The prevalence of type 2 diabetes mellitus (T2DM) rapidly rose over the past three decades worldwide.1 In Spain, the prevalence of T2DM (2012) is 14%,2 and the mortality rate associated with the condition is 18.3/100,000 men and 24.9/100,000 in women.3

T2DM does not impact all population groups equally, existing important differences according to sex, socioeconomic status and ethnicity.3–5 Socially disadvantaged groups are more exposed to obesogenic environments, and experience more difficulties in adopting healthy lifestyles (i.e. eating habits, physical activity, etc.), caused by social determinants of health.5–12 Several studies have observed an inverse association between educational level and worse prognosis of T2DM,3–5 which has been attributed to increased difficulties in processing oral communication,13 less awareness of the importance of diabetes self-management14 and less cohesive support networks14,15 in patients with a lower educational level.

A number of studies have examined the effectiveness of different types of interventions specially designed to improve diabetes self-management in socially vulnerable patients.15–19 Most of these interventions consisted in the use of psychoeducational strategies and targeted ethnic minorities or groups with lower socioeconomic status. Although, there was a great diversity of procedures and type of interventions, a moderate reduction of HbA1c outcome were observed in these systematic reviews.15–19

Evidence suggests that adequate patient-practitioner communication has a number of different benefits, including positive effects on patients’ compliance with medical recommendations.20 However, there is a scarce evidence available regarding the potential of interventions based on improving patient-practitioner communication to improve diabetes self-management in patients with low educational levels, much more if the intervention was performed by a medical doctor. Thus, Chapin et al.21 evaluated the effectiveness of an intervention consisting in the use of a visual tool to provide feedback to patients by displaying glycosylated haemoglobin values graphically over time, and relating them to the patients’ self-reported self-management activities. The authors observed that after the intervention 51% of the patients achieved adequate glycaemic control (HbA1c <7%, 53.01mmol/mol). Because its low cost of the intervention and easy transferability to routine clinical practice, we decided to adapt this intervention, implement it in a primary care setting in Spain, and evaluate its impact on patients’ health.

The aim of this study was to test whether an intervention based on improving patient-practitioner communication, compared with standardised usual care can improve diabetes self-management in patients with a low educational level.

A detailed description of the methodology used of this study is available elsewhere.22

Study design

Pragmatic cluster randomised controlled trial (Fig. 1).

Figure 1.

Study flow diagram.

(0.17MB).

This study examined the effectiveness of an intervention to improve diabetes self-management in patients with low educational level and inadequate glycaemic control by improving patient-provider communication. Patients both from the intervention and control group, significantly improved their glycaemic control after the study period. However, a higher reduction in HbA1c was observed in the intervention group. The intervention produced higher positive impact in those patients with higher levels of social support and without comorbidities. A dosage effect was observed, with each additional session being associated with a 0.2% decrease in HbA1c.

This the first study conducted in Spain that implemented and evaluated an intervention to improve diabetes self-management in a group of socially vulnerable patients. The study presents several methodological strengths, namely an adequate follow-up of outcome measures throughout the study period (including not only baseline and endpoint measures, but also every three months). Furthermore, randomization was conducted at the GP (and not patient) level, which prevented potential contamination bias. Furthermore, potential variability between GPs (clustering effect) was adequately controlled in our multilevel analysis. The HbA1c reductions were more notable after sixth months of follow up, these results could be justified by the need for a minimum number of session to achieve an intervention effect, although performance bias could not be excluded, because the HbA1c measures were performed every 3 months, instead each 6 months as usual care.

However, the study also has several limitations. First, although two intervention groups were initially considered (with and without telephone reinforcement),22 we experienced considerable difficulties in reaching and delivering the reinforcement to most of them. Because of that, we finally decided to analyse together the groups and therefore the specific effect of the reinforcement could not be formally evaluated. Second, although the proportion of patients in the intervention and control group was similar, the number providers in the intervention group (six GPs) was higher than in the control group (with only three GPs). However, results from the multilevel analysis suggested that the variability attributable to the provider level (cluster effect) was not significant, and therefore it is unlikely that the unbalanced number of providers per group has biased our results. Third, it was not possible to carry out a “double blind” study because the GPs themselves were the responsible for delivering the intervention. Finally, we cannot rule out the possibility that the GPs and/or patients might have modified their usual behaviour during the study period because they knew they were being studied (Hawthorn effect), which would at least partially explain the positive changes observed in the control group.

Although statistically significant, the reduction of HbA1c observed after the intervention is not clinically relevant, and it is substantially lower than the effect reported by Chapin et al.21 in their previous study. This could reflect the differences between control groups in both two studies. Thus, although mean HbA1c decreased in the control groups of both studies, the reduction was substantially higher in our study (−0.38%) than in the study by Chapin et al.21 (−0.18%). Moreover, it is worth noting that the number of sessions the participants attended was directly associated with the impact of our intervention, and therefore the modest effect might be a result of the low attendance observed in our study.

Apart from some exceptions,24 our results are consistent with other previous studies.25–28 The comparison with previous literature however is limited for two main reasons: 1) most of the previous studies were conducted in the U.S., a country with a healthcare system considerably different from the Spanish; and 2) with the exception of the study by Chapin et al.,21 the studies are significantly different to ours in terms of the type of intervention examined and population targeted.

Consistent to previous studies,24–28 most participants in this study presented multiple comorbidities and low social support. The intervention produced better results in patients with higher levels of social support. Part of the intervention consisted in encouraging patients to discuss with their relatives the results displayed in their DSMRS, which could have been a facilitating factor. In order to successfully tackle social inequalities in health however, the identification of effective strategies for patients with lower levels of social support is very much needed. Similarly, the intervention produced better results in patients without comorbidities. Adequate diabetes self-management is especially challenging in patients with multiple chronic conditions. The impact of multimorbidity on quality of care (including self-care) is an area of growing interest in primary care.29 Although there is still little scientific evidence regarding what constitutes high quality healthcare for patients with multiple conditions, our intervention is in line with available recommendations, since its main aim is to improve patient-practitioner communication.

A systematic review by members of our team30 identified a set of common characteristics of successful interventions in promoting adequate self-management, which included simple, face to face, and individually delivered; based on cognitive reframing techniques; and involving peer providers. The intervention tested in our study contained all these characteristics. Although a higher focus on cognitive techniques related to healthcare for patients with comorbidities and low social support, could have produced a greater positive impact.

Diabetes care in Spain, as in other developed countries, is increasingly expensive. It has been estimated that patients with T2DM in Spain use between 2 and 6 times more direct resources than patients with other long-term conditions.3 Differences in resources and healthcare costs between the intervention and the control group were minimal; the only additional costs in the intervention group were the take home prints offered to the patients. The average appointment duration were not different in both the intervention and control groups, and no additional testing or materials were used in the intervention group. Although we have not carried out a formal cost-effectiveness analysis, the feasibility and minimal cost of this intervention would permit its implementation as part of routine healthcare in those areas with higher proportion of patients with low educational levels.

This study is one of the first clinical trials in Spain to evaluate an intervention conducted in the primary care setting to improve health outcomes in a group of socially vulnerable patients. Despite of the high number of studies published each year highlighting the existence of important social inequalities in health in Spain, up to date there has been little interest in designing, implementing and evaluating strategies aiming to improve the health of disadvantaged groups. There is no doubt that clinical trials in primary care are complex and more susceptible to bias than clinical trials in more controlled settings. However, simple interventions in the primary care setting such as the one describe here can be widely and easily implemented, and have the potential to benefit a large proportion of the population. More research in this area is therefore essential.

This study analysed an intervention implemented in a primary care setting to improve diabetes self-management in patients with a low educational level. The results suggested that the intervention produced a modest improvement in glycaemic control, although no significant improvements were observed in the secondary outcomes examined. More research is needed to identify effective strategies that can be implemented in primary care to contribute to tackling social inequalities in health in patients with diabetes.

Alberto Ruano-Ravina.

The corresponding author on behalf of the other authors guarantee the accuracy, transparency and honesty of the data and information contained in the study, that no relevant information has been omitted and that all discrepancies between authors have been adequately resolved and described.

C. Bermúdez Tamayo, G. Pastor Moreno, J. Bolívar Muñoz, I. Ruiz Pérez and IRC designed the study. F. Quesada Jiménez, P. Cruz Vela, A.M. de los Ríos Álvarez, M.A. Prados Quel, E. Moratalla López, S. Domínguez Martín and J.A. Lopez de Hierro were involved in data analysis and interpretation. A. Olry de Labry Lima and M. Johrid carried out the statistical analysis. C. Bermúdez Tamayo, G. Pastor Moreno, J. Bolívar Muñoz, I. Ruiz Pérez, A. Olry de Labry Lima, M. Johrid and I. Ricci Cabello conducted the literature searches and wrote a draft of the manuscript. All results were discussed among the authors. All authors contributed to and have approved the final manuscript.

Clinical Trials U.S. National Institutes of Health, NCT01849731.

https://clinicaltrials.gov/ct2/show/NCT01849731?term=NCT+01849731&rank=1

Regional Health Ministry (Andalusia, Spain). The funder of this study had no role in study design, data analysis, data collection, data interpretation, or writing of the report.

One of the authors (C. Bermúdez Tamayo) belongs to the Gaceta Sanitaria editorial committee, but was not involved in the editorial process of the manuscript.