I was recently asked to present on what are the essential ingredients for a health communication campaign and what type of impact should be expected from them. For the answer, I turned to Leslie Snyder who has studied the effectiveness of health communication campaigns. In her most recent publication on the subject, she combined the results of several reviews of the literature that together examined over 400 campaigns on a variety of health topics.
Her conclusion: The question isn’t whether health communication campaigns are effective – it’s what is the average effect size they achieve (how much change do they result in)?
Across all these studies she found that targeted behaviors increase above baseline by an average of about 5 percentage points; a baseline level of a behavior usually is increased, for example, from 60 to 65%. Campaigns for seat belt use (15%), dental care (13%) and adult alcohol reduction (11%) campaigns have had the strongest effects, while youth alcohol and drug campaigns have had the least (1-2%).
Among other risk behaviors that were included in a sufficient number of studies to allow her to arrive at estimates of impact:
- Family planning (6%)
- Youth smoking prevention (6%)
- Heart disease reduction (including nutrition and physical activity (5%)
- Sexual risk taking (4%)
- Mammography screening (4%)
- Adult smoking prevention (4%)
- Youth alcohol prevention and cessation (4-7%)
- Tobacco prevention (4%)
Preliminary findings on risk behaviors among an even smaller number of studies are that in international breast feeding campaigns the average effect size is r = .17 (or 17%), for fruit and vegetable campaigns r = .08 and for in-school nutrition programs aimed at 4th-5th graders the r = .12.
Obviously, there are several caveats to these conclusions including the reach and frequency of messaging, the audience, the number of channels that were used and differences in measurement and evaluation. However, as a rule-of-thumb, the 5% figure may be a good place to start when you are trying to estimate the impact of a health communications campaign. And another reason to suggest you move beyond 1P marketing.
Leslie also found a number of factors that are associated with improved outcomes.
- Promote adoption of healthier behaviors or substitutions over stopping or preventing unhealthy ones.
- Habitual behaviors are more difficult to modify than one-off ones (e.g., screening behaviors)
- Have behavior change as an explicit goal or objective
- Use formative research in design and planning
- Focus on homogeneous population groups
- Communicate directly with your audience and not just through intermediaries
- Have multiple executions of messages
- Have a high frequency of exposure to the messages
- Practice media multiplexity (using multiple channels)
- Strive for sustained activity to mitigate the observed declines in behavior change after the campaign ends
And at the end of the presentation I added four more rules for developing successful social marketing programs.
- Behaviors need to be relevant to audiences – not producers of the message
- Opportunities and access to engage in new behaviors is necessary
- Incentives, not barriers, determine behavior change
- People live in social networks – tap into them
So as you are writing your social marketing plan, some empirically-based places to start.