Using the matrixed multiple case study methodology to understand site differences in the outcomes of a Hybrid Type 1 trial of a peer-led healthy lifestyle intervention for people with serious mental illness

Site differences in implementation trial outcomes are common but often not examined. In a Hybrid Type 1 trial examining the effectiveness-implementation of a peer-led group life-style balance (PGLB) intervention for people with serious mental illness (SMI) in three supportive housing agencies, we found that PGLB recipients' physical health outcomes differed by study sites. The matrixed multiple case study methodology was used to explore how implementation outcomes and changes in context of usual care (UC) services contributed to these site differences. Two implementation outcomes (i.e. PGLB fidelity ratings and intervention recipients' acceptability of PGLB and UC) and changes in healthcare services integration at the study sites were examined. ANOVAs were used to examine site differences in fidelity ratings and client satisfaction. Directed content analysis was used to analyze leadership interviews to identify changes in the context of UC services. Site 3 showed a trend approaching significance (P = .05) towards higher fidelity ratings. High levels of satisfaction with PGLB were reported at all sites. Significant differences in PGLB recipients' satisfaction with UC were found, with Site 3 reporting the lowest levels of satisfaction. Agency leaders reported an increase in prioritizing client's health throughout the trial with sites differing in how these priorities were put into action. Differences in PGLB recipients' satisfaction with UC, and changes in healthcare service integration seemed to have contributed to the site differences in our trial. The matrixed multiple case study methodology is a useful approach to identify implementation outcomes contributing to the heterogeneity of multisite implementation trial results.

Examining Place-Based Neighborhood Factors in a Multisite Peer-Led Healthy Lifestyle Effectiveness Trial for People with Serious Mental Illness

People with severe mental illness (SMI) experience significantly higher obesity-related comorbidities and premature mortality rates than healthy populations. The physical and social characteristics of neighborhoods where people with SMI reside can play an important role in promoting or hindering healthy eating and physical activity. However, this is seldom considered when designing and testing health behavior interventions for these populations. This study used baseline data from an obesity control trial for low-income, minority people with SMI to demonstrate the utility of assessing neighborhood- and city-level place-based factors within the context of lifestyle interventions. GIS was used to create a zip-code-level social and built environment geodatabase in New York City and Philadelphia, where the trial occurred. Chi-square and t-tests were used to assess differences in the spatial distribution of health-related built and social environment characteristics between and within cities and diet and physical activity outcomes. All types of neighborhood characteristics showed significant environmental differences between and within cities. Several neighborhood characteristics were associated with participants' baseline healthy eating and physical activity behaviors, emphasizing that place-based factors may moderate lifestyle interventions for SMI patients. Future behavioral interventions targeting place-dependent behaviors should be powered and designed to assess potential moderation by place-based factors.

Impact of Moderating Demographic Variables on a Health Intervention for People with Serious Mental Illness

Purpose

Healthy lifestyle interventions can improve the health of people with serious mental illness (SMI). Little is known whether demographic variables moderate the effectiveness of these interventions on health outcomes.

Method

Data from an effectiveness trial of a peer-led healthy lifestyle intervention (PGLB) for people with SMI examine whether age, racial/ethnic minoritized status, and gender moderated the effectiveness of PGLB compared to usual care (UC) in achieving clinically significant improvements in weight, cardiorespiratory fitness, and cardiovascular disease (CVD) risk reduction.

Results

Compared to UC, PGLB was most beneficial for participants age 49 and younger for achieving clinically significant weight loss and from racial/ethnic minoritized communities for achieving clinically significant weight loss and reductions in CVD risk.

Conclusions

These findings suggest the impact of healthy lifestyle interventions for people with SMI may not be uniform and adaptations may be needed to make these interventions responsive to the needs of diverse populations.

Learning, doing and sticking with it: A qualitative study on achieving clinically significant reduction in cardiovascular disease risk in a healthy lifestyle intervention for people with serious mental illness

People with serious mental illness (SMI; e.g. schizophrenia) have mortality rates two to three times higher than the general population, largely due to a higher prevalence of cardiovascular disease (CVD). Healthy lifestyle interventions can improve the health of people with SMI, but information about why these interventions work for some and not others is scarce. Our study aims to qualitatively explore differences in these two groups' overall experiences and application of the intervention. Data were drawn from a randomised effectiveness trial of a peer-led healthy lifestyle intervention. Qualitative data from interviews and focus groups with 21 participants were linked to their 12-month outcome data. Grounded theory was used to compare the experiences of participants who achieved clinically significant CVD risk reduction (i.e. clinically significant weight loss or clinically significant improvements in cardiorespiratory fitness) versus those who did not. Three qualitative themes: learning, change, sticking with it - differentiated participants who achieved CVD risk reduction and those that did not. Participants achieving CVD risk reduction described learning and applying specific knowledge and skills related to a healthy lifestyle when making health decisions, made healthy concrete changes to diet and physical activity, and stuck with those changes. Participants not achieving clinically significant CVD risk reduction reported surface-level learning about healthy lifestyle practices, difficulty sticking with healthy changes, and were more likely to report ambiguous or no changes. Our findings suggest that healthy lifestyle interventions for people with SMI should provide experiential in-vivo learning experiences while periodically assessing participants' understanding and then tailoring the intervention to their needs. It is important to build self-efficacy for health behaviour changes by creating early perceptions of success, which was found to enhance motivation and sustain behaviour change. Helping people with SMI develop and strengthen their support systems will also be an important factor for building and sustaining health behaviour changes.