Center for Injury Research and Prevention

Assessing Content Validity for mHealth App Development

September 3, 2015
theory clouds_digital health researchUsing theory and evidence to guide app
development is key for effective mHealth tools.

A key step in the “best practice” development of mHealth apps is to use theory and evidence to guide app development. A recent meta-analysis of 85 studies of eHealth interventions for health behavior change found that interventions that made greater use of theory (i.e., linking theoretical constructs to intervention techniques) had larger impact for their users.

But what does this mean in practice? How does an app developer go from theory- and evidence-based ideas regarding key intervention targets to actually create an effective app or eHealth intervention? And how do we know if we have been successful in getting our app to match its theoretical basis?

To help guide the development of mHealth apps that are grounded in solid evidence and theory, and thus more likely to be effective, our CIRP@CHOP team recently published guidelines for assessing content validity in the development of eHealth interventions. We introduced a new definition of content validity for mHealth and eHealth that builds upon well-established attributes of content validity in the development of questionnaires and other measurement instruments. For each activity or feature within an app, we suggest assessing three core dimensions of content validity:

  • Relevance: Is the activity pertinent to its intended intervention target ? (i.e., “Is this arrow aimed in the right direction?” )
  • Likely effectiveness:  Do evidence, theory, and expert judgment suggest that this specific activity will successfully modify the intended intervention target?( i.e., “Is this arrow likely to hit the target?”)
  • Appropriateness for a specific intended audience: This is defined by age, culture, or other factors.

Our approach is summed up in this very practical five-step method:

1. Specify key intervention targets that this app or e-Health intervention is intended to address.

2. Delineate specific intervention activities that address each target.

3. Use the Content Validity Survey Tool to assess each activity for relevance to its target, likely effectiveness, and appropriateness for a specific intended audience.

4. Recruit independent experts with relevant content knowledge to complete the Content Validity Survey Tool. 

5. Score and analyze results and refine the intervention as needed.

In the paper, we illustrate this process by showing how we used each step in our development of Coping Coach, an eHealth intervention that aims to prevent or reduce posttraumatic stress in young people who have experienced different types of acute, single-incident traumatic events. We encourage app developers to see content validity assessment as a crucial checkpoint that promotes time- and cost-efficient development of interventions that will make a real difference in users’ health outcomes.