Reliability of Self-Reported Tobacco Use in Bipolar Disorder: An Exploratory Study of Euthymic Patients Visiting a Tertiary Care Hospital in India

Abstract

Background: Unlike schizophrenia, only a little attention has been paid to tobacco dependence in patients with bipolar disorder despite a similarly high prevalence and predisposition to health risks. The euthymic phase is especially suitable for tobacco screening by the treating psychiatrist. However, the validity of self-report for tobacco use in this patient population remains undetermined. Aim: The current study aims to assess the validity of self-reported tobacco use in euthymic bipolar disorder. Method: The psychiatric out-patients with DSM-IV TR diagnosis of bipolar type-I in remission who were males, ⩾ 18 years, and euthymic as established by current scores of < 7 on HAM-D and < 4 on YMRS. Patients were specifically asked for the recent use of tobacco in any form. Ten ml urine sample was obtained after informed consent and subjected to a quantitative cotinine estimation by direct enzyme-linked immunosorbent assay. Results: A total of 100 patients were screened, of which 79 were finally included. The self-report or recent tobacco use showed only a moderate concordance with urinary cotinine (k=0.518) and cotinine-creatinine ratio (k=0.492). Over 15% patients had denied the use of tobacco, but tested positive on urinary cotinine assessment. The sensitivity of self-report was 73.3% compared to urinary cotinine. The denial among users was 26.7% and denial among those with negative self-report was 30.8%. Conclusion: Mental health professionals should be vigilant for detection of tobacco dependence among remitted bipolar patients, who may not be so forthcoming about their tobacco use.