Despite the growing problem of tobacco use in sub-Saharan Africa, national population-based data on the prevalence and correlates to inform locally grounded policies, strategies and interventions are sparse.
Using the WHO STEPwise approach to chronic disease risk factor surveillance, population-based national cross-sectional survey was conducted on participants aged 25-64 years in Malawi. A multi-stage cluster sample design and weighting were used to produce a national representative data for that age range.
A total of 5,206 participants (65.5% females, 87.4% rural) took part in the survey. The prevalence of current smoking, smokeless tobacco, and tobacco use (smoking or smokeless) in men and women were 25.9%, 1.9% and 27.1% and 2.9%, 5.0%, 6.8% respectively. In both sexes the prevalence of smoking, smokeless, tobacco use was 14.1%, 3.5% and 16.7% respectively. Tobacco use was more frequent in men than women (27.1% vs 6.8%), increased with increasing age (11.7% vs 27.5% in 25-34, 55-64 year age group), rural than urban areas (10.9% vs 6.6%). About 87.6% of the current smokers, smoked daily and the mean age at which they started smoking was 22 years with no differences by gender. Traditional forms (self-made hand-rolled cigarettes and smokeless) were more common than manufactured cigarettes. About 22.2% of all participants were exposed to passive smoking in the home, 25.4% at the workplace.
Tobacco use and passive smoking was a major public health concern in Malawi. Data provided by this study could be used for surveillance, developing evidence-informed multi-sectoral policy, strategies and interventions.
1. World Health Organisation, Malawi Country Office, Lilongwe, Malawi
2. University of Malawi, College of Medicine, Community Health Department, Lilongwe, Malawi
3. Ministry of Health, Lilongwe, Malawi
RecievedSep 3 2013 AcceptedOct 15 2013 PublishedOct 23 2013
CitationKelias P. Msyamboza, Chimwemwe Mvula, Damson Kathyola (2013) Prevalence and correlates of tobacco smoking, use of smokeless tobacco and passive smoking in adult Malawians: National population-based NCD STEPS survey. Science Postprint 1(1): e00002. doi:10.14340/spp.2013.10A0004
Copyright©2013 The Authors. Science Postprint published by General Healthcare Inc.. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs 2.1 Japan (CC BY-NC-ND 2.1 JP) License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
FundingThis study was co-funded by Malawi Ministry of Health and World Health Organisation. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of this manuscript.
Competing interestsThe authors declare that they have no competing interests.
Author contributionsKPM, CM and DK conceived and designed the study. KPM, CM and DK conducted the study. KPM analyzed the data: KPM, CM and DK wrote the manuscript: All the authors read and approved the final manuscript.
Corresponding authorKelias P. Msyamboza
AddressWHO Country Office, ADL House, City Centre, P.O. Box 30390, Lilongwe 3, Malawi.
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Tobacco epidemic is one of the major public health threats worldwide. Globally, tobacco use kills nearly 6 million people (about 1 in 10 adult deaths) annually of whom more than 5 million are from direct tobacco use and more than 600 000 are non-smokers exposed to second-hand smoke. It is the second (6.3%) leading cause, after high blood pressure (7.0%), of disability adjusted life years (DALYS). Recent WHO projection, suggests that, if unchecked, tobacco-related deaths per year will increase to more than eight million (about 1 in 6 adult deaths) by the year 2030. More than 80% of those deaths will occur in low- and middle-income countries 1-4. The health effects of tobacco use are well documented and include various types of cancer (lung, oral, stomach, kidney, breast, larynx, pancreas and esophagus), chronic obstructive pulmonary disease, heart diseases, miscarriages, poor sperm quality, impotence, sudden infant death syndrome and low birth weight 5. Globally, the leading causes of deaths attributable to direct smoking, passive smoking and use of smokeless tobacco are cardiovascular diseases, chronic obstructive pulmonary disease and lung cancer causing 1.69, 0.97 and 0.85 million deaths annually respectively 2.
Sub-Saharan Africa is at the early stages of the tobacco epidemic with estimates of tobacco-attributable deaths of 5–7% in men and 1–2% in women compared to at least 15% in males in developing regions of the Americas, the Eastern Mediterranean, the Western Pacific, and Southeast Asia 6. Unlike in high income countries, in Sub-Saharan Africa, self-made hand-rolled cigarettes and smokeless tobacco (snuff or chewing) are consumed more than manufactured cigarettes 7.
Malawi is the leading producer of tobacco in Africa followed by Zimbabwe and Tanzania 8. Malawi is the most tobacco-reliant country in the world with tobacco accounting for 65% of foreign earnings 8-9. Malawi is one of the few countries which have not yet ratified the WHO Framework Convention on Tobacco Control (FCTC). Description of the extent, social distribution and surveillance of prevalence of tobacco use provide evidence to inform policies and interventions for prevention and control of tobacco use 8. However, population-based data on the prevalence and correlates of tobacco use in adults to inform baseline data for surveillance, anti-smoking advocacy, policies and interventions are scarce. Between July and September 2009, a national population-based cross-sectional survey was conducted on adults aged 25-64 years old using WHO STEPS survey tools to determine the magnitude of chronic non-communicable diseases and their risk factors in Malawi. One in four (25.9%) men and 2.9% of women (both sexes 14.1%) were current tobacco smokers 10-11. In this paper, the detailed findings on the prevalence and correlates of tobacco use (smoking, smokeless tobacco and passive smoking) are presented.
The detailed materials and methods have been presented previously 11. In summary, this study was a nationwide population- household- based cross-sectional survey designed according to a WHO STEPwise approach to chronic disease risk factor surveillance 12. A multi-stage cluster sample design was used to produce a national representative data. Eligible participants were all adults aged 25-64 years. Based on the required sample size which was calculated and adjusted using the standard formula, 144 enumeration areas (EAs) were randomly selected nationwide using the probability proportional to size (PPS) sampling method. In each EA, 40 households were randomly selected using systematic sampling method and in each household, only one eligible participant was selected using the Kish sampling method, built-in personal digital assistant (PDA, HP iPAQ). Demographic and lifestyle data were collected using WHO NCD STEPS survey questionnaire. The questionnaire was programmed on PDA. The English questionnaire was translated into two main local languages (Chichewa and Tumbuka).
Data were collected electronically using PDAs programmed with WHO e-STEPS software. Data on the PDAs were downloaded into the computer installed with WHO NCD STEPS software. The files of each participant were then merged using the participant identity (PID) number cross-checked with participant name, EA number or village/township name and other particulars where necessary. After merging, common variables in the dataset were matched and inconsistencies were corrected. Data were weighted by calculating sample weights for all records using the probability of selection at each stage of sampling. Thus, for each participant his/her weight was calculated by multiplying the probability of EA selection, the probability of household selection, the probability of participant selection within the household and age-sex population distribution in Malawi. The participant's weight was equal to the inverse of this product. Data analysis was conducted using WHO e-STEPs software and Epi Info, version 3.5.1 (Centres for Disease Control and Prevention, Atlanta, Ga). Chi-square tests were used to evaluate differences in proportions and student’s t-test for differences in means.
Ethical approval was granted by the Malawi National Health Sciences Research and Ethics Committee. Written informed consent was obtained before participants were enrolled in the study using the WHO NCD STEPS survey consent form.
A total of 5,451 eligible adults were selected and approached to participate in the survey. Of these, 245 (4.5%) refused/were not available while 5,206 (95.5%) consented and took part in the study. Of the 5,206 participants that took part in the survey, about two thirds (67.5%) were females, 87.4% were from rural areas, about one in four (24.7%) had no formal education and 73.1% were married or cohabiting.
About one in four (25.9%) men aged 25-64 years were current tobacco smokers compared to the prevalence of 2.9% in women. The use of smokeless tobacco (snuff or chewing) was more common in women than men (5.0% vs 1.9%). The prevalence of tobacco use (smoking or smokeless) was 27.1% in men and 6.8% in women (all p<0.05). In both men and women, the prevalence of tobacco use increased with increasing age; 22.0% vs 36.6%, 11.7% vs 27.5% in men and women aged 25-34, 55-64 years respectively. Overall (both sexes), the prevalence of smoking, smokeless and tobacco use was 14.1%, 3.5% and 16.7% respectively. Tobacco smoking was more common in rural than urban areas (10.9% vs 6.6%, p<0.05). Table 1 summarises the prevalence of tobacco use by gender and age.
About 87.6% of the current smokers (n=545), smoked tobacco daily and the mean age at which they started smoking was 22 years with no differences by gender. The commonest type of cigarettes was self-made hand-rolled cigarettes with a mean number of cigarettes per day of 5.0, seconded by manufactured cigarettes 2.8 cigarettes per day. Men smoked more cigarettes per day than women (mean number of cigarettes per day 5.2 vs 3.3). About 7.3% of 1690 male, 1.8% of 3516 female respondents said they were smokers but they stopped smoking. Overall (both sexes), 4.5% were ex-tobacco smokers and 1.5% were ex-smokeless tobacco users. The mean number of years since cessation of tobacco smoking was 9.3 in men, 10.3 in women, overall 9.5 (table 2, table 3 and table 4).
About 23.0% of 1432 men, 21.4% of 2047 women and 22.2% overall (both sexes) said they were exposed to environmental tobacco smoke (passive smoking) in the home on one or more occasions in the past 7 days. About 34.1% of men, 17.0% of women, overall 25.4% were exposed to passive smoking at workplace on one or more occasions in the past 7 days (table 5).
This study is one of the few large national population-based studies that has demonstrated that Malawi is one of the countries in sub-Saharan Africa where smoking is becoming epidemic with a high prevalence of at least one in four (27%) men as current tobacco users and at least a quarter of the population (25.4%) was exposed to passive smoking. Our estimated prevalence of tobacco use (smoking and smokeless) was similar to previous estimates from secondary data of 19% to 31% in men, 3% to 9% in women 13-15. Uncontrolled widespread growing, availability and influence of tobacco industry on the existence of weak or no public health restrictions and policy on tobacco advertisement, promotion, sponsorship and ban on public smoking contributed to high prevalence of smoking in Malawi 16-17.
The findings that self-made hand-rolled cigarettes were the commonest, with current smokers smoking an average of 5 cigarettes per day compared to 2.8 for those smoking manufactured cigarettes, tobacco smoking was more common in rural than urban areas (10.9% vs 6.6% p<0.05) and that a high (22%-25%) proportion of the population was exposed to passive smoking in homes and workplaces revealed by this study were a demonstration of the readily availability of tobacco and lack of public health restrictions and policy on the ban in smoking in public places and tobacco advertisement. The finding that other forms of cigarettes not manufactured ones and use of smokeless tobacco being common in sub-Saharan Africa was also reported by other studies 8. This may suggest that, although taxation on cigarettes was shown to be an effective way of discouraging smoking in developed countries where a tax increase that increased tobacco prices by 10% decreased tobacco consumption by about 4%-8% 1, this strategy may not be effective in sub-Saharan Africa and Malawi because majority of the tobacco users, smoke self-made hand-rolled cigarettes and use smokeless tobacco. This emphasises the need for local data to inform locally grounded actions and strategies to control both traditional and modern forms of tobacco consumption hence the importance of this study.
In adolescents, Muula et. al. estimated a national prevalence of current smoking in Malawi of 3.2% in males and 1.8% in females; overall 2.5%. In Blantyre the prevalence was 3.0% while in Lilongwe was 6.2% (9.1% in males, 2.8% in females). Exposure to tobacco-related advertisements through billboards, television, newspapers and magazines was significantly associated with smoking 18-20. This stresses the need for banning tobacco advertisements, promotion and sponsorship.
In sub-Saharan Africa, despite high (at least 25%) prevalence of current smoking, particularly in men, the incidence of lung cancer is low in comparison to other cancers. The reasons for relatively low prevalence of lung cancer in the presence of high prevalence of tobacco smoking in sub-Saharan Africa are unknown. Under-reporting, misdiagnosis, competing high levels of HIV and AIDS related cancers could be the possible explanations 21. The comprehensive data on the burden of chronic obstructive pulmonary disease (COPD) and ischaemic heart disease (IHD) attributable to smoking are lacking in sub-Saharan Africa. Nonetheless, globally, smoking is well known to be strongly associated with lung cancer, COPD and IHD and is the leading contributory factor 2, 5, 22.
Documentation of the existence of high tobacco use in Malawi calls for development and implementation of community and primary health based evidence-informed policies, strategies and interventions to raise awareness, screen tobacco users and provide support on cessation. The WHO primary health care approach for prevention and control of non-communicable diseases and their risk factors- WHO package for essential non-communicable diseases (WHO- PEN) protocols could be used to screen tobacco users and provide support on cessation 23. High out-patient department (OPD) utilisation rate of 1,288 visits per 1, 000 population in public health facilities and the existence of well-structured and utilised community primary health care out- reach clinics could be used as an opportunity to screen tobacco users 24-25.
The population-based data on the high prevalence of current smokers, traditional forms of tobacco use, passive (second- hand) smoking by sex, age and urban/rural demonstrated by this study therefore could be used to mobilise resources, develop and implement locally grounded multi-sectoral policy and anti-smoking lobby on the ban of tobacco advertising, promotion, sponsorship and smoking in public places and homes and community and primary health care based interventions to screen tobacco users and provide advice and support for cessation.
Over-representation of females was one of the limitations of this study; two thirds of participants were females. However, it was unlikely that this had an influence on the results for women because data were weighted (standardised) for age and sex to national population. The over representation of females was not by study design because at household level, eligible participants were randomly selected using the Kish sampling method built-in the PDAs. Refusals/non-availability (though relatively small, 245 (5%) out of 5,451 eligible participants), was another limitation of this study. Specifically, males aged 25–34 years were the ones that were under-represented based on 2008 National Statistical Office Population figures (42.5% vs 47.5%, p<0.05). The under representation of men in this age group was due to some being away from home at the time of the survey. It was not known if this group had different survey characteristics. All the other age groups were representative of the national population. There were no differences in the refusal/non-availability between males and females and no replacements were made. About 88% of all the 5,206 participants were from rural areas. This was not due selection bias but was in line with the population distribution in Malawi which is 85% rural 26.
Tobacco use (smoking and smokeless) and passive (second-hand)
smoking was a major public health concern in Malawi, particularly among
males and in rural areas. Data provided by this study could be used as
baseline for surveillance of tobacco use in adults, mobilise resources,
inform the development and implementation multi-sectoral policy and
anti-smoking lobby on the ban of tobacco advertisement, promotion,
sponsorship and smoking in public places and homes. Incorporation of
screening of tobacco users and support for cessation in primary health
care settings could help to prevent and control the epidemic. Taxation
as a strategy may have limited impact in Malawi because majority of the
tobacco users use self-made hand-rolled cigarettes and smokeless tobacco
not manufactured cigarettes.