Comparison of recruitment and retention among demographic subgroups in a large diverse population study of diet.

OBJECTIVE: We examined the feasibility of conducting a longitudinal study of diet among diverse populations by comparing rates of response throughout recruitment and retention phases by demographic and other characteristics. METHODS: Using quota sampling, participants were recruited from 3 geographically and demographically diverse integrated health systems in the United States. Overall, 12,860 adults, ages 20-70, were invited to participate via mail. Participation first required accessing the study's website and later meeting eligibility criteria via telephone interview. Enrollees were asked to provide two 24-hour dietary recalls, either interviewer-administered or self-administered on the web, over 6 weeks. Stepped monetary incentives were provided. RESULTS: Rates for accessing the study website ranged from 6% to 23% (9% overall) across sites. Site differences may reflect differences in recruitment strategy or target samples. Of those accessing the website, enrollment was high (≥ 87%). Of the 1185 enrollees, 42% were non-Hispanic white, 34% were non-Hispanic black, and 24% were Hispanic. Men and minorities had lower enrollment rates than women and non-Hispanic whites, partially due to less successful telephone contact for eligibility screening. Once enrolled, 90% provided 1 recall and 80% provided both. Women had higher retention rates than men, as did older compared to younger participants. Retention rates were similar across race/ethnicity groups. CONCLUSIONS: While study recruitment remains challenging, once recruited most participants, regardless of race/ethnicity, completed two 24-hour dietary recalls, both interviewer-administered and self-administered on the web. This study demonstrates the feasibility of collecting multiple 24-hour recalls including less expensive automated self-administered recalls among diverse populations.

Dietary Flavonoid Intake Reduces the Risk of Head and Neck but Not Esophageal or Gastric Cancer in US Men and Women.

Background: Flavonoids are bioactive polyphenolic compounds found in fruits, vegetables, and beverages of plant origin. Previous studies have shown that flavonoid intake reduces the risk of certain cancers; however, few studies to date have examined associations of flavonoids with upper gastrointestinal cancers or used prospective cohorts.Objective: Our study examined the association between intake of flavonoids (anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols, and isoflavones) and risk of head and neck, esophageal, and gastric cancers.Methods: The NIH-AARP Diet and Health Study is a prospective cohort study that consists of 469,008 participants. Over a mean 12-y follow-up, 2453 head and neck (including 1078 oral cavity, 424 pharyngeal, and 817 laryngeal), 1165 esophageal (890 adenocarcinoma and 275 squamous cell carcinoma), and 1297 gastric (625 cardia and 672 noncardia) cancer cases were identified. We used Cox proportional hazards regression models to estimate HRs and CIs for the associations between flavonoid intake assessed at study baseline and cancer outcomes. For 56 hypotheses examined, P-trend values were adjusted using the Benjamini-Hochberg (BH) procedure for false discovery rate control.Results: The highest quintile of total flavonoid intake was associated with a 24% lower risk of head and neck cancer (HR: 0.76; 95% CI: 0.66, 0.86; BH-adjusted 95% CI: 0.63, 0.91; P-trend = 0.02) compared with the lowest quintile. Notably, anthocyanidins were associated with a 28% lower risk of head and neck cancer (HR: 0.72; 95% CI: 0.62, 0.82; BH-adjusted 95% CI: 0.59, 0.87; P-trend = 0.0005), and flavanones were associated with a 22% lower risk of head and neck cancer (HR: 0.78; 95% CI: 0.68, 0.89; BH-adjusted 95% CI: 0.64, 0.94; P-trend: 0.02). No associations between flavonoid intake and risk of esophageal or gastric cancers were found.Conclusions: Our results indicate that flavonoid intake is associated with lower head and neck cancer risk. These associations suggest a protective effect of dietary flavonoids on head and neck cancer risk, and thus potential as a risk reduction strategy.

Comparison of Interviewer-Administered and Automated Self-Administered 24-Hour Dietary Recalls in 3 Diverse Integrated Health Systems.

Twenty-four-hour dietary recalls provide high-quality intake data but have been prohibitively expensive for large epidemiologic studies. This study's goal was to assess whether the web-based Automated Self-Administered 24-Hour Recall (ASA24) performs similarly enough to the standard interviewer-administered, Automated Multiple-Pass Method (AMPM) 24-hour dietary recall to be considered a viable alternative. In 2010-2011, 1,081 adults from 3 integrated health systems in Detroit, Michigan; Marshfield, Wisconsin; and Kaiser-Permanente Northern California participated in a field trial. A quota design ensured a diverse sample by sex, age, and race/ethnicity. Each participant was asked to complete 2 recalls and was randomly assigned to 1 of 4 protocols differing by type of recall and administration order. For energy, the mean intakes were 2,425 versus 2,374 kcal for men and 1,876 versus 1,906 kcal for women by AMPM and ASA24, respectively. Of 20 nutrients/food groups analyzed and controlling for false discovery rate, 87% were judged equivalent at the 20% bound. ASA24 was preferred over AMPM by 70% of the respondents. Attrition was lower in the ASA24/AMPM study group than in the AMPM/ASA24 group, and it was lower in the ASA24/ASA24 group than in the AMPM/AMPM group. ASA24 offers the potential to collect high-quality dietary intake information at low cost with less attrition.