12A.4 What makes an effective health warning?

Last updated: July 2019     

Suggested citation:Scollo, M., Hippolyte, D., & Miller, C. 12A.4 What makes an effective health warning? In Scollo, MM and Winstanley, MH [editors].  Tobacco in Australia: Facts and issues. Melbourne: Cancer Council Victoria; 2019. Available from: https://www.tobaccoinaustralia.org.au/chapter-12-tobacco-products/attachment-12-1-health-warnings/12a-4-what-makes-an-effective-health-warning

There is growing evidence on the characteristics of effective warnings labels1 for cigarettes and other tobacco products. Research on the effects of health warnings on cigarettes can be divided into research on the content of the warnings and research on the form these warnings should take. There is direct research on form.  Much of the early knowledge about the effects of content is either from analogue studies done when considering which warnings to implement or from other areas of communication research not specifically related to warnings about tobacco on packs in the marketplace. There is now also a small body of direct research on the characteristics of effective content of warning labels for cigarette packs.

12A.4.1 What content should warnings cover?

Warnings need to cover all the important health risks to fully inform consumers about the health consequences of smoking. They must also give consumers enough information to fully understand all the material issues relevant to those risks. People need to understand not just that risk increases, but also what contracting a disease would mean to the longevity and quality of their life. They need to understand the risk of contracting a disease, the lived effects of currently available treatments, and the likely prognosis. Conveying such information is not straightforward. Smokers bring to these warnings their own ‘sender–receiver’ relationship made up of preconceived knowledge and ideas, as well as self-protective and self-exempting beliefs and reactions. For example, while smokers generally know that tobacco use is harmful, they tend to underestimate the health risks to themselves and often perceive other smokers to be at greater risk for disease than themselves (see Section 3.34)

A review of theories and evidence, largely from social psychology,2 suggests that warnings are more likely to be effective in increasing understanding of tobacco-related risk if they:

  • take into account the relevant attitudes of the consumers who use tobacco products
  • combine information that is likely to invoke strong fear responses with information about how risk can be avoided
  • convey a sense of the social as well as the physical consequence of negative health effects
  • promote discussion about smoking among smokers’ friends and family
  • confront self-exempting beliefs
  • are presented in a way that minimises the inevitable process by which repeated exposure gradually diminishes effect.

Health warnings need to

  • cover a broad range of health effects
  • emphasise morbidity as well as mortality
  • cover the same health effect from the points of view of people of different ages and at different stages of smoking uptake and cessation3
  • use language that is clear, strong and direct 2
  • explain how the effect occurs in concrete terms
  • paint a picture of what life would feel like should a disease be contracted
  • be frequently rotated and updated to include new images and information that explores different aspects of the particular risk. 2

A small body of literature now also provides some evidence on the content of warning labels.4, 5 One study in the US 4 examined the effects of different types of content that may contribute to the effectiveness of testimonial graphic warning labels (GWLs). Beginning with a testimonial GWL that contained an image of a person and a basic warning statement (e.g., ‘Smoking can kill you’), it examined the impact of adding: (a) text detailing the person's name, age and health status (identifiers); and (b) explanatory statements that elaborated on the basic warning using a testimonial or non-testimonial message. There was little evidence that adding identifiers or the explanatory statements enhanced effectiveness; rather, there was some evidence that testimonial explanatory statements reduced effectiveness.

Warnings framed as losses from smoking can be complemented by messages framed as benefits of quitting. One study 5 compared the effects of warning labels that stress short-term losses of smoking as well as labels that stress both short- and long-term benefits that can be obtained when one quits smoking. Findings show enhanced effects of gain over loss frames and short-term over long-term consequences on warning labels for attitudes and intentions.5 Gain-framed messages showed stronger effects on intentions to quit smoking than loss-framed messages when warning labels concerned short-term outcomes.

12A.4.2 What form should warnings take?

Major reports have been produced in Canada,6-13  Australia,14-19 Europe,20  New Zealand,21, 22 the US,23 and elsewhere to guide the design of health warnings. This is a growing field of research as to optimal design of warnings.24, 25  See the University of Waterloo’s Tobacco Labelling Resource Centre for up-to-date information.

Wording matters

Obscure text warnings have little impact. Messages should be short and direct. Comprehension and impact of warnings is greatly increased if they are expressed in clear, simple language. 10, 18, 19, 26 Messages that depict health risks in a vivid and emotionally arousing manner are likely to be most effective. 27

Health literacy plays an important role in influencing how smokers respond to different risk messages. Analysis of warnings on cigarette packaging in the US indicates that comprehending them requires college-level education,28 greatly reducing usefulness with young people, less educated people and people with poorer reading skills. Studies by the Centre for Behaviour Research in Cancer identified a number of risk-related words which many adolescents poorly understand and which should be avoided in warnings messages.14  Factual messages were found to produce higher perceived risk and strong expectations for quitting amongst persons with high health literacy.26 In contrast, emotional messages produced higher perceived risk and stronger expectations for quitting among smokers with lower health literacy.26

Size matters

Size can refer to the size of the font of the message or the size of any picture or the amount of space given over to the warning. It is likely that all elements of size are important.

Several studies have established that larger font size is more effective than smaller font size.11, 14, 29, 30  Eye tracking studies of youth observing cigarette print advertisements in the US indicated that adolescents paid scant attention to the very small warnings on advertisements required in the mid-1980s.31

Psychological theory would suggest that smokers would be more likely to recall larger warnings, with bigger warnings associated with greater appreciation and acceptance of risk.2, 32 Reviews of the evidence25, 33 report that this has been borne out in experiments studying various sizes of warnings prior to the introduction of strengthened health warnings.11, 13, 14, 22, 34-36 i  Post-implementation research also confirms that increased warning size (at least up to 50% of the front surface),  increases warning effectiveness.8, 15, 29, 37   

Research undertaken for the Canadian Government11 to guide the design of new warnings implemented in 2012 found that health warnings occupying 75% of the pack were more effective than warnings occupying 50% of the pack in conveying information about the health risks of smoking. The study examined a total of 38 effectiveness indicators, grouped into seven sets:

1. Perceived communication impact (5 indicators)

2. Personal persuasiveness (1)

3. Persuasiveness associated with six social styles of smokers (6)

4. Smoker image (12)

5. Product image (9)

6. Emotional impact (4)

7. Packaging attractiveness (1)

Two sets of indicators were less sensitive to warning size increase: smoker image (personality traits) and product image (cigarette attributes). These image indicators required at least option C (90%) in order to generate significant effects, but these effects remained small even with option D (100%) when contrasted with current scenario A (50%). Findings suggest that while increasing the size of warnings on cigarette packages improves communication impact, increased size is not nearly as effective in negatively affecting the image of smokers or perception of cigarette product attributes.

Graphic elements matter

The importance of font size, headings and layout in aiding consumer comprehension for consumer medicines information is well understood.1

At least two studies have shown that smokers prefer health warnings to appear in a boxed section.21, 22 Research on chemical products indicates that textural warning labels with coloured background were perceived to have more impact than those in black and white.38 Full-colour warnings capture attention for longer than black-and-white warnings among both youth and adult smokers.39 Contrasting colours such as black lettering on a white background are the easiest to read and comprehend on cigarette packets.14, 40 The background to text can serve to focus more or less attention on the text compared to the graphic component of health warnings.18, 19

Findings from a review of tobacco company research on pack colours that make pack elements more prominent, attractive and keep consumers’ attention provides additional insight into the most effective graphic elements.41 According to this research, black is more visually prominent, and placing dark pack elements on a contrasting light background makes them stand out more. Black text on a white background is more prominent than white text on a black background. Yellow most quickly and effectively seizes and holds consumers’ attention and signals warning or danger, while white connotes health and safety. Using black text on a bright contrasting background color, particularly yellow, attracts consumers’ attention to the message.    

Placement matters

Australian research conducted prior to the introduction of graphic health warnings in 2006 found that over 90% of packs displayed in public venues (mainly café tables) were front up.42 Smokers tend to have the front of the pack facing them rather than the back each time they remove a cigarette for smoking.  Experimental work has also shown that the top of the front is likely to have greater impact than the bottom of the front.14 Smokers show better recall for warnings that appear on the front, compared to the side of packages.6, 14, 21, 36 Few smokers have reported citing packages as a source of information where warnings appeared on the side of the pack.43, 44

Research found that the 2006 Australian graphic warnings, which averaged more than 50% of the two main sides (30% of the front and 90% of the back), had weaker effects than the Canadian warnings, which had 50% of both sides dedicated to warnings, suggesting that the back of the pack is less effective than the front, presumably because material on the front is noticed more often.45  The 2018 government sponsored survey on the graphic health warnings introduced in Australia in 2012 found that over half (52%) of smokers and recent quitters learned about the health harms of tobacco products from the written warnings on the front of the pack, compared  to the back of the pack (37%) or the side of the pack (29%).46

A Philip Morris document also highlights the importance of positioning on the front of packages:

Government required warnings placed on the largest packaging panel, often called the front and/or back, are the biggest marketing threat to all of us in Asia...’  47.

Pictures work best

Health communication theory and practices suggest that health warnings with pictures are more likely to draw attention, result in greater information processing and improve memory for the health message.33 A major review notes:33

Experimental research on cigarette warnings has also found that picture-based warnings are more likely to be rated as effective than text-only warnings on a range of outcomes, including as a deterrent for new smokers and as a means to increase cessation among current smokers.33

There is also an increasing body of real-world evidence showing that graphic warnings are more effective because they lead to more frequent and deeper processing of warning information than text-only warnings.45, 48-52 Smokers place lower value on cigarettes with graphic health warnings than with text-based warnings.53, 54 This is supported by some experimental research comparing warnings of the same size and theme but differing in presentation. 55, 56

Focus group research in Australia indicated that smokers were much less likely to be able to avoid the image than the text-based component of the proposed new health warnings. Eye tracking research conducted in 2018 on Australia’s graphic health warnings (2012) found that pictorial components garnered the highest level of attention being the area where participants first looked and looked at for longest.46 Among smokers, the front graphic image area was the first area most commonly looked at (72%); followed by the back graphic image area (14%) and then the front top warning message area (14%). Among non-smokers, the front graphic image area was the first health warning area most commonly looked at (93%); followed by the front top warning message area (7%).

A study comparing the reactions of Chinese smokers to pictorial warnings with the current text-based warnings indicated that smokers were about four-times more likely to report thinking about quitting when confronted with pictorial warnings than with packs bearing the current warnings, and about four times less likely to offer cigarettes to others as gifts if these were packaged with strong health warnings.57

Following the introduction of pictorial health warnings in Canada, more than 90% of smokers reported noticing the change. Forty-four per cent of smokers said the new warnings increased their motivation to quit. In a study conducted for the government in Canada,58 more than one-third of former smokers indicated that warning labels had influenced their decision to quit. In a survey of Canadian ex-smokers who had quit in the three years up to October 2001, those who had quit after the introduction of the health warnings were 2.8 times more likely to cite the warning labels as an influence on their quitting than those who quit before their introduction.59

In countries with large pictorial warnings such as Australia, Thailand, and Uruguay, more than 85% of smokers cite packages as a source of health information.25 Pictorial warnings may be particularly important in communicating health information to people with impaired literacy.60 Graphic health warnings also appear to have a far greater impact on young people than text-based warnings.61 Studies of early text-based warnings in the US62 and Australia63 indicated limited impact on young people. Studies examining the impact of improved text warnings in the UK64 found that these did help to communicate the dangers associated with smoking and prompted a small number of smokers to forgo cigarettes and take action to avoid warnings. However the depth of processing was low and the textual warnings do not appear to be achieving their full potential among young smokers. In Canada by contrast, six years after their introduction, more than 90% of Canadian young people agreed that picture warnings on Canadian packages provide them with ‘important information about the health effects of smoking’, ‘are accurate’ and ‘made smoking seem less attractive’.9  Graphic warnings in Australia also appear to have had a much more significant impact on young people 65—see Section 12A.1.5.

Several researchers have examined the types of health warnings that are most effective with young people. Graphic warnings depicting short term effects of smoking may be more effective than those depicting long term effects of smoking. One study examined the emotions generated by warnings depicting short term health outcomes compared to long term health outcomes, to identify common features among the most effective warnings. Warnings that featured more immediate health outcomes elicited much stronger negative emotions from both smokers and susceptible non-smokers compared to long term health outcomes. Among young adolescents in the US aged 11–13 exposed to graphic warnings and text only warnings, adolescents accurately recalled pictorial warnings more often than text-only warnings (82% vs. 19%).66 Recognition of warnings was also higher for pictorial than text-only warnings (82% vs. 34%) and pictorial warnings drew greater attention and elicited greater negative emotional reactions.66 These findings support incidental findings of studies in Nigeria,67 Lebanon,68 and the US69 that young adults found graphic warnings depicting short term effects of smoking more effective than those depicting long term effects of smoking.

Potential adverse outcomes of graphic health warnings?

Some researchers have expressed concerns about whether graphic health warnings will assist smokers to sustain quit attempts.70 However, a study on attitudes of US smokers to current US warnings compared with Canadian-style71 and other graphic health warnings55, 56 have shown stronger negative attitudes to the graphic warnings, without signs of defensive reactions. Greater fear and disgust have been associated with greater likelihood of quitting.55, 56, 72

Warning label disparagement among smokers indicates greater warning relevance and processing and does not result in counterproductive effects on cessation efforts.73 Researchers73 assessed the relationship between one form of warning label disparagement, the frequency of making fun of health warning labels, and subsequent cessation attempts. The study analysed data on adult smokers from Australia, Canada, Mexico and the US between 2012-2014. Between 24%–31% of smokers reported making fun of the warnings at least once in the past month in each country, across all waves.  This type of health warning disparagement was an independent predictor of subsequent cessation attempts in all countries except the US.55 Even avoidance of health warnings does not predict a lower likelihood of quitting; indeed, there is evidence that it may actually be associated with increased quitting45, 74 as higher levels of negative emotional reaction to graphic health warning labels have a positive association with quit intentions .

Context of the pack matters

It is now well established that warnings need to be on a pre-specified background (e.g. white for black text), otherwise companies can effectively blend the warning into the design of the pack.75 Smokers recall warnings more effectively on mock packets with a plain background than they do on real, highly stylised cigarette packets.35, 76-78 This strongly suggests that plain packaging would increase the effectiveness of health warnings. Plain packaging is discussed at length in InDepth 11A Packaging as promotion: Evidence for and effects of plain packaging.

i A series of studies conducted by Environics Research company for the Canadian Cancer Society in June 2006 similarly found that warnings sized at 75% of the front of the pack would be more effective than those sized 50 or 60%



Relevant news and research

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