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

Aims: To assess the efficacy (change in HbA_1c) 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 HbA_1c. 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 HbA_1c 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.