Recontacting Participants in the Observing Protein and Energy Nutrition (OPEN) Study: Re-OPEN
Public ClinicalTrials.gov record NCT00339677. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Recontacting Participants in the Observing Protein and Energy Nutrition Study: ReOPEN
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This study will evaluate the structure of error in self-reporting instruments on diet, in following up the Observing Protein and Energy Nutrition Study (OPEN) conducted in 1999 and 2000. The OPEN study, the largest of its kind, resulted in a wealth of nutritional biomarker data-measurable indicators of changes in organisms at the level of molecules or cells. A biomarker could help in understanding how environment and disease are related and about disease risks. Furthermore, its findings showed that the relative estimates of disease risk may be weakened by a food frequency questionnaire and a 24-hour questionnaire. Scientists have long recognized that self-reported information from questionnaires and interviews contains errors, but there has been uncertainty about the structure of such errors. For the proposed study, a food record and a food checklist-adjusted food frequency questionnaire will be compared with the previously used questionnaires, to determine whether the newer study instruments present less chance of measurement error. The results may provide better tools for a study on nutritional epidemiology, that is, the incidence and other aspects of disease and nutrition. OPEN study participants will be invited for follow-up. Patients who completed the 1999-2000 study who are not currently pregnant or a liquid weight loss diet may be eligible for this study. The original study recruited men and women 40 to 69 years of age. A letter with summary results from the original OPEN study will be sent to each of the 482 participants. Both the Food Record and the food checklist, called the Daily Food List, are instruments to be given. The Food Record asks the participant to record all foods and beverages consumed. The Daily Food List asks respondents to write in to the number of times a limited number of food categories are consumed. In addition, respondents will be asked to complete the National Cancer Institute Diet History Questionnaire (DHQ), identical to the one that they completed in the original OPEN study, regarding the previous 12 months. Participants will randomly be assigned to one of two groups. All will receive four study mailings over a 3-month period: the DHQ, First 4-Day Food Record (4-day FR), Second 4-day FR, and Booklet of 7-Day Food Lists (7-day FL), the latter listing selected foods that the participants will mark if consumed on the reporting day. Study Group A will receive the DHQ, first 4-day FR, second 4-day FR, and 7-day FL. Study Group B will receive the DHQ, 7-day FL, first 4-day FR, and second 4-day FR. Within 10 days after receiving the DHQ, participants will be called to schedule an appointment for a 30- to 45-minute visit. Participants will undergo the following procedures: * Complete the Physical Activity Questionnaire (by telephone for those who have moved out of the local area or are unable to attend the visit) * Have weight measured * Be asked about whether he or she has recently developed certain medical conditions, experienced dramatic changes in diet, or gained special education in nutrition The completion time for each instrument in dietary assessment is approximately as follows: * DHQ-60 minutes. * Each 4-day FR-80 minutes (20 minutes a day). * 7-day FL-35 to 49 minutes (5 to 7 minutes a day).
Study identification
- NCT ID
- NCT00339677
- Recruitment status
- Completed
- Study type
- Observational
- Phase
- Not listed
- Enrollment
- 384 participants
Conditions and interventions
Conditions
Interventions
Not listed
Eligibility (public fields only)
- Age range
- 19 Years to 69 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Nov 5, 2003
- Primary completion
- Dec 21, 2004
- Completion
- Feb 23, 2020
- Last update posted
- Feb 24, 2020
2003 – 2020
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| National Cancer Institute (NCI), 9000 Rockville Pike | Bethesda | Maryland | 20892 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT00339677, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Feb 24, 2020 · Synced Sep 11, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT00339677 live on ClinicalTrials.gov.