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The New Zealand Diabetes Passport Study: a randomized controlled trial of the impact of a diabetes passport on risk factors for diabetes-related complications

The Original NewUK Article article Zealand Diabetes Oxford, Diabetic DME Blackwell 1464-5491 20 Medicine Publishing Science Ltd,Ltd. 2003Passport Study D. Simmons et al.

D. Simmons, G. D. Gamble*, S. Foote†, D. R. Cole‡ and G. Coster§

Abstract Waikato Clinical School, University of Auckland, Hamilton, *Diabetes Projects Trust, Otara, Auckland, †Paradigm IPA, Hawkes Bay, ‡Diabetes Centre, Christchurch Hospital, and §Division of General Practice and Primary Health Care, University of Auckland, Hamilton, New Zealand Accepted 22 April 2003

Aims To assess the efficacy (change in HbA1c) of a patient-held communication,

self-empowerment and educational device for people with diabetes (the New Zealand Diabetes Passport) in patients with poor glycaemic control. Research design and methods A 12-month, multicentre, general practice-based

randomized controlled trial in urban, provincial and rural New Zealand involving 398 people with poorly controlled Type 1 or Type 2 diabetes. The intervention included a specifically designed and piloted New Zealand Diabetes Passport including information relating to diabetes knowledge, self-assessments, and guidance concerning how to engage with diabetes health professionals. The primary end point was change in HbA1c. Assessments were made at 0, 6 and 12 months. Results Two hundred and twenty-two patients received the Passport, 176 the control booklet, coming from 69 and 66 general practitioners, respectively. Use of the Passport was associated with a relative reduction in HbA1c of 0.4% (P = 0.017) and a relative increase in weight of 1.0 kg/m2 (P = 0.028), but no changes in diabetes knowledge, attitudes to diabetes or risk factors for diabetic tissue damage. Conclusions The dissemination of the New Zealand Diabetes Passport, in isolation, was not associated with improvements in either diabetes knowledge or self-empowerment. While a small improvement in glycaemic control occurred, this was probably due to changes in insulin therapy in the intervention group. It is possible that linking the use of the Passport with other behavioural and educational interventions may make the Passport more useful. Further study is required to confirm the effect of such multifaceted interventions.

Diabet. Med. 21, 214–217 (2004)

Introduction The importance of self-care, a patient-centred approach to care and patient enablement, is well recognized among diabetic patients [1,2]. In the 1980s, the concept of a diabetes passport

Correspondence to: Professor David Simmons, Waikato Clinical School, University of Auckland, Waikato Hospital, Private Bag 3200, Hamilton, New Zealand. E-mail: [email protected]

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was introduced as a means of enhancing communication between those involved in the care of a diabetic patient, improving patient knowledge in an ongoing manner and assisting communication between the patient and health professionals [3]. Since this time, diabetes passports have become available elsewhere (e.g. Europe, USA) but none has been rigorously evaluated. Diabetes is a major public health problem in New Zealand [4], with care largely delivered in general practice with referral

© 2004 Diabetes UK. Diabetic Medicine, 21, 214–217

Original article

to diabetes services when necessary. We now describe the development of the New Zealand Diabetes Passport (a tool for patient empowerment and improved co-ordination), and a multicentre randomized controlled trial to assess the efficacy of the Passport among patients with poor glucose control. Reduction in HbA1c was the primary endpoint, taken because of its direct correlation with outcomes in both Type 1 and Type 2 diabetes [5,6].

Methods The 9th draft of the Passport was used in the trial. Earlier drafts were developed by a team of general practitioners (GPs), diabetes nurse specialists, diabetes specialists, diabetic patients and pharmaceutical company staff for patients with Type 1 or Type 2 diabetes. Modifications were made based upon feedback from five focus groups (two GP, two European and one Maori patient group) and 20 Type 1 and Type 2 diabetic patients who had taken the penultimate draft home for 1 week. The Passport was designed to guide those obtaining the booklet without associated face-to-face education of either patients or health professionals. To achieve this, simple and clear instructions were included on each page on how to use the book and what questions to ask health professionals. The 11 sections are: 1 Naming of those involved in diabetes care* 2 Patients’ charter detailing mutual responsibilities 3 Patient contract* 4 Self-assessment pages* 5 Clinical data including targets** 6 Diabetes education ticklist* 7 Medication list* 8 Tailored action plans for hypoglycaemia, sick days, foot care, holiday/travel, food, activity, self blood glucose monitoring** 9 Additional detailed information (e.g. answers for selfassessment pages) 10 Glossary 11 Appointment scheduler. Sections were completed by the patient alone (*) or with a health professional (**). The Control booklet consisted of a new glucose monitoring booklet with a shared care card inserted in the back page. The Passport and the Control booklets were identical in size and external appearance. Intervention patients received a Passport and a Control booklet. Control patients received two Control booklets. Randomized controlled trial

This was a multicentre, general practice-based randomized controlled trial in Auckland, Hawkes Bay and Ashburton, New Zealand, including 58, 70 and seven GPs from each area, respectively. Practices were randomly selected, stratified to include 10 large (= three GPs/practice) and 10 small (= two GPs) practices, from each of South, Central and North / West Auckland. Where a practice declined, a new practice of similar size was invited. All GPs in Hawkes Bay and Ashburton were invited to participate (three declined). Randomization to Passport or Control practice used random number sheets.

© 2004 Diabetes UK. Diabetic Medicine, 21, 214–217

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Diabetic patients were included if aged 18 – 65 years, were hyperglycaemic (previous HbA1c > 8.5% or fructosamine > 300 µmol/l), had no terminal malignancies, dementia or psychiatric illness and were able to communicate effectively in English. Eligible subjects were identified from the practice register and up to six selected randomly (non-stratified, using a random number sheet) for invitation into the study. Where patients declined, a randomly selected replacement was contacted. The local study co-ordinator presented an overview of the study to each practice, and provided an explanation pack ‘How to use your new educational package’ for either Passport or Control booklets. GPs were not advised which booklet they were trialling. Local diabetes services were made aware of both booklets and asked not to comment to patients regarding their preferences. Research nurse activities were standardized at an initial training session. The research nurse was kept blinded by providing the booklets in a closed packet, opened after the nurse/ patient had departed. Patients were advised they were testing a new diabetes educational tool and to visit their general practice for advice on how to use the allocated booklet. No further information was given, as instructions are written in the Passport. Blinding of patients was attempted through the use of identical covers on the Passport and Control booklets. Assessments made at 0, 6 and 12 months included demographic data, knowledge of diabetes [7], attitudes to diabetes, anthropometry measures, blood pressure and foot care. Patients were asked to attend the local laboratory for non-fasting lipid and glucose measurements if none was available in the GP records. Results were sent to the GP. A finger prick sample for HbA1c was taken using sodium heparinized capillaries and placed within 1 ml of an aqueous solution of EDTA and KCN (0.25 mmol/l) (BioRad Labs Hercules, CA, USA), and forwarded immediately to a single laboratory for analysis using cation exchange high performance liquid chromatography (Diamat Variant, reference range upper limit 6.4%; BioRad Labs). HbA1c measurements were conducted in batches at the completion of the study. The study was approved by the three local ethics committees. Statistical analysis

Data were analysed using SPSS for Windows (v 9.0, SPSS Inc., Chicago, IL, USA) and SAS (v 8.0, SAS Institute Inc., Cary, NC, USA). All tests were two-tailed with P < 0.05 considered statistically significant. Geometric means are shown for non-normally distributed variables (e.g. change over time). A multivariate approach was employed for continuous variables using either the GP or patient as the unit of analysis in a random effects mixed model to allow for clustering. Since size of practice was a stratification variable it was adjusted for in the model. Analyses were also compared using a two-sample t-test weighted by the number of patients in each practice with the practice as the unit of analysis [8]. The Mantel–Haenszel test was used to compare discrete variables. Missing values were imputed using a maximum likelihood method within the MIXED procedure of SAS. The results of all methods of analysis, and for each method for handling missing data were consistent, so only the results of the two-sample t-test are presented. Other non-normal variables are described using median (interquartile range) and compared using the Mann–Whitney test.

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The New Zealand Diabetes Passport Study • D. Simmons et al.

Table 1 Baseline characteristics and changes in the Passport and Control groups Baseline

Change over 12 months

Passport

Control

Passport

Control

N % Male (n) % European (n) % Beneficiary Probable Type 1 diabetes, % Age, years Age at diagnosis, years Known hypertension, % Known ischaemic heart disease, % Known dyslipidaemia, %

222 56.3 (125) 62.6 40.5 27.9 49 (10) 39 (13) 39.6 14.0 15.8

176 48.9 (86) 68.8 44.9 22.7 54 (10) 43 (14) 44.3 13.6 15.3

193

150

HbA1c (%) Body mass index (kg/m2) Systolic BP (mmHg) Diastolic BP (mmHg) Total cholesterol (mmol /l) % with good footcare % with same/improved footcare % current smokers % stopped smoking

9.4 (1.5) 31.8 (6.7) 138 (20) 83 (11) 5.6 (1.0) 51.6

9.2 (1.6) 31.9 (7.9) 143 (22) 82 (11) 5.7 (1.2) 56.3

−0.3 weight: +1.2 kg −1 −1 0.3 83.9

17.6

P*

+0.1 +0.2 kg −2 0 0.3

0.017 0.028 NS NS NS

88.7

NS

13.1 3/30 (10%)

4/18 (22%)

NS

Insulin treated, % Units/day Use meter for self blood glucose monitoring, %

46.8 31 (42) 85.1

47.7 32 (41) 87.5

+8.2 +3 +9.3

+5.4 0 +6.1

NS NS NS

Exercising regularly, % Knowledge score, % Know when Eyes due, %

63.1 81 (18) 68.5

58.5 83 (20) 76.1

+13.9 +3 +1.5

+8.9 +1 +0.6

NS NS NS

−0.08

−0.07

NS

0.23 −0.07 0.15 0.02 0.04

0.50 0.00 0.27 −0.10 −0.14

NS NS NS NS NS

Scale for the following: 1 = agree, 3 = neither agree nor disagree, 5 = don’t agree I want to know as much as I can about 1.34 (0.63) 1.25 (0.61) my diabetes I don’t worry about my diabetes 3.67 (1.40) 3.69 (1.39) I don’t believe I have diabetes 4.65 (0.91) 4.70 (0.90) I control my diabetes 2.10 (1.09) 2.12 (1.18) I don’t want people to know I have diabetes 4.34 (1.17) 4.35 (1.17) If I didn’t have to worry about food life 2.36 (1.61) 2.48 (1.68) would be easier

Data are mean (SD) or percentage (n). *Significance of difference between Passport and Control after 12 months. Probable Type 1 diabetes considered if onset < 30 years and insulin commenced within 12 months.

Results Sixty-nine and 66 GPs entered patients into the Passport (n = 222) and Control (n = 176) groups, respectively, with three (2– 4) and two (2– 4) patients per GP, respectively (P < 0.05). Drop-outs from the trial were similar from each group [29 (13.1%) vs. 26 (14.8%)]. Patient blinding was partly successful (% thought Passport: Passport 24.9%, Control 16.0%; % thought Control: Passport 12.7%, Control 16.0%). Results were similar for each study area. Table 1 shows the characteristics of the two groups and any changes seen. Of non-Europeans, 62% were Maori. Figure 1 shows the relative reduction in HbA1c of 0.4% seen among the intervention group (P = 0.017) who also increased their weight by 1 kg (P = 0.028). Total insulin dose increased by 3 U/person overall (P = 0.03). This

was particularly evident (non-significantly) among the intervention group. No other significant differences were found between the two groups, particularly sulphonylurea or metformin use (baseline overall 62.4%, 60.3%, respectively), diabetes knowledge, attitudes to diabetes or self-care activities.

Discussion In hyperglycaemic patients, use of the Passport alone was associated with an absolute reduction in HbA1c of 0.4% when compared with the control group. Extrapolating from the DCCT [5] and UKPDS [6], such a small reduction in glycaemia would predict only a 10–15% reduction in microvascular complications. No evidence of increased diabetes knowledge, self-care or self-empowerment was shown and hence the tool

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patients in the primary care setting may also be of benefit. As a result of these findings, we are now developing studies to evaluate the Passport further. Acknowledgements

Figure 1 Change in HbA1c over time among Passport (hatched blocks) and Control (light blocks) subjects (mean ± 95% CI shown).

is unlikely to have had much direct effect on patient behaviour. However, there was a significantly greater increase in patient weight, and possibly an increase in insulin use, suggesting the intervention did lead to changes in clinical management. The design of this study was difficult. We wished to assess whether distributing the Passport on its own had an impact on diabetes care, this being at a time when patient access to information is increasing and when many GPs are already involved in diabetes quality initiatives. We feel that the randomized format of the study should have overcome these external influences. Although patient blinding was largely successful, the slight difference in the recruitment rate in the ‘Passport practices’ could suggest possible selection bias (despite matched characteristics at baseline). In other areas of lifestyle or behaviour change, multifaceted interventions have been shown to be more effective than the summation of single interventions. The study effect may therefore have been greater had the intervention patient group, and / or their carers, received additional intervention (e.g. face-toface instruction). A small number of patients commented upon the difficulty of using the Passport in the time available for a consultation, and finding ways to protect time for diabetic

© 2004 Diabetes UK. Diabetic Medicine, 21, 214–217

Paddy Twigg, Carole Fleming, Sue Wright, Alison Wagstaff and Terri Spedding for assisting with Passport Design. Roche Diagnostics for funding and support, Eli Lilly and the Hawkes Bay Research Foundation, BioRad Laboratories for providing HbA1c capillary collection kits and supporting HbA1c analyses, Barbara Gatland and the team of the Diabetes Projects Trust, South Auckland for support, and research nurses Ailua Fatialofa, Delwyn Gibson, Margaret Rodgers, Karen Wright, Michelle McKenzie. Our thanks also go to participating general practitioners and patients.

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