Danielle M Nash, Dr. Jason A Gilliland, Dr. Susan E Evers, Dr. Piotr Wilk & Dr. M Karen Campbell. JNEB Journal Club November 3, 2014

Transcription

1 Danielle M Nash, Dr. Jason A Gilliland, Dr. Susan E Evers, Dr. Piotr Wilk & Dr. M Karen Campbell JNEB Journal Club November 3, 2014

2 Presentation Overview Background Objective/ Rationale Methods Prenatal Health Project & Linkage to Geographic Database Variables Outcome: Modified Diet Quality Index for Pregnancy (DQI-P m ) Analysis Results Descriptive Analyses Univariate Linear Regression Multivariate Linear Regression Discussion Strengths & Limitations Implications for Research & Practice

3 Background

4 Pregnant Women are not Meeting Food & Nutrition Guidelines Previous studies in the U.S. have shown that overall diet quality for pregnant women is low Dietary folate and iron intake has also been shown to be low among pregnant women (NHANES III; ): The mean intake of folate was 288 µg/day compared to recommended value of 520 µg/day The mean intake of iron was 5.34 mg/day compared to recommended value of 22 mg/day

5 Our Prior Findings on Diet in Pregnancy 1. Pregnant women did not meet food guide recommendations for the following: Fruits/vegetables: 65% did not meet recommendations Grains: 90% did not meet recommendations 2. Pregnant women did not meeting nutrient (RDA) recommendations for the following: Iron: 31% did not meet RDA Zinc: 18% did not meet RDA Folate: 16% did not meet RDA

6 Individual-level Predictors of Diet Quality in Pregnancy Strong Evidence Age Parity Education Physical activity Smoking status Social support Mixed Evidence Ethnicity Marital status Planned pregnancy Occupation status Income Nausea during pregnancy Mental health (anxiety, depression, stress) Food environment?

7 Food Environment (Access to Food) in the General Population Erie County, NY: Number of restaurants within a five minute walk of participants homes was positively related to BMI A greater distance from an unhealthy food source (e.g., convenience store), relative to a healthy one was negatively related to BMI Impoverished neighbourhoods generally have poorer access to healthy food sources (especially rural areas)

8 Food Environment and Diet Quality in Pregnancy

9 Rationale for our Study Pregnant women are not consuming adequate nutrition during pregnancy There is mixed evidence on the factors that contribute to poor diet quality during pregnancy Sparsity of studies assessing the association between the food environment and diet quality during pregnancy Lack of Canadian studies

10 Objective To advance the knowledge on determinants of diet quality in pregnancy by focusing on both personal characteristics and the food environment.

11 Conceptual Model Pregnancy Symptoms Severity of Nausea Fatigue* Baseline Variables Age Ethnicity Marital status Planned pregnancy Presence of children Parity Occupational Status Financial Limitations Low income Welfare dependence* Financial strain Mental Health Anxiety Depression Stress Social Support Health Behaviours Physical activity Smoking Pregnant Women s Diet Quality Education *Variables were not measured for the study Access to Healthy Foods Distance to travel by car*, bus* or foot to reach food sources Density of supermarkets, fast food restaurants & convenience stores Access to transportation (car)* Geographical residence

12 Methods

13 Prenatal Health Project (PHP) Cohort A prospective cohort study of pregnant women 2357 participants recruited from 7 ultrasound clinics across London, Ontario between Jan 2002 Dec 2005 Eligible if: weeks of gestation, singleton pregnancy, living in London or Middlesex County, able to understand and sign the consent form, and 16 years of age or older Ineligible if: any known fetal anomalies Telephone interview booked for the following week to collect data; participants provided with a copy of the FFQ

14 PHP Data Collection Participants contacted approximately one week after recruitment to complete the pre-arranged telephone interview The interview collected data regarding: demographics, previous pregnancies, health behaviours, social support, mental health, and usual diet using a Food Frequency Questionnaire (FFQ) FFQ had been validated in a pilot in the local population and assessed to be a validated tool to estimate usual food consumption of the participants over the past month

15 Linkage to Geographic Database Geographic Information System (GIS) used to link PHP participants to a geographic database by home address to determine food environment variables used in the analysis Food retailers listed in a comprehensive food inventory database for the City of London and surrounding Middlesex County

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17 Outcome: Modified Diet Quality Index for Pregnancy (DQI-P m ) Component Canadian Recommendation Max Score Max % Score Grains 7 servings/day 10 10/70*100% Fruits/Vegetables 8 servings/day 20 20/70*100% Dietary Folate Equivalents 520 µg/day (EAR) 10 10/70*100% Calcium 1000 mg/day ages 19 (AI) 1300 mg/day ages < 19 (AI) 10 10/70*100% Iron 22 mg/day (EAR) 10 10/70*100% % Energy from Total Fat 20-35% 10 10/70*100% DQI-P m All the above %

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20 Food Environment Variables Proximity distance to nearest food source Density/ presence number of food sources within 500 m and 1000 m Food sources for above included: Convenience store Fast food restaurant Grocery store Grocery store or local market with fresh food Rural/ urban residence

21 Analysis Descriptive statistics for all variables (predictors and diet quality components) Univariable and multivariable linear regression analyses were conducted in SAS 9.1 Variables in the univariable analyses with a P < 0.2 were entered into the multivariate model Modeling was conducted as a stepwise procedure variables were entered in blocks according to conceptual model with automated backwards elimination at each step Third model was trimmed to create parsimonious model with only variables significant at P < 0.05

22 Results

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25 DQI-P m Components: Descriptive Statistics & Sufficiency of Intake Variable Mean Median SD Missing # with Sufficient Intake: food only (%) # with Sufficient Intake: food + supplements (%) DQI-P m (%) (2.47) 107(4.85) Grains (servings/day) Fruit/Vegetables (servings/day) (11.47) N/A (37.85) N/A Fat Energy (%) (92.33) N/A Calcium (mg/day) (57.80) N/A* Iron (mg/day) (4.73) 1575(69.02) Dietary Folate Equivalents (µg/day) (33.22) 1913(83.83)

26 Univariable Linear Regression (Predictors of QQI-P m ) Personal Predictor Variables Beta (p-value) Age 0.27(<.0001) Residency in Canada Lifetime (born in Canada) > 5 years 5 years -0.52(0.6489) 3.56(0.0153) Marital Status Married Common-law Single/separated/divorced Parity 0 1 Planned Pregnancy No Yes Education Level Completed university/college Other Work Force Participation Employed full-time Employed part-time Not employed voluntarily Household Income < 30k 30k-79,999 80k -4.73(<.0001) -5.16(<.0001) 2.16(0.0011) -2.49(0.0008) -3.61(<.0001) -1.22(0.2175) -0.37(0.7420) -4.45(<.0001) -2.21(0.0021)

27 Univariable Linear Regression Continued Personal Predictor Variables Beta (p-value) Difficulty Affording Food Very/somewhat difficult Not very difficult Not at all difficult -3.42(0.0234) -1.48(0.0504) Nausea Severity No diet change/doctor visit Changed diet/no doctor visit Visited doctor 1.10(0.1294) 0.91(0.3434) Exercise Under-exercisers Optimal Over-exercisers -3.88(<.0001) -1.19(0.3131) Smoking during Pregnancy No Yes -5.79(<.0001) Depression (CES-D) No Yes -2.90(0.0007) Anxiety (STAI) (<.0001) Social Support from Partner (0.0002) Social Support from Family (0.0001) Social Support from Friends (0.0003)

28 Univariable Linear Regression - continued (Geographic Variables) Geographic Predictor Variables Beta (p-value) Geographical Residence Rural Urban (0.9740) Presence of Convenience Stores within 500 m (0.0059) Presence of Fast Food Restaurants within 500 m (0.0018) Presence of Grocery Stores or Local Markets within 500 m (0.1570) Presence of Convenience Stores within 1000 m (0.0317) Presence of Fast Food Restaurants within 1000 m (0.2217) Presence of Grocery Stores or Local Markets within 1000 m (0.4196) Distance to Nearest Convenience Store (Km) (0.8838) Distance to Nearest Fast Food Restaurant (Km) (0.8473) Distance to Nearest Grocery Store (Km) (0.9793) Distance to Nearest Grocery Store or Local Market (Km) 0.46 (0.1961)

29 Predictor Variables Model 1 N=2252 R 2 =0.024 Beta (p-value) Model 2 N=2134 R 2 =0.026 Model 3 N=2086 R 2 =0.048 Parsimonious N=2209 R 2 =0.046 Residency in Canada Marital Status Lifetime (born in Canada) > 5 years 5 years Married Common-law Single/separated/divorced Parity 0 1 Education Level Completed university/college Other Nausea Severity No diet change/doctor visit Changed diet/no doctor visit Visited doctor Exercise Under-exercisers Optimal Over-exercisers -0.88(0.4377) 2.98(0.0420) -4.09(<.0001) -4.29(0.0009) 1.56(0.0237) -0.80(0.4960) 3.71(0.0194) -2.98(0.0034) -2.26(0.1259) 2.17(0.0012) -1.62(0.0542) -0.99(0.4046) 3.79(0.0160) -2.54(0.0142) -1.27(0.3833) 2.61(0.0001) -1.11(0.1844) 1.19(0.1072) 1.40(0.1582) -3.43(0.0005) -0.34(0.7803) -0.89(0.4355) 3.31(0.0239) -3.07(0.0016) -2.42(0.0666) 2.57(0.0001) (0.0001) -0.79(0.5042) Smoking during Pregnancy No Yes -2.22(0.0780) -3.28(0.0060) Anxiety (STAI) (Continuous) -0.84(0.0249) -0.95(0.0072) Social Support from Family (Continuous) 0.54(0.1492) 0.73(0.0357) Social Support from Friends (Continuous) 0.59(0.1090) Presence of Fast Food Restaurants within 500 m (0.0847)

30 Main Findings High diet quality of 79.7% as measured by DQI-P m Most important determinants of a low diet quality were: born in Canada, common-law, nulliparity, sub-optimal exercise, smoking during pregnancy, high anxiety levels, and low social support from family Food environment: variables were significant in univariable analyses but not in multivariable analyses Fast food restaurants within 500 m: approaching significance in the multivariable analysis

31 Discussion

32 Discussion High diet quality observed likely due to highly educated cohort (cohort similar to London, Ontario birthing population) High diet quality of married women compared to common-law (previous studies show similar to divorced or single women) Recent immigrants to Canada have better diet quality which is consistent with previous research Number of previous pregnancies positively associated with diet quality which is opposite of previous research

33 Discussion Cont. Previous research showed that proximity to grocery stores, supermarkets and convenience stores was significantly associated with diet quality in pregnancy (did not assess fast food restaurants) In our study, we found that number of fast food restaurants and convenience stores within participants homes was significantly associated with diet quality (but this was not sustained in multivariable analyses)

34 Strengths & Limitations Strengths Cohort of women from PHP large prospective study FFQ accurate to rank individuals according to usual consumption; validated GIS specific Limitations Cohort of women from PHP convenience sample FFQ inaccurate nutrient values GIS inherent errors Small R 2 likely missing important determinants of diet quality in model

35 Implications for Research & Practice Novel research, which incorporates sociodemographic, pregnancy-related and geographic variables to determine predictors of diet quality Pregnant women are more likely to have lower diet quality if they were born in Canada, common-law, nulliparous, less physically active, smokers, more anxious, and perceiving less social support from their family

36 Implications for Research & Practice The low R 2 of our models suggests the need for future research to explore other predictors of diet quality in pregnancy Future research is also needed to determine interventions to successfully increase diet quality Considering the results of this study, interventions targeting the food environment likely will not have a significant impact on diet quality

37 Acknowledgments Funding: CIHR & OGSST Thank you to the JNEB for publishing our study!