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.

Early newborn ritual foods correlate with delayed breastfeeding initiation in rural Bangladesh.

BACKGROUND: Early and exclusive breastfeeding may improve neonatal survival in low resource settings, but suboptimal breastfeeding still exists in areas with high infant mortality. Prelacteal feeding, the practice of giving a non-breastmilk food as a neonate's first food, has been associated with suboptimal breastfeeding practices. We examined the association of feeding a non-breastmilk food in the first three days of life (early neonatal food, or ENF) with time from birth to initiation of breastfeeding among 25,286 Bangladeshi mother-neonate pairs, in a secondary analysis of a randomized controlled trial in northwestern rural Bangladesh conducted from 2001-2007. METHODS: Trained interviewers assessed the demographic characteristics during pregnancy. At three months postpartum, the interviewers visited participants again and retrospectively assessed demographic and breastfeeding characteristics surrounding the birth. We assessed the relationship between ENF and time to initiation of breastfeeding in hours in both unadjusted and adjusted linear regression analyses. We also calculated reverse cumulative distribution curves for time to initiation of breastfeeding and analyses were stratified by an infant's ability to breastfeed normally at birth. RESULTS: The mean ± SD time from birth to initiation of breastfeeding was 30.6 ± 27.9 hours. Only 2,535 (10.0%) of women reported initiating breastfeeding in the first hour after birth and 10,207 (40.4%) reported initiating breastfeeding in the first 12 hours after birth. In adjusted linear regression analyses, feeding ENF was associated with a significant increase in time, in hours, to breastfeeding initiation both among children not able to breastfeed at birth (37.4; 95% CI 33.3, 41.5) and among children able to breastfeed at birth (13.3; 95% CI 12.7, 14.0). CONCLUSIONS: Feeding ENF was strongly associated with delayed initiation of breastfeeding, even after adjusting for other related factors and stratifying on the neonate's ability to suckle normally after birth. More research is needed to understand the impact of these findings on optimal breastfeeding in this setting. It is possible that ENF feeding and the ability to breastfeed immediately after birth are interrelated in their respective associations to suboptimal breastfeeding initiation. This study in a large population representative of other populations in rural South Asia, demonstrates significantly longer times to breastfeeding initiation than previously appreciated, with a possible important role of ENF feeding. TRIAL REGISTRATION: The randomized controlled trial on which this analysis is based, "Impact of Maternal Vitamin A or Beta-Carotene Supplementation on Maternal and Infant Mortality in Bangladesh", was registered with ClinicalTrials.gov as trial number ID GHS-A-00-03-00019-00 and identifier NCT00198822. The identifier was first received September 12, 2005 (retrospectively registered). The first participant was enrolled in August 2001.

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.

Vitamin E, vitamin A, and zinc status are not related to serologic response to influenza vaccine in older adults: an observational prospective cohort study.

It has been hypothesized that micronutrient levels play a role in the immune response to vaccination; however, population-level research on the association between micronutrient levels and immune response to influenza vaccination is needed. In this study, we hypothesized that decreasing levels of nutrients would be associated with decreased hemagglutination inhibition (HAI) responses to influenza vaccination. Therefore, the purpose of this study was to determine whether serum vitamin A, vitamin E, or zinc levels are associated with influenza vaccine response determined by HAI titer in adults 65 years or older. Participants in this study included 205 community-dwelling adults 65 years or older who resided in Marshfield, WI, USA, from fall 2008 through spring 2009. Participants received trivalent influenza vaccine and donated blood samples before and 21 to 28 days after vaccination. Prevaccination levels of serum retinol, α-tocopherol, and zinc as well as prevaccination and postvaccination HAI titer levels were measured. No participants were vitamin A or vitamin E deficient; 20% had low serum zinc levels (<70 µg/dL). Continuous variables and categorical quartiles coding for vitamin A, vitamin E, and zinc levels were not related to prevaccination or postvaccination seroprotection or seroconversion for any of the vaccine components (influenza A [H1N1], A [H3N2], or B), after adjusting for age, sex, body mass index, and prevaccination HAI geometric mean titer. In conclusion, our study population showed no association between variations in levels of serum vitamin A, vitamin E, or zinc and influenza vaccine response as measured by HAI in adults older than 65 years. Thus, associations between micronutrients and other measures of vaccine response, such as cell-mediated immune parameters, should also be explored.

Early neonatal feeding is common and associated with subsequent breastfeeding behavior in rural Bangladesh.

Exclusive breastfeeding of newborns, a practice recommended by WHO, is hindered in many countries by practices such as prelacteal feeding (feeding other foods before breast milk is fed to infants). This paper describes maternal and infant characteristics and trends over time associated with early neonatal feeding (ENF) in Bangladesh. The analysis used data from 24,992 participants in a randomized controlled trial supplementing vitamin A and ß-carotene to women in northwestern rural Bangladesh. A majority of newborns (89.2%) were fed substances other than breast milk in the first 3 d of life. Early neonatal feeding practices were found to be significantly associated with lower maternal education, higher gravidity, lower socioeconomic status, and younger maternal age. A perceived inability to suckle normally after birth was closely related to the risk of an infant being fed a food other than breast milk in the first 3 d of life [OR = 0.09 (95% CI: 0.08, 0.11)]. Only 18.8% of newborns fed an early neonatal food were exclusively breastfed between 3 d and 3 mo postpartum compared with 70.6% of those not fed an early neonatal food during this period (P < 0.05). Early neonatal feeding practices should be addressed when scaling-up exclusive breastfeeding in South Asia. Maternal education, antenatal care, and support during labor and delivery may help reduce ENF and promote exclusive breastfeeding.

Vitamin D is not associated with serologic response to influenza vaccine in adults over 50 years old.

Vitamin D deficiency has been implicated in risk of respiratory illness. We determined whether serum vitamin D levels are related to influenza vaccine response measured by hemagglutination antibody inhibition (HAI) titer in adults aged ≥50 years old. The study was a prospective cohort study conducted over two influenza seasons (fall 2008-spring 2009 and fall 2009-spring 2010) in Marshfield, WI and Nashville, TN including 1103 community-dwelling adult volunteers ≥50 years of age. Pre-vaccination levels of serum vitamin D and HAI titer levels pre- and 21-28 days post-influenza vaccination were measured. Seroprotection was defined as HAI ≥40; seroconversion was defined as ≥4-fold rise in HAI titers from pre- to post-vaccination. More than 25% of participants were vitamin D deficient (<25ng/mL). Vitamin D measured as a continuous variable was not related to pre- or post-vaccination seroprotection or seroconversion for any vaccine strain in any year. Vitamin D deficiency was associated with a greater frequency of post-vaccination seroprotection for seasonal H1N1 in the first year of the study, but was not related to seroprotection or seroconversion for any other strain in either year. No consistent association was found between vitamin D levels or vitamin D deficiency and serologic response to influenza vaccination in older adults. Cell-mediated immune parameters should also be explored in order to further investigate possible relationships between micronutrient status and influenza vaccine response.

Vitamin D and influenza.

Vitamin D has become increasingly recognized in the literature for its extra-skeletal roles, including an effect on inflammation and the immune response to infection. Our goal was to describe the role of vitamin D in the immune response and implications for the risk of influenza infection in humans. In this review, we first consider literature that provides molecular and genetic support to the idea that vitamin D is related to the adaptive and innate immune responses to influenza infection in vitro and in animal models. We then discuss observational studies and randomized controlled trials of vitamin D supplementation in humans. Finally, we consider some of the knowledge gaps surrounding vitamin D and immune response that must be filled.