- Email: [email protected]
Epidemiological study of smoking among Japanese physicians
Preventive Medicine 51 (2010) 164–167
Contents lists available at ScienceDirect
Preventive Medicine j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / y p m e d
Epidemiological study of smoking among Japanese physicians Yoshitaka Kaneita a,⁎, Takeo Uchida b, Takashi Ohida a a b
Division of Public Health, Department of Social Medicine, Nihon University School of Medicine, 30-1, Ohyaguchikamimachi, Itabashi-ku, Tokyo 173-8610, Japan The Japan Medical Association, Japan
a r t i c l e
i n f o
Available online 8 May 2010 Keywords: Smoking Physicians Japan
a b s t r a c t Objective. In this study, we attempted to clarify recent changes in the prevalence of smoking among Japanese physicians and factors related to smoking among physicians. Method. We conducted three self-administered questionnaire surveys on members of the Japan Medical Association in 2000, 2004, and 2008. In each survey, 3000 male and 1500 female physicians were randomly selected. Results. The total number of effective responses was 3771 in 2000, 3633 in 2004, and 3486 in 2008. The prevalence of smoking among male physicians decreased significantly from 27.1% in 2000 to 21.5% in 2004, and then to 15.0% in 2008 (p b 0.01). The prevalence of smoking among female physicians was 6.8%, 5.4%, and 4.6%, in 2000, 2004, and 2008, respectively (p = 0.07). With regard to factors associated with being a current smoker, the odds ratios were significantly high for “male gender,” “greater number of days on call/night shift,” and “habit of daily alcohol consumption.” Conclusions. The prevalence of smoking among Japanese male physicians has shown a declining trend. When planning antismoking measures for physicians, the number of days on call/night shift as well as the habit of daily alcohol consumption must be taken into consideration. © 2010 Elsevier Inc. All rights reserved.
Introduction
Methods
In 1999, the World Health Organization advocated that physicians, as role models for healthy living, should not smoke, and that they should not condone smoking by their patient (World Health Organization, 1999). It has been reported that smoking-cessation guidance and intervention by physicians have a significant effect on patients' smoking behaviour. Thus, importance has been placed on an antismoking attitude among physicians (Goldberg et al., 1993; Hollis et al., 1993). In this context, in 2000, the Japan Medical Association (JMA) and our study group jointly began conducting epidemiological surveys of the smoking behaviour of members of the JMA (Ohida et al., 2001; Kaneita et al., 2008). In the present study, we examined changes in the prevalence of smoking among Japanese physicians by analysing the results of three nationwide surveys conducted on members of the JMA in 2000, 2004, and 2008. We also examined factors related to smoking among physicians.
Procedure and sample The present study was approved by the Board of Directors of the JMA. In accordance with the Declaration of Helsinki, the privacy of the subjects was protected. In the present study, we conducted three cross-sectional nationwide surveys on smoking among members of the JMA. The three surveys were executed in 2000, 2004 and 2008. The subjects were 3000 male and 1500 female physicians selected randomly at each survey. The method of collecting data was the same in the three surveys. The following four items were distributed by mail to the subjects: a selfadministered questionnaire, a letter requesting cooperation in the survey, a medium-sized return envelope, and a small envelope for enclosing the questionnaire. Each subject was asked to enclose the filled-in questionnaire in the small envelope and seal it, then put it in the medium-sized return envelope to return it to the JMA. To identify those who did not return questionnaires, on the medium-sized return envelope a label bearing the subject's name and address was attached. On the questionnaire and the small envelope, no name and address were to be written. Those who did not return questionnaires were identified from the list of subjects and the labels attached to the medium-sized return envelopes. A second package was sent to each subject who had not returned a questionnaire, again seeking their cooperation. This follow-up procedure was repeated up to three times. Questionnaire
⁎ Corresponding author. Fax: +81 3 3972 5878. E-mail address: [email protected] (Y. Kaneita). 0091-7435/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.ypmed.2010.04.015
There were 40 items on the questionnaire, covering the following topics: (i) past and current smoking status, (ii) views on smoking, (iii) interventions
Y. Kaneita et al. / Preventive Medicine 51 (2010) 164–167
165
aimed at smoking-cessation experienced at medical institutions, (iv) smoking-cessation guidance given to patients, (v) alcohol drinking behaviour, (vi) working hour, night shift, and holiday, (vii) exercise habit, (viii) sleep status, (ix) psychology situation and (x) personal data, such as gender, age, medical specialty, and working form.
were gender, type of clinical institution affiliated to, number of days on call/night shift, and alcohol consumption (Table 2).
Definitions
We observed a statistically significant decline in the prevalence of smoking among male physicians. In contrast, the decline in the prevalence of smoking among female physicians was not statistically significant. However, the p-value in the chi-squared test was 0.07, which was very close to the value considered to be statistically significant (≤0.05). Tobacco control measures were included in the National Health Promotion campaign promoted by the Ministry of Health, Labour and Welfare in Japan since 2000. Public-relations (PR) activities via various forms of media, measures for the prevention of passive smoking, and propagation of smoking-cessation programmes have been promoted as a part of this campaign. For example, enforcement of laws and ordinances has gradually resulted in the prevention of passive smoking in public places in the Japanese society. In addition, since 2006, a major proportion of the total cost of the treatment for nicotine dependency has been covered by public health insurance systems. Furthermore, the JMA has exhaustively addressed the tobacco control measures. In 2003, the JMA announced their “Declaration for the Nation's Medical Professions to Combat Smoking”. This was a 7-item antismoking guideline that included an item stating that the JMA would promote an antismoking attitude among its physicians and medical professionals (The Japan Medical Association, 2003). The JMA also conducted PR and health education activities via booklets and the internet. Successful outcomes have been achieved through such tobacco control measures adopted by various institutions. The prevalence of smoking among the general population of Japan tended to decline in the recent years, whereas that among Japanese men and women declined from 53.5% in 2000 to 39.5% in 2008 and from 13.7% in 2000 to 12.9% in 2008, respectively (Japan Tobacco Inc., 2008). This trend of decline in the prevalence of smoking is commonly observed among Japanese physicians as well as among the general population. Multiple logistic regression analysis showed a significantly high adjusted odds ratio with regard to being a current smoker among physicians who were working night shifts or were on call 8 times or more per month. Few previous studies conducted either in Japan or overseas have examined the association between the number of days
Discussion
Respondents were classified as current smokers, past smokers and never smokers. “Current smokers” are those who currently smoke every day or occasionally. “Past smokers” are current nonsmokers who used to smoke habitually for 6 months or more. The person who did not belong to either of the previous two categories was defined as the “nonsmoker”. Statistical analyses First, we calculated the prevalence of smoking according to gender. We employed chi-squared tests to evaluate differences in data obtained in the three surveys. We employed Tukey's method for multiple comparisons. Second, we conducted a logistic regression analysis to examine factors associated with being a current smoker by using the data for the participants of the 2008 survey. Being a current smoker was input as a response variable, and gender, age group, employment status, type of clinical institution affiliated to, average work hours, number of holidays, number of days on call/ night shift, alcohol consumption, and exercise habit were input as covariates.
Results Valid responses were obtained from 3771 subjects (male: 2500 and female: 1271) for the survey in 2000, from 3633 subjects (male: 2432 and female: 1201) for the survey in 2004 and 3486 subjects (male: 2298 and female: 1188) for the survey in 2008. The prevalence of smoking in male physicians in 2008 was 15.0%, which was significantly low in comparison with the figures of 27.1% in 2000 and 21.5% in 2004 (Table 1). The prevalence of smoking in female physicians in 2008 was 4.6%, which was lower than that in 2000 (6.8%) and in 2004 (5.4%); however, this decrease was not statistically significant. With regard to changes in the prevalence of smoking according to age group, among male physicians we observed a significant decline across all age groups, except for those in their 20s. Among female physicians, we observed a statistically significant decline only among those in their 70s or higher. Multiple logistic regression analyses showed that the factors that were significantly associated with subjects being current smokers
Table 1 Changes in the prevalence of smoking among Japanese physicians from 2000 to 2008. Year
Age group
Total
20–29
30–39
40–49
50–59
60–69
70–
Number of physicians Prevalence of smoking, % Number of physicians Prevalence of smoking, % Number of physicians Prevalence of smoking, %
23 26.1 21 9.5 12 8.3 NS
264 30.7 214 28.0 132 16.7 p b 0.05
662 31.0 616 24.0 503 15.7 p b 0.01
577 27.6 634 24.4 700 17.0 p b 0.01
476 23.7 399 17.8 407 15.2 p b 0.01
498 22.9 548 15.9 544 11.4 p b 0.01
2500 27.1 2432 21.5 2298 15.0 p b 0.01
Number of physicians Prevalence of smoking, % Number of physicians Prevalence of smoking, % Number of physicians Prevalence of smoking, %
55 1.8 37 2.7 24 0.0 NS
292 5.5 275 6.9 213 5.2 NS
332 7.8 349 5.7 351 6.3 NS
215 7.4 222 6.8 284 3.5 NS
120 5.8 125 0.8 145 5.5 NS
257 8.2 193 4.7 171 2.3 pb0.05
1271 6.8 1201 5.4 1188 4.6 NS
Male In 2000 In 2004 In 2008 Chi-squared test Female In 2000 In 2004 In 2008 Chi-squared test
The chi-squared test was performed to examine the difference at the prevalence of smoking in 2000, 2004 and 2008. Abbreviations: NS = not significant.
166
Y. Kaneita et al. / Preventive Medicine 51 (2010) 164–167
Table 2 Factors associated with current smokers among Japanese physicians in 2008.
Gender Female Male Age (per 1 year) Employment status Employer Employee Type of clinical institution affiliated to Clinic Hospital Miscellaneous Working hour per day (per 1 h) Number of holidays per month (per 1 day) Number of days on call/night shift per month None Less than 1 time 1 time 2–3 times 4–7 times 8 times or more Alcohol consumption Do not drink at all Drink 1 time or less per week Drink 2–4 times per week Drink 5–6 times per week Drink every day Exercise habit Never Seldom Sometime Often Every day
Crude OR
95% CI
p-Value
Adjusted OR
95% CI
1.00 3.64 1.00
2.71 0.99
–
1.00 0.96
0.78
1.00 1.14 0.51 1.05 0.96
p-Value
4.88 1.01
b0.01 NS
1.00 3.60 0.99
2.55 0.98
–
5.10 1.00
b0.01 NS
–
1.19
NS
1.00 1.25
0.89
–
1.76
NS
0.91 0.26 1.01 0.93
– –
1.42 0.97 1.09 1.00
NS b0.05 b0.05 b0.05
1.00 0.97 0.32 0.99 1.01
0.68 0.12 0.94 0.97
– –
1.39 0.84 1.05 1.05
NS b0.05 NS NS
1.00 1.70 0.90 1.16 1.52 2.43
1.15 0.55 0.78 1.06 1.65
– – – – –
2.53 1.47 1.74 2.18 3.56
b0.05 NS NS b0.05 b0.01
1.00 1.30 0.73 0.93 1.18 2.08
0.84 0.43 0.59 0.77 1.36
– – – – –
2.02 1.24 1.48 1.80 3.18
NS NS NS NS b0.01
1.00 0.89 1.02 1.73 2.29
0.62 0.71 1.19 1.67
– – – –
1.26 1.46 2.49 3.14
NS NS b0.01 b0.01
1.00 0.78 0.77 1.27 1.81
0.53 0.52 0.84 1.27
– – – –
1.16 1.15 1.91 2.59
NS NS NS b0.01
1.00 1.18 1.05 0.95 1.04
0.83 0.76 0.65 0.69
– – – –
1.67 1.44 1.39 1.55
NS NS NS NS
1.00 1.13 0.91 0.80 0.85
0.77 0.64 0.53 0.54
– – – –
1.64 1.29 1.21 1.32
NS NS NS NS
All the items included in this table were input as covariates in the logistic model. In each section, the missing data have been excluded from the statistical analyses. Abbreviations: OR = odds ratio. CI = confidence interval. NS = not significant.
on call/night shift and physicians' smoking behaviour. From the results of our study, it will be necessary to consider the number of days on call/night shift when planning antismoking measures for physicians. The adjusted odds ratio with regard to current smoking for those who consumed alcohol daily was significantly higher than for those who “never consumed alcohol.” It has been observed not only among physicians but also in various other groups that smoking and alcohol consumption have a mutually facilitative role (Nakamura et al., 1996; Kaneita et al., 2007). Considering this correlation, comprehensive healthcare measures against alcohol consumption and smoking habits must be undertaken. Study limitations and strengths The present study has some limitations. First, smoking behaviour among physicians was evaluated only using self-administered questionnaires, not using biological and chemical measurements. Second, the prevalences of smoking among the target group of this study may be underestimates of the true prevalences if many smokers did not return our questionnaires. However, the final response rate in this study was high, at about 80%, similar to that in previous studies. Therefore, the difference between the results of this study and the actual prevalence of smoking among the target group may be relatively small but would depend on the smoking behaviour of the nonresponders. Third, only cigarette smoking was evaluated in this study. If pipe smoking and cigar smoking were added, the resulting overall prevalence of smoking would be higher. However, the market shares of leaf tobacco for pipe smoking (0.02%) and cigars (0.05%) in Japan in 2008 were extremely low and the impact of these forms of tobacco use probably was quite small (National Tax Administration Agency, 2008). Fourth, all physicians in Japan are not members of JMA.
About 60% of the physicians in Japan are a member of JMA. Therefore, the subjects of the present study do not perfectly represent all Japanese physicians. A further improvement is necessary in the future. Conclusion Throughout the three surveys, we confirmed an ongoing trend for favourable results in terms of smoking cessation, including a decrease in the prevalence of smoking among male physicians. We also demonstrated that the smoking behaviour of physicians was associated with gender, the types of clinical institutions to which they were affiliated, the number of days on call/night shift, and alcohol consumption. Thus, on the basis of the present findings, we believe that the JMA must promote further smoking-cessation activities among its members. Conflict of interest statement The authors declare that there are no conflicts of interest.
Acknowledgments We wish to express our thanks to Dr. Hideya Sakurai, Dr. Takashi Tsuchiya, Mr. Kazuhiro Fujimaki, Mr. Nobuhide Sakuma, Ms. Mayumi Shiba (the Japan Medical Assosiation) for their help in this study. References Goldberg, R.J., Ockene, I.S., Ockene, J.K., Merriam, P., Kristeller, J., 1993. Physicians' attitudes and reported practices toward smoking intervention. J. Cancer Educ. 8, 133–139. Hollis, J.F., Lichtenstein, E., Vogt, T.M., Stevens, V.J., Biglan, A., 1993. Nurse-assisted counseling for smokers in primary care. Ann. Intern. Med. 118, 521–525.
Y. Kaneita et al. / Preventive Medicine 51 (2010) 164–167 Japan Tobacco Inc., 2008. Nationwide Cigarette Smoking Survey[in Japanese] 2008 (Available at: http://www.health-net.or.jp/tobacco/product/pd090000.html). Kaneita, Y., Tomofumi, S., Takemura, S., et al., 2007. Prevalence of smoking and associated factors among pregnant women in Japan. Prev. Med. 45, 15–20. Kaneita, Y., Sakurai, H., Tsuchiya, T., Ohida, T., 2008. Changes in smoking prevalence and attitudes to smoking among Japanese physicians between 2000 and 2004. Public Health 122, 882–890. Nakamura, Y., Sakata, K., Yanagawa, H., 1996. Relationships between smoking habits and other behavior factors among males: from the results of the 1990 National Cardiovascular Survey in Japan. J. Epidemiol. 6, 87–91.
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National Tax Administration Agency, 2008. The Annual Statistical Report[in Japanese] 2008(Available at: http://www.nta.go.jp/kohyo/tokei/kokuzeicho/tokei.htm Accessed August 1, 2009). Ohida, T., Sakurai, H., Mochizuki, Y., et al., 2001. Smoking prevalence and attitudes toward smoking among Japanese physicians. JAMA 285, 2643–2648. The Japan Medical Association, 2003. The Declaration for the Nation's Medical Professions to Combat Smoking[in Japanese] 2003(Available at: http://www. med.or.jp/plaza/pdf/145.pdf). World Health Organization, 1999. Leave the Pack Behind. World Health Organization, Geneva, Switzerland.
Contents lists available at ScienceDirect
Preventive Medicine j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / y p m e d
Epidemiological study of smoking among Japanese physicians Yoshitaka Kaneita a,⁎, Takeo Uchida b, Takashi Ohida a a b
Division of Public Health, Department of Social Medicine, Nihon University School of Medicine, 30-1, Ohyaguchikamimachi, Itabashi-ku, Tokyo 173-8610, Japan The Japan Medical Association, Japan
a r t i c l e
i n f o
Available online 8 May 2010 Keywords: Smoking Physicians Japan
a b s t r a c t Objective. In this study, we attempted to clarify recent changes in the prevalence of smoking among Japanese physicians and factors related to smoking among physicians. Method. We conducted three self-administered questionnaire surveys on members of the Japan Medical Association in 2000, 2004, and 2008. In each survey, 3000 male and 1500 female physicians were randomly selected. Results. The total number of effective responses was 3771 in 2000, 3633 in 2004, and 3486 in 2008. The prevalence of smoking among male physicians decreased significantly from 27.1% in 2000 to 21.5% in 2004, and then to 15.0% in 2008 (p b 0.01). The prevalence of smoking among female physicians was 6.8%, 5.4%, and 4.6%, in 2000, 2004, and 2008, respectively (p = 0.07). With regard to factors associated with being a current smoker, the odds ratios were significantly high for “male gender,” “greater number of days on call/night shift,” and “habit of daily alcohol consumption.” Conclusions. The prevalence of smoking among Japanese male physicians has shown a declining trend. When planning antismoking measures for physicians, the number of days on call/night shift as well as the habit of daily alcohol consumption must be taken into consideration. © 2010 Elsevier Inc. All rights reserved.
Introduction
Methods
In 1999, the World Health Organization advocated that physicians, as role models for healthy living, should not smoke, and that they should not condone smoking by their patient (World Health Organization, 1999). It has been reported that smoking-cessation guidance and intervention by physicians have a significant effect on patients' smoking behaviour. Thus, importance has been placed on an antismoking attitude among physicians (Goldberg et al., 1993; Hollis et al., 1993). In this context, in 2000, the Japan Medical Association (JMA) and our study group jointly began conducting epidemiological surveys of the smoking behaviour of members of the JMA (Ohida et al., 2001; Kaneita et al., 2008). In the present study, we examined changes in the prevalence of smoking among Japanese physicians by analysing the results of three nationwide surveys conducted on members of the JMA in 2000, 2004, and 2008. We also examined factors related to smoking among physicians.
Procedure and sample The present study was approved by the Board of Directors of the JMA. In accordance with the Declaration of Helsinki, the privacy of the subjects was protected. In the present study, we conducted three cross-sectional nationwide surveys on smoking among members of the JMA. The three surveys were executed in 2000, 2004 and 2008. The subjects were 3000 male and 1500 female physicians selected randomly at each survey. The method of collecting data was the same in the three surveys. The following four items were distributed by mail to the subjects: a selfadministered questionnaire, a letter requesting cooperation in the survey, a medium-sized return envelope, and a small envelope for enclosing the questionnaire. Each subject was asked to enclose the filled-in questionnaire in the small envelope and seal it, then put it in the medium-sized return envelope to return it to the JMA. To identify those who did not return questionnaires, on the medium-sized return envelope a label bearing the subject's name and address was attached. On the questionnaire and the small envelope, no name and address were to be written. Those who did not return questionnaires were identified from the list of subjects and the labels attached to the medium-sized return envelopes. A second package was sent to each subject who had not returned a questionnaire, again seeking their cooperation. This follow-up procedure was repeated up to three times. Questionnaire
⁎ Corresponding author. Fax: +81 3 3972 5878. E-mail address: [email protected] (Y. Kaneita). 0091-7435/$ – see front matter © 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.ypmed.2010.04.015
There were 40 items on the questionnaire, covering the following topics: (i) past and current smoking status, (ii) views on smoking, (iii) interventions
Y. Kaneita et al. / Preventive Medicine 51 (2010) 164–167
165
aimed at smoking-cessation experienced at medical institutions, (iv) smoking-cessation guidance given to patients, (v) alcohol drinking behaviour, (vi) working hour, night shift, and holiday, (vii) exercise habit, (viii) sleep status, (ix) psychology situation and (x) personal data, such as gender, age, medical specialty, and working form.
were gender, type of clinical institution affiliated to, number of days on call/night shift, and alcohol consumption (Table 2).
Definitions
We observed a statistically significant decline in the prevalence of smoking among male physicians. In contrast, the decline in the prevalence of smoking among female physicians was not statistically significant. However, the p-value in the chi-squared test was 0.07, which was very close to the value considered to be statistically significant (≤0.05). Tobacco control measures were included in the National Health Promotion campaign promoted by the Ministry of Health, Labour and Welfare in Japan since 2000. Public-relations (PR) activities via various forms of media, measures for the prevention of passive smoking, and propagation of smoking-cessation programmes have been promoted as a part of this campaign. For example, enforcement of laws and ordinances has gradually resulted in the prevention of passive smoking in public places in the Japanese society. In addition, since 2006, a major proportion of the total cost of the treatment for nicotine dependency has been covered by public health insurance systems. Furthermore, the JMA has exhaustively addressed the tobacco control measures. In 2003, the JMA announced their “Declaration for the Nation's Medical Professions to Combat Smoking”. This was a 7-item antismoking guideline that included an item stating that the JMA would promote an antismoking attitude among its physicians and medical professionals (The Japan Medical Association, 2003). The JMA also conducted PR and health education activities via booklets and the internet. Successful outcomes have been achieved through such tobacco control measures adopted by various institutions. The prevalence of smoking among the general population of Japan tended to decline in the recent years, whereas that among Japanese men and women declined from 53.5% in 2000 to 39.5% in 2008 and from 13.7% in 2000 to 12.9% in 2008, respectively (Japan Tobacco Inc., 2008). This trend of decline in the prevalence of smoking is commonly observed among Japanese physicians as well as among the general population. Multiple logistic regression analysis showed a significantly high adjusted odds ratio with regard to being a current smoker among physicians who were working night shifts or were on call 8 times or more per month. Few previous studies conducted either in Japan or overseas have examined the association between the number of days
Discussion
Respondents were classified as current smokers, past smokers and never smokers. “Current smokers” are those who currently smoke every day or occasionally. “Past smokers” are current nonsmokers who used to smoke habitually for 6 months or more. The person who did not belong to either of the previous two categories was defined as the “nonsmoker”. Statistical analyses First, we calculated the prevalence of smoking according to gender. We employed chi-squared tests to evaluate differences in data obtained in the three surveys. We employed Tukey's method for multiple comparisons. Second, we conducted a logistic regression analysis to examine factors associated with being a current smoker by using the data for the participants of the 2008 survey. Being a current smoker was input as a response variable, and gender, age group, employment status, type of clinical institution affiliated to, average work hours, number of holidays, number of days on call/ night shift, alcohol consumption, and exercise habit were input as covariates.
Results Valid responses were obtained from 3771 subjects (male: 2500 and female: 1271) for the survey in 2000, from 3633 subjects (male: 2432 and female: 1201) for the survey in 2004 and 3486 subjects (male: 2298 and female: 1188) for the survey in 2008. The prevalence of smoking in male physicians in 2008 was 15.0%, which was significantly low in comparison with the figures of 27.1% in 2000 and 21.5% in 2004 (Table 1). The prevalence of smoking in female physicians in 2008 was 4.6%, which was lower than that in 2000 (6.8%) and in 2004 (5.4%); however, this decrease was not statistically significant. With regard to changes in the prevalence of smoking according to age group, among male physicians we observed a significant decline across all age groups, except for those in their 20s. Among female physicians, we observed a statistically significant decline only among those in their 70s or higher. Multiple logistic regression analyses showed that the factors that were significantly associated with subjects being current smokers
Table 1 Changes in the prevalence of smoking among Japanese physicians from 2000 to 2008. Year
Age group
Total
20–29
30–39
40–49
50–59
60–69
70–
Number of physicians Prevalence of smoking, % Number of physicians Prevalence of smoking, % Number of physicians Prevalence of smoking, %
23 26.1 21 9.5 12 8.3 NS
264 30.7 214 28.0 132 16.7 p b 0.05
662 31.0 616 24.0 503 15.7 p b 0.01
577 27.6 634 24.4 700 17.0 p b 0.01
476 23.7 399 17.8 407 15.2 p b 0.01
498 22.9 548 15.9 544 11.4 p b 0.01
2500 27.1 2432 21.5 2298 15.0 p b 0.01
Number of physicians Prevalence of smoking, % Number of physicians Prevalence of smoking, % Number of physicians Prevalence of smoking, %
55 1.8 37 2.7 24 0.0 NS
292 5.5 275 6.9 213 5.2 NS
332 7.8 349 5.7 351 6.3 NS
215 7.4 222 6.8 284 3.5 NS
120 5.8 125 0.8 145 5.5 NS
257 8.2 193 4.7 171 2.3 pb0.05
1271 6.8 1201 5.4 1188 4.6 NS
Male In 2000 In 2004 In 2008 Chi-squared test Female In 2000 In 2004 In 2008 Chi-squared test
The chi-squared test was performed to examine the difference at the prevalence of smoking in 2000, 2004 and 2008. Abbreviations: NS = not significant.
166
Y. Kaneita et al. / Preventive Medicine 51 (2010) 164–167
Table 2 Factors associated with current smokers among Japanese physicians in 2008.
Gender Female Male Age (per 1 year) Employment status Employer Employee Type of clinical institution affiliated to Clinic Hospital Miscellaneous Working hour per day (per 1 h) Number of holidays per month (per 1 day) Number of days on call/night shift per month None Less than 1 time 1 time 2–3 times 4–7 times 8 times or more Alcohol consumption Do not drink at all Drink 1 time or less per week Drink 2–4 times per week Drink 5–6 times per week Drink every day Exercise habit Never Seldom Sometime Often Every day
Crude OR
95% CI
p-Value
Adjusted OR
95% CI
1.00 3.64 1.00
2.71 0.99
–
1.00 0.96
0.78
1.00 1.14 0.51 1.05 0.96
p-Value
4.88 1.01
b0.01 NS
1.00 3.60 0.99
2.55 0.98
–
5.10 1.00
b0.01 NS
–
1.19
NS
1.00 1.25
0.89
–
1.76
NS
0.91 0.26 1.01 0.93
– –
1.42 0.97 1.09 1.00
NS b0.05 b0.05 b0.05
1.00 0.97 0.32 0.99 1.01
0.68 0.12 0.94 0.97
– –
1.39 0.84 1.05 1.05
NS b0.05 NS NS
1.00 1.70 0.90 1.16 1.52 2.43
1.15 0.55 0.78 1.06 1.65
– – – – –
2.53 1.47 1.74 2.18 3.56
b0.05 NS NS b0.05 b0.01
1.00 1.30 0.73 0.93 1.18 2.08
0.84 0.43 0.59 0.77 1.36
– – – – –
2.02 1.24 1.48 1.80 3.18
NS NS NS NS b0.01
1.00 0.89 1.02 1.73 2.29
0.62 0.71 1.19 1.67
– – – –
1.26 1.46 2.49 3.14
NS NS b0.01 b0.01
1.00 0.78 0.77 1.27 1.81
0.53 0.52 0.84 1.27
– – – –
1.16 1.15 1.91 2.59
NS NS NS b0.01
1.00 1.18 1.05 0.95 1.04
0.83 0.76 0.65 0.69
– – – –
1.67 1.44 1.39 1.55
NS NS NS NS
1.00 1.13 0.91 0.80 0.85
0.77 0.64 0.53 0.54
– – – –
1.64 1.29 1.21 1.32
NS NS NS NS
All the items included in this table were input as covariates in the logistic model. In each section, the missing data have been excluded from the statistical analyses. Abbreviations: OR = odds ratio. CI = confidence interval. NS = not significant.
on call/night shift and physicians' smoking behaviour. From the results of our study, it will be necessary to consider the number of days on call/night shift when planning antismoking measures for physicians. The adjusted odds ratio with regard to current smoking for those who consumed alcohol daily was significantly higher than for those who “never consumed alcohol.” It has been observed not only among physicians but also in various other groups that smoking and alcohol consumption have a mutually facilitative role (Nakamura et al., 1996; Kaneita et al., 2007). Considering this correlation, comprehensive healthcare measures against alcohol consumption and smoking habits must be undertaken. Study limitations and strengths The present study has some limitations. First, smoking behaviour among physicians was evaluated only using self-administered questionnaires, not using biological and chemical measurements. Second, the prevalences of smoking among the target group of this study may be underestimates of the true prevalences if many smokers did not return our questionnaires. However, the final response rate in this study was high, at about 80%, similar to that in previous studies. Therefore, the difference between the results of this study and the actual prevalence of smoking among the target group may be relatively small but would depend on the smoking behaviour of the nonresponders. Third, only cigarette smoking was evaluated in this study. If pipe smoking and cigar smoking were added, the resulting overall prevalence of smoking would be higher. However, the market shares of leaf tobacco for pipe smoking (0.02%) and cigars (0.05%) in Japan in 2008 were extremely low and the impact of these forms of tobacco use probably was quite small (National Tax Administration Agency, 2008). Fourth, all physicians in Japan are not members of JMA.
About 60% of the physicians in Japan are a member of JMA. Therefore, the subjects of the present study do not perfectly represent all Japanese physicians. A further improvement is necessary in the future. Conclusion Throughout the three surveys, we confirmed an ongoing trend for favourable results in terms of smoking cessation, including a decrease in the prevalence of smoking among male physicians. We also demonstrated that the smoking behaviour of physicians was associated with gender, the types of clinical institutions to which they were affiliated, the number of days on call/night shift, and alcohol consumption. Thus, on the basis of the present findings, we believe that the JMA must promote further smoking-cessation activities among its members. Conflict of interest statement The authors declare that there are no conflicts of interest.
Acknowledgments We wish to express our thanks to Dr. Hideya Sakurai, Dr. Takashi Tsuchiya, Mr. Kazuhiro Fujimaki, Mr. Nobuhide Sakuma, Ms. Mayumi Shiba (the Japan Medical Assosiation) for their help in this study. References Goldberg, R.J., Ockene, I.S., Ockene, J.K., Merriam, P., Kristeller, J., 1993. Physicians' attitudes and reported practices toward smoking intervention. J. Cancer Educ. 8, 133–139. Hollis, J.F., Lichtenstein, E., Vogt, T.M., Stevens, V.J., Biglan, A., 1993. Nurse-assisted counseling for smokers in primary care. Ann. Intern. Med. 118, 521–525.
Y. Kaneita et al. / Preventive Medicine 51 (2010) 164–167 Japan Tobacco Inc., 2008. Nationwide Cigarette Smoking Survey[in Japanese] 2008 (Available at: http://www.health-net.or.jp/tobacco/product/pd090000.html). Kaneita, Y., Tomofumi, S., Takemura, S., et al., 2007. Prevalence of smoking and associated factors among pregnant women in Japan. Prev. Med. 45, 15–20. Kaneita, Y., Sakurai, H., Tsuchiya, T., Ohida, T., 2008. Changes in smoking prevalence and attitudes to smoking among Japanese physicians between 2000 and 2004. Public Health 122, 882–890. Nakamura, Y., Sakata, K., Yanagawa, H., 1996. Relationships between smoking habits and other behavior factors among males: from the results of the 1990 National Cardiovascular Survey in Japan. J. Epidemiol. 6, 87–91.
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National Tax Administration Agency, 2008. The Annual Statistical Report[in Japanese] 2008(Available at: http://www.nta.go.jp/kohyo/tokei/kokuzeicho/tokei.htm Accessed August 1, 2009). Ohida, T., Sakurai, H., Mochizuki, Y., et al., 2001. Smoking prevalence and attitudes toward smoking among Japanese physicians. JAMA 285, 2643–2648. The Japan Medical Association, 2003. The Declaration for the Nation's Medical Professions to Combat Smoking[in Japanese] 2003(Available at: http://www. med.or.jp/plaza/pdf/145.pdf). World Health Organization, 1999. Leave the Pack Behind. World Health Organization, Geneva, Switzerland.