Developing a problem-based self-management training in both an intensive and condensed format, adapted for low literacy, was feasible. Both the intensive format, which modeled standard PST, and the condensed format, which more closely modeled current practice in diabetes, covered the necessary components of PST as a behavior change intervention. Participants in each intervention experienced the program as helpful and easy to understand. At immediate post-intervention, participants in both programs demonstrated knowledge gain. However, at 3 months post-intervention, only the intensive intervention was effective in improving knowledge, problem-solving skills, self-care, and A1C. This study extends findings regarding effective elements of PST delivery26
to diabetes and suggests that a traditional PST delivery model (intensive), but not an abbreviated model is effective for key diabetes behavioral and clinical outcomes.
Our treatment effect on A1C of −0.72% at 3 months post-intervention is higher than mean reductions reported in meta-analyses of diabetes self-management educational and behavioral interventions of 0.43% overall,27
and 0.26% at 1–3 months of follow-up.28
Problem-solving skill at follow-up seems to partially mediate the treatment effect on A1C, as it attenuated the observed treatment effect on A1C change by 0.15%. Although this attenuation only reach marginal statistical significance in this small pilot trial, it may warrant further investigation in future studies. Few changes were observed from baseline to follow-up in frequencies of participants prescribed diabetes medications (none, pills only, insulin only, insulin and pills), further suggesting that changes in A1C were generally not due to medication initiation or advancement. In fact, one participant in the intensive program who was on insulin and oral agents at baseline was able to successfully discontinue insulin during follow-up.
Neither intervention had a significant effect on blood pressure or lipids at the group level of analysis. One explanation is that, unlike A1C, smaller subsets of participants had suboptimal blood pressure at baseline, and fewer had suboptimal lipids (Table ). Intervention effects seen in these subgroups yielded smaller mean change in these outcomes when averaged over the entire group. Importantly, the individual changes patients experienced in SBP, DBP, and LDL were clinically meaningful.
This was a comparative effectiveness study of two active interventions rather than an examination of an active intervention vs. a control condition. An attention control is not appropriate in this study design,29
as it would not allow comparison of the actual behavioral procedures as they are implemented in practice. The condensed format can be considered a “best practices” version of the current, brief approaches to problem-solving training within diabetes patient education, which tend to be less structured and less comprehensive in use of the formal PST approach.9,11
One of the strengths of our study was the high trial completion rate, resulting in few missing data. In such a case, some may consider using the “complete case” analysis, wherein only the outcome differences between baseline and follow-up among patients who completed the trial are used for the analysis. The results of such analyses would only be valid if data were missing completely at random. Instead, we opted to use the mixed effects modeling approach for our ITT analysis, an approach that is valid, with proper modeling, under the more realistic case where the probability of missing data may depend on the variables observed in the study.
The study has limitations. Due to the sample size, we were not powered to detect between-group changes in outcomes other than A1C. The effect sizes for knowledge, HPSS, and SDSCA yielded by this study will aid sample size planning for future evaluations of those behavioral variables. Second, this study was focused on intervention development and testing of feasibility and acceptability. As such, the follow-up period was of relatively short duration (3 months post-intervention, corresponding with 6—9 months following baseline assessment). Nevertheless, the study demonstrated statistically significant between-group changes in A1C as well as significant within-group improvements in a number of key behavioral parameters, showing promise for effectiveness. The intensive program requires testing with a longer follow-up period to monitor maintenance of the observed skill gain, which has been found to improve with time when problem-solving has been taught effectively,11
maintenance of clinical improvements, and cost-effectiveness of this intervention approach.
Finally, the study addresses a delivery model consideration. There has been a shift toward more social- and community-based interventions for improving diabetes control in vulnerable populations, as those approaches have many advantages. Moreover, reviews of the evidence base have concluded that vulnerable populations may not benefit as much from clinic-based, didactic, moderate intensity approaches.30
In contrast, our study suggests that clinic-based interventions can succeed in these populations. Adoption and attendance were high with delivery within a healthcare setting. Second, providing rather rigorous content and didactic materials was acceptable and deemed useful. Participants reported taking their workbooks with them to the grocery store, doctors’ appointments, and sharing with coworkers and family. Importantly, this clinic-based delivery required that materials be designed for suitability, which is feasible and effective using available guidelines. Finally, while more social-based interventions may be particularly useful for support-building, the combined education and problem-solving training intervention is designed for skill-building for behavior change;11
participants found the approach relevant due to its focus on life challenges that stood in the way of managing their diabetes. With newer healthcare approaches to chronic disease care, such as patient-centered medical home, ways of providing effective self-management training, particularly for vulnerable populations, are needed. Combining education with problem-solving training for behavior change is a viable, reimbursable treatment within some existing practice models,31
and it may be an approach for delivery by healthcare professionals within the newer self-management support models.