Background
Tobacco use is a leading cause of morbidity and mortality all over the world and in Sub-Saharan Africa, and is currently in stage 1 of the tobacco epidemic continuum [
1‐
3], Stage 1, being the onset of a rising smoking epidemic, but the prevalence still low (< 15%) [
1]. In the past several decades, Western European countries reported the highest tobacco consumption rate (37% prevalence among men and 25% among women) [
4], however, the trend had changed in the past two decades, with cigarette consumption on the decline while it had increased in Africa.
The rising prevalence of tobacco use in Nigeria might be linked to the uncensored marketing strategies of tobacco companies and poor tobacco control policies in the country [
5,
6].
For example, according to the tobacco control act in Nigeria of 2015, outdoor smoking in recreational centre of any form is prohibited [
7]. Unfortunately, implementing the regulations has not been applauded by both Houses of the National Assembly [
6].
For instance, in Nigeria, cigarette importation has grown more than a hundred folds between 1970 and 2000 [
8]. In addition, in Africa, except for Egypt, and South Africa, Nigeria has the largest tobacco market [
8].
Thus, Nigeria continues to dominate in smoking epidemic. Estimates show that smoking increases the risk for coronary heart disease by 2 to 4 times, stroke by 2 to 4 times, men developing lung cancer by 25 times and women developing lung cancer by 25.7 times [
9]. Smoking is also associated with other chronic diseases such as depression [
10] and alcohol abuse [
11,
12]. Currently, there are several hypotheses that explain the association between smoking and depression. One is the self-medication hypothesis that postulates that individuals with depression smoke to alleviate their symptoms [
13]. The alternative hypothesis is that smoking increases an individual’s susceptibility to environmental stressors because it dysregulates the hypothalamic–pituitary–adrenal system, resulting in hypersecretion of cortisol, thereby leading to depression [
14].
Smoking also has documented ethnic [
15], sex [
16], age [
17] and rural-urban [
18] variability.
Strikingly is a rapid epidemiological shift of recreational activities in Nigeria to outdoor-open spaces, such as motor-parks, by the road sides, the majority of which are unlicensed premises for such activities [
19]. Owners of such open-places entice consumers by providing sources of entertainment, thereby encouraging patrons to smoke without any restriction.
In some countries of the world, outdoor smoke-free policies, despite their criticism have become popular and socially accepted, with public support over time [
20] and in all, there are 78 countries in the world with outdoor/quasi-outdoor spaces smoking restrictions [
21].
However, in developing countries such as Nigeria, the efforts aimed at reducing outdoor smoking is thwarted by inability to enforce drug policy and most smokers favour [
6].
Therefore, our aim in the present study was to determine the prevalence and predictors of outdoor smoking in selected open social joints in Nigeria. We also assessed the relationship between readiness to quit smoking and pack years of smoking. Furthermore, we assessed the association between smoking and depression as well as the association between smoking and alcohol consumption. This is because a key finding from our recent report on outdoor drinking among the same population shows an association between depression and alcohol [
22]. In this study, we defined open spaces as roofless joints such as motor-parks, by the roadsides or street corners.
Results
We interviewed 1393 subjects in all; however, data were complete for 1119. The mean age (SD) of all respondents was 39.10 (12.06) years (Not in any Table). The sociodemographic characteristics of the respondents are presented in Table
1.
Table 1
Sociodemography of Smokers (N = 1119)
Age
| Total | N | % | N | % | | |
< 24 | 147 | 86 | 66.7 | 41 | 32.3 | 7.1(df5) | 0.2 |
25–34 | 310 | 188 | 60.6 | 122 | 39.4 |
35–44 | 328 | 198 | 60.4 | 130 | 39.6 |
45–54 | 224 | 152 | 67.9 | 72 | 32.1 |
55–64 | 98 | 68 | 69.4 | 30 | 30.6 |
> 64 | 32 | 22 | 68.8 | 10 | 31.3 |
Gender |
Male | 826 | 554 | 67.1 | 272 | 32.9 | 14.5 | < 0.001 |
Female | 293 | 160 | 54.6 | 133 | 45.4 | | |
Marital Status |
Married | 634 | 417 | 65.8 | 217 | 34.2 | 2.5 | 0.1 |
Unmarried | 484 | 296 | 61.2 | 188 | 38.8 |
Religion |
Christianity | 1010 | 641 | 63.5 | 369 | 36.5 | 0.5 | 0.5 |
Islam | 109 | 73 | 67.0 | 36 | 33.3 |
Ethnicity |
Igbo | 255 | 167 | 65.5 | 88 | 34.6 | 13.2 (df4) | 0.01BS |
Yoruba | 556 | 337 | 60.6 | 219 | 39.4 |
Middle Belt | 257 | 184 | 71.6 | 73 | 28.4 |
Hausa | 30 | 15 | 50.0 | 15 | 50.0 |
Others (Minority) | 21 | 11 | 52.4 | 10 | 47.6 |
In Employment |
Yes | 955 | 609 | 63.8 | 346 | 36.2 | 0.01 | 0.9 |
No | 162 | 104 | 64.2 | 58 | 35.8 |
Years of Education |
0 | 253 | 166 | 65.6 | 87 | 34.4 | 10.4 (df3) | 0.01 BS |
1–6 | 502 | 300 | 59.8 | 202 | 40.2 |
7–12 | 286 | 202 | 70.6 | 84 | 29.4 |
> 12 | 78 | 46 | 59.0 | 32 | 41.0 |
Residence |
Urban | 308 | 213 | 69.2 | 95 | 30.8 | 5.3 | 0.02 |
Rural/Semi-rural | 810 | 501 | 61.8 | 310 | 19.6 |
Income |
Low income earner | 627 | 404 | 64.4 | 223 | 35.6 | 0.2 | 0.6 |
High income earner | 492 | 310 | 63.0 | 182 | 37.0 |
Depression |
Yes | 465 | 318 | 68.4 | 147 | 31.6 | 7.2 | 0.007 |
No | 654 | 396 | 60.6 | 258 | 39.4 |
Alcohol Use |
Yes | 995 | 654 | 65.7 | 341 | 34.3 | 14.4 | < 0.001 |
No | 124 | 60 | 48.4 | 64 | 51.6 | |
Out of the 1119 respondents, the prevalence of current outdoor smoking was (63.8%). The mean pack years of smoking of all respondents were 19.38 ± 17.16 years. There was no significant difference in the age distribution of smokers compared with non-smokers X2 = 7.1, p = 0.2. A significantly higher proportion of smokers were men, X2 = 14.5, p < 0.001. There was also a significant ethnic variation in the prevalence of smoking X2 = 13.2, p = 0.01. Prevalence of smoking also significantly vary based on years of education X2 = 10.4, p = 0.01 and residence, X2 = 5.3, p = 0.02. Smoking was also significantly more prevalent among those with depression, X2 = 7.2, p = 0.007, and also among those who were current drinkers, X2 = 14.4, p < 0.001.
Predictors of outdoor smoking were depression OR = 1.41, 95% CI (1.09–1.83) and alcohol use OR = 2.12, 95% CI (1.44–3.13) (Table
2).
Table 2
Predictors of Smoking
Ethnicity |
Igbo | 1 |
Yoruba | .278 | .289 | .929 | 1 | .335 | 1.321 | .750 | 2.325 |
Middle Belt | .299 | .419 | .510 | 1 | .475 | 1.348 | .594 | 3.063 |
Hausa | −.332 | .521 | .407 | 1 | .523 | .717 | .258 | 1.991 |
Others (Minority) | −.385 | .516 | .555 | 1 | .456 | .681 | .248 | 1.872 |
Education Years |
0 | 1 |
1–6 | −.494 | .290 | 2.902 | 1 | .088 | .610 | .346 | 1.077 |
7–12 | −.032 | .409 | .006 | 1 | .938 | .969 | .435 | 2.158 |
> 12 | −.272 | .373 | .531 | 1 | .466 | .762 | .367 | 1.583 |
Residence |
Urban | 1 |
Rural /Semi-rural | −.136 | .165 | .679 | 1 | .410 | .873 | .631 | 1.206 |
Depression |
Yes | .345 | .132 | 6.830 | 1 | .009 | 1.411 | 1.090 | 1.828 |
No | 1 |
Alcohol Use |
Yes | .753 | .198 | 14.432 | 1 | .000 | 2.123 | 1.440 | 3.130 |
No | 1 |
Smoking intensity significantly varies according to age, F = 214.01,
p < 0.001 (Table
3). Post-hoc analysis shows that the difference was partly due to a lower mean pack years of respondents < 24 years of age compared with respondents 45–54 years of age, 55–64 years of age and > 64 years of age,
p < 0.001 respectively, partly due a lower mean pack years of respondents 25–34 years old compared to those 35–44 years, 45–54 years, 55–64 years and > 64 years, p < 0.001 respectively, and also partly due to a lower pack years of respondents 35–44 years compared to those 45–54 years old, 55–64 years old and also > 64 years old, p < 0.001 respectively (Not in Table
1).
Table 3
Sociodemographic Characteristics by Smoking Intensity (N = 714)
Age | N | Mean | SD | Statistics | P |
< 24 | 86 | 10.59 | 10.21 | 214.01F (df5) | < 0.001 |
25–34 | 188 | 8.47 | 8.03 |
35–44 | 198 | 13.85 | 6.83 |
45–54 | 152 | 27.43 | 13.09 |
55–64 | 68 | 46.72 | 14.48 |
> 64 | 22 | 56.68 | 25.34 |
Gender |
Male | 554 | 20.50 | 17.56 | 3.2 t | 0.01 |
Female | 160 | 15.52 | 15.09 |
Marital Status |
Married | 417 | 20.63 | 16.84 | 2.4 t | 0.017 |
Unmarried | 296 | 17.53 | 17.41 |
Religion |
Christianity | 641 | 19.60 | 17.26 | 0.99 t | 0.31 |
Islam | 73 | 17.50 | 16.25 |
Ethnicity |
Igbo | 167 | 20.43 | 20.72 | 2.83 F (df 4) | 0.02 |
Yoruba | 337 | 20.80 | 16.91 |
Middle Belt | 184 | 15.81 | 13.17 |
Hausa | 15 | 17.91 | 13.54 |
Others (Minority) | 11 | 21.79 | 22.28 |
In Employment |
Yes | 609 | 19.13 | 16.92 | 0.99 t | 0.32 |
No | 104 | 20.93 | 18.57 |
Years of Education |
0 | 166 | 20.23 | 20.38 | 3.48 F | 0.016 |
1–6 | 300 | 20.82 | 17.06 |
7–12 | 202 | 16.12 | 13.31 |
> 12 | 46 | 21.24 | 18.67 |
Residence |
Urban | 213 | 17.85 | 15.77 | −1.55 | 0.1 |
Rural/Semi-rural | 501 | 20.04 | 17.69 |
Income |
Low income earner | 404 | 23.15 | 18.75 | 5.2 t | < 0.001 |
High income earner | 310 | 16.49 | 15.23 |
Depression |
Yes | 318 | 21.31 | 17.53 | 2.7 t | 0.007 |
No | 396 | 17.84 | 16.72 |
Alcohol Use |
Yes | 654 | 18.82 | 21.88 | 2.2 t | 0.03 |
No | 60 | 14.72 | 21.88 |
Mean pack years was also significantly higher in men compared with women, t = 3.2,
p = .0.01 and in married respondents, t = 2.4,
p = 0.07. There was also a significant ethnic difference in the mean pack years, F = 2.83,
p = 0.02 (Table
3). Post-hoc multiple pairwise comparisons indicate that the difference was due to a higher mean pack years of respondents of Yoruba ethnicity compared with those from the middle belt,
p = 0.013 (Not in Table
3).
There was also a significant difference in the mean pack years of respondents according to their years of education, F = 3.48,
p = 0.016 (Table
3). Post-hoc multiple pairwise comparisons indicate that the difference was due to a higher mean pack years of respondents with 1–6 years of education compared with respondents with 7–12 years of education,
p = 0.014 (Not in Table
3).
Mean pack years was also significantly higher among high income earners, t = 5.2,
p < 0.001, among respondents with depression t = 2.7,
p = 0.007 and those who were alcohol users, t = 2.2,
p = 0.03 (Table
3).
Predictors of high pack years were depression OR = 1.47, 95% CI (1.08–2.01), being married, OR = 1.78, 95% CI (1.29–2.45), high income, OR = 1.95, 95% CI (1.42–2.68) and alcohol use OR = 2.82, 95% CI (1.51–5.27) (Table
4).
Table 4
Predictors of High Pack Years
Intercept | .510 | .754 | .458 | 1 | .499 |
Depression |
Present | .387 | .160 | 5.852 | 1 | .016 | 1.472 | 1.076 | 2.013 |
Absent | 1 |
Marital Status |
Married | .574 | .164 | 12.186 | 1 | .000 | 1.775 | 1.286 | 2.450 |
Unmarried | 1 |
Ethnicity |
Igbo | −.440 | .673 | .427 | 1 | .513 | .644 | .172 | 2.409 |
Yoruba | −.019 | .657 | .001 | 1 | .977 | .981 | .271 | 3.554 |
Middle Belt | −.694 | .715 | .942 | 1 | .332 | .499 | .123 | 2.029 |
Hausa | −.661 | .919 | .517 | 1 | .472 | .516 | .085 | 3.128 |
Others (Minority) | 1 |
Years of Education |
0 | .149 | .430 | .120 | 1 | .729 | 1.161 | .500 | 2.695 |
1–6 | .433 | .450 | .926 | 1 | .336 | 1.542 | .638 | 3.728 |
7–12 | .292 | .572 | .260 | 1 | .610 | 1.339 | .436 | 4.111 |
> 12 | 1 |
Income |
High | .670 | .161 | 17.230 | 1 | .000 | 1.954 | 1.424 | 2.681 |
Low | 1 |
Alcohol Use |
Yes | 1.038 | .318 | 10.624 | 1 | .001 | 2.823 | 1.512 | 5.268 |
No | 1 |
The highest proportion of smokers (82.5%) were in the pre-contemplation stage and only 4.6% were in the preparation stage. There was no significant relationship between stage of readiness to quit smoking and mean pack years of smoking, F = 0.3,
p = 0.5 (Table
5).
Table 5
Stage of Readiness to Quit and Mean Pack Years of Smoking (N = 714)
Pre-contemplation | 589 | 82.5 | 19.62 | 17.55 | 0.3 | 0.5 |
Contemplation | 92 | 12.9 | 18.04 | 16.15 |
Preparation | 33 | 4.6 | 19.01 | 12.52 |
Action | – | – | – | – |
Discussion
This study evaluated the prevalence and correlates of outdoor smoking in open recreational locations in Nigeria. To the best of our knowledge, this is the first study that accessed outdoor smoking in such setting in Nigeria.
Prevalence of smoking
We found that 63.8% were current smokers. This figure is much higher than the smoking prevalence reported in Nigeria (20.6%) [
30], India (21%) [
39], Canada (16%), and America (20%) [
40]. However, compared with smoking prevalence in similar social settings such as bar, night clubs and gaming events, our result is close to the 70% reported by Trotter and colleagues in Australia [
41]. Studies have generally indicated that bar attendance and nightclubs are a nexus for risky behaviour across all age groups, including smoking and drinking [
42,
43].
Sociodemography and smoking
Contrary to previous reports [
30,
44], our univariate analysis shows that age, sex, employment, marital status, and income level were not associated with smoking. It is likely that different individuals with heterogeneous demography congregate at bars and nightclubs to smoke and drink irrespective of their [
43].
However, contrary to previous research findings associating low education with smoking [
18], we found high education to be associated with smoking. We also found smoking to be associated with urban areas. Most studies have highlighted that smoking is more prevalent in rural areas [
45]. As pointed out earlier, these associations were lost after regression analysis.
The potential explanation for these paradoxical demographic associations could be difference in the study population. While the current study was carried out among patrons of outdoor bars, other studies with whom the present study is compared are general population survey/household surveys [
30,
40,
44].
Consistent with previous literatures [
30,
40], smokers in our sample comprised of predominantly men. This may be because men are more likely to be involved in risk taking behaviours such as drinking and smoking [
46], men also strive for leadership and sexual prowess [
47].
Our univariate analysis also shows significant ethnic disparities in smoking rate. This is consistent with reports from Nigeria [
48] and also from other parts of the world [
49]. However, the association was lost after regression analysis.
Smoking and depression
In line with previous reports [
50,
51], we found a significant association between smoking and depression. This observation could be explained by the self-medication hypothesis [
13], that smoking causes depression [
14], or could also be a product of shared genetic risk factors [
52]. Nevertheless, the high prevalence of depression among the smokers in this sample calls for attention because smoking is a risk factor for suicide [
53], so also is depression [
54].
Smoking and alcohol use
Consistent with previous reports [
11,
12], we also found that smoking was associated with alcohol use. It is conceptualized that the setting of smoking, such as bars and open recreational clubs is potential places where smoking and drinking is promoted by marketers [
43].
Concurrent use of alcohol and tobacco is particularly salient, given the increased the risk of various forms of cancer, cardiovascular diseases and is predictive of illicit drug use [
55].
Pack years
Our present investigation shows that smoking intensity heightened with increasing age. Indeed, respondents who were above 54 years of age had over 27 pack year smoking history. To corroborate this, previous reports showed that those who had 30
pack-
years history of smoking were between the
ages of 55 and 80 [
56,
57]. Unfortunately, only 4.5% of the smokers were prepared to quit smoking.
As expected, we observed that mean pack years was lower in women. This may be because women generally smoke fewer cigarettes per day and have lower nicotine dependence [
16,
58], or because of social disapproval in this part of the world. However, we noted that the mean pack year was higher among those who were married. A potential explanation is that marriage is a function of age; therefore married respondents are expected to have higher mean pack years of smoking because they are more likely to be older.
Regarding ethnicity, education and pack years of smoking, although there were significant associations during univariate analysis, these associations were lost after regression analysis.
Notable is the significant association between high-income and high pack years. This may be due to the ability of high income earners to have the continued economic strength of purchasing cigarettes over the years. It has been argued that affordability of cigarette is an important factor in promoting smoking. Specifically the Global Tobacco Economics Consortium [
59] found that a 50% increase in cigarette prices will lead to significant smoking cessation in 13 middle-income countries.
Alcohol
The association between high pack years of smoking and alcohol consumption suggests that the co-use of tobacco and alcohol goes beyond experimentation. Indeed a temporal association has implications for the development of tobacco related morbidity and mortality [
60], and chronic exposure to both alcohol and tobacco has been found to increase the risk of cancers of the lung [
61], mouth, throat, oesophagus, and upper aerodigestive tract [
62].
Depression
In support of a previous report that found a significant association between depression and higher mean pack years of smoking [
63], we found that depression was a predictor of pack years of smoking. This suggests that depression and cumulative smoking may be related, although the design of the present study could not explain the direction of the association.
Pack years and readiness to quit smoking
The finding that the stage of readiness to quit smoking was not associated with mean pack years is of utmost public health attention. So also is our finding that over 90% of these smokers were not yet prepared to quit. Our data deductively serves to guide and stimulate additional research for the development of country specific tobacco control programs across all ages, given the public health importance of tobacco-related diseases such as cancers, cardiovascular diseases and diabetes [
64,
65]. Also important is the issue of second hand smoking (SHS), given that non-smokers usually report SHS exposure in most outdoor settings in which smokers report smoking [
66].
Policy and research implications
The present study has implications for prevention of cancers and other diseases associated with smoking. Public health initiatives need to recognize that bars and public drinking places may create unique opportunities for cancer and cardiovascular diseases prevention.
To corroborate this, anti-smoking interventions for bar patrons have been associated with decreases in binge drinking [
67]. The high percentage of non-smokers in the current investigation highlights the need to develop voluntary smoke-free rules in outdoor settings.
An interesting finding in the current study is that sociodemographic correlates and predictors of smoking and pack years are similar in certain areas and dissimilar in others. By implication, future studies require to identify the complex mechanism responsible for the development of heavy smoking of time and implement strategies to address this.
Strengths and limitations
An important strength of the current study is the large sample size, which has increased the power of the results. However, we are mindful of the ethical dilemma of a large sample size and its financial as well as human resource implication. We also recognize the tendency of large sample size magnifying the bias associated with error resulting from the sampling or study design. Nevertheless, we focus on the representativeness of the study sample, considering that participants were recruited over three months and a large sample has the advantage of increasing the power of the study.
Also the location-bound sampling method employed in the present investigation poses a possible selection bias. The possibility of demand bias should be entertained, given that participants were selected from a list of licensed recreational premises obtained the state government. However, this potential information bias was minimized by interviewing the participants as soon as they arrived at the bars when they were less likely to have been drinking or engaged in other bar activities capable of compromising their attention for the study.
Another limitation to the study is the fact that all participants on a table were sampled - this could result in social desirability bias especially if answers are overheard by their peers.
There are usually methodological shortcomings using location-based sampling because of judgment errors by the researcher. However, this is the only feasible method of data collection that fits the study objective. The descriptive nature of the study also makes a cause-effect relationship difficult to deduct from the study.
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