@article {Hovanec489, author = {Jan Hovanec and Tobias Wei{\ss} and Holger Koch and Beate Pesch and Thomas Behrens and Benjamin Kendzia and Marina Arendt and Nico Dragano and Susanne Moebus and B{\"o}rge Schmidt and Thomas Br{\"u}ning and Karl-Heinz J{\"o}ckel}, title = {Smoking and urinary cotinine by socioeconomic status in the Heinz Nixdorf Recall Study}, volume = {73}, number = {6}, pages = {489--495}, year = {2019}, doi = {10.1136/jech-2018-211952}, publisher = {BMJ Publishing Group Ltd}, abstract = {Background Associations of socioeconomic status (SES) and smoking-related diseases depend on uniform validity of self-reported smoking habits in different SES groups. We investigated the influence of SES on validity of self-reported smoking status by means of urinary cotinine.Methods We determined total urinary cotinine in the baseline population of the Heinz Nixdorf Recall Study. Participants with cotinine\>200 {\textmu}g/L were potential current smokers. We defined upper and lower 20\% of the gender-specific distribution of the International Socio-Economic Index (ISEI) as high and low SES, respectively, else as intermediate. We analysed the association of self-reported smoking status and cotinine by ISEI and additional SES measures, stratified by gender. In self-reported non-smokers, we estimated age-adjusted ORs with 95\% CI to detect differences by SES in the validity of self-reported smoking status.Results In 2004 men and 1887 women, 78\% and 80\%, respectively, reported to be non-smokers. Median cotinine concentrations were 2 {\textmu}g/L in non-smokers, and 3651 {\textmu}g/L in male and 3127 {\textmu}g/L in female smokers. Based on cotinine in non-smokers, 2.0 \% of men (n = 32) and 1.8 \% of women (n = 27) were potential smokers, with lower proportions in the subgroup of never-smokers (men: 0.7\%, women: 0.5\%). The validity of self-reported smoking status did not substantially differ by SES. Tendencies for increased underreporting were indicated for women with low ISEI (OR 1.35; 95\% CI 0.54 to 3.39) and men in blue-collar jobs (OR 1.39; 95\% CI 0.67 to 2.87).Conclusion Validity of self-reported smoking status in this elderly German cohort was high and did not depend on SES.}, issn = {0143-005X}, URL = {https://jech.bmj.com/content/73/6/489}, eprint = {https://jech.bmj.com/content/73/6/489.full.pdf}, journal = {Journal of Epidemiology \& Community Health} }