Screening for Diabetes: A view from the coal-face Not all cases of undetected diabetes would be detected by this method (estimated …
Screening for Diabetes: A view from the coal-face
Recent research published by researchers from Devon and Somerset in Family
Practice1 suggests a pragmatic system for targeted screening for type 2
diabetes, based on searching general practice computer records for risk
factors However, what would implementing such a system mean in terms of
practice workload, and what are the pros and cons of implementing such a
system? This article discusses some of these issues and provides workload
estimates for Caucasian and South Asian populations figures for other
ethnic groups are not currently available
Pragmatic Targeted Screening
The proposed system is relatively straightforward You computer-search your
practice database for patients aged over 50 with a body mass index BMI,
ever recorded of 27 or more Age 30 or 40 with no limit on BMI is more
appropriate for Asian and probably Afro-Caribbean populations Then you
invite the patients on the list for a fasting plasma glucose FPG test
Invitees should be followed up by phone to confirm attendance and the
fasting procedure If the result is 61 mmol/l or more, then you arrange a
second test you can use a second FPG, but a 2-hr Glucose
Tolerance Test
is recommended for maximum detection rate Diagnostic values for IFG, IGT
hyperglycaemia and diabetes can be found at
http://wwwdiabetesorguk/infocentre/carerec/diagnosidoc
Outcomes for Caucasian Populations
Based on the Family Practice study[1], we can estimate that in a typical
practice of 5000 patients, with recorded BMI data for 77 patients, we
would expect to invite 555 111 of population and test around 340 people
61 uptake This will detect around 15 new cases of diabetes, and 12
cases of IFG assuming an OGT test is used for following up suspected
cases If blood pressure is also monitored, the research data suggest that
37 would have previously undiagnosed high blood pressure 160 systolic or
90 diastolic on 2 occasions
Outcomes for Asian Populations
Recent studies in Bradford[2] suggest that we should screen all patients
over 30, irrespective of BMI In a practice with 500 Asian patients, we
would expect to invite 310 62 of the population are over 30 and test
189 This would detect around 33 cases of diabetes, and at least as many
cases of IFG /IGT
Workload and Cost Implications
The workload per 5000 people screened and 550 tested is estimated to be 1-
2
hours constructing the necessary computer searches, 100 hours of
receptionist time booking and following-up appointments, 80 hours of
practice nurse clinic time 61 uptake, 10-15 minutes per patient, plus
around 012 per blood test The total cost will clearly vary depending on
payscales, but would probably be 4000 to 5000
The ongoing costs of treating new cases of diabetes, hyperglycaemia and
high blood pressure are not included here However, the costs of not
treating these conditions should also be considered increased
complications on eventual diagnosis, progression from IFG /IGT to frank
diabetes, progression from hypertension to heart disease
Other Considerations
The British Diabetic Assocation recommend treating IFG /IGT with lifestyle
advice and if glucose still above 6 mmol/litre after 3 months to consider
an oral hypoglycaemic agent Solid evidence from large studies in the US
and Finland shows that minor changes in diet and physical activity can
substantially reduce progression from IGT to diabetes Practices should
seek to inform themselves about best-practice in encouraging this [eg
Diabetes UK website, Cochrane reviews of lifestyle intervention in
diabetes, Expert
Patient programmes]
The optimum period for repeat screening is not known However, current US
guidelines recommend repeat diabetes screening every 3 years
For practices with low BMI coverage, a useful first step would be to mount
a campaign of systematically recording BMI for all adults Around 85 of
patients will attend the practice for some reason within a 2-year period,
and a practical approach may be to ask patients to record their own height
and weight in the waiting room
Other pragmatic ways to enhance the screening effort include adding
diabetes testing to cardiovascular and other routine clinics, where
patients have known risk factors age, BMI, heart disease, hypertension,
gestational diabetes, family history of type 2 diabetes, Asian or Afro-
Caribbean ethnicity
Pros and Cons
The targeted screening approach above has several advantages -the
identification of a high-risk patient list is simple and quick; FPG
testing is easier to implement in general practice than cumbersome
glucose tolerance tests; it is relatively cheap and the workload seems
feasible
However, the workload implications of treating detected illness,
especially
in areas with high Asian populations, require additional
resource-planning Constructing separate lists for different ethnic
groups may also present a significant practical challenge
Not all cases of undetected diabetes would be detected by this method
estimated around 20-30 would be found Hence, although this cheap-
and fast system can detect substantial numbers, practices will need to
develop strategies for identifying the remainder
It is strongly in the patients interest to know if they have
undiagnosed diabetes, and most patients would want to know However,
screening may cause inconvenience, discomfort, and anxiety for some
Work by Dr Shahid Alis Bradford group suggests that a number of Asian
people dont want to know the results of their screening test The way
screening is presented providing full information, emphasising the
benefits of early treatment, acknowledging anxiety is therefore
crucial
Implementing a pro-active diabetes case-finding programme will help
practices meet NSF standards and GMS contract performance indicators
1 Greaves CJ, Stead J, Hattersley A, Ewings P, Brown
P, Evans P A simple
pragmatic system for detecting new cases of type 2 diabetes in primary
care Family Practice 2004;211:57-62
2 Shahid A et al Comparison of haemoglucated glycosolated haemoglobin and
laboratory measurements of random blood glucose in opportunistic case
detection of type 2 diabetes in general practice Paper In Submission
Source:devonpct.nhs.uk
