Overview of MOST

Black BoxWhat is the multiphase optimization strategy (MOST)?

MOST is a comprehensive, principled, engineering-inspired framework for optimizing and evaluating multicomponent behavioral interventions. MOST includes a randomized, controlled trial (RCT) for intervention evaluation, but unlike the standard approach to intervention development, also includes other steps before the RCT. These steps are aimed at intervention optimization using criteria selected by the scientist. The goal may be to develop a cost-effective intervention, an intervention that achieves a specified level of effectiveness, the briefest intervention that achieves a minimum level of effectiveness, or any other reasonable goal. The MOST framework relies heavily on resource management by strategic use of highly efficient experimental designs. MOST is designed to be practical, and holds out the possibility of achieving more rapid long-run improvement of interventions without a dramatic increase in intervention research resources.

 

 

Where can I read more about MOST?

View the MOST recommended reading list.

 

 

What qualifies as a “multicomponent behavioral intervention”?

A multicomponent behavioral intervention is any multicomponent intervention in which at least one of the components is behavioral. In other words, an intervention that combines behavioral and pharmaceutical components would be considered behavioral according to this definition.

 

 

What is an intervention component?

In MOST we define an intervention component as any part of an intervention that can reasonably be separated out for study. This definition is meant to be both broad and practical, because what constitutes a component can be very different in different situations. A component can be a part of the content of the intervention, such as topics in a drug abuse prevention program; a feature of the intervention that promotes compliance or adherence, such as reminder phone calls; features aimed at improving fidelity, such as a phone number for program delivery staff to call with questions; or any other aspect of a behavioral intervention.

 

An intervention scientist conducts MOST because he or she needs to make decisions about what to include in an intervention. If you are asking yourself “Should I include X?” then X can probably be considered a component of the intervention.

 

An intervention component can impact efficacy, effectiveness, and/or cost-effectiveness. To contrast some very different takes on intervention components, read the articles in the reference list below.

 

References

Caldwell, L. L., Smith, E. A., Collins, L. M., Graham, J. W., Lai, M., Wegner, L., Vergnani, T., Matthews, C., & Jacobs, J. (2012). Translational research in South Africa: Evaluating implementation quality using a factorial design. Child and Youth Care Forum, 41, 119-136. PMCID: PMC3375728

Collins, L. M., Baker, T. B., Mermelstein, R. J., Piper, M. E., Jorenby, D. E., Smith, S. S., Schlam, T. R., Cook, J. W., & Fiore, M. C. (2011). The multiphase optimization strategy for engineering effective tobacco use interventions. Annals of Behavioral Medicine, 41, 208-226.

Strecher, V. J., McClure, J. B., Alexander, G. W., Chakraborty, B., Nair, V. N., Konkel, J. M., Greene, S. M., Collins, L. M., Carlier, C. C., Wiese, C. J., Little, R. J., Pomerleau, C. S., Pomerleau, O. F. (2008). Web-based smoking cessation programs: Results of a randomized trial. American Journal of Preventive Medicine, 34, 373-381.

 

 

How is MOST different from the traditional approach to intervention development?

Figure 1 below is an example flow chart of MOST, taken from Collins et al., 2011. This flow chart shows the steps, or phases, of MOST as it is applied in the study described in that article. The objective of that study is to develop an optimized clinic-based smoking cessation intervention. The flow chart is described in more detail in the article.

 

The flow chart begins with an information input/output box; the list inside reads: “Theory.  Scientific literature.  Clinical experience.  Data analysis results.  Other.”   Then proceed to an action box with Step 1 “Establishment of theoretical model.”   Next is an action box: Step 2 “Identification of set of intervention components to be examined.”    Next is an action box: Step 3A “Experimentation to examine individual intervention components.  Step 3A leads to Step 3B.  An alternate path leads to the information input/output box “Centralized database.”    The information input/output box “Centralized database” is outside of the main steps of the flow chart.  The information input/output box “Centralized database” in turn leads to an action box also outside of the main flow chart steps.  The action box reads “Exploratory data analyses.”  The arrow from this action box returns to the very beginning of the chart with the information input/output box: “Theory.  Scientific literature.  Clinical experience.  Data analysis results.  Other.”  From Step 3A, proceed to Step 3B, the action box “Refinement via experimentations and other methods.”  This action is optional.  Step 3B is followed by Step 4.  Step 3B also has an alternate path to the information input/output box “Centralized database.”  Step 4 is an action box “Assembly of beta intervention.”  Step 4 leads to a decision point: “Is beta intervention expected to be effective?”.  If the answer is no, then return to Step 1 “Establishment of theoretical model.”  If the answer is yes, then proceed to Step 5.  Step 5 is an action box “Confirmation of effectiveness of beta intervention via RCT [randomized controlled trial]”.  Step 5 has two arrows.  One leads to the information input/output box “Centralized database.”  The other arrow from Step 5 leads to a decision point: “Is beta intervention effective?”.    If the answer to this question is no, then return to Step 1 “Establishment of theoretical model.”  If the answer is yes, proceed to Step 6.    Step 6 is a product “Release of new intervention.”  This is the end of the flow chart.

 

With kind permission from Springer Science+Business Media: Figure 1 from

Collins, L. M., Baker, T. B., Mermelstein, R. J., Piper, M. E., Jorenby, D. E., Smith, S. S., Schlam, T. R., Cook, J. W., & Fiore, M. C. (2011). The multiphase optimization strategy for engineering effective tobacco use interventions. Annals of Behavioral Medicine, 41, 208-226.

 

Figure 1 shows some of the ways in which MOST is different from typical intervention development practice. Today the typical intervention scientist would start with Step 1, Establishment of theoretical model, and Step 2, Identification of a set of intervention components to be examined. The intervention scientist would then go directly to Step 4, Assembly of beta version of intervention. This step consists of forming a version of the intervention out of the intervention components. The scientist would probably skip the decision point between Steps 4 and 5, and go directly to Step 5, confirmation of effectiveness of the beta intervention via an RCT.

 

In the traditional approach to intervention development and evaluation little attention is paid to investigating the contribution of individual intervention components. MOST inserts some steps between Steps 2 and 4 that are aimed at assessing this. In Step 3A, the efficacy/effectiveness of individual intervention components is assessed experimentally. (As discussed in other questions in this FAQ, this is feasible when highly efficient experimental designs are used.) In Step 3B, additional experimentation is done for refining purposes to address very specific questions. Collins et al. (2011) walks through this flow chart and illustrates it using a smoking cessation study.

 

MOST is a framework, not an off-the-shelf procedure, so the details can vary somewhat from study to study. This means that a variation on this flow chart may do a better job of describing a different application of MOST.

 

 

What is the resource management principle?

The resource management principle is one of the fundamental principles underlying MOST. According to this principle, research resources—money, experimental subjects, time, equipment, personnel, etc.—must be managed strategically to move intervention science forward fastest. Sometimes this will mean thinking creatively about the following:

 

  • using experimental designs other than the standard RCT and its relatives, when it is more efficient to do so;
  • taking calculated risks to move science forward faster;
  • conducting experimentation in a sequential way so that the results of one experiment inform the planning and execution of the next one; and
  • doing what will move intervention science forward fastest and best in the long run, even if it means somewhat slower progress, or the appearance of slower progress, in the short run.

 

 

What is the continuous optimization principle?

The continuous optimization principle is one of the fundamental principles underlying MOST. According to this principle, optimization is an ongoing process. Every behavioral intervention, including the theoretical model that provides its conceptual foundation, is a perennial work in progress. Once an intervention has been optimized, a cycle of MOST should be started again to effect further improvements. An intervention can always be made more potent or more efficient.

 

Return to MOST home page.

 

Read about establishing a theoretical model.

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