Condition category
Nutritional, Metabolic, Endocrine
Date applied
15/12/2016
Date assigned
06/01/2017
Last edited
04/01/2017
Prospective/Retrospective
Retrospectively registered
Overall trial status
Ongoing
Recruitment status
Recruiting

Plain English Summary

Background and study aims
Diabetes is a lifelong condition that causes a person's blood sugar level to become too high. Previous studies have shown that people with type 2 diabetes are at increased risk of complications and mortality (death) compared to people without type 2 diabetes. Despite treatment, people with type 2 diabetes have higher levels of cardiovascular (heart disease) risk factors, such as high blood pressure, cholesterol and glucose levels. Diabetes care in the Netherlands was in need of improvement. For this reason, in 1996 centrally organised diabetes care was started in the region West-Friesland, a semi-urban region with 200,000 inhabitants and representative for a Western-European population, resulting in the Hoorn Diabetes Care System cohort (DCS). The DCS centre is responsible for the quality of type 2 diabetes care and uses managed care plans, working with contracted general practitioners (GPs). The managed care plan encompasses the care provided by a person’s GP, according to the Dutch College of GPs’ treatment guidelines for type 2 diabetes, and a standardised annual assessment organised centrally by the DCS centre. All people with type 2 diabetes in the region are included in the DCS cohort, which provides a unique opportunity for research.

Who can participate?
All people (all ages) with type 2 diabetes living in the West-Friesland region of the Netherlands

What does the study involve?
People with type 2 diabetes visit the DCS centre as part of the routine diabetes care. During this annual measurement, blood samples are taken to look at diabetes-related risk factors, blood pressure is measured and participants are asked about their smoking, medication use and other diseases. Anonymised electronic records are kept of these annual measurements and the participants are informed about the use of these records for research purposes. For specific research projects, in addition to the routine measurements, people are approached individually. When participants agreed to participate, additional questionnaires are filled in by the patients, or extra blood or urine samples are taken, depending on the type of the specific study.

What are the possible benefits and risks of participating?
Participants visit a specialized diabetes care center and their care is strictly monitored. Participation does not involve any extra risk compared to usual diabetes care.

Where is the study run from?
1. Diabetes Zorgsysteem locatie Hoorn (Netherlands)
2. Diabetes Zorgsysteem locatie Enkhuizen (Netherlands)
3. Diabetes Zorgsysteem locatie Hoogwoud/Opmeer (Netherlands)
4. Diabetes Zorgsysteem locatie Medemblik (Netherlands)
5. Diabetes Zorgsysteem locatie Slootdorp (Netherlands)
6. Diabetes Zorgsysteem locatie Wervershoof (Netherlands)
7. Diabetes Zorgsysteem locatie Venhuizen (Netherlands)

When is the study starting and how long is it expected to run for?
March 1996 to January 2030

Who is funding the study?
1. VU University Medical Center (Netherlands)
2. Dutch Federation of University Medical Centres (Netherlands)
3. Health insurers (Netherlands)
4. Netherlands Organisation for Scientific Research (Netherlands)
5. Netherlands Organisation for Health Research and Development (Netherlands)
6. Dutch Diabetes Foundation (Netherlands)
7. European Foundation for the Study of Diabetes (Germany)
8. International Diabetes Federation (Belgium)
9. European Innovative Medicine Initiative (Belgium)
10. European Union (Belgium)

Who is the main contact?
1. Dr Petra Elders (p.elders@vumc.nl)
2. Prof. Giel Nijpels (g.nijpels@vumc.nl)
3. Dr Amber van der Heijden (a.vanderheijden@vumc.nl)

Trial website

Contact information

Type

Scientific

Primary contact

Dr Petra Elders

ORCID ID

Contact details

Van der Boechorststraat 7
Amsterdam
1081 BT
Netherlands
+31 (0)20 4448354
p.elders@vumc.nl

Type

Scientific

Additional contact

Prof Giel Nijpels

ORCID ID

Contact details

Van der Boechorststraat 7
Amsterdam
1081 BT
Netherlands
+31 (0)20 4449659
g.nijpels@vumc.nl

Type

Scientific

Additional contact

Dr Amber van der Heijden

ORCID ID

Contact details

Van der Boechorststraat 7
Amsterdam
1081BT
Netherlands
+31 (0)20 4448409
a.vanderheijden@vumc.nl

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

1

Study information

Scientific title

The Hoorn Diabetes Care System cohort (DCS): an observational prospective cohort study

Acronym

DCS

Study hypothesis

People with type 2 diabetes (T2D) have a doubled morbidity and mortality risk compared to persons with normal glucose tolerance. Despite treatment, target values for cardiovascular risk factors are not achieved. The Hoorn Diabetes Care System cohort (DCS) study is a prospective longitudinal cohort study representing a complete dataset on the natural course of T2D, with repeated clinical measures and outcomes during follow-up.

Ethics approval

Ethics Review Committee of the VU University Medical Center Amsterdam, 09/07/2009, ref: NL27783.029.09

Study design

Observational prospective cohort study

Primary study design

Observational

Secondary study design

Longitudinal study

Trial setting

Community

Trial type

Treatment

Patient information sheet

Not available in web format, please use contact details to request a participant information sheet

Condition

Type 2 diabetes

Intervention

The DCS cohort study is an observational study and no specific intervention of treatment is performed.

All people with type 2 diabetes from all the 103 general practitioners in the West-Friesland region of the Netherlands are included in the cohort. In this prospective cohort study, examination of persons with type 2 diabetes of the DCS cohort is performed annually and include measurement of, among others, all diabetes-related risk factors and medication use. Microvascular complications are assessed by measuring kidney function, and screening feet and eyes. Information on cardiovascular disease is obtained by self-report, electrocardiography and electronic patient registrations.

In subgroups of the cohort, biobanking and additional measurements were performed to obtain information on, for example lifestyle, depression, and genomics. Finally, the cohort is linked to data on registrations on cancer and all-cause mortality.

Intervention type

Other

Phase

Drug names

Primary outcome measures

1. Microvascular complications, measured annually:
1.1. Nephropathy: urinary albumin-creatinine ratio (mg/mmol), from an overnight first-voided urine sample
1.2. Kidney function estimated according to the Modification of Diet in Renal Disease (MDRD) formula. Microalbuminuria was defined as urinary albumin-creatinine ratio>2.0 mg/mmol
1.3. Retinopathy, measured by fundus photography of both eyes. All photographs were graded according to the EURODIAB classification score: grade 0: “no retinopathy,” grade 1: “minimal non-proliferative retinopathy,” grade 2: “moderate non-proliferative retinopathy,” grade 3: “severe non-proliferative or pre-proliferative retinopathy,” grade 4: “photocoagulated retinopathy,” and grade 5: “proliferative retinopathy”
1.4. Diabetic foot, determined by dermatologic and musculoskeletal inspection; check for skin pressure and foot deformity; neurological assessment including test of protective sensation using a 10-g monofilament and test of vibratory sensation using a 128-Hz tuning fork; assessing presence of peripheral arterial disease (PAD) by foot pulses; and assessing presence of limited joint mobility. Complications of the foot are categorized according to the classification system of the International Working Group on the Diabetic Foot: 0: no neuropathy, 1: neuropathy, 2: neuropathy and deformity or PAD, 3: history of foot ulceration or a lower-extremity amputation

2. Cardiovascular complications, measured by:
2.1. Self-reported events during the annual visit
2.2. Electrical conduction system, a standard resting 12-lead electrocardiogram coded according to the Minnesota coding, measured annually.
2.3. Electronic patient registration from the regional hospital and GP, updated every three years. In this morbidity and mortality registration, cardiovascular diseases are coded according to the International Classification of Diseases, Injuries and Causes of Death, ninth revision, including ICD-9 codes 390 to 459, and 798

3. Cancer: via linkage with information on cancer morbidity which was obtained from the nationwide Netherlands Cancer Registry. Topography and morphology are coded according to the International Classification of Diseases for Oncology (ICDO). Data on primary treatment, chemoradiation, radiotherapy, hormone therapy and surgery have been included

4. Mortality: checked every six months using the National population registry and cause of death determined using GP records and coded as explained above using the morbidity and mortality registry. Cause of death is coded according to the ICD-9

Secondary outcome measures

Quality of life and physical functioning, assessed by self-reported questionnaires at a single timepoint in 2006

Overall trial start date

01/03/1996

Overall trial end date

01/01/2030

Reason abandoned

Eligibility

Participant inclusion criteria

All people (all ages) with type 2 diabetes living in the West-Friesland region of the Netherlands

Participant type

Patient

Age group

All

Gender

Both

Target number of participants

16,000

Participant exclusion criteria

No exclusions

Recruitment start date

01/10/1996

Recruitment end date

01/01/2030

Locations

Countries of recruitment

Netherlands

Trial participating centre

Diabetes Zorgsysteem locatie Hoorn
Maelsonstraat 7
Hoorn
1624 NP
Netherlands

Trial participating centre

Diabetes Zorgsysteem locatie Enkhuizen
Molenweg 7b
Enkhuizen
1601 SR
Netherlands

Trial participating centre

Diabetes Zorgsysteem locatie Hoogwoud/Opmeer
Raadhuisstraat 5
Hoogwoud
1718 BM
Netherlands

Trial participating centre

Diabetes Zorgsysteem locatie Medemblik
Compagniesingel 7
Medemblik
1671 KC
Netherlands

Trial participating centre

Diabetes Zorgsysteem locatie Slootdorp
Brink 53
Slootdorp
1774 BB
Netherlands

Trial participating centre

Diabetes Zorgsysteem locatie Wervershoof
Olympiaweg 141
Wervershoof
1693EK
Netherlands

Trial participating centre

Diabetes Zorgsysteem locatie Venhuizen
Twijver 66a
Venhuizen
1602BW
Netherlands

Sponsor information

Organisation

VU University Medical Centre

Sponsor details

EMGO Institute for Health and Care Research
Department of General Practice & Elderly Care Medicine
Van der Boechorststraat 7
Amsterdam
1081 BT
Netherlands
+31 (0)20 4448354
p.elders@vumc.nl

Sponsor type

University/education

Website

Funders

Funder type

University/education

Funder name

VU University Medical Center

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

Dutch Federation of University Medical Centres

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

Health insurers

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

Nederlandse Organisatie voor Wetenschappelijk Onderzoek

Alternative name(s)

Netherlands Organisation for Scientific Research, Dutch National Scientific Foundation, Dutch National Science Foundation, NWO

Funding Body Type

government organisation

Funding Body Subtype

Federal/National Government

Location

Netherlands

Funder name

ZonMw

Alternative name(s)

Netherlands Organisation for Health Research and Development

Funding Body Type

private sector organisation

Funding Body Subtype

other non-profit

Location

Netherlands

Funder name

Dutch Diabetes Foundation

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

European Foundation for the Study of Diabetes

Alternative name(s)

EFSD

Funding Body Type

private sector organisation

Funding Body Subtype

foundation

Location

Germany

Funder name

International Diabetes Federation

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

European Innovative Medicine Initiative

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Funder name

European Union

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

A manuscript on the cohort profile of the DCS is submitted and currently under review. Several papers using the data of the DCS cohort have already been published and more papers on DCS data are in preparation or planned.

IPD sharing plan
The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Petra Elders (p.elders@vumc.nl).

Intention to publish date

01/03/2017

Participant level data

Available on request

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes