The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
The Green Card Pilot: a randomised controlled trial of an education/reward intervention to aid diabetes self-management.
Scientific title
The Green Card Pilot: a randomised controlled trial of an education/reward intervention to aid diabetes self-management
Secondary ID [1] 281859 0
Universal Trial Number (UTN)
Trial acronym
Green Card
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Type II Diabetes 288226 0
Condition category
Condition code
Metabolic and Endocrine 288589 288589 0 0
Diet and Nutrition 288590 288590 0 0
Other diet and nutrition disorders
Public Health 289143 289143 0 0
Health service research

Study type
Description of intervention(s) / exposure
tailored personal health information(diet, exercise), and small retail discounts ($5 vouchers discounting local purchase by as patient rewards redeemable at local merchants administered by PI of the study and health services personnel in one-on-one face-to-face sessions (initial) and by mail (subsequent) 4x over 12 months.

participants attend a single face-to-face session at baseline (Approx 1 hour). Further information and rewards are then mailed at months 4, 8, and 12.

$5 discount vouchers were awarded upon successful achievemnt of outcome goals (i.e. reduce HBa1c) at months 4, 8 and 12).
Intervention code [1] 286419 0
Comparator / control treatment
routine GP care
Control group

Primary outcome [1] 288743 0
5% improvement in mean response of matched participant/control pairs of study subjects (a reduction in mean Hb1Ac to 8%) as detemined by serum assay
Timepoint [1] 288743 0
1 year, monitored at 3 month intervals
Secondary outcome [1] 300888 0
Blood pressure automatic sphygmomanometer
Timepoint [1] 300888 0
1 year, monitored at 3 month intervals
Secondary outcome [2] 302213 0
lipids (LDL/HDL) by serum assay
Timepoint [2] 302213 0
1 year, monitored at 3 month intervals
Secondary outcome [3] 302214 0
waist measurement
Timepoint [3] 302214 0
1 year, monitored at 3 month intervals

Key inclusion criteria
persons diagnosed with Type II diabetes under care of a GP
Minimum age
18 Years
Maximum age
90 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
persons with conditions other than diabetes or not under care of a GP

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Participants were drawn from a general practice in rural New South Wales, Australia. Those who agreed to participate were given a participants information statement and signed a consent form for participation. They were then enrolled via a 15minute appointment with the study organiser or an assisting senior medical student.

Allocation not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
simple randomisation- coin toss
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Chi Square for significance of differences between groups.

Sample size calculation: Data from the Australian National Diabetes Information Audit & Benchmarking (ANDIAB) final report for 2009, based on a sample of 8563 people with diabetes, indicate that the mean HbA1c in people with Type I Diabetes is normally distributed with a mean of 8.4% and standard deviation 1.5. If we are to detect a 5% improvement in the mean response of matched pairs of study subjects (a reduction in mean Hb1Ac to 8%), we will need to study 65 experimental subjects and 65 control subjects to be able to reject the null hypothesis that this response difference is zero with probability (power) 0.9 at p< 0.05.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 286657 0
Name [1] 286657 0
University of Sydney
Address [1] 286657 0
University Centre for Rural Health, North Coast
PO Box 3074
61 Uralba St
Lismore NSW 2480
Country [1] 286657 0
Funding source category [2] 286658 0
Commercial sector/Industry
Name [2] 286658 0
Roche Products Pty Limited ("Roche")
Address [2] 286658 0
4-10 Inman Road
Dee Why NSW 2099
Country [2] 286658 0
Primary sponsor type
University of Sydney
PO Box 3074
61 Uralba St.
Lismore NSW 2480
Secondary sponsor category [1] 285436 0
Commercial sector/Industry
Name [1] 285436 0
Roche Products Pty Limited ("Roche")
Address [1] 285436 0
4-10 Inman Road
Dee Why NSW 2099
Country [1] 285436 0

Ethics approval
Ethics application status
Ethics committee name [1] 288729 0
The University of Sydney Human Research Ethics Committee
Ethics committee address [1] 288729 0
Level 6
Jane Foss Russell Building G02
The University of Sydney NSW 2006
Ethics committee country [1] 288729 0
Date submitted for ethics approval [1] 288729 0
Approval date [1] 288729 0
Ethics approval number [1] 288729 0

Brief summary
Although it is widely accepted that lifestyle interventions In type 2 diabetes have a beneficial effect in delaying the negative health impact of the disease, achieving and maintaining long term gains remains problematic. Can gains in this area be made by combining an intervention program with a mechanism (the green card) for providing structured visual feedback, along with positive incentives, to induce people to persist with lifestyle change?

Aims: The project aims to improve management of type 2 diabetics by:
* providing a visual record through which a person with type 2 diabetes and their clinician can track their progress on core predictors of long term health
* providing positive feedback into personal health trends
* acting as a reminder that encourages adherence to diabetes control, including regular health checks
* offering small retail incentives at participating stores which act as a positive re-enforcement to lifestyle changes.
* Including educational material relevant to type 2 diabetics in a brochure mailed out to participants with their health summary.

Research Plan
The green card project is a mixed method cohort study intended to assist type 2 diabetics in their own management of the disease. It codifies three predictive areas of long term diabetic health: HbA1c, Blood Pressure (BP) and lipid profile, into a simple visual colour card.

Each of the areas will be graded against a clinical value, with the highest values (furthest from the normal range) in the red zone at the top, moving down to the lowest (normal range) in the green zone at the bottom. Points will be accrued in each area in the following ways:
* 100 points for attending a regular health check
* 100 points for moving away from the red, and towards the green zone
* 200 points for being in the green zone.

Participants (minimum sample size 130) will be recruited via their GPs,

Key area GPs who would be involved in the project have been consulted. They view this project to be appropriate for a clinical setting and have expressed willingness to participate.

Qualitative data will be obtained through a participants’ survey at baseline and in 12 months. Questions incorporated the Health Belief Model and Social Cognitive Theory to assess participants’ individual understanding of their type 2 diabetes, the perceived importance of lifestyle changes, and the perceived ability to make and sustain lifestyle changes.

One potential concern in a project such as The Green Card is that a failure to accrue points under the positive incentives provided may have a negative effect, discouraging the kinds of changes desired. People with co morbidities or lower educational backgrounds in particular may be at risk of failure to adhere and thus fail to gain rewards

To prevent this, the card has been designed so that one area of points acquisition relies solely on the regular use of lipid lowering medication. This will ensure that participants who have enrolled in the project, but who are not able at a given point to commence active lifestyle changes, should still see an improvement in their points score profile. Likewise, HbA1C is a component of the card. Since HbA1C is extremely responsive to even small amounts of exercise, which may not have an effect on waist measurement within the three month assessment period, this measure will more easily show up as a positive change and a sensitive predictor of improvement in this area.

Scientific basis of the study

Large scale trials such as the Danish Steno-2 trial (Gaede, P et al 2003, and 2008) have established the benefits of lifestyle modification as an adjunct to pharmacological treatment of Type 2 Diabetes. In the Steno-2 trial, which has now been followed up for more than 13 years, health outcomes of participants vs. controls (receiving standard care) showed an absolute risk reduction of 20%, and a relative risk reduction of 50%.

A meta-analysis into the long term effectiveness of lifestyle and behavioural intervention in adults with type 2 diabetes (Norris 2004) concluded: “weight loss and control in the long term appear to be difficult to achieve in adults with type 2 diabetes employing currently used lifestyle and behavioural strategies…Perhaps other strategies in conjunction with lifestyle interventions should be considered.”

A search of the literature revealed no exactly comparable prototype for the present study. However, two central defining ideas correlate with findings in related studies. These are: 1.) The promising results of supported self-efficacy in diabetes management (Rieger 2009). Efficacy has been demonstrated across a wide spectrum of socio-economic and ethnic groups (Sarkar 2006). 2.) support mechanisms for maintaining lifestyle change in diabetes management should be open ended and ongoing.(Funnell 2007)

Positive incentives have been shown to be of significant benefit in the treatment of a number of chronic conditions and habits. A recent RCT enrolling 878 US employees in a trial comparing positive financial incentives in smoking cessation vs. education only showed significantly higher rates of cessation in the incentives group compared to the education only group (Vollp NEJM 2009). A comprehensive review of Pay-for -Performance programs in the US (Vollp Health Affairs 2009) found that positive incentives were a cost effective strategy to improve a range of destructive behaviours including diet, smoking and asthma control. The most effective models used ‘frequent small rewards’, providing ‘tangible and visible’ incentives for good behaviour.

Potential Significance
The potential significance of this study is its potential to demonstrate that provision of positive incentives, through motivation and educational tools, accompanied by appropriate clinical support, can maximize the benefit of existing and future interventions to control type 2 diabetes. Given the large cost of diabetes to the community and the health care system, any initiative which enhances the effect of intervention strategies into this disease would represent a considerable health benefit.

Gaede P, Vedel P, Larsen N. et al; Multifactorial Intervention and Cardiovacular Disease in Patients with Type 2 Diabetes. The New England Journal of Medicine 2003;348(5):383-393
Gaede P, Lund-Andersen H, Parving H, Pedersen O; Effect of a Multifactorial Intervention on Mortality in Type 2 Diabetes.. The New England Journal of Medicine 2008;358:580-591
Norris S, Zhang X, Avenell A, et al; Long-term effectiveness of lifestyle and behavioral weight loss interventions in adults with type 2 diabetes: a meta-analysis. American Journal of Medicine 2004;117(10):762-764
Rieger E; The use of motivational enhancement strategies for the maintenamce of weight loss among obese individuals: a preliminary investigation. Diabetes Obesity and Metabolism 2009;11:637-640
Funnell M, Tang T, Anderson R; From DSME to DSMS: Developing Empoerment-Based Diabetes Self-Management Support. Diabetes Spectrum 2007;20(4):221-226
Sarkar U, Fisher L, Schillinger D; Is self-efficacy associated with diabetes self-management across race/ethnicity and health literacy?.Diabetes Care 2006;29(4):823-829
Vollp K, Paully M, Glick H, et al; A Randomized, Controlled trial of financial Incentives in Smoking Cessation. The New England Journal of Medicine 2009;360(7):699
Vollp K, Pauly M, Loewenstein G, Bangsberg D; P4P4P: An Agenda for Research on Pay-For-Performance for Patients, Health Affairs 2009;28(1):206-215
Trial website
Trial related presentations / publications
Griffiths B, Birden H, Rolfe M. The Green Card Pilot: A Randomized Controlled Trial of an Education/Reward Intervention to Aid Diabetes Self-management. J Health Edu Res Dev. 2015;3(140):2.
Public notes
Attachments [1] 1158 1158 0 0

Principal investigator
Name 37430 0
Ms Bronwen Griffiths, MPH
Address 37430 0
University Centre for Rural Health
PO Box 3074
Lismore, NSW 2480
Country 37430 0
Phone 37430 0
+61 (0)429419130
Fax 37430 0
Email 37430 0
Contact person for public queries
Name 37431 0
Dr Hudson Birden
Address 37431 0
Dr. Hudson Birden

Discipline of Public Health & Tropical Medicine
College of Public Health, Medical and Veterinary Sciences l Australian Institute of Tropical Health and Medicine
James Cook University
Townsville, Queensland, 4811 Australia
Location: Building DB41; Room 114 JCU
Country 37431 0
Phone 37431 0
+61 0437575047
Fax 37431 0
Email 37431 0
Contact person for scientific queries
Name 37432 0
Dr Hudson Birden
Address 37432 0
Dr. Hudson Birden
Discipline of Public Health & Tropical Medicine
College of Public Health, Medical and Veterinary Sciences l Australian Institute of Tropical Health and Medicine
James Cook University
Townsville, Queensland, 4811 Australia
Location: DB41 - MU114 (Building DB41; Room 114) JCU CRICOS Provider Code: 00117J
Country 37432 0
Phone 37432 0
+61 0437575047
Fax 37432 0
Email 37432 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary