Does Behaviour Change Communication Work?

I have become interested in the potential of behaviour change communication to reduce suffering. But does behaviour change communication even work? If yes, how much does it work?

Effect sizes differ across topics.

According to Snyder,

The average health campaign affects the intervention community by about 5 percentage points.

Average health campaign, r = .05

International breastfeeding campaigns, r = .18
Seatbelt campaigns, r = .15
Dental care campaigns, r = .13
In-school nutrition campaigns for youth, r = .12
Adult alcohol reduction, r = .11
Fruit and vegetable media campaigns, r = .08
Heart disease prevention, r = .05
Sexual risk taking, r = .04
Mammography screening, r = .04
Adult smoking prevention, r = .04
Tobacco prevention, r =.04


Average family planning campaign, r = .06

• Effects on knowledge, r = .11
• Effects on attitudes, r = .07
• Effects on communicating with spouse, r = .05

Average youth smoking campaign, r = .06
Average youth alcohol and smoking prevention, r = .04-.07
Average youth drug and marijuana campaign, r = .01-.02

• Effects on knowledge, r = -.01-.01
• Effects on attitudes, r = .03

DMI claims that it can lower child mortality rates in "most low-income countries" by 16-23%. Given that (1) DMI's campaigns are aimed at populations where health issues are rampant and (2) that they tend to play their messages repeatedly over a long-term time span, I think that number is at least realistic. I don't know of any other behaviour change communication campaign claiming to have such a high impact, however.

DMI offers more data on their effectiveness:

• A behaviour change radio campaign can save 74,500 under-five lives and 2,500 maternal lives every year.

• This assumes that we can reach 16 million radio listeners over the age of 15 on a regular basis.

• We can predict impact by disease (e.g. for under-fives: 26% diarrhea, 23% pneumonia, 23% malaria, 26% neonatal).

•  We can predict impact by behaviour (e.g. exclusive breastfeeding up from 16% to 29%, saving 6,400 lives per year.)

• We can predict the cost-effectiveness of our campaigns (a nationwide campaign in DRC would cost $2 per DALY).

DMI provides a lot of facts about their media interventions but they don't publicly demonstrate all the steps leading toward these figures. I would like to see something like: 

"X people have malaria each year. Y% of people with malaria die from it per year. If our malaria interventions are aired with A frequency for B months, we can increase the amount of malaria survivors by C%, saving Z lives. This campaign would cost D dollars and would thus cost $2 per DALY."

It's difficult to take a charity at their word if we aren't provided with the concrete evidence.

If the average health campaign boosts effectiveness by 5%, is that good enough? Is it worth the trouble of a media campaign if it's only going to increase conversions from 13% to 18%? If we're talking about life and death issues, and production costs are reasonable, then it's pretty clear to me that the campaigns are worth it. The 5% conversion boost might not be strong enough to make health communication the optimal health intervention, however, especially if the behaviour change it's targeting is of relatively low importance. If DMI's ~20% child mortality reduction figures are accurate, then their media interventions should clearly be high priority health interventions.