Diet History Questionnaire: Canadian Version
Overview
The Diet History Questionnaire (DHQ) and the DHQ nutrient database
were modified for use in Canada through the collaborative efforts
of Dr. Amy Subar and staff at the Risk Factor Monitoring and Methods
Branch, and Dr. Ilona Csizmadi and colleagues in the Division of
Population Health and Information at the Alberta
Cancer Board in Canada. While the modifications
were primarily carried out in order to develop a nutrient database
that reflected Canadian nutrient fortification practices,
a few questionnaire changes were also made to the DHQ.
Modifications to the Standard US DHQ
Two line items were removed from the standard DHQ as
they referred to products currently not available in Canada; highly
fortified cereals (Total, Product 19, and Right Start) and potato
chips made with Olean or Olestra fat substitutes. In addition,
a number of items not on the original version of the DHQ were added.
The question that queried intake of orange and grapefruit juice
was modified by adding an embedded question to determine the proportion
of orange and grapefruit juice intake that was fortified with calcium.
To better capture vitamin D intake, a separate question was added
to ascertain the intake of supplemental vitamin D not included
in multivitamin preparations. Finally, Splenda (sucralose), a modified
sugar that is not fully absorbed or metabolized and is 600 times
sweeter than sucrose, was added as a third possible choice in the
category of artificial sweeteners.
The Questionnaire Data
Dictionary used with Diet*Calc software
was modified with respect to column location and variable coding
in order to be consistent with the Canadian-modified DHQ data
file. The Canadian DHQ has been programmed in TELEform for
scanning data entry and creation of the data file.
Modifications to the Nutrient Database
The methods used to modify the nutrient database to reflect Canadian
food fortification practices are described in detail in the manuscript:
Csizmadi I, Kahle L, Ullman R, Dawe U, Palmer
Zimmerman T, Friedenreich CM, Bryant HE, Subar AF. Adaptation
and evaluation of the National Cancer Institute’s Dietary
History Questionnaire and nutrient database for use in Canadian
populations. Submitted: Public
Health Nutr.
Briefly, 2,411 foods in the original nutrient database were identified
as those most likely to differ in food composition as a result
of differences in food fortification practices between the US and
Canada. These foods were examined for differences in 12 nutrients:
vitamins A, C, B6, B12, and D, thiamin, riboflavin, niacin, folate,
calcium, iron, and zinc. These nutrients were selected as those
most relevant to the study of associations between diet and chronic
disease.
Food composition data for Canada were obtained from the Canadian
Nutrient File (CNF, Version 2001b) . This large relational
database compiled by the Nutrition Research Division at Health
Canada, is the most comprehensive and valid source of Canadian
food composition information. The database contains average values
for the content of 112 nutrients in 4,943 foods available in Canada.
Although much of the CNF data are derived from the United States
Department of Agriculture Nutrient
Database for Standard Reference (SR13), the
nutrient composition does vary with respect to fortification and
regulatory standards specific to Canada and includes foods and
brand names available only in Canada.
Twenty-five percent of the 2,411 foods originally identified for
examination required modification to reflect Canadian levels of
food fortification. All of the 25 percent were modified for folate,
and approximately 7 percent to 10 percent were modified for riboflavin,
calcium, iron, zinc, niacin, thiamin, and vitamins A, B6, B12 and
C. In addition, 262 foods or 11 percent of the foods were modified
for vitamin D.
The most frequently affected foods with respect to nutrient modifications
were ready-to-eat cereals and commercially prepared baked products.
In addition, milk replacements (rice and soy) are fortified with
vitamins D, A, B12, riboflavin, zinc and calcium in Canada but
not in the 1994-96 CSFII nutrient database. The fortification of
margarine with vitamin D in Canada and not in the US is also noteworthy
due to its widespread presence in the daily diet.
Questions pertaining to the Canadian versions of the DHQ and nutrient
database may be sent to tomorrow@cancerboard.ab.ca.
Current Studies Using the Modified Canadian DHQ
The Alberta Cohort Study (The Tomorrow Project®: PI
Dr. Heather Bryant) - The
Tomorrow Project, a research initiative of the Alberta
Cancer Board with funding from the Alberta Cancer Foundation, is
a prospective cohort study that aims to determine how lifestyle,
diet, physical activity, and other behaviours are likely to influence
cancer risk in the population of Alberta, Canada. As of September
2005, approximately 18,500 Albertans aged 35-69 years, without
a cancer diagnosis at enrolment, have been enrolled into the cohort.
Participants have been asked to complete the Canadian version of
the DHQ, as well as questionnaires designed to assess health, lifestyle
and past year physical activity. Recruitment to the cohort is ongoing.
Case-control study of endometrial cancer – PI
Dr. Christine Friedenreich of the Alberta Cancer Board is
conducting a population-based case-control study of lifestyle risk
factors for endometrial cancer risk in Alberta, Canada. A sample
of 500 incident cases and 1000 population controls are completing
interviewer-administered questionnaires, providing blood samples
and completing the Canadian version of the DHQ. Data collection
will be completed in early 2006.
Alberta Physical Activity and Breast Cancer Prevention
Trial (ALPHA Trial) – Co-PIs Dr. Christine Friedenreich
and Dr. Kerry Courneya (Alberta Cancer Board and University of
Calgary) are conducting a two-armed, two-site randomized controlled
intervention trial of aerobic exercise among 320 postmenopausal,
previously sedentary women aged 50-74 years of age. The exercise
intervention involves five days per week of aerobic exercise
while the control group is maintaining their regular lifestyle.
At baseline and at the end of the 12 month long intervention,
the participants complete several questionnaires and tests including
the Canadian version of the DHQ.
DHQ & Diet*Calc Files for the Canadian Version
Canadian DHQ & Diet*Calc Files |
dhq.canadian.zip -
all files |
The contents of the zip file are:
- Questionnaire (PDF)
- Questionnaire Data Dictionary:
- Nutrient Database
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