Validation of Self-Reported Smoker and Second Hand Smoke Exposure by Urinary Cotinine within The Malaysian Cohort Project

Abstract

Background: Validation of self-reported questionnaire is very crucial in ensuring the quality and reliability of data collection. Objective: The aim of this study were i) to validate the questionnaire on tobacco smoke intake and second hand smoke exposure among The Malaysian Cohort (TMC) subjects through the determination of urinary cotinine levels, ii) to determine the optimal cut-off point of urine cotinine that discriminates smokers from non-smokers and iii) to estimate misclassification rate between self-reported smoking and urinary cotinine level.Methods: Urine samples from a total of 775 The Malaysian Cohort subjects (104 smokers, 102 former smokers and 569 non-smokers) were obtained and urinary cotinine levels were determined by high-performance liquid chromatography (HPLC). Differences between groups were compared using Kruskal Wallis and Mann-Whitney tests. The Receiver Operating Characteristic (ROC) curved was performed to define the optimal urinary cotinine cut-off point.Results: Urinary cotinine concentration significantly (p<0.001) correlated with smoking status (r=0.46), the average number of cigarettes smoked per day (r=0.53), duration of smoking (r=0.33) and number of cigarettes packed per year (r=0.47). Smokers and second hand smokers have significantly higher median cotinine levels (978.40 and 21.31 respectively) compared to non-smokers (15.52) and non-exposed (13.60) subjects. Cotinine level at cut-off value of 1.51 ng/mg creatinine is able to distinguish smokers and non-smokers with a sensitivity of 84.62% and specificity of 81.97%.Conclusion: The Malaysian Cohort self-reported smoking questionnaire is a reliable tool in assessing the use of tobacco and second hand smoke exposure among the subjects.

Verifying the accuracy of self-reported smoking behavior in female volunteer soldiers

“…The female volunteer soldiers' self-reported smoking behavior and urine cotinine tests were found to be lower consistent in this study (Kappa = 0.703) than the results of the following studies 11 , 20 , 29 . The military service and basic military training conscripts' self-reported smoking behavior was shown to be highly consistent with their urinary cotinine levels (Kappa = 0.918) 20 .…”

“…The military service and basic military training conscripts' self-reported smoking behavior was shown to be highly consistent with their urinary cotinine levels (Kappa = 0.918) 20 . Within the Malaysian cohort project, urinary cotinine concentration was found to be correlated with self-reported smoking status, indicating that the self-reported smoking questionnaire is a reliable tool for assessing the tobacco use (Kappa = 0.822) 29 . Canadian Health Measures Survey also found self-reported smoking status can be used to calculate realistic smoking rate among Canadians (Kappa = 0.950) 11 .…”

A Preliminary Study for The Development and Psychometric Properties of Secondhand Smoke Exposure Assessment Tools

“…The sensitivity of the questionnaire was estimated at 42.3%; speci city was estimated at 96.7%; the positive predictive value was 84.6%; and the negative predictive value was 81.7%. According to the questionnaire results, the prevalence of smoking was 13.42%, while according to cotinine levels > 1.51 ng/mg, it was 26.84%, which indicates the low sensitivity of a selfreport questionnaire for assessing SHS exposure [14]. In the present study, we tried to increase the questionnaire validity by assessing the psychometric properties.…”

“…In the rst step, we carried out a literature review for creating tool items to assess SHS exposure [14,9,15,11,10,12,16]. Initially, 109 items were extracted from a literature review; after excluding repetitious questions and articles whose research population were children, the number of questions decreased to 26 items.…”