Complex Interventions? Insights through Process Evaluation

By: Queena Luu

LSHTM MSc Public Health, Health Service Research, student

Public health deals with a variety of interventions that interact not only with the healthcare system but the broader social, political, and economic contexts. Thus, large scale health interventions can be inherently complex with a range of components, outcomes, and stakeholders involved.

Assessing the effectiveness of interventions directs attention to measurements of outcomes. Process evaluation expands on such findings by answering questions beyond ‘does this intervention work?’ to ‘what components of the intervention lead to the results?’ and, ‘how implementation strategies affect outcome measures?’

Dr. Stefanie Dringus from LSHTM gave a one-day training on operationalizing process evaluation. Attendees were introduced to the key domains of process evaluations: building strategies to address context, implementation, and mechanisms of impact. The training led to discussions about the degree to which interventions are adapted to the local context and how focus groups may reveal what aspects (‘active ingredients’) of multi-component interventions were most impactful for participants.

After reviewing the theory, attendees were given the chance to simulate the development of a process evaluation for a hypothetical community role model-based intervention. The intervention had the goal of reducing risk factors associated with sexual behavior among young people. In small groups, attendees developed logic models and discussed methods to evaluate the process through which the intervention was implemented.

Groups brought up various issues associated with measuring primary and secondary outcomes because the intervention had many seminar-based components. My group also touched upon the need to use mix methods to understand the mechanisms of implementation including using focus groups and in-depth interviews to understand how receptive young people were to coach-led discussions that addressed sensitive topics.  We also discussed how the coverage of the intervention, and how data is collected, can influence the outcome measures.

After reconvening, various groups presented their logic models. Each group had approached the process evaluation design from different angles – from constructing detailed tables for each of the research domains to using highlighters to cross reference different research questions and their associated process evaluation methods that need to be explored.

At the conclusion of the workshop, there was a rich discussion on how the roll-out and data collection for intervention studies need to be placed in the local context. Complex interventions are embedded into various layers of the community, and it is important to be critical about what questionnaires are administered, how rapport affects responses, and how the process evaluation team, the outcome evaluation team, and the community are communicating with each other.

Process evaluation is one key component into understanding how and why interventions work – this is especially important given the increasingly complex interventions that are being implemented to address determinants of health.

Blog reports on a student workshop on process evaluation organized by the Centre for Evaluation’s. Read more about process here.