What is the effect of different incentive levels on the participation rate for a mailed survey and telephone interview?

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

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN95158258

Enrollment

300

Registered

2013-10-04

Start date

2013-06-01

Completion date

Unknown

Last updated

2015-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Participation rate within patients with type 2 diabetes Nutritional, Metabolic, Endocrine Non-insulin-dependent diabetes mellitus

Interventions

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 resea

Eligibility

Sex/Gender

All

Inclusion criteria

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

Exclusion criteria

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

Design outcomes

Primary

Measure	Time frame
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.	—

Measure

Time frame

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.

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Secondary

Measure	Time frame
Not provided at time of registration	—

Countries

Netherlands

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026