Research Design and Methods
Participants in the EWLW were recruited individually through a social service agency that served as the programs sponsor and through advertisements in neighborhood newspapers that targeted African-American audiences. African-American women ages 2555 years and living in the neighborhoods were eligible for the study if they did not have diabetes, were not pregnant, and were >20% over ideal body weight, as determined by self-report (BMI >27). Eligible subjects were randomly assigned to a treatment or control group. Baseline data were collected before the intervention, at posttest intervals (immediately after the 3-month program), and at a 3-month follow-up assessment. The total study time period was 6 months. There was no further intervention during the posttreatment period for the treatment group. Participants in the control group did not receive any intervention during the treatment or follow-up phases, but were given a self-help workbook that reflected the content of the program and were offered a half-day workshop on healthy, low-fat eating after their follow-up assessment.
The EWLW was developed as a result of the collaborative partnership of health professionals affiliated with Washington University and peer educators from the Wellness Initiative of the sponsoring agency. Peer educators, who were African-American women from the target community with no background in nutrition or education, were recruited by the lead agency to deliver the intervention. The peer educators were trained by a team consisting of dietitians, social workers, and health educators over a 4-month period (~3 half-days per week). A more detailed description of the training and peer-led, community approach is described elsewhere [14,15,16].
The manual-based program consisted of six group sessions (approximately six to eight participants per group) and six individual sessions with a peer educator, integrated over the 3-month intervention phase. Participants met weekly with the peer educator. Each individual session focused on a dietary pattern that represented a way to reduce fat in the diet, including "avoid fat as seasoning," "substitution" of specially manufactured foods for higher fat counterparts, "modify meat" or removing fat and skin from meat, "avoid fried foods," and "replacement" or replacing high-fat foods with fruits, vegetables, grains, and bread. During the individual sessions, the peer educator assessed each participants stage or readiness to change each of the five dietary patterns, and then tailored the session content to that stage.
The content of the six group sessions focused on specific skill areas that included the following: 1) "rate your plate" (participants learned how to assess the fat in their diet and target areas for change, 2) label reading (emphasizing portion size and the total fat and saturated fat content of food), 3) comparison shopping (emphasizing skills to purchase low-fat foods on a budget), 4) recipe modification (keeping culturally rich recipes in the diet while reducing fat content), 5) eating out (making healthy food choices in fast food and other restaurants), and 6) coping with high-risk situations.
To assess program integrity, sessions were randomly audiotaped and scored by independent raters using detailed session checklists. Results of the process evaluation indicated that the peer educators delivered 91.42% of the content across 12 sessions and that the overall accuracy of information delivered was 88.52% (averaged across the three peer educators). The EWLW process evaluation methods and results are discussed in more detail elsewhere .
Evaluation of the effectiveness of the intervention was performed on data from before and after treatment and from follow-up assessments on the following behavioral and physical outcome variables. In addition, structured interview questions were asked to obtain information regarding demographics and medical history. Demographic information included variables such as age, marital status, number of children, educational status, work status, and monthly income.
Dietary knowledge. Participants knowledge was assessed by 15 items originally developed by Kristal and colleagues , and then modified for the present study.
Label-reading knowledge. This assessment tool was developed for this program and consisted of 10 items (Cronbachs alpha = 0.74) that tested the respondents ability to interpret fat and calorie content in foods through reading sample food labels.
Attitudes about diet and health. Attitudes were assessed using a revised 10-item scale (Cronbachs alpha = 0.62) . Items measured attitudes regarding the importance of meat, models (what friends do), attitudes about high-fat meals, and attitudes toward eating fiber-rich foods, such as fruits and vegetables, on a four-point Likert scale ("strongly agree" to "strongly disagree"). Higher scores indicated healthier attitudes toward low-fat diets.
Dietary patterns. Eating patterns were assessed using the Eating Patterns Questionnaire, a 1994 revised version of the Fat and Fiber-Related Diet Habits Questionnaire . In the revised questionnaire, 34 items on a four-point scale ("always" to "never") related to food patterns addressed in the program were assessed (total scale Cronbachs alpha = 0.83). Five dietary patterns were measured: "avoid fat as seasoning" (alpha = 0.50), "substitution" (alpha = 0.61), "modify meat" (alpha = 0.67), "avoid fried foods" (alpha = 0.71), and "replacement" (alpha = 0.61). Higher scores on the Eating Patterns Questionnaire indicated lower fat dietary habits.
Readiness to change dietary patterns. The Staging of Eating Patterns Assessment determined participants general readiness to perform each of the aforementioned five dietary patterns. Each pattern was assessed by one item; subjects responded to a five-point scale that indicated their degree of readiness to make or maintain changes based on Prochaskas five stages of change. Validation of this assessment measure has been previously demonstrated . To present the findings in a parsimonious manner, stages were combined to create two variables: pre-action (including precontemplation, contemplation, and preparation) and action (including action and maintenance).
Fat and daily energy intake. Participants daily intake of fat and energy was measured by the Food Frequency Questionnaire (FFQ). The FFQ has become a well-accepted method for quantifying usual nutrient intake because, in part, it minimizes the high intra-individual, day-to-day variability in nutrient intake without relying on multiple day assessments of actual foods consumed. The FFQ used in the present study was developed for the Womens Health Trial-Feasibility Study in Minority Populations .
Height and weight. Each subjects height and weight were assessed while she was wearing indoor clothing without shoes. Body weight was measured using a Health-O-Meter physician beam scale. Scales were calibrated quarterly using standard weights. BMI was calculated by taking the subjects weight divided by her height squared.
The design of this study was a two (treatment versus control) by three (pretest, posttest, and follow-up) factorial design. For outcome measures that were either interval or ratio level measures, differences between the two conditions (pre- versus posttest and pretest versus follow-up) were tested using the ANCOVA procedure, with baseline values as the covariate. The t statistics and associated two-tail significance levels were based on the post hoc comparisons of each outcome measure between treatment and control conditions. For the staging of dietary patterns (action versus pre-action) variables, ANCOVA via logistic regression was used to determine significant differences between conditions.
The sample consisted of 294 African-American women who completed the pre- and posttest and follow-up assessments. Table 1 compares the sociodemographic characteristics of the participants in the treatment and control groups at baseline assessment. Comparisons between the participants in the two conditions indicated that there were no significant differences between the treatment and control groups in any of the participant characteristics. The retention rate for study participants was 73.7%. Comparisons were made to determine if there were any differences between the women who completed pre- and posttest and follow-up assessments (n = 294) and those who dropped out of the study (n = 104)that is, completed pretests, but not posttests and follow-up tests. Results showed that those who completed the study were older than the dropouts (mean age 40.7 vs. 37.3 years, respectively; t (396) = 3.75, P < 0.001). Participation rates among those that completed the study showed that 68.6% attended at least 10 of 12 possible sessions (mean = 9.4 sessions).
Diabetes Care. 2002;25(5) © 2002 American Diabetes Association, Inc.
Cite this: A Controlled Evaluation of Staging Dietary Patterns to Reduce the Risk of Diabetes in African-American Women - Medscape - May 01, 2002.