Validity of self-reported mammography uptake in the Belgian health interview survey: selection and reporting bias.

BACKGROUND: The validity of self-reported mammography uptake is often questioned. We assessed the related selection and reporting biases among women aged 50-69 years in the Belgian Health Interview Survey (BHIS) using reimbursement data for mammography stemming from the Belgian Compulsory Health Insurance organizations (BCHI). METHODS: Individual BHIS 2013 data (n = 1040) were linked to BCHI data 2010-13 (BHIS-BCHI sample). Being reimbursed for mammography within the last 2-years was used as the gold standard. Selection bias was assessed by comparing BHIS estimates reimbursement rates in BHIS-BCHI with similar estimates from the Echantillon Permanent/Permanente Steekproef (EPS), a random sample of BCHI data, while reporting bias was investigated by comparing self-reported versus reimbursement information in the BHIS-BCHI. Reporting bias was further explored through measures of agreement and logistic regression. RESULTS: Mammography uptake rates based on self-reported information and reimbursement from the BHIS-BCHI were 75.5% and 69.8%, respectively. In the EPS, it was 64.1%. The validity is significantly affected by both selection bias {relative size = 8.93% [95% confidence interval (CI): 3.21-14.64]} and reporting bias [relative size = 8.22% (95% CI: 0.76-15.68)]. Sensitivity was excellent (93.7%), while the specificity was fair (66.4%). The agreement was moderate (kappa = 0.63). Women born in non-EU countries (OR = 2.81, 95% CI: 1.54-5.13), with high household income (OR = 1.27, 95% CI: 1.02-1.60) and those reporting poor perceived health (OR = 1.41, 95% CI: 1.14-1.73) were more likely to inaccurately report their mammography uptake. CONCLUSIONS: The validity of self-reported mammography uptake in women aged 50-69 years is affected by both selection and reporting bias. Both administrative and survey data are complementary when assessing mammography uptake.

The Belgian health examination survey: objectives, design and methods.

BACKGROUND: In 2018 the first Belgian Health Examination Survey (BELHES) took place. The target group included all Belgian residents aged 18 years and older. The BELHES was organized as a second stage of the sixth Belgian Health Interview Survey (BHIS). This paper describes the study design, recruitment method and the methodological choices that were made in the BELHES. METHODS: After a pilot period during the first quarter of the BHIS fieldwork, eligible BHIS participants were invited to participate in the BELHES until a predefined number (n = 1100) was reached. To obtain the required sample size, 4918 eligible BHIS participants had to be contacted. Data were collected at the participant's home by trained nurses. The data collection included: 1) a short set of questions through a face-to-face interview, 2) a clinical examination consisting of the measurement of height, weight, waist circumference, blood pressure and for people aged 50 years and older handgrip strength and 3) a collection of blood and urine samples. The BELHES followed as much as possible the guidelines provided in the framework of the European Health Examination Survey (EHES) initiative. Finally 1184 individuals participated in the BELHES, resulting in a participation rate of 24.1%. Results for all the core BELHES measurements were obtained for more than 90% of the participants. CONCLUSION: It is feasible to organize a health examination survey as a second stage of the BHIS. The first successfully organized BELHES provides useful information to support Belgian health decision-makers and health professionals. As the BELHES followed EHES recommendations to a large extent, the results can be compared with those from similar surveys in other EU (European Union) member states.

Is the European Health Interview Survey online yet? Response and net sample composition of a web-based data collection.

BACKGROUND: The European Health Interview Survey (EHIS) provides cross-national data on health status, health care and health determinants. So far, 10 of the 30 member states (MS) opted for web-based questionnaires within mixed-mode designs but none used it as the sole mode. In the context of future EHIS, the response rate and net sample composition of a web-only approach was tested. METHODS: A Belgian study with a target sample size of 1000 (age: 16-85) was organized using the EHIS wave 3 model questionnaire. The sample was selected according to a multistage, clustered sampling procedure with geographical stratification. Field substitution was applied; non-participating households were replaced by similar households regarding statistical sector, sex and age. There was one reminder letter and a €10 conditional incentive. RESULTS: Considering all substitutions, a 16% response rate was obtained after sending one reminder. Elderly, Brussels Capital inhabitants, people living without a partner and those with a non-Belgian nationality were less responding. By design, there were no differences between the initial and final net sample regarding substitution characteristics. Nevertheless, people living without a partner, non-Belgians and lower educated people remain underrepresented. CONCLUSION: There was a low response rate, particularly for some population groups. The response rate was lower than those of MS using mixed-mode designs including web, especially these comprising interviewer-based approaches. Despite the long and complex questionnaire, there was a low break off rate. So far, web-only data collection is not an acceptable strategy for population-based health surveys but efforts to increase the response should be further explored.

Mixing mixed-mode designs in a national health interview survey: a pilot study to assess the impact on the self-administered questionnaire non-response.

BACKGROUND: Many population health surveys consist of a mixed-mode design that includes a face-to-face (F2F) interview followed by a paper-and-pencil (P&P) self-administered questionnaire (SAQ) for the sensitive topics. In order to alleviate the burden of a supplementary P&P questioning after the interview, a mixed-mode SAQ design including a web and P&P option was tested for the Belgian health interview survey. METHODS: A pilot study (n = 266, age 15+) was organized using a mixed-mode SAQ design following the F2F interview. Respondents were invited to complete a web SAQ either immediately after the interview or at a later time. The P&P option was offered in case respondents refused or had previously declared having no computer access, no internet connection or no recent usage of computers. The unit response rate for the web SAQ and the overall unit response rate for the SAQ independent of the mode were evaluated. A logistic regression analysis was conducted to explore the association of socio-demographic characteristics and interviewer effects with the completed SAQ mode. Furthermore, a logistic regression analysis assessed the differential user-friendliness of the SAQ modes. Finally, a logistic multilevel model was used to evaluate the item non-response in the two SAQ modes while controlling for respondents' characteristics. RESULTS: Of the eligible F2F respondents in this study, 76% (107/140) agreed to complete the web SAQ. Yet among those, only 78.5% (84/107) actually did. At the end, the overall (web and P&P) SAQ unit response rate reached 73.5%. In this study older people were less likely to complete the web SAQ. Indications for an interviewer effect were observed as regard the number of web respondents, P&P respondents and respondents who refused to complete the SAQ. The web SAQ scored better in terms of user-friendliness and presented higher item response than the P&P SAQ. CONCLUSIONS: The web SAQ performed better regarding user-friendliness and item response than the P&P SAQ but the overall SAQ unit response rate was low. Therefore, future research is recommended to further assess which type of SAQ design implemented after a F2F interview is the most beneficial to obtain high unit and item response rates.

A Novel Approach to Optimize Vitamin D Intake in Belgium through Fortification Based on Representative Food Consumption Data.

BACKGROUND: Food fortification is a promising means to improve vitamin D intake of a population. Careful selection of food vehicles is needed to ensure that nearly all individuals within the population benefit from the fortification program. OBJECTIVES: The aim of the study was to develop and apply a model that simultaneously selects the optimal combination of food vehicles and defines the optimal fortification level that adequately increases vitamin D intake in the population without compromising safety. METHODS: Food consumption data from the Belgian Food Consumption Survey 2014 (n = 3200; age 3-64 y) were used. The optimization model included 63 combinations of 6 potential vehicles for food fortification, namely "bread," "breakfast cereals," "fats and oils," "fruit juices," "milk and milk beverages," and "yogurt and cream cheese." The optimization procedure was designed to minimize inadequate or excessive vitamin D intake in each of the food combinations. This allowed the relative ranking of the different combinations according to their fortification utility. The estimated average requirement and upper intake level were used as thresholds. An age-specific and population-based approach enabled the sensitivity of the population subgroups to adverse health effects to be taken into account. Feasibility, technical aspects, and healthiness of the food vehicles were used to select the optimal combination. RESULTS: Multiple combinations of food vehicles significantly reduced the prevalence of inadequate vitamin D intake within the Belgian population (from 92-96% to <2%). Taking other aforementioned criteria into account, the fortification of "milk and milk beverages" and "bread" with 6.9 µg vitamin D/100 kcal was proposed as an optimal fortification scenario. CONCLUSIONS: The optimization model allows identification of an effective fortification scenario to improve vitamin D intake within the Belgian population based on acceptable risks of inadequate and excessive intake. The model can be extended to other micronutrients and other populations.

Habitual food consumption of the Belgian population in 2014-2015 and adherence to food-based dietary guidelines.

BACKGROUND: Between 2014 and 2015 a second National Food Consumption Survey was conducted in Belgium in order to evaluate the habitual food consumption in the general Belgian population and to compare it with food-based dietary guidelines (FBDG) and results of the 2004 Food Consumption Survey. METHODS: A representative sample of the Belgian population was randomly selected from the National Population Register following a multistage stratified sampling procedure. Information on dietary intake was collected from 3146 subjects between 3 and 64 year old through two non-consecutive 24-hour dietary recalls using GloboDiet®. In addition, a self-administered food frequency questionnaire was completed. The distribution of habitual food consumptions and proportion of persons who did not meet the recommendations were estimated with SPADE. RESULTS: For most of food groups analysed, the habitual consumption did not comply with FBDG. The consumption of nutrient-poor and energy-dense foods (e.g. alcohol, soft drinks and snacks) was excessive (35% of total energy intake), while the consumption of most other food groups was below the minimum recommended. A large majority of the population had an inadequate consumption of dairy products (98%), vegetables (95%), fruit (91%), potatoes, rice and pasta (88%) bread and cereals (83%) and water and sugar-free drinks (73%). Males had higher consumption of most food groups than females, thereby complying more often with FBDG. For all food groups, except dairy products and fruit, the consumption increased with age. The proportion of individuals meeting FBDG was the highest among young children (3-5 years) and the worst among adolescents aged 14-17 years old. Habitual consumption remained stable between 2004 and 2014 in the population aged 15-64 years old for all food groups except for increased consumption of water and sugar-free drinks (1180 to 1289 g/d) and decreased consumption of spreadable and cooking fat (27 to 19 g/d), red meat (34 to 25 g/d) and bread and cereals (173 to 142 g/d). CONCLUSIONS: The habitual food consumption of the Belgian population (3-64 years) in 2014-2015 deviates largely from FBDG, particularly among adolescents aged between 14 and 17 years old. Few improvements were observed between 2004 and 2014 in the population between 15 and 64 years old. Further efforts are therefore necessary to improve dietary habits in Belgium, in order to prevent and reduce diet-related diseases.

Determinants of unit nonresponse in multi-mode data collection: A multilevel analysis.

BACKGROUND: Multi-mode data collection is widely used in surveys. Since several modes of data collection are successively applied in such design (e.g. self-administered questionnaire after face-to-face interview), partial nonresponse occurs if participants fail to complete all stages of the data collection. Although such nonresponse might seriously impact estimates, it remains currently unexplored. This study investigates the determinants of nonresponse to a self-administered questionnaire after having participated in a face-to-face interview. METHODS: Data from the Belgian Health Interview Survey 2013 were used to identify determinants of nonresponse to self-administered questionnaire (n = 1,464) among those who had completed the face-to-face interview (n = 8,133). The association between partial nonresponse and potential determinants was explored through multilevel logistic regression models, encompassing a random interviewer effect. RESULTS: Significant interviewer effects were found. Almost half (46.6%) of the variability in nonresponse was attributable to the interviewers, even in the analyses controlling for the area as potential confounder. Partial nonresponse was higher among youngsters, non-Belgian participants, people with a lower educational levels and those belonging to a lower income household, residents of Brussels and Wallonia, and people with poor perceived health. Higher odds of nonresponse were found for interviews done in the last quarters of the survey-year. Regarding interviewer characteristics, only the total number of interviews carried out throughout the survey was significantly associated with nonresponse to the self-administered questionnaire. CONCLUSIONS: The results indicate that interviewers play a crucial role in nonresponse to the self-administered questionnaire. Participant characteristics, interview circumstances and interviewer characteristics only partly explain the interviewer variability. Future research should examine further interviewer characteristics that impact nonresponse. The current study emphasises the importance of training and motivating interviewers to reduce nonresponse in multi-mode data collection.

Do sociodemographic characteristics associated with the use of CAM differ by chronic disease?

BACKGROUND: Complementary and alternative medicine (CAM) is oftenused to alleviate the discomfort, disability and pain involved in many chronic diseases. Besides this, females, middle-aged and higher educated people are also known to use CAM the most. This study explores whether the sociodemographic characteristics associated with CAM use differ by type of disease. METHODS: The following data were taken from the Belgian Health Interview Survey 2013 for the individuals aged 15+ years (n = 8942): sociodemographic characteristics, past 12-month diseases (using a list) and contact with a homeopath, chiropractor, acupuncturist and/or osteopath (CAM-therapists) in the past year. The association between CAM use and disease, controlled for gender, age, education and conventional medicine use, was assessed through logistic regressions. When interactions with the sociodemographic characteristics were found, stratified regressions were conducted. RESULTS: People with musculoskeletal diseases [odds ratio (OR) = 2.6], allergy (OR = 1.4) and severe headache (OR = 1.5) had higher odds of using CAM in the past year with statistical significance. For musculoskeletal diseases, the odds of using CAM was higher, with statistical significance, for every sociodemographic subclass. For allergy, CAM use was higher among men, people aged 45+ years and lower educated people, while for severe headache CAM use was higher among women, people aged 45+ years and higher educated people, all with statistical significance. CONCLUSIONS: Sociodemographic characteristics associated with CAM use differ by diseases. The role of CAM in disease management cannot be ignored. Making physicians aware for which disease CAM is used and by whom, may facilitate disease management.

Contribution of chronic diseases to educational disparity in disability in France: results from the cross-sectional "disability-health" survey.

BACKGROUND: This study aimed 1) to assess whether the contribution of chronic conditions to disability varies according to the educational attainment, 2) to disentangle the contributions of the prevalence and of the disabling impact of chronic conditions to educational disparities. METHODS: Data of the 2008-09 Disability Health Survey were examined (N = 23,348). The disability indicator was the Global Activity Limitation Indicator (GALI). The attribution method based on an additive hazard model was used to estimate educational differences in disabling impacts and in the contributions of diseases to disability. Counterfactual analyses were used to disentangle the contribution of differences in disease prevalence vs. disabling impact. RESULTS: In men, the main contributors to educational difference in disability prevalence were arthritis (contribution to disability prevalence: 5.7% (95% CI 5.4-6.0) for low-educated vs. 3.3% (3.0-3.9) for high-educated men), spine disorders (back/neck pain, deformity) (3.8% (3.6-4.0) vs. 1.9% (1.8-2.1)), chronic obstructive pulmonary diseases (2.4% (2.3-2.6) vs. 0.6% (0.5-0.7)) and ischemic heart /peripheral artery diseases (4.1% (3.9-4.3) vs. 2.4% (2.2-3.0)). In women, arthritis (9.5% (9.1-9.9) vs. 4.5%, (4.1-5.2)), spine disorders (4.5% (4.3-4.7) vs. 2.1% 1.9-2.3) and psychiatric diseases (3.1% (3.0-3.3) vs. 1.1% (1.0-1.3)) contributed most to education gap in disability. The educational differences were equally explained by differences in the disease prevalence and in their disabling impact. CONCLUSIONS: Public health policies aiming to reduce existing socioeconomic disparities in disability should focus on musculoskeletal, pulmonary, psychiatric and ischemic heart diseases, reducing their prevalence as well as their disabling impact in lower socioeconomic groups.

Contribution of chronic conditions to gender disparities in health expectancies in Belgium, 2001, 2004 and 2008.

Background: We aimed to investigate the contribution of chronic conditions to gender differences in disability-free life expectancy (DFLE) and life expectancy with disability (LED) in Belgium in 2001, 2004 and 2008. Methods: Data on disability and chronic conditions from participants of the 2001, 2004 and 2008 Health Interview Surveys in Belgium were used to estimate disability prevalence by cause using the attribution method. Disability prevalence was applied to life tables to estimate DFLE and LED using the Sullivan method. Decomposition techniques were used to assess the contribution of mortality and disability and further of causes of death and disability to gender disparities in DFLE and LED. Results: Higher LE, DFLE and LED were observed for women compared with men in all years studied. A decrease in the gender gap in LE (2001: 5.9; 2004: 5.6; 2008: 5.3) was observed in our cross-sectional approach followed by a decrease in gender differences in DFLE (2001: 1.9; 2004: 1.3; 2008: 0.5) and increase in LED (2001: 4.0; 2004: 4.4; 2008: 4.8). The higher LED in women was attributed to their lower mortality due to lung/larynx/trachea cancer, ischaemic heart diseases, and external causes (2001 and 2004) and higher disability prevalence due to musculoskeletal conditions (2008). Higher DFLE was observed in women owing to their lower mortality from lung/larynx/trachea cancer, ischaemic heart diseases, digestive cancer and chronic respiratory diseases. Conclusion: To promote healthy ageing of populations, priority should be given to reduce the LED disadvantage in women by targeting non-fatal diseases, such as musculoskeletal conditions.

Consumption of ultra-processed food products and diet quality among children, adolescents and adults in Belgium.

PURPOSE: To assess the dietary share of ultra-processed foods (UPF) among Belgian children, adolescents and adults and associations with diet quality. METHODS: Data from the national Food Consumption Surveys 2004 (N = 3083; ≥ 15 years) and 2014-2015 (N = 3146; 3-64 years) were used. Two 24-h recalls (dietary records for children) were used for data collection. Foods consumed were classified by the level of processing using the NOVA classification. The usual proportion of daily energy intake from UPF was determined using SPADE (Statistical Program to assess dietary exposure). RESULTS: In 2014/2015, 36.4% of foods consumed were ultra-processed, while 42.4% were unprocessed/minimally processed. The usual proportion of daily energy intake from UPF was 33.3% (95% CI 32.1-35.0%) for children, 29.2% (95% CI 27.7-30.3%) for adolescents and 29.6% (95% CI 28.5-30.7%) for adults. There were no differences in UPF consumption between 2004 and 2014/2015. The products contributing most to UPF consumption were processed meat (14.3%), cakes, pies, pastries (8.9%), sweet biscuits (7.7%) and soft drinks (6.7%). The UPF dietary share was significantly lower during consumption days when participants met the WHO salt intake recommendation (≤ 5 g/day) and when saturated fat was ≤ 10% of their total energy intake. The dietary share of unprocessed/minimally processed foods was significantly higher during consumption days when participants met the WHO salt and fruit/vegetable intake (≥ 400 g/day) recommendations and when saturated fat was ≤ 10% of their total energy intake. CONCLUSIONS: The UPF dietary share is substantial and associated with lower diet quality. Internationally recommended policies to limit UPF accessibility and marketing need to be implemented to reduce UPF consumption.

Methods to assess the contribution of diseases to disability using cross-sectional studies: comparison of different versions of the attributable fraction and the attribution method.

BACKGROUND: This study aims to illustrate the differences between approaches proposed for apportioning disability to different diseases in a multicausal situation, i.e. the unadjusted attributable fraction (AF), the adjusted AF, the average AF and the attribution method (AM). This information is useful to better interpret results obtained from cross-sectional data and help policy makers decide on public health strategies. METHODS: Data for 29 931 individuals, representative of the French household population, who participated in the 2008-09 cross-sectional Disability-Health Survey, were included. Disability was defined as any limitation reported with the Global Activity Limitation Indicator. Unadjusted AFs were calculated using Levin's formula. Adjusted AFs were estimated for each disease by calculating predicted probabilities of disability for each individual in the dataset, under the assumption that the individual is unexposed to this specific disease (logistic model). Average AFs are based on the same methodology, but have the additional advantage that the average AFs for different diseases sum to the total AF associated with eliminating all diseases. AM accounts for competing risks and partitions total disability prevalence into additive contributions of different diseases and background disability (additive model). RESULTS: All methods obtained similar results with respect to the estimates of the disease contribution to disability prevalences and to ranking of the diseases, except unadjusted AFs, as the method ignores multimorbidity. Confounders other than diseases, such as age and gender, should be accurately taken into account. CONCLUSIONS: Conceptual differences, strengths and limitations of the different approaches were discussed.

Contribution of chronic conditions to smoking differences in life expectancy with and without disability in Belgium.

Background: Smoking is the leading cause of premature mortality and morbidity. This study aimed at assessing the impact of smoking on life expectancy (LE) and LE with (LED) and without disability (DFLE). We further estimated the contribution of disability and mortality and their causes to differences in LED and DFLE by smoking. Methods: Data on disability, chronic conditions, and smoking from 17 148 participants of the 1997, 2001, 2004 Belgian Health Interview Surveys were used to estimate causes of disability using the attribution method. A 10-year mortality follow-up of survey participants was used. The Sullivan method was applied to estimate LED and DFLE. The contribution of disability and mortality and of causes of disability and death to smoking differences in LED and DFLE was assessed using decomposition methods. Results: Never smokers live longer than daily smokers. DFLE advantage at age 15 of +8.5/+4.3 years (y) in men/women never compared with daily smokers was the result of lower mortality (+6.2y/+3y) and lower disability (2.3y/1.3y). The extra 0.3y/1.6y LED in never smokers was due to lower mortality (+2.6y/+2.9y) and lower disability (-2.3y/-1.3y). Lower mortality from lung/larynx/trachea cancer, chronic respiratory, and ischaemic heart diseases was the main contributor to higher LED and DFLE in never smokers. Lower disability from musculoskeletal conditions in men and chronic respiratory diseases in women increased LED and DFLE in never smokers. Conclusions: Mortality and disability advantage among never smokers contributed to longer DFLE, while mortality advantage contributed to their longer LED.

Measurement agreement of the self-administered questionnaire of the Belgian Health Interview Survey: Paper-and-pencil versus web-based mode.

Before organizing mixed-mode data collection for the self-administered questionnaire of the Belgian Health Interview Survey, measurement effects between the paper-and-pencil and the web-based questionnaire were evaluated. A two-period cross-over study was organized with a sample of 149 employees of two Belgian research institutes (age range 22-62 years, 72% female). Measurement agreement was assessed for a diverse range of health indicators related to general health, mental and psychosocial health, health behaviors and prevention with kappa coefficients and intraclass correlation (ICC). The quality of the data collected by both modes was evaluated by quantifying the missing, 'don't know' and inconsistent values and data entry mistakes. Good to very good agreement was found for all categorical indicators with kappa coefficients superior to 0.60, except for two mental and psychosocial health indicators namely the presence of a sleeping disorder and of a depressive disorder (kappa≥0.50). For the continuous indicators high to acceptable agreement was observed with ICC superior to 0.70. Inconsistent answers and data-entry mistakes were only occurring in the paper-and-pencil mode. There were no less missing values in the web-based mode compared to the paper-and-pencil mode. The study supports the idea that web-based modes provide, in general, equal responses to paper-and-pencil modes. However, health indicators based upon factual and objective items tend to have higher measurement agreement than indicators requiring an assessment of personal subjective feelings. A web-based mode greatly facilitates the data-entry process and guides the completing of a questionnaire. However, item non-response was not positively affected.

Joint Data Analysis in Nutritional Epidemiology: Identification of Observational Studies and Minimal Requirements.

Background: Joint data analysis from multiple nutrition studies may improve the ability to answer complex questions regarding the role of nutritional status and diet in health and disease. Objective: The objective was to identify nutritional observational studies from partners participating in the European Nutritional Phenotype Assessment and Data Sharing Initiative (ENPADASI) Consortium, as well as minimal requirements for joint data analysis. Methods: A predefined template containing information on study design, exposure measurements (dietary intake, alcohol and tobacco consumption, physical activity, sedentary behavior, anthropometric measures, and sociodemographic and health status), main health-related outcomes, and laboratory measurements (traditional and omics biomarkers) was developed and circulated to those European research groups participating in the ENPADASI under the strategic research area of "diet-related chronic diseases." Information about raw data disposition and metadata sharing was requested. A set of minimal requirements was abstracted from the gathered information. Results: Studies (12 cohort, 12 cross-sectional, and 2 case-control) were identified. Two studies recruited children only and the rest recruited adults. All studies included dietary intake data. Twenty studies collected blood samples. Data on traditional biomarkers were available for 20 studies, of which 17 measured lipoproteins, glucose, and insulin and 13 measured inflammatory biomarkers. Metabolomics, proteomics, and genomics or transcriptomics data were available in 5, 3, and 12 studies, respectively. Although the study authors were willing to share metadata, most refused, were hesitant, or had legal or ethical issues related to sharing raw data. Forty-one descriptors of minimal requirements for the study data were identified to facilitate data integration. Conclusions: Combining study data sets will enable sufficiently powered, refined investigations to increase the knowledge and understanding of the relation between food, nutrition, and human health. Furthermore, the minimal requirements for study data may encourage more efficient secondary usage of existing data and provide sufficient information for researchers to draft future multicenter research proposals in nutrition.

Do Current Fortification and Supplementation Programs Assure Adequate Intake of Fat-Soluble Vitamins in Belgian Infants, Toddlers, Pregnant Women, and Lactating Women?

Abstracts: Adequate intakes of fat-soluble vitamins are essential to support the growth and development of the foetus, the neonate, and the young child. By means of an online self-administered frequency questionnaire, this study aimed to evaluate the intake of vitamins A, D, E, and K in Belgian infants (n = 455), toddlers (n = 265), pregnant women (n = 161), and lactating women (n = 165). The contribution of foods, fortified foods, and supplements on the total intake was quantified. 5% of toddlers, 16% of pregnant women, and 35% of lactating women had an inadequate vitamin A intake. Conversely, excessive vitamin A intakes were associated with consumption of liver (products). Furthermore, 22% of infants were at risk for inadequate vitamin D intake due to the lack of prophylaxis, while consumption of highly dosed supplements posed a risk for excessive intakes in 6%-26% of infants. Vitamin D intake in pregnant women and lactating women was inadequate (median of 51%, respectively, 60% of the adequate intake). In all groups, the risk for inadequate intake of vitamin E and K was low. Contribution of fortified foods to vitamin A, D, E, and K intake was minor, except in toddlers. National fortification strategies should be investigated as an alternative or additional strategy to prevent vitamin D and A deficiency. There is a need to revise and set uniform supplement recommendations. Finally, non-users of vitamin D prophylaxis need to be identified for targeted treatment.

The genetic structure of the Belgian population.

BACKGROUND: National and international efforts like the 1000 Genomes Project are leading to increasing insights in the genetic structure of populations worldwide. Variation between different populations necessitates access to population-based genetic reference datasets. These data, which are important not only in clinical settings but also to potentiate future transitions towards a more personalized public health approach, are currently not available for the Belgian population. RESULTS: To obtain a representative genetic dataset of the Belgian population, participants in the 2013 National Health Interview Survey (NHIS) were invited to donate saliva samples for DNA analysis. DNA was isolated and single nucleotide polymorphisms (SNPs) were determined using a genome-wide SNP array of around 300,000 sites, resulting in a high-quality dataset of 189 samples that was used for further analysis. A principal component analysis demonstrated the typical European genetic constitution of the Belgian population, as compared to other continents. Within Europe, the Belgian population could be clearly distinguished from other European populations. Furthermore, obvious signs from recent migration were found, mainly from Southern Europe and Africa, corresponding with migration trends from the past decades. Within Belgium, a small north-west to south-east gradient in genetic variability was noted, with differences between Flanders and Wallonia. CONCLUSIONS: This is the first study on the genetic structure of the Belgian population and its regional variation. The Belgian genetic structure mirrors its geographic location in Europe with regional differences and clear signs of recent migration.

Contribution of chronic conditions to functional limitations using a multinomial outcome: results for the older population in Belgium and Brazil.

BACKGROUND: The global phenomenon of population ageing is creating new challenges in both high and middle income countries, as functional limitations are expected to increase with age. The attribution method has been proposed to identify which conditions contribute most to disability using cross-sectional data. Although the original method was based on binary outcomes, we recently proposed an extension to multinomial responses, since different disability levels are often investigated in surveys. This is the first application of the extended method to evaluate differences in the contribution of chronic conditions to functional limitations in the older population of Brazil and Belgium. METHODS: Representative data from individuals aged ≥65 years who participated in the 2008 or 2013 Health Interview Surveys in Belgium (N = 4521) or in the 2008 National Household Sample Survey in Brazil (N = 28,437) were analysed. Individuals were classified as without, moderate or severe functional limitations, based on three activities of daily living: eating, showering, and toileting. Six chronic conditions common to the surveys - diabetes, heart diseases, musculoskeletal conditions, depression, chronic respiratory diseases, and cancer - were included in the analysis. Separate multinomial additive hazards models by gender for each country were fitted. RESULTS: The prevalence of moderate functional limitations was larger in men in Brazil (8.4%) compared to Belgium (6.0%) and similar in women (approximately 12.0%). Conversely, the severe prevalence in men was similar in the two countries (around 8.0%) and higher in women from Belgium (16.6%) than from Brazil (9.1%). Musculoskeletal conditions were the main contributors to the prevalence of functional limitations in men and women in Belgium but only in men and women with moderate functional limitations in Brazil. Depression and heart diseases contributed most to the severe prevalence of functional limitations in men and women in Brazil, respectively. CONCLUSIONS: Our findings provide a better understanding of differences in the prevalence of different levels of functional limitations in Brazil and Belgium. These differences can be related to differences in socioeconomic conditions, health care access and quality, disease diagnosis, stage of epidemiology transition, life expectancy, and the prevalence of lifestyle risk factors in the two countries.

The added value of food frequency questionnaire (FFQ) information to estimate the usual food intake based on repeated 24-hour recalls.

BACKGROUND: Statistical methods to model the usual dietary intake of foods in a population generally ignore the additional information on the never-consumers. The objective of this study is to determine the added value of Food Frequency Questionnaire (FFQ) data allowing distinguishing the never-consumers from the non-consumers while modeling the usual intake distribution. METHODS: Three food items with a different proportion of never-consumers were selected from the database of the Belgian food consumption survey of 2004 (N = 3200). The usual intake distribution for these food items was modeled with the Statistical Program for Analysis of Dietary Exposure (SPADE) and modeling parameters were extracted. These parameters were used to simulate (a) a new database with two 24-h recalls per respondent and (b) a "true" usual intake distribution. The usual intake distribution from the new database was obtained by modeling the 24-h recalls with SPADE, once without and once with the inclusion of the FFQ data on the never-consumers. Ratios were calculated for the different percentiles of the usual intake distribution: the modeled usual intake (g/day) (for both SPADE with and without the inclusion of FFQ data on never-consumers) was divided by the corresponding percentile of the simulated "true" usual intake (g/day). The closer the ratio is to one, the better the model fits the data. RESULTS: Inclusion of the FFQ information to identify the never-consumers did not improve the estimation of the higher percentiles of the usual intake distribution. However, taking into account this FFQ information improved the estimation of the lower percentiles of the usual intake distribution even when the proportion of never-consumers was low. CONCLUSIONS: The inclusion of FFQ information to identify the never-consumers is beneficial when interested in the whole usual intake distribution or in the lower percentiles only, no matter how low the proportion of never-consumers for that food item may be. However, when interest is only in the higher percentiles of the usual intake distribution, inclusion of FFQ information to identify the never-consumers will have no benefit.

Educational inequalities in premature mortality by region in the Belgian population in the 2000s.

BACKGROUND: In Belgium, socio-economic inequalities in mortality have long been described at country-level. As Belgium is a federal state with many responsibilities in health policies being transferred to the regional levels, regional breakdown of health indicators is becoming increasingly relevant for policy-makers, as a tool for planning and evaluation. We analyzed the educational disparities by region for all-cause and cause-specific premature mortality in the Belgian population. METHODS: Residents with Belgian nationality at birth registered in the census 2001 aged 25-64 were included, and followed up for 10 years though a linkage with the cause-of-death database. The role of 3 socio-economic variables (education, employment and housing) in explaining the regional mortality difference was explored through a Poisson regression. Age-standardised mortality rates (ASMRs) by educational level (EL), rate differences (RD), rate ratios (RR), and population attributable fractions (PAF) were computed in the 3 regions of Belgium and compared with pairwise regional ratios. The global PAFs were also decomposed into the main causes of death. RESULTS: Regional health gaps are observed within each EL, with ASMRs in Brussels and Wallonia exceeding those of Flanders by about 50% in males and 40% in females among Belgian. Individual SE variables only explained up to half of the regional differences. Educational inequalities were also larger in Brussels and Wallonia than in Flanders, with RDs ratios reaching 1.8 and 1.6 for Brussels versus Flanders, and Wallonia versus Flanders respectively; regional ratios in relative inequalities (RRs and PAFs) were smaller. This pattern was observed for all-cause and most specific causes of premature mortality. Ranking the cause-specific PAFs revealed a higher health impact of inequalities in causes combining high mortality rate and relative inequality, with lung cancer and ischemic heart disease on top for all regions and both sexes. The ranking showed few regional differences. CONCLUSIONS: For the first time in Belgium, educational inequalities were studied by region. Among the Belgian, educational inequalities were higher in Brussels, followed by Wallonia and Flanders. The region-specific PAF decomposition, leading to a ranking of causes according to their population-level impact on overall inequality, is useful for regional policy-making processes.