# Presentation: 241829

## Community Interventions

- Why Aren’t They Working
- As Desired:
- The Issue of Mediating Mechanisms

**Tom Baranowski, Ph.D.**
**Lillian S. Lin, Ph.D.**
**David Wetter, Ph.D.**
**Ken Resnicow, Ph.D.**
**Marsha Davis Hearn, Ph.D., MPH**

**Notes:**
�	Recognize Co-Authors

�	Ideas have been knocking around for about a year

�	I am going to say some controversial things about the lack of effectiveness of our large community interventions

�	My purpose is not to castigate us, not to suggest that we no longer do community interventions

�	 But to point to improved ways of doing business

## Community Interventions

**Community Interventions**

**Notes:**
�	A number of projects in dietary & other behaviors have had little or weak results

## Pawtucket Heart Health Project
Stanford Five City Project
Minnesota Heart Health Project
C.O.M.M.I.T.
C.A.T.C.H.
Take Heart
Teach Well

**Stanford Five City Project**
**Minnesota Heart Health Project**
**C.O.M.M.I.T.**
**C.A.T.C.H.**
**Take Heart**
**Teach Well**

**Community Interventions**

**Notes:**
�	These include some of the most widely publicized projects, at least in the disease prevention community

�	I am not arguing that there have been no successes; but the successes have been weak; and many projects have had no effects

## Community Interventions

**Substantial funding**
**Multiple years of intervention**
**Large samples**
**State of the art theory**
**Sophisticated statistics**
**Leading health promotion research teams**

**Community Interventions**

**Notes:**
�	Ten to fifteen years ago we bemoaned not being able to conduct our programs the “right” way

�	The recent studies have remedied much of that

## Community Interventions

**Tighten analyses of health problems**
**More carefully select objectives**
**Select methods most likely to be effective**
**Employ marketing strategies**
**Employ incremental approach to development, implementation & evaluation**

**Community Interventions**

**Notes:**
�	A number of other investigators have recognized this problem

�	Winett admonished us to do everything better

## Community Interventions

**Requires many types of expertise**
**Blending expertise in cooperative teams**
**Relying on implementors other than our staff**
**Difficulties in recruitment, implementation & measurement**

**Community Interventions**

**Notes:**
�	Others have noted the many difficulties in conducting community trials

�	The implementation problem

-	Argues for behavioral efficacy trials where we provide incentives to maximize exposure, rather than effectiveness trials

-	Argues for thorough process evaluation

�	Rather than selling behavior change to our sponsors we must sell learning more about change

## Community Interventions

**Community Interventions**

## Community Interventions

**Focus on “mechanisms of action”:**
**Understand the underlying processes & influences**
**Build intervention once understand process**

**Community Interventions**

**Notes:**
�	One alternative model would be the Biomedical Research Model

-	The emphasis is on first understanding the phenomena of interest, and then applying interventions based on that understanding

## Community Interventions

**Mediating Mechanism Model**

- “The” Intervention

- Mediating Theoretical Variable(s)

**(mediating variables = theoretical constructs)**

- Targeted Behavior

- IM

- MB

- IB

**Community Interventions**

**Notes:**
�	The mediating Mechanism Model is a conceptual way of focusing on theoretical constructs in our interventions
-	The theoretical variables are the ones used to explain the outcome of interest

�	As example:  Gimme 5 project; so I pick on my own work
-	Target behavior: consumption of F&V
-	Mediating variables based on focus groups (SCT)
-	Availability-Accessibility of F&V
-	Preferences for veggies
-	Skills in preparing F&V
-	Intervention: school curriculum, newsletters & videos sent home to parents, point of purchase education in local grocery stores

## Community Interventions

**SCT:****	****Self efficacy**
**TRA:****	****Attitude to the act**
**HBM:****	****Perceived susceptibility**

**Community Interventions**

**Notes:**
�	Mediating variables can come from any behavioral theory

## Community Interventions

**1 -****	****Intervention must be related to mediating variable**
**2 -****	****Intervention must be related to behavioral outcome**
**3 -****	****Mediating variable must be related to behavioral outcome**
**4 -****	****The relation between the intervention and behavioral outcome should be reduced when controlling for the mediating variable**

**Community Interventions**

**Notes:**
�	The statistical procedures for establishing whether a variable mediates an intervention have been established

## Community Interventions

**Are theoretical variables**
**Can be many of them**
**If I ********B with no M, then do not understand the process (otherwise black box)**

**Community Interventions**

**Notes:**
�	I am using the mediating variable paradigm as a framework for analyzing our current situation in evaluating outcomes of interventions

�	I am taking position that if we have an intervention that leads to behavior change with no mediating variables then we do not understand what is happening and need to find the mediating processes

-	Building on mediating processes is the only way to build a science of behavioral intervention

-	Not knowing the mediating processes is capitalizing on change or on intuition, but is not a science

## I  M  B 

**in behavior**

- I  M  B

- r******I ******** M**

- r ****** M ******** B**

**Community Interventions**

**Notes:**
�	A small refinement in our mediating variable paradigm is that the goal of intervention is change in mediating variables and change in behavior

�	G5: intervention  increases preference  increases consumption

## Community Interventions

**M should be mutable (eliminates personality variables except as tailoring or stratifying variables)**
**Helpful to have M which know how to change**

**Community Interventions**

**Notes:**
�	Several logical implications can be drawn from imposing this mediating variable paradigm

�	M should be mutable: H-LOC

�	Helpful to have M which know how to change

-	SCT has been popular because methods for promoting change is its constructs were part of its development

## Community Interventions

**r************ M ******** B  ****places a limit on  ****r ****I ******** B**
**(better theory predicts more variance in outcome behavior)**

**Community Interventions**

**Notes:**
�	An implication of this statement is that intervention designers should work with theories that are more predictive or promotive of change

## Community Interventions

**r********I ******** M  ****places another limit on  ****r********I ******** B**
**(interventions need to be shown to influence mediating variables)**

**Community Interventions**

**Notes:**
�	We should choose interventions that have been demonstrated to impact mediating variables

## Community Interventions

**r********I ******** B    ******** ****r********I ******** M  **** ****•   r******** M ******** B**
**r********2********I ******** B  ******** ****r**** I ******** M ****  ****• r******** M ******** ****) ****2**
**(the two paths are multiplicative)**

**Community Interventions**

**Notes:**
�	Can be proven that these paths are multiplicative

�	This multiplicative relationship places severe limits on what we can expect for effects

## Community Interventions

**The rule of .3**
**Mostly from cross-sectional research**

**Community Interventions**

**Notes:**
�	Let’s analyze the two paths

�	Mention Stafleu et al

## Community Interventions

**Community Interventions**

**Notes:**
�	More studies make same point

## Community Interventions

**Community Interventions**

## Community Interventions

**Community Interventions**

**Notes:**
�	There is one exception to this pattern

## Community Interventions

**Community Interventions**

## Community Interventions

**Community Interventions**

## Community Interventions

**Concern -****	****Problem with I ********B: how change I except  by manipulating SN & AA?**
**	****- Positive response bias?**

**Community Interventions**

**Notes:**
�	Within TRA there is some set of modifying variables between Intention & Behavior

-	These are as yet unspecified
-	Perhaps availability & accessibility fill the role

�	Measurement is also a problem

-	Need more attention to reliability of multi item scales (have been happy to show any relationship in the past; need better than that now)

## Community Interventions

**Show mostly small changes**
**Changes not in all mediating variables**
**Inconsistency in changes over time in mediating and outcome variables**
**Some hypothesized mediators moderated impact**
**Mediating processes are not same for related outcome behaviors**
**Mediation not usually demonstrated**
**Mostly low values**

**Community Interventions**

## Community Interventions

**r************ ******
**r********IM**** ******
**r********2********IB**** =  .25 ****2**** = .0625**

**Community Interventions**

**Notes:**
�	This example shows that with even moderately high initial correlations the percentage of variance accounted for in outcomes is low

�	Most of our obtained correlations are not as high as .5

## Community Interventions

**I ******** M****1****  ******** M****2****  ******** M****3**** ********B**

**Community Interventions**

**Notes:**
�	In many projects we anticipate successive cascading relationships to occur

-	e.g. G5 - PI, purch, avail, access, consumption

-	Remembering the multiplicativeness of the relationships suggests very low effects on outcomes

## Community Interventions

**Enormous importance of theory**
**Need better theory**
**More theoretical research**
**More Funding for theoretical research**
**Find subgroups among whom theory seems to work better**
**Select theories for intervention that account for more of the variability in behavior**

**Community Interventions**

## Community Interventions

**New ideas in theory**
**TTM**
**Syntheory**
**Other?**
**More clearly define factors affecting behavior with known theoretical models**
**More integrative work**

**Community Interventions**

## Community Interventions

**Better measurement**
**More that 1 item per scale**
**Adapted to each target group**

**Community Interventions**

## Community Interventions

**Enormous importance of theory**
**Refine our methods for affecting theoretical mediating variables**
**Do research showing how much change in behavior we can expect from unit change in mediating variables**
**Fund research focusing on effects of intervention on mediating variables**

**Community Interventions**

## Community Interventions

**Do not fund outcome effectiveness studies until show can affect mediating variables at some acceptable level (MIN: results in behavior change)**
**Should decrease costs of individual studies**
**Should increase speed of results**

**Community Interventions**

## Community Interventions

**Intervene at each point in a cascading sequence of effects**
**When outcome studies funded**
**Do the mediational analyses**

**Community Interventions**

## Community Interventions

**We need a better understanding of mechanism**

**Community Interventions**

## Community Interventions

**Involve behavioral scientists in their health related dietary change programs**
**Thoroughly evaluate these programs so we can learn from them**

**Community Interventions**

**Notes:**
�	I know that industry and others will continue to fund some outcome studies because of the PR value

�	Thank you for graciously listening to my analyses of our current situation

## Theory in Intervention

**Intervention Design**

**Implementation**

**Mediating Variables**

**Outcomes**

**Moderating Variables**

**Rewards?**

**Theory in Intervention**

## Theory/Model of Program Intervention Implementation

- - Fidelity
- - Extent

- Resources
- - Types
- - Levels

- Reach
- - Depth
- - Spread

- Content
- - Types
- - Levels

- Design & Development of Intervention

**B**
**A**
**R**
**R**
**I**
**E**
**R**
**S**
- - Type
- - Diff

- (Baranowski T, Stables G.  Process Evaluation of the 5-A-Day Projects. _Health Education & Beh_ 2000, 27:157-166.)

**Theory/Model of Program Intervention Implementation**