Student: Anne-Marie Cumins
Supervisors: Professor Les Toop, Dr Graham McGeoch, Maggie Wilson [Dept Public Health & General Practice and Pegasus Health]
Sponsor: Pegasus Health
Diabetes is recognised as a major health concern in New Zealand. Reducing the incidence and impact of diabetes is one of the thirteen priority health objectives in the New Zealand Health Strategy . Currently there is no up-to-date national prevalence data for diabetes but it is estimated at 4% of the total population [1, 2], 90% of which is Type 2 Diabetes , with the prevalence for Maori and Pacific populations being approximately three times higher than among other New Zealanders . It is also estimated that for every person in New Zealand with diagnosed diabetes there is another with undiagnosed diabetes  .
Type 2 Diabetes can go undetected for up to 12 years because it develops gradually and in its early stages, is often not severe enough for patients to notice any symptoms, but during this time micro- and macro-vascular complications may still develop [3, 6-8]. Therefore, at diagnosis as many as 50% of patients already have diabetic complications including damage to their eyes, kidneys and nervous system [8-10]. Studies have shown that effective treatment of diabetes may reduce or prevent the micro-vascular complications of diabetes [7-12]. Not only is diabetes a major health concern, it is an expensive health issue. PriceWaterhouse Coopers Ltd estimated that in 2001 the cost of Type 2 Diabetes in New Zealand approached $400million and is predicted to rise to more than $1000 million by 2021 .
Screening for diabetes is controversial but has been recommended at 3 year intervals  in Europeans = 50 years of age, non-Europeans = 40 years, and 10 years earlier in both groups if they are considered at 'high risk” – that is, they have co-morbidities known to raise their risk of having diabetes; these include obesity, hypertension or cardiovascular disease; or if they have a parent or sibling with diabetes .
Studies suggest that 80-90% of people will visit a general practitioner at least once a year [10, 13]. It is the setting most likely to have the information needed to identify people at 'high risk' and also the established systems capable of recalling people for follow-up . Risk factor screening is still recommended in New Zealand but a study done by Simmons et al. showed that many of those with undiagnosed diabetes (25%) and abnormal glucose tolerance (31.4%) have no diabetes risk factors .
Med-tech 32 is a computerised general practice management system used by most Pegasus Health member General Practices. It contains clinical information, laboratory results and medication lists among other things. A query builder is a simple tool within Med-tech that allows the user to pull out data from this system in response to specific information requests.
Over summer 2005/2006, 165 GPs in Pegasus Health took part in an audit to identify all European adults = 50 years and all non-European adults = 40 years in their patient population who had not been screened for diabetes in the previous 3 years. These GPs were provided with a list of their patients who had not been screened and each developed a system to invite these adults to have a fasting glucose test to screen for diabetes.
This project aims to:
- determine the proportion of eligible patients subsequently screened for diabetes in a 12month period
- determine the proportion of diabetes subsequently identified
- attempt to describe the strengths and weaknesses of the various practice recall systems used.
All 165 GPs who participated in the first audit were invited to participate this year. A researcher visited each participating practice to collect the data for those GPs taking part – that is, the number of their registered patients = 40 years, including ethnicity, age and NHI, with:
- no laboratory data containing glucose, carbohydrate master or fasting status (terms used by laboratories for outlining glucose results)
No patient names were included. This data was imported into an Excel spreadsheet and sorted to delete information on Europeans between 40-49 years. In addition, data specific to Maori and Pacific Island patient populations was extracted for separate analysis. Each general practitioner was asked to fill out a structured questionnaire detailing the methods they used in their practice for screening eligible patients, the time taken to set up these recall systems and to comment on the system's relative strengths and weaknesses. Data was entered into an Excel spreadsheet for statistical analysis. A crude thematic analysis was carried out on the questionnaire data.
160 of the 165 GPs invited agreed to take part and were visited for data collection over a 6 week period. In 2005 the mean proportion of 'at risk' patients who had been screened was 54.47% while in 2006, the mean proportion screened had risen to 66.60%. This was an increase in the mean proportion of screened patients of 12.13% and can be seen as a shift in the frequency of % screened in the histograms shown below.
The percentage of 'at risk' patients with a classification of diabetes rose from 4.54% to 4.62%, a difference of 0.08%.
For the period 2002-2005, the mean proportion of Maori patients screened was 52.35%; this increased to 58.44% for the period 2003-2006. Maori patients with diabetes made up 5.77% of the Maori population considered to be at risk of developing diabetes in 2005. This proportion rose to 7.05% in 2006. In 2005, the proportion of Pacific Island patients screened was 56.71% and this rose to 63.92% in 2006. Pacific Island patients with diabetes made up 7.74% of the Pacific Island population considered to be at risk in 2005. This rose to 11.74% in 2006.
Of the 160 questionnaires given out, 102 questionnaires were returned. Of all the methods for identifying and inviting patients to be screened, the mostly commonly reported was opportunistic screening – that is, when the patient visited their GP for another reason. 82 of the 102 General Practice teams who responded (80.39%) reported using this method, saying that it is “simple” and “effective” but “time consuming” and “missed non-regular attendees”. 54 GPs reported using an alert system on their patient management system which pops up on the computer screen when the patient visits the doctor as a reminder. Again these were reported as being “effective” but using this system missed those who did not attend the practice often. 42 sent out letters, 17 phoned their patients and 6 GPs reported not using the list they were provided with.
A large proportion of GPs (65 out of 102) reported using multiple methods. Of those 65, the most common combination was a pop-up alert on their patient management software as well as opportunistic screening. 25 GPs reported using this combination, commenting that it is “effective”, “cost and time efficient”. The second most common combination was an alert system, sending letters to patients on the list and using opportunistic screening. 18 GPs used this and said that this system is “thorough” but “time consuming”, especially to start with. 6 practice teams reported using all methods – that is, an alert system, letters, phone calls and opportunistic screening while 2 others reported combining diabetes screening with cholesterol blood testing or with a cardiovascular risk assessment.
This study suggests that audit and feedback increased overall screening rates among general practitioners by an average of 12% but this did not generate a large increase in detection of diabetes (0.08%). Among Maori and Pacific Island patients, a relatively small increase in screening rates resulted in much larger increase in detection – 1.28% and 4.00% respectively. Practitioners commented that increased screening involves extra work and cost for the practice. This project supports the evidence base which proposes opportunistic screening is probably the best method with a targeted approach to non-Europeans [8, 13].
- New Zealand Health Strategy. DHB toolkit: Diabetes, to reduce the impact and incidence of diabetes.; 2003.
- Moore MP, Lunt H. Diabetes in New Zealand. Diabetes Res Clin Pract. 2000 Oct;50 Suppl 2:S65-71.
- Stephens JW, Williams R. Time to stop talking about screening for diabetes? Diabet Med. 2006;23:1163-4.
- Joshy G, Simmons D. Epidemiology of diabetes in New Zealand: revisit to a changing landscape. N Z Med J. 2006;119(1235):U1999.
- American Diabetes A. Screening for type 2 diabetes. Diabetes Care. 2004 Jan;27 Suppl 1:S11-4.
- Colagiuri S, Hussain Z, Zimmet P, Cameron A, Shaw J, AusDiab. Screening for type 2 diabetes and impaired glucose metabolism: the Australian experience. Diabetes Care. 2004 Feb;27(2):367-71.
- Harris MI, Eastman RC. Early detection of undiagnosed diabetes mellitus: a US perspective.[see comment]. Diabetes Metab Res Rev. 2000 Jul-Aug;16(4):230-6.
- Borch-Johnson KL, T. Glumer, C. Sandbaek, A. Screening for Type 2 diabetes - should it be now? Diabet Med. 2003;20:175-81.
- Wareham NJ, Griffin SJ. Should we screen for type 2 diabetes? Evaluation against National Screening Committee criteria.[see comment]. Bmj. 2001 Apr 21;322(7292):986-8.
- Welborn TA, Reid CM, Marriott G. Australian Diabetes Screening Study: impaired glucose tolerance and non-insulin-dependent diabetes mellitus. Metabolism. 1997 Dec;46(12 Suppl 1):35-9.
- Feig DS, Palda VA, Lipscombe L, Canadian Task Force on Preventive Health C. Screening for type 2 diabetes mellitus to prevent vascular complications: updated recommendations from the Canadian Task Force on Preventive Health Care. Cmaj. 2005 Jan 18;172(2):177-80.
- Kenealy T, Braatvedt G, Scragg R. Screening for type 2 diabetes in non-pregnant adults in New Zealand: practice recommendations.[see comment]. N Z Med J. 2002 Apr 26;115(1152):194-6.
- Kenealy T, Arroll B, Petrie KJ. Patients and computers as reminders to screen for diabetes in family practice. Randomized-controlled trial. J Gen Intern Med. 2005 Oct;20(10):916-21.
- Simmons D, Thompson CF, Engelgau MM. Controlling the diabetes epidemic: how should we screen for undiagnosed diabetes and dysglycaemia? Diabet Med. 2005 Feb;22(2):207-12.