Dear Editor,

We read with great interest the article by Garcimartin and colleagues1 entitled "The Impact of Motivational Interviewing on Self-care and Health-Related Quality of Life in Patients with Chronic Heart Failure." Considering that we have had similar experiences in implementing an educational intervention with motivational interviewing (MI), we take this opportunity to raise a few important reflections and considerations that may enhance experimental design and methodologies, thus reinforcing the level of evidence in future studies.

In recent decades, MI has emerged as a promising approach for promoting and maintaining healthy behaviors. Motivational interviewing consists of a tailored patient-centered intervention that explores the ambivalence in human behaviors and extends empathy to people struggling with behavior change. By eliciting intrinsic motivation, MI encourages the patient to become the main actor in the behavior change process.2 We now have abundant evidence of MI's effectiveness in a variety of chronic and acute health conditions, including substance addictions.3 Pooled evidence from recent systematic reviews demonstrates that self-care, rehospitalization, and quality of life are among the most MI-responsive outcomes.4,5

In their recent study, Garcimartin et al assessed the effectiveness of MI in improving self-care and quality of life in patients with heart failure (HF). This study had a pretest-posttest design with enrollment of 93 patients in the intervention arm and 93 historical control subjects. After 6 months, the intervention had significantly improved self-care; although quality of life had increased in both groups, improvements did not reach statistical significance in either group. It is worth noting that the Garcimartin et al study was not randomized and without concurrent controls. In addition, although some important demographic and clinical characteristics such as age, ventricular ejection fraction, and self-care at baseline were matched to ensure at least partial balancing, the sample was unbalanced at baseline for some variables. These drawbacks have the potential to undermine the authors' conclusions regarding causal effects of the intervention.

Despite its limitations, the Garcimartin et al study is interesting for a couple of reasons. First, the authors provided feedback on the MI intervention with the Motivational Interviewing Treatment Integrity (MITI) code, a validated behavioral coding system that measures the fidelity and quality of MI sessions.6 The MITI score was high in this study, indicating that the intervention had been delivered as intended. Second, MI sessions were longer, more intensive, and more frequent than those reported in other studies. Briefly, an initial intervention of approximately 45 minutes was followed by subsequent 30-minute visits. Six or seven sessions occurred for a period of 6 months. This is consistent with published recommendations that HF interventions should last 30 minutes and be more intensive for the first month's follow-ups.7

A few years ago, our group conducted a randomized controlled trial (the MOTIVATE-HF study).8 The aim of the study was to evaluate the effectiveness of MI in improving self-care (primary end point), as well as a few secondary outcomes measured in patients with HF (generic and disease-specific quality of life, physical symptoms, anxiety and depression, sleep quality, mortality, and use of healthcare services) and in their informal caregivers (contribution to self-care, preparedness, self-efficacy).9 We randomized a total of 510 patients and caregivers in 3 arms: arm 1, in which only the patients received the MI intervention; arm 2, in which both patients and caregivers received the intervention; and arm 3, which received standard care.

Like Garcimartin et al's group, we found that the intervention was effective in improving patient self-care; at 3 months from enrollment, both arm 1 and arm 2 had improved statistically and clinically, and we observed a 10% increase in the number of patients with adequate self-care. Further analyses of secondary outcomes demonstrated that MI was also effective in improving quality of life in the intervention groups at 9 and 12 months; this was particularly evident in arm 2, where MI was also administered to informal caregivers.10 Unexpectedly, we also found that, at 3 months, patient mortality was reduced in arm 2 only.11 These results highlight the importance of informal caregiver participation in psychoeducational processes, at least when MI is used. One strength of the MOTIVATE-HF study is its randomization, which is the criterion standard for trial designs; another strength is the participation of the caregivers, in whom MI intervention seems to have significantly ameliorated several patient outcomes, including self-care. One limiting factor in our study was that the MITI scale score was slightly below adequacy, suggesting there could have been further room for improvement in the delivery of the intervention.12

In conclusion, on the basis of the study by Garcimartin et al and of our own experience, we wish to underscore a few important insights that could illuminate future scientific investigations. First, whenever possible, samples in intervention studies should be randomized to avoid selection bias and to ensure that confounding variables are balanced between the trial groups. Second, it is important to invest time in the training of practitioners so that they may perform high-quality MI sessions. We recommend that this aspect be integrated with intervention fidelity monitoring to prevent deviations in MI delivery across time and/or between individuals receiving the interventions. Third, MI sessions should be appropriately delivered in terms of frequency and intensity. Evidence suggests that training sessions should last a minimum of 30 minutes and be scheduled more often in the short term and less frequently in the long term.7 Finally, in light of our results, we recommend a dyadic approach to delivering MI sessions; dyad-level interventions have the intrinsic advantage of targeting processes such as coping efforts, communication, and reciprocal support behaviors between patients and caregivers.

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