Claim: 49% of men and 34.1% of women in South Africa smoke tobacco. Is this true? Africa Check investigates.
In October, a tweet by the Foundation for a Smoke-Free World says so: "49% of men and 34.1% of women in South Africa smoke, but only 51% of smokers have heard of vapo[u]r products. We must raise awareness around harm reduction."
49% of men and 34.1% of women in South Africa smoke, but only 51% of smokers have heard of vapor products. We must raise awareness around harm reduction.
- Smoke-Free World (@SmokeFreeFdn) October 15, 2018
But is it true? A reader asked Africa Check to verify South Africa's share of smokers.
Data from a global smoking poll
The Foundation for a Smoke-Free World is a non-profit organisation. It is mainly funded by one of the biggest tobacco companies in the world, Philip Morris International, which also sells smoke-free nicotine products such as e-cigarettes and vaporisers.
The foundation's communication manager, Nicole Bradley, told Africa Check the statistics came from their State of Smoking 2018 global poll.
The survey asked more than 17 000 adults from 13 different countries about how often they smoked, their attempts to quit and whether they had ever heard of or used smoke-free products.
In South Africa, 1 000 people older than 18 were interviewed face-to-face from 29 November to 11 December 2017 in five unnamed regions.
The survey claimed to represent the entire adult population, but the interviews were done using questionnaires in English and Afrikaans only.
When they were asked if they smoked tobacco products like cigarettes, cigars, cigarillos or pipes, 44.8% of the men and 27.5% of the women said they smoked them regularly, Bradley told Africa Check. Another 4.1% of men and 6.5% of women said that they smoked them occasionally.
Issues with sampling and weighting of variables
This is much higher than previous estimates of smoking in South Africa. In a presentation about the poll results, the foundation itself displayed World Health Organization (WHO) figures for 2015.
These showed that 31.4% of men and 6.5% of women older than 15 in South Africa smoked tobacco products. (Note: This data was "age adjusted", meaning it can be compared between countries.)
"The most glaring problem with the State of Smoking poll is the small sample size in each country," Nicole Vellios, research officer at the Economics of Tobacco Control Project at the University of Cape Town, told Africa Check. "It is not possible to conduct a robust analysis at a national level on such a small sample."
Evan Blecher, an economist at the University of Illinois at Chicago Health Policy Center, also thought the South African sample size was "too small to get a really accurate view of smoking. The reason for that... is that smoking prevalence differs widely by race, gender and location."
Making sure a survey represents all the country's population groups "is absolutely necessary for any sampling in South Africa given the large racial inequalities, which extends to smoking as it does with many other behaviours or economies in South Africa", Blecher said. "I don't think one can draw any inference on the population level smoking prevalence numbers without understanding how it was weighted by race."
He pointed out that black people, South Africa's largest population group, smoked the least. One "gold standard" survey, the 2013 South African National Health and Nutrition Examination Survey by the Human Sciences Research Council (HSRC), found that only 17.4% of black people older than 15 had ever smoked.
There were also wide differences between regions, Blecher said. For example, the HSRC study found that only 14.4% of people older than 15 surveyed in Limpopo province had ever smoked, compared to 38.5% in the Western Cape province.
"If you end up oversampling white, coloured or Indian people (because your sample is too heavily focused on urban areas, or English and Afrikaans speakers), your overall share of smokers will be higher," Blecher explained.
Roughly 20% of South Africans are smokers
South Africa has "very good smoking prevalence estimates", Blecher said. He directed Africa Check to the National Income Dynamics Study. This is a project of the South African Labour and Development Research Unit at the University of Cape Town.
The fifth round of this panel survey was done in 2017, when about 24 000 adults in South Africa were surveyed. It found that 35.7% of men and 8.1% of women older than 18 smoked cigarettes, Vellios said. (Note: This was in line with the HSRC study, which found that 32.8% of men and 10.1% of women reported that they had ever smoked tobacco.)
Vellios said roughly one in five South African adults smoked, a trend that had stayed "pretty flat" over the past decade.
Source: National Income Dynamics Study Wave 1-5, extracted by Kirsten van der Zee
Conclusion: Better studies show that in South Africa, about a third of men and 10% of women smoke tobacco
The Foundation for a Smoke-Free World said its global State of Smoking survey for 2018 had found that 49% of men and 34.1% of women in South Africa regularly or occasionally smoked tobacco.
The foundation's survey only asked 1 000 people in South Africa about their smoking habits, and only using questionnaires in English or Afrikaans. Experts said this sample was too small to represent all the people in South Africa when it comes to smoking.
More thorough surveys - by the University of Cape Town and the Human Sciences Research Council - found that about one in three men and one in 10 women in South Africa smoke cigarettes or had smoked tobacco before. Overall, roughly 20% of the country's people are smokers.
Explainer: Better surveys show South Africa has far fewer smokers.
The Foundation for a Smoke-Free World's 2018 survey found that 49% of men and 34.1% of women in South Africa smoked tobacco.
The foundation only surveyed 1,000 people in English or Afrikaans.
More thorough studies have found smoking to be less common in South Africa.
Edited by Anim van Wyk