Condition category
Nutritional, Metabolic, Endocrine
Date applied
14/08/2013
Date assigned
04/10/2013
Last edited
07/10/2013
Prospective/Retrospective
Retrospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Non-response is an important issue for studies using a written questionnaire. For different reasons, potential participants are reluctant to complete questionnaires. Our aim is to find the best possible level of incentive (when using a written questionnaire and additional telephone interview) to participate in a study.

Who can participate?
Patients with diabetes who are aged 18 years or over can participate in this study.

What does the study involve?
Patients are randomly allocated to one of four groups. Patients are offered four different levels of incentive (either 5, 7.50, 10 or 12.50 euros, according to the group that they are allocated to) to participate in a written survey and an additional telephone interview.

What are the possible benefits and risks of participating?
All patients are part of the study, even if they do not participate (as we are studying the participation rate). The benefit for those who do participate is a gift card with a value of between 5 and 12.50 euros. There are no risks involved.

Where is the study run from?
This study is run from 7 GP practices; 5 of them in the city of Arnhem and 2 in the region ‘Achterhoek’ (including the towns Aalten and Gendringen), Netherlands.

When is study starting and how long is it expected to run for?
Recruitment of patients started in June 2013 and will last until August 2014.

Who is funding the study?
The study is funded by the European Union, Belgium.

Who is the main contact?
Mr Jan Koetsenruijter, j.koetsenruijter@iq.umcn.nl
Professor Michel Wensing, m.wensing@iq.umcn.nl

Trial website

Contact information

Type

Scientific

Primary contact

Prof Michel Wensing

ORCID ID

Contact details

Geert Grooteplein 21
Nijmegen
6500 HB
Netherlands

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

N/A

Study information

Scientific title

The effect of different incentive levels on the participation rate for a mailed survey and telephone interview: a randomized controlled trial

Acronym

Study hypothesis

Higher incentives will lead to a higher response rate, but this effect is not linear. For example, the relative increase of response will become smaller as the incentive becomes higher. Moreover, we expect this curve to be different between high and low deprivation areas.

Ethics approval

Committee on Research Involving Human Subjects (CMO) region Arnhem - Nijmegen (Commissie Mensgebonden Onderzoek [CMO] regio Arnhem – Nijmegen), 08/04/2013, ref: 2013/098

Study design

Randomized controlled trial

Primary study design

Interventional

Secondary study design

Randomised controlled trial

Trial setting

GP practices

Trial type

Screening

Patient information sheet

Not available in web format, please contact j.koetsenruijter@iq.umcn.nl to request a patient information sheet

Condition

Participation rate within patients with type 2 diabetes

Intervention

Patients are randomized within a GP practice. At the GP practice the patient is handed over an anonymous and closed envelope with a specific level of incentive and a questionnaire included. Both researcher and the employee at the GP practice do not know the level of the included incentive.
Respondents are offered four different levels of incentive to participate in a written survey and an additional telephone interview. The incentives are 5, 7.50, 10 and 12.50 euros. This is the only difference between the four treatment arms. There is no follow-up planned.

Intervention type

Other

Phase

Not Applicable

Drug names

Primary outcome measures

Participation rate will be studied within three different areas with different levels of deprivation (subgroup analysis). The participation rate is measured by the total amount of completed questionnaires and telephone interviews, divided by the total number of distributed questionnaires. This rate will be calculated for each level of incentive. There is only one time point as each participant can only complete the questionnaire once.

Secondary outcome measures

Not provided at time of registration

Overall trial start date

01/06/2013

Overall trial end date

01/08/2014

Reason abandoned

Eligibility

Participant inclusion criteria

1. Medical diagnosis of diabetes (not a patient-reported diagnosis)
2. Type 2 diabetes only (no type 1, but comorbidities such as cardiovascular disease are allowed)
3. Male and female, 18 years or over

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

300

Participant exclusion criteria

1. No established diagnosis of diabetes, but obesity or high risk for developing diabetes
2. Mix of type 2 and type 1 (not pure type 2 diabetes)
3. Pregnancy
4. Pregnancy-related diabetes
5. Recent/current major surgery or medical procedures
6. Severe cognitive or psychiatric handicap
7. Terminal illness/receiving palliative care
8. Absence of translators (e.g. family members) for patients with insufficient language skills

Recruitment start date

01/06/2013

Recruitment end date

01/08/2014

Locations

Countries of recruitment

Netherlands

Trial participating centre

Geert Grooteplein 21
Nijmegen
6500 HB
Netherlands

Sponsor information

Organisation

Radboud University Medical Centre (Netherlands)

Sponsor details

Postbus 9101
Nijmegen
6500 HB
Netherlands

Sponsor type

Hospital/treatment centre

Website

http://www.umcn.nl

Funders

Funder type

Government

Funder name

European Union (Belgium)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes