Rutten_Q8_Layout 1 04/09/2009 11:37 Page 32
Screening for Type 2 Diabetes – The ADDITION Netherlands Study
Guy EHM Rutten
and Paul GH Janssen
1. Professor of Diabetology; 2. General Practitioner, Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht
To investigate whether early treatment of screening-detected diabetic patients is beneficial, the Anglo–Danish–Dutch Study of Intensive
Treatment in People with Screen-Detected Diabetes in Primary Care (ADDITION) has been initiated. A total of 56,978 subjects 50–70 years
of age without diabetes from 79 general practices in The Netherlands were invited to participate in a stepwise screening programme. Five
hundred and eighty-six participants (1.0%) were diagnosed with type 2 diabetes. The score on the initial risk questionnaire was higher if
glucose metabolism was more disturbed. The yield of screening varied widely between practices. A lower yield was not associated with
an appropriate practice organisation regarding diabetes care, nor with a speciality of the GP in diabetes. Opportunistic screening in
general practice seems preferable to population-based screening. Intensified multifactorial treatment of patients with screening-detected
type 2 diabetes in general practice reduced the cardiovascular risk factor levels significantly after just one year without worsening health-
related quality of life. After three years of follow-up, screened participants without diabetes but with an elevated risk score had
comparable cardiovascular event rates to patients with diabetes. Screened individuals without diabetes are at risk of lacking optimal
control of cardiovascular risk factors.
Cardiovascular disease, healthcare delivery, impaired glucose tolerance, impaired fasting glucose, primary care, screening, type 2 diabetes
Disclosure and Acknowledgements: The authors are grateful to Professor Ronald Stolk and Dr Kees Gorter for their substantive contributions to the article. The ADDITION
Netherlands study is made possible by unrestricted grants from Novo Nordisk, GlaxoSmithKline and Merck.
Received: 6 May 2009 Accepted: 16 June 2009
Correspondence: Guy Rutten, Professor of Diabetology in Primary Care, University Medical Centre Utrecht, Julius Centre for Health Sciences and Primary Care, PO Box
85500, 3508 GA Utrecht, The Netherlands. E: G.E.H.M.Rutten@umcutrecht.nl
The prevalence of type 2 diabetes is rapidly increasing.
Most people This article describes the results of population-based screening for
are asymptomatic at diagnosis and the assumption is made that early diabetes in The Netherlands and the associations of the yield of the
diagnosis and treatment of type 2 diabetes will be beneficial, although screening with characteristics of general practitioners (GPs) and
definitive evidence is lacking.
The American Diabetes Association practices. Furthermore, we report on the one-year results of the
stated that there is sufficient indirect evidence to justify opportunistic intervention trial. Finally, we followed people in different glucose
screening in a clinical setting.
Recently, the International Diabetes regulation categories over three years regarding the extent of
Federation also recommended opportunistic screening.
In The healthcare utilisation and the risk of cardiovascular disease (CVD).
Netherlands, the Dutch College of General Practitioners recommends
opportunistic screening (case-finding) for diabetes in people at risk of Patients and Methods
type 2 diabetes.
To investigate whether early treatment of patients Patients
with screening-detected diabetes is beneficial, the Anglo–Danish– In The Netherlands, the entire population is registered with a GP.
Dutch Study of Intensive Treatment in People with Screen-Detected Therefore, the screened population may be considered a representative
Diabetes in Primary Care (ADDITION) has been initiated.
sample of the full population. All 56,978 patients, who were 50–70 years
of age and not known to have diabetes at study entry, from 79 general
ADDITION is a multicentre randomised controlled trial that consists practices in the south-western region of The Netherlands were invited
of a screening study and a subsequent intervention trial with a to participate in the screening programme.
follow-up of five years. In the screening study, the feasibility of
identifying persons with type 2 diabetes is evaluated. In the Exclusion criteria for the intervention study were: any contraindications
intervention study (a single-blind, multipractice trial with practice- or history of major intolerance to any of the drugs used in the study; a
level randomisation), the effects of routine care in general practice history of alcoholism, drug abuse, psychosis, personality disorder or
according to national guidelines are compared with those of an another emotional, psychological or intellectual problem that would
intensified, multifactorial treatment on cardiovascular mortality and likely invalidate informed consent or limit the ability to comply with the
morbidity (non-fatal myocardial infarction and non-fatal stroke), protocol requirements; and those being treated for a malignant disease
revascularisation and amputations. or otherwise having a poor prognosis.
32 © TOUCH BRIEFINGS 2009