Accuracy of self-reported tobacco use in newly diagnosed cancer patients

Abstract

Purpose Accurate identification of tobacco use is critical to implement evidence-based cessation treatments in cancer patients. The purpose of this study is to evaluate the accuracy of self-reported tobacco use in newly diagnosed cancer patients. Methods Tobacco use questionnaires and blood samples were collected from 233 newly diagnosed cancer patients (77 lung, 77 breast, and 79 prostate cancer). Blood was analyzed for cotinine levels using a commercially available enzyme-linked immunosorbent assay. Patients with cotinine measurements exceeding 10 ng/mL were categorized as current smokers. Smoking status based upon cotinine levels was contrasted with self-report in current smokers, recent quitters (1 or less year since quit), non-recent quitters (>1 year since quit), and never smokers. Multivariate analyses were used to identify potential predictors of discordance between self-reported and biochemically confirmed smoking. Results Cotinine confirmed 100 % accuracy in self-reporting of current and never smokers. Discordance in cotinine and smoking status was observed in 26 patients (15.0 %) reporting former tobacco use. Discordance in self-reported smoking was 12 times higher in recent (35.4 %) as compared with non-recent quitters (2.8 %). Combining disease site, pack-year history, and employment status predicted misrepresentation of tobacco use in 82.4 % of recent quitters. Conclusions Self-reported tobacco use may not accurately assess smoking status in newly diagnosed cancer patients. Patients who claim to have recently stopped smoking within the year prior to a cancer diagnosis and lung cancer patients may have a higher propensity to misrepresent tobacco use and may benefit from biochemical confirmation.

Prevalence and Correlates of Smoking and Cessation-Related Behavior among Survivors of Ten Cancers: Findings from a Nationwide Survey Nine Years after Diagnosis

“…Similar to other large population-based surveys of cancer survivors, a limitation is self-report of smoking status and other health-related variables. Self-report of smoking in this study may not be a significant source of bias, however, as a study of newly diagnosed patients with cancer found that self-report of current and never smoking corresponded 100% with cotinine validation (39). In contrast, it was those who self-reported recent quitting within a year for whom there were discrepancies between self-report and biochemical validation; in the current study, however, only 1.2% of respondents reported quitting within a year of our assessment of smoking status.…”

Does Quitting Smoking Make a Difference Among Newly Diagnosed Head and Neck Cancer Patients?

“…This may be because, given the social stigma associated with smoking among head and neck cancer patients, 45 self-reported smoking may be less accurate than biochemically verified smoking status and might introduce misrepresentation of continuing smokers. 8,[45][46][47] However, the misrepresentation of current smokers can be minimized by repeated assessment of self-report smoking status as was done in this and another study conducted with head and neck cancer patients. 45 Several hypotheses have been proposed to explain the relationship between smoking after diagnosis and higher mortality.…”

Tobacco smoking and alcohol drinking at diagnosis of head and neck cancer and all‐cause mortality: Results from head and neck 5000, a prospective observational cohort of people with head and neck cancer

“…First, as in most previous studies, assessments of smoking and alcohol intake were based on participants’ self‐reports. Prior work has shown that self‐reports can often provide an inaccurate assessment of tobacco and alcohol use, particularly in people who have recently been diagnosed with cancer 48. This would most likely result in an underestimation of the effects of smoking and drinking on HNC survival.…”