Ohi K, Shimada T, Kuwata A, Kataoka Y, Okubo H, Kimura K, Yasuyama T, Uehara T, Kawasaki Y. Smoking Rates and Number of Cigarettes Smoked per Day in Schizophrenia: A Large Cohort Meta-Analysis in a Japanese Population.
Int J Neuropsychopharmacol 2019;
22:19-27. [PMID:
30239793 PMCID:
PMC6313124 DOI:
10.1093/ijnp/pyy061]
[Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/13/2018] [Accepted: 07/10/2018] [Indexed: 12/27/2022] Open
Abstract
Background
Cigarette smoking is consistently more common among schizophrenia patients than the general population worldwide; however, the findings of studies in Japan are inconsistent. Recently, the smoking rate has gradually decreased among the general population.
Methods
We performed a meta-analysis of smoking status in a large Japanese cohort of (1) 1845 schizophrenia patients and 196845 general population and (2) 842 schizophrenia patients and 766 psychiatrically healthy controls from 12 studies over a 25-year period, including 301 patients and 131 controls from our study.
Results
In our case-control sample, schizophrenia patients had a significantly higher smoking rate than healthy controls (P=.031). The proportion of heavy smokers (P=.027) and the number of cigarettes smoked per day (P=8.20×10-3) were significantly higher among schizophrenia patients than healthy controls. For the smokers in the schizophrenia group, atypical antipsychotics dosage was positively correlated with cigarettes per day (P=1.00×10-3). A meta-analysis found that schizophrenia patients had a higher smoking rate than the general population for both men (OR=1.53, P=.035; schizophrenia patients, 52.9%; general population, 40.1%) and women (OR=2.40, P=1.08×10-5; schizophrenia patients, 24.4%; general population, 11.8%). In addition, male schizophrenia patients had a higher smoking rate than male healthy controls (OR=2.84, P=9.48×10-3; schizophrenia patients, 53.6%; healthy controls, 32.9%), but the difference was not significant for women (OR=1.36, P=.53; schizophrenia patients, 17.0%; healthy controls,14.1%). Among both males and females, schizophrenia patients had a higher smoking rate than both the general population (OR=1.88, P=2.60×10-5) and healthy controls (OR=2.05, P=.018). These rates were not affected by the patients' recruitment year (P>.05). The cigarettes per day values of schizophrenia patients and the general population were 22.0 and 18.8, respectively.
Conclusions
Schizophrenia patients are approximately 2 times more likely to smoke than the general population and healthy controls based on data collected over a decade in Japan.
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