The Moderating Effects of Race and Ethnicity on a Motivational Interviewing Intervention for Improving Physical Health Among Patients With Peripheral Artery Disease: Secondary Analysis of a Pilot Randomized Trial.
Zhu Y & Collins T • JMIR formative research • 2026
This pilot study found that motivational interviewing (MI) improved 6-minute walk distance more among participants of 'other' race and ethnicity than non-Hispanic White participants (DiD=44.0 m), and that improvements in walking distance and weight loss were highly consistent in both direction and size across social determinants of health strata.
Key Findings
Results
Pretest-posttest changes in 6-minute walk distance were significantly greater among participants of 'other' race and ethnicity than among non-Hispanic White participants in the MI intervention.
Difference-in-differences (DiD) = 44.0 m, 95% CI 19.2–164.2; P=.004
No other SDOH variables showed statistically significant DiDs for 6-minute walk distance
Comparisons were conducted using Wilcoxon and Kruskal-Wallis nonparametric tests
This was identified as a potential effect modification by race and ethnicity
Results
Significant median pretest-posttest increases in 6-minute walk distance were observed in multiple specific SDOH subgroups.
College or higher educational attainment: 48.8 m increase (95% CI 28.0–61.4)
Unmarried individuals: 40.4 m increase (95% CI 0.5–56.0)
Those living with family: 55.7 m increase (95% CI 30.5–199.5)
Those who talked to and saw family or friends 3 or more times a week: 46.4 m increase (95% CI 17.2–69.4)
Those without unmet daily needs: 46.5 m increase (95% CI 7.6–67.1)
Results
No significant difference-in-differences for weight loss were observed with any SDOH variable.
Despite no significant DiDs, significant median weight loss was observed in every SDOH stratum where a significant increase in 6-minute walk distance was also observed
Significant weight loss was additionally observed in 5 SDOH strata not associated with significant walking distance gains: male individuals, household income below US $30,000, never served in military, employed status, and no stress
The improvements in weight loss and walking distance were described as 'highly consistent in both direction and size across SDOH strata'
Methods
The pilot randomized trial assigned participants to face-to-face or telephone motivational interviewing (MI) or a smartphone app control.
MI group: n=16; smartphone app group: n=13
Participants were community dwellers in Wichita, Kansas, recruited through community outlets and screened for PAD
Primary outcome was 6-minute walk distance change; secondary outcome was body weight reduction
Follow-up period was 3 months
SDOH, demographics, and adverse childhood experiences were measured using survey instruments; ClinicalTrials.gov NCT03694652
Background
The parent pilot trial found that MI (face-to-face or telephone) was more efficacious than the smartphone app after 3 months for both increasing 6-minute walk distance and reducing body weight.
This secondary analysis was conducted to explore whether SDOH are associated with MI intervention effects
The study aimed to generate intervention heterogeneity hypotheses rather than confirm them
Authors noted this was 'the first to explore potential SDOH-related intervention effect modification and heterogeneity' in this context
Discussion
The authors identified likely mediation pathways through health literacy and social support consistent with established associations between SDOH and general functions in patients with PAD.
Findings were described as 'consistent with established associations between SDOH and general functions in patients with PAD'
Authors suggested 'likely mediation pathways through health literacy and social support'
Future interventions were recommended to consider heterogeneity 'to target socially disadvantaged patients with PAD to bridge disparities and maximize benefits'
What This Means
This research suggests that a motivational interviewing (MI) intervention—delivered either face-to-face or by telephone—may not benefit all patients with peripheral artery disease (PAD) equally. In a small pilot study of 29 patients in Kansas, the researchers found that participants from racial and ethnic minority groups (categorized as 'other' race and ethnicity) showed notably larger improvements in walking ability compared to non-Hispanic White participants when receiving MI, with an average difference of about 44 meters in the 6-minute walk test. This hints that the intervention may be especially effective for certain racial and ethnic groups, though the small sample size means this finding should be interpreted cautiously.
The study also found that improvements in both walking distance and body weight tended to cluster together across various social groups. People who had college education, lived with family, had frequent social contact, or had their basic daily needs met tended to show significant gains in walking ability. Weight loss improvements appeared in those same groups and additionally in men, lower-income individuals, employed people, those who had never served in the military, and those reporting no stress. Notably, no single social factor consistently explained who benefited more from MI versus the app (no statistically significant 'difference-in-differences' were found for weight loss with any social factor).
This research suggests that social factors like race, education, social support, and economic stability may shape how well motivational interviewing works for people with PAD. Because PAD reduces blood flow to the legs and limits walking ability, finding effective ways to help all patients—especially those from disadvantaged backgrounds—is important for reducing health disparities. The authors caution that these are hypothesis-generating findings from a very small pilot study, and larger trials are needed to confirm whether tailoring MI interventions to specific social groups could maximize benefits and close health gaps.
Zhu Y, Collins T. (2026). The Moderating Effects of Race and Ethnicity on a Motivational Interviewing Intervention for Improving Physical Health Among Patients With Peripheral Artery Disease: Secondary Analysis of a Pilot Randomized Trial.. JMIR formative research. https://doi.org/10.2196/82926