Comparison of a computer-based food frequency questionnaire for calcium intake with 2 other assessment tools

Evaluation of tools used to measure calcium and/or dairy consumption in adults

OBJECTIVE

To identify and critique tools for the assessment of Ca and/or dairy intake in adults, in order to ascertain the most accurate and reliable tools available.

DESIGN

A systematic review of the literature was conducted using defined inclusion and exclusion criteria. Articles reporting on originally developed tools or testing the reliability or validity of existing tools that measure Ca and/or dairy intake in adults were included. Author-defined criteria for reporting reliability and validity properties were applied.

SETTING

Studies conducted in Western countries.

SUBJECTS

Adults.

RESULTS

Thirty papers, utilising thirty-six tools assessing intake of dairy, Ca or both, were identified. Reliability testing was conducted on only two dairy and five Ca tools, with results indicating that only one dairy and two Ca tools were reliable. Validity testing was conducted for all but four Ca-only tools. There was high reliance in validity testing on lower-order tests such as correlation and failure to differentiate between statistical and clinically meaningful differences. Results of the validity testing suggest one dairy and five Ca tools are valid. Thus one tool was considered both reliable and valid for the assessment of dairy intake and only two tools proved reliable and valid for the assessment of Ca intake.

CONCLUSIONS

While several tools are reliable and valid, their application across adult populations is limited by the populations in which they were tested. These results indicate a need for tools that assess Ca and/or dairy intake in adults to be rigorously tested for reliability and validity.

Relative validity of the Iowa Fluoride Study targeted nutrient semi-quantitative questionnaire and the block kids' food questionnaire for estimating beverage, calcium, and vitamin D intakes by children

OBJECTIVE

Food frequency questionnaires are commonly developed and subsequently used to investigate relationships between dietary intake and disease outcomes; such tools should be validated in the population of interest. We investigated the relative validities of the Iowa Fluoride Study targeted nutrient semi-quantitative questionnaire and Block Kids' Food Questionnaire in assessing beverage, calcium, and vitamin D intakes using 3-day diaries for reference.

DESIGN

Cross-sectional.

SUBJECTS

Children who completed Iowa Fluoride Study nutrient questionnaire at age 9.0+/-0.7 years (n=223) and/or the Block Kids' Food Questionnaire at age 8.3+/-0.3 years (n=129) and 3-day diaries during similar time periods.

MAIN OUTCOMES

Intakes of beverages, calcium, and vitamin D.

STATISTICAL ANALYSES

Spearman correlation coefficients, weighted kappa statistics, and percentages of exact agreement were used to estimate relative validities.

RESULTS

Correlations between milk intakes (r=0.572) reported on diaries and the Iowa Fluoride Study nutrient questionnaires were higher than correlations for 100% juice, juice drinks, soda pop, and water (r=0.252 to 0.379). Correlations between milk intakes (r=0.571) and 100% juice intakes (r=0.550) reported on diaries and Block Kids' Food Questionnaires were higher than correlations for other beverages (r=0.223 to 0.326). Correlations with diaries for calcium (r=0.462) and vitamin D (r=0.487) intakes reported on Iowa Fluoride Study nutrient questionnaires were similar to correlations with diaries for calcium (r=0.515) and vitamin D (r=0.512) reported on Block Kids' Food Questionnaires. Weighted kappa statistics were similar between the Iowa Fluoride Study nutrient questionnaires and the Block Kids' Food Questionnaires for milk, 100% juice, and vitamin D, but were higher on the Iowa Fluoride Study nutrient questionnaires than on the Block Kids' Food Questionnaires for calcium. Percentages of exact agreement were higher for calcium, but lower for vitamin D for intakes reported on the Iowa Fluoride Study nutrient questionnaires compared to the Block Kids' Food Questionnaires relative to diaries.

CONCLUSIONS

Both the Iowa Fluoride Study nutrient questionnaire and the Block Kids' Food Questionnaire provide reasonable estimates of milk, calcium, and vitamin D intakes when compared to 3-day diaries.

Development of the Iowa bone nutrient food frequency questionnaire based on data from the US Department of Agriculture Continuing Survey of the Food Intake by Individuals

An easily administered food frequency questionnaire (FFQ)/dietary screener was developed for current (adult) and retrospective (adolescent) intakes of nutrients important for bone development and maintenance. This tool quantified serving sizes and nutrients from foods using gender and age specific techniques. Nutrients of interest were calcium, vitamin D, caffeine and alcohol, and 15 categories of foods were selected for inclusion based on frequency of intake and nutrient density. Calcium-contributing foods were selected from published dietary intake assessment tools. Foods contributing vitamin D, caffeine and alcohol were selected based on nutrient density and Midwest consumption practices. Serving sizes were quantified in standard serving units or as small, medium and large servings. Food items selected for the FFQ/dietary screener were matched to foods from the United States Department of Agriculture (USDA) Continuing Survey of Food Intakes by Individuals (CSFII). Calcium, caffeine and alcohol values were assigned using CSFII data files at median values per 100g intake. CSFII midpoint tertile frequency of intake values for males and females 14-18 and 25-45 years old were used to establish serving weights for small, medium and large servings. CSFII data files provide an efficient way for estimating typical intakes, serving sizes and nutrient values for target groups. Age- and gender-derived data provided realistic estimates of nutrient intakes when using FFQ/dietary screener assessment method.

Reliability and Validity of a Brief Questionnaire to Assess Calcium Intake of Middle-School–Aged Children

OBJECTIVE

Evaluate the validity and reliability of a short (10-item) calcium food frequency questionnaire (FFQ) for use with middle-school-aged (11 to 14 years of age) children.

DESIGN

The calcium FFQ was completed twice, with 1 week between administrations. Three 24-hour dietary recalls were collected from each participant after the second administration of the calcium FFQ.

SUBJECTS/SETTING

Students in an ethnically diverse middle school in Minneapolis, MN (n=248).

MAIN OUTCOME MEASURES

Calcium intake estimates from the calcium FFQ and dietary recalls.

STATISTICAL ANALYSES

Correlations between calcium intake estimates from the first and second questionnaire administrations of the calcium FFQ were calculated and paired t tests were conducted to compare mean calcium intake estimates from each questionnaire administration. Mean intake estimates from the calcium FFQ and the dietary recalls were compared. Also, correlations between intake estimates from the calcium FFQ and the recalls were calculated.

RESULTS

Correlation between calcium intake estimates derived from the first and second administration of the calcium FFQ was 0.74. Mean calcium intake estimates from the calcium FFQ and the average of the three dietary recalls were 856 mg/day and 993 mg/day, respectively (P<0.001). The correlation between calcium intake estimates derived from the calcium FFQ and the average of the recalls was 0.43.

CONCLUSIONS

Reliability of the FFQ was found to be good while validity was weaker, with calcium intake from the calcium FFQ moderately associated with estimates from dietary recalls. Where a brief instrument for assessing calcium intake of middle-school-aged children is needed, the calcium FFQ evaluated in this study may be useful.

Stages of Change Algorithm for Calcium Intake by Male College Students

Using a sample of college-aged men, we evaluated the validity of a staging algorithm for dairy calcium intake that had been previously validated in a sample of college women. College-aged men enrolled at a private university in the United States were randomly selected to participate. The sample consisted of 180 male participants. Self-reported calcium intake was measured using a 26-item food frequency questionnaire. Stages of change classifications were based on a four-question algorithm for dairy calcium intake and a three-item self-efficacy questionnaire. Significant differences were found between dairy/calcium intake levels between pre-contemplation, contemplation/preparation, and action/maintenance groups. Results also showed that 46% of participants were in the action/maintenance stage. There was a significant difference in self-efficacy between members of the pre-action and action stages. The study suggests that this stage of change algorithm for dairy calcium intake is valid for use in a male college student population.

Overview of computerized dietary assessment programs for research and practice in nutrition education

Computerized dietary assessment programs are often used for nutrition education research and practice. This article provides an informal overview of 29 dietary assessment programs mentioned in the literature covered by MEDLINE from 1996 to 2003, along with the components and capabilities of these programs derived from additional sources as needed. According to the literature, the advantages of using computers for dietary assessment include standardization of the questioning sequence, fast and easy processing, immediate results, and increased flexibility. The disadvantages include the need for typing skills and computer literacy, as well as potential bias in the responses if an interviewer is required.

Development and Assessment of a Short Instrument for Assessing Dietary Intakes of Calcium and Vitamin D

OBJECTIVE

To validate a short food frequency screening instrument designed to assess dietary intakes of calcium and vitamin D.

DESIGN

Cross-sectional surveys and food diaries.

PARTICIPANTS

Twenty-seven university employees.

MAIN OUTCOME MEASURES

Calcium and vitamin D intakes of participants were assessed using three instruments: a 7-day food diary, the Block-National Cancer Institute Health Habits and History Questionnaire (HHHQ), and a short screening instrument derived from the HHHQ. The accuracy of participants' reports of calcium and vitamin D intakes on the HHHQ and short screening instrument were checked against the food diaries. The validity of the full survey and the screening instrument were judged according to their correlation with the food diaries.

RESULTS

Estimates of calcium and vitamin D intakes derived from the 7-day food diary and the short screening instrument were significantly correlated (r = 0.66 and 0.72, respectively, P < .001). The mean differences between estimates derived from the short screening instrument and those derived from the 7-day food diary were 223 mg/day for calcium and 47 IU/day for vitamin D. The positive predictive value of the short screening instrument in identifying individuals with low nutrient intakes, as assessed by the 7-day food diary, was 91.7% for calcium and 100.0% for vitamin D.

CONCLUSION

The short screening instrument provides reasonably accurate estimates of calcium and vitamin D intakes. Although it cannot replace more comprehensive nutritional assessments, the screening instrument may provide quick assessments of calcium and vitamin D intakes. Given that many individuals consume suboptimal levels of these nutrients, pharmacists may use the screening instrument to evaluate patients' needs for calcium and/or vitamin D supplements and, thus, reduce their risk for developing osteoporosis.

Relative validation of a beverage frequency questionnaire in children ages 6 months through 5 years using 3-day food and beverage diaries

OBJECTIVE

To determine the relative validity of a quantitative beverage frequency questionnaire in assessing beverage, calcium, and vitamin D intakes using 3-day food diaries for reference.

DESIGN

Parents were asked to complete questionnaires for the preceding week and diaries for the following week for their children. Calcium and vitamin D intakes were estimated from human milk, infant formulas, and cow's milk ("beverages") for questionnaires and diaries and from "all foods and beverages" for diaries. Data collected at 6 and 12 months and 3 and 5 years of age as part of the Iowa Fluoride Study (N=700) were analyzed cross-sectionally.

SUBJECTS

Children (N=240); 60 randomly selected from each quartile of energy intake at 6 months of age.

STATISTICAL ANALYSES

Spearman correlation coefficients, weighted kappa statistics, and percentages of exact agreement were used to assess associations between tools.

RESULTS

Correlations between mean daily beverage intakes estimated from questionnaires and diaries ranged from 0.95-0.99 for human milk, 0.84-0.85 for infant formula, 0.63-0.86 for cow's milk, 0.54-0.69 for juice/drinks, 0.26-0.59 for liquid soft drinks, 0.35-0.74 for powdered soft drinks and 0.54-0.70 for water. Correlations between mean daily nutrient intakes estimated from questionnaires and diaries "beverages" ranged from 0.64-0.74 for calcium and 0.60-0.80 for vitamin D; and between questionnaires and diaries "all foods and beverages" ranged from 0.41-0.63 for calcium and 0.43-0.80 for vitamin D.

APPLICATIONS

A quantitative beverage frequency questionnaire can provide a relative estimate of beverage, calcium, and vitamin D intakes.

Development and validation of a stages of change algorithm for calcium intake for college female students

OBJECTIVES

The purpose of this study was to develop and validate a staging algorithm for calcium intake.

METHODS

Three hundred seventy-six college-aged females at a private university were randomly selected to participate. After 8.5% of the data were omitted due to incomplete surveys, the sample consisted of 344 female participants. Calcium intake was measured as self-reported consumption with a 26-item food frequency questionnaire. Stages of change classifications were based on a four-item algorithm for calcium intake, and self-efficacy was measured with three items.

RESULTS

Significant differences were found between calcium intake levels between precontemplation, contemplation/preparation and action/maintenance. Results also showed that 40% of the participants were in action/maintenance and were consuming the Dietary Reference Intake level of 1,000 mg of daily calcium. Participants in the action and maintenance stages had significantly higher self-efficacy than the preaction group.

CONCLUSION

The study suggests that the stages of change algorithm may be used as an effective tool in assessing daily calcium intake among a college female population.

Osteoporosis knowledge, calcium intake, and weight-bearing physical activity in three age groups of women

The purpose of this study was to determine the extent and integration of osteoporosis knowledge in three age groups of women and compare knowledge to calcium intake and weight-bearing physical activity (WBPA). In this cross-sectional study, knowledge, calcium intake and WBPA were assessed using probe interviews, a food frequency and an activity questionnaire, respectively. Seventy-five white women were separated into three groups: young (25-35 years), middle aged (36-46 years) and postmenopausal (50+ years). Concept maps were used to assess knowledge (concepts, integration and misconceptions). Calcium intakes from diet, supplements and fortified orange juice were estimated as were minutes of daily WBPA. Analysis of covariance was used to compare knowledge, calcium intake and WBPA by age group. Covariates included education, family history, physical problems making exercise difficult, and lactose intolerance. Chi square analysis was used to determine differences in these covariates across age groups. Correlations and regression analysis were used to determine relationships between knowledge and behaviors. Knowledge scores averaged 32-44 points (183 possible). Average calcium intake in all groups exceeded the Dietary Reference Intake's recommended Adequate Intake but 20-24% consumed less than 60% of the AI. Housework, walking at work, and standing at home and work accounted for 90% of WBPA. Knowledge about osteoporosis was limited and not associated with age, WBPA or calcium intake. Calcium intake and WBPA were not associated with age. Practitioners need to provide explicit information on osteoporosis and risk reducing behaviors to women of all ages.