M8	% of self-reported current smokers (plus misclassified non-smokers) who report being non-smokers	185	11.59 (10.00 to 13.17)	60	7.92 (5.19 to 10.65)	10.10
M9	% of self-reported current smokers (plus misclassified non-smokers) who report being never smokers	66	4.64 (2.73 to 6.54)	21	4.02 (1.68 to 6.35)	-
M10	% of self-reported current smokers (plus misclassified non-smokers) who report being ex-smokers	66	7.72 (5.95 to 9.50)	21	5.69 (3.54 to 7.84)	-
M11	% of true non-smokers who report being current smokers	137	3.65 (2.84 to 4.45)	43	7.67 (6.14 to 9.20)	8.84

^aThe lower cut point.

^bThe higher, more conservative, cut point.