The American Journal of Managed Care February 2011
Psychological Family Intervention for Poorly Controlled Type 2 Diabetes
Objective: To evaluate the effectiveness of a psychological, family-based intervention to improve diabetes-related outcomes in patients with poorly controlled type 2 diabetes.
Methods: This study was a randomized controlled trial of a psychological family-based intervention targeted at individuals with poorly controlled type 2 diabetes. Recruitment and follow-up occurred at specialist diabetes clinics. Patients were randomly allocated to an intervention group (n = 60) or a control group (n = 61). Poor control was defined as at least 2 of the patient's last 3 glycated hemoglobin (A1C) readings at >8.0%. The intervention consisted of 2 sessions delivered by a health psychologist to the patient and a family member in the patient's home, with a third session involving a 15-minute follow-up telephone call.
Results: At 6-month follow-up, the intervention group reported significantly lower mean A1C levels than the control group (8.4% [SD = 0.99%] vs 8.8% [SD = 1.36%]; P = .04). The intervention was most effective in those with the poorest control at baseline (A1C >9.5%) (intervention 8.7% [SD = 1.16%, n = 15] vs control 9.9% [SD = 1.31%, n = 15]; P = .01). The intervention group also reported statistically significant improvements in beliefs about diabetes, psychological well-being, diet, exercise, and family support.
Conclusions: After participating in a family-based intervention targeting negative and/or inaccurate illness perceptions, patients with poorly controlled type 2 diabetes showed improvements in A1C levels and other outcomes. Our results suggest that adding a psychological, family-based component to usual diabetes care may help improve diabetes management.
(Am J Manag Care. 2011;17(2):105-113)
As an adjunct to usual care, a psychological family-based intervention improved glycemic control in patients with poor glycemic control.
- Those with particularly poor control derived the most benefit from the intervention.
- Participants regarded the home setting as a key element of the intervention.
- This intervention could potentially be delivered by any trained member of the multidisciplinary diabetes team.
Evidence suggests that people with poorly controlled type 2 diabetes have distinctly different perceptions or beliefs about diabetes compared with people who have good control.5 The current theoretical framework guiding research in this area is the Self-Regulatory Model of Leventhal et al6 (eAppendix at www.ajmc.com). According to this model, illness perceptions influence self-management behaviors, which in turn may influence health outcomes. For example, the perception that type 2 diabetes is an acute illness and the belief that diabetes has a negative impact on a person’s life have been found to be associated with poorer metabolic control.7 People with poorly controlled type 2 diabetes are also more likely to report that their diabetes is caused only by genetic factors,8,9 thereby potentially limiting their motivation to change unhealthy behaviors.
Thus, interventions focusing on changing negative and/or inaccurate beliefs about diabetes may lead to better self-management and glycemic control. However, family members’ perceptions about diabetes may also influence diabetes outcomes,8-10 for example, by impacting their decisions to provide support for disease management. Importantly, family-oriented research in type 2 diabetes has been relatively underinvestigated.11 The current study assesses the effectiveness of a psychological family-based intervention for patients with poorly controlled type 2 diabetes.
Study Design, Participants, and Settings
This study involved a 6-month prospective randomized controlled trial. Participants were recruited from specialist diabetes clinics at a large suburban hospital. In Ireland, usual care for poorly controlled type 2 diabetes generally involves annual attendance at a specialist outpatient clinic, with interim care provided by family practitioners. There is no national remunerated structured care delivery program; thus, clinicians follow protocols based on international guidelines (eg, those of the American Diabetes Association).
Patients were included in the study if they had type 2 diabetes for more than 1 year, were over 18 years old, and had persistently poor glycemic control, defined as having at least 2 of their last 3 glycated hemoglobin (A1C) readings at 8.0% or higher. Assessments of A1C coincided with patients’ last 3 clinic visits, generally at the time of recruitment and at 6 and 12 months previously. Patients with a recruitment A1C of less than 8.0% were included if their previous assessments were greater than 8.0%. Patients nominated the family member who was most involved in helping them with their diabetes management to participate. Family members were defined as those having a close relationship and regular contact with the patient, although they were not required to be living with patients or to be a blood relative (eg, a close friend could participate). Family members were required to be over 18 years old and to have no history of diabetes. Participants provided written informed consent to participate. Ethical approval was granted by the Hospital Ethics Committee.
Primary outcomes included A1C, illness perceptions (using the Brief Illness Perception Questionnaire),12 and psychological well-being (using the 12-item Well-Being Questionnaire).13 Secondary outcomes included blood pressure, body mass index, diabetes self-management (using the Summary of Diabetes Self-care Activities Questionnaire),14 self-efficacy (using the UK version of the Diabetes Management Self-Efficacy Scale),15 and family support (using the Diabetes Family Behavior Checklist).16 All questionnaires are psychometrically robust and have demonstrated sensitivity to change (see the trial protocol17).
Randomization, Allocation Concealment, and Blinding
An independent statistician (AK) allocated participants to groups by a remote computer-generated random number sequence. Concealment of the allocation sequence was also ensured by randomizing participants after they had been recruited and had completed baseline assessments. Outcome assessors were blinded to group allocation. Due to the psychological nature of the intervention, the psychologist and participants were not blinded.
The intervention consisted of 3 weekly sessions delivered by a health psychologist (KMK) who had received 16 hours of training in motivational interviewing. The first 2 sessions lasted 45 minutes each and took place in the patient’s home with their family member. The third session involved a 10-to 15-minute follow-up telephone call. Intervention sessions were individually tailored to participants’ needs and attempted to (1) challenge and clarify any inaccurate and/or negative perceptions about diabetes, (2) examine how these perceptions influenced self-management, and (3) develop written personalized action plans to improve self-management and mobilize family support. The intervention used techniques from health psychology18 and motivational interviewing19 such as exchanging information, eliciting change talk, reducing resistance, building self-efficacy, problem solving, and goal setting/action planning. Details are published in the intervention manual.17 Both the intervention and control groups continued to receive their usual diabetes care.
A power analysis based on A1C and psychological well-being as the primary outcomes indicated that a sample size of 86 gave 80% power to detect an absolute change of 0.9% in glycemic control and of 3 points on the Well-Being Questionnaire. These changes have been related to clinical outcomes.20 Thus, a sample size of 122 (61 per group) was required to ensure at least 80% power, if a response rate of 70% was achieved.
All analyses were “intention-to-treat” using Stata/SE version 10 (StataCorp LP, College Station, TX). Regression modeling was used to compare primary and secondary outcomes in the comparison groups, with prespecified adjustments made for known prognostic factors, including duration of diabetes and change in response to insulin as fixed effects, and baseline A1C as a covariate. Statistical significance was set at 5% for primary outcomes and at 1% for secondary outcomes. When testing the data for the statistical assumptions underlying regression, it emerged that there was a significant interaction between the independent variable (randomized controlled trial group) and a covariate (baseline A1C). This interaction was not anticipated and was not prespecified in the analysis protocol. However, as recommended by statisticians,21,22 this interaction effect was controlled for by including it as a covariate and was further investigated by “blocking” participants according to the covariate. A per-protocol analysis excluding participants who did not receive the full intervention was also conducted. These results did not differ from the intention-totreat analysis and are not described.
A total of 121 patients were recruited (Figure 1), 60 of whom were randomized to the intervention group and 61 to the control group. There were no baseline differences between the groups with regard to sociodemographic and clinical characteristics, nominated family members (Table 1), or the proportion of participants showing a trend toward improvements in glycemic control (control group = 14/61 vs intervention group = 18/60). There were also no differences between participants with completed and missing follow-up data or between participants who received the intervention and those who did not (Figure 1). Nonparticipants were still asked to attend for follow-up assessment.
At 6-month follow-up (Table 2), there was a modest statistically significant difference in A1C of 0.4% between the groups (control group mean of 8.80% [SD = 1.36%] vs intervention group mean of 8.41% [SD = 0.99%]; P = .04). Interaction effects were investigated by grouping participants into 3 blocks (Figure 2): (1) baseline A1C 8.0% to 8.4%, (2) baseline A1C 8.5% to 9.4%, and (3) baseline A1C >9.5%. There were no significant differences in follow-up A1C between groups in block 1 or block 2. In block 3 there was a statistically significant difference of 1.2% in follow-up A1C levels between the groups (intervention mean of 8.70% [SD =1.16%], n = 15, vs control mean of 9.95% [SD = 1.31%], n = 15; B = –1.28, SE (B) = 0.49; P = .01; 95% confidence interval, = –2.29 to -0.26). There were no significant differences between the baseline A1C levels in this block 3 group.
The intervention group reported statistically significant changes across all illness perception dimensions except “consequences” and “timeline.” Thus, the intervention group reported better personal control, a better understanding of diabetes, and an increased belief in treatment effectiveness. They also reported fewer symptoms and lower levels of diabetes concern and distress. Significantly fewer participants in the intervention group attributed their diabetes to genetic factors, whereas a significantly greater number perceived their diabetes to be caused by a sedentary lifestyle. The intervention group also reported statistically significant improvements in all aspects of psychological well-being, adherence to general dietary and exercise recommendations, diabetes self-efficacy, and family support. There were no differences in fruit, vegetable, and fat intake, blood glucose testing, foot care, body mass index, or blood pressure (Table 3).
Process evaluation methods are detailed in the trial protocol. 17 Findings indicate that the intervention was delivered per protocol and was acceptable to participants. Reasons for participants not receiving the intervention (24/60) are detailed in Figure 1.
Our findings suggest that a psychological family-based intervention for patients with poorly controlled type 2 diabetes led to improvements in glycemic control, diabetes perceptions, psychological well-being, self-management behaviors, and family support.