Emil Kupek

Food intake and circadian rhythms in shift workers with a high workload.

Shift work is associated with nutritional and health problems. In the present study, the food intake of garbage collectors of the city of Florianopolis (Brazil) was investigated using a dietary survey method based on meal recording during 24 h and adapted for the Brazilian food context. Three different shifts (morning, afternoon, and night) were compared (n=22 per shift). Age, body weight and body mass index (BMI) were similar for all groups. Daily energy expenditure was high in all three shifts, especially in morning shift workers. No difference in daily energy intake was found, in spite of differences in food choices and circadian ingestion rhythms. Energy intake was high and close to levels previously reported in athletes. Several factors not associated with shifts had significant impact on ingestion: hour of the day, time since the last meal, age, and BMI. Ingested foods were analyzed in groups based on nutrient content. Shifts significantly influenced intake of starches, alcoholic drinks, and sweets. In different periods of the day, food and nutrient intake were considerably affected by shifts. The analysis of circadian distribution of food choices and nutrient intake is important in shift workers, because total daily intake may not reveal shift-associated differences.

Clinical, provider and sociodemographic predictors of late initiation of antenatal care in England and Wales

Objective To identify factors that are predictive of late initiation of antenatal care in England and Wales.

Beyond logistic regression: structural equations modelling for binary variables and its application to investigating unobserved confounders

BackgroundStructural equation modelling (SEM) has been increasingly used in medical statistics for solving a system of related regression equations. However, a great obstacle for its wider use has been its difficulty in handling categorical variables within the framework of generalised linear models.MethodsA large data set with a known structure among two related outcomes and three independent variables was generated to investigate the use of Yules transformation of odds ratio (OR) into Q-metric by (OR-1)/(OR+1) to approximate Pearsons correlation coefficients between binary variables whose covariance structure can be further analysed by SEM. Percent of correctly classified events and non-events was compared with the classification obtained by logistic regression. The performance of SEM based on Q-metric was also checked on a small (N = 100) random sample of the data generated and on a real data set.ResultsSEM successfully recovered the generated model structure. SEM of real data suggested a significant influence of a latent confounding variable which would have not been detectable by standard logistic regression. SEM classification performance was broadly similar to that of the logistic regression.ConclusionThe analysis of binary data can be greatly enhanced by Yules transformation of odds ratios into estimated correlation matrix that can be further analysed by SEM. The interpretation of results is aided by expressing them as odds ratios which are the most frequently used measure of effect in medical statistics.

Clinical, provider and sociodemographic determinants of the number of antenatal visits in England and Wales

The objective of this study was to measure the independent effects of clinical factors and non-clinical factors, such as provider and sociodemographic characteristics, on the number of antenatal visits made by women in England and Wales. The study was based on a survey of the secondary case records of 20,771 women with singleton pregnancies who were delivered between 1 August 1994 and 31 July 1995. The women in the survey attended one of nine maternity units in Northern England and North Wales selected within those areas to reflect geographical variations, as well as variations in the size and teaching status of the institution. A multivariate Poisson regression model was developed to examine differences in the number of antenatal visits made by women with different clinical and non-clinical characteristics. After controlling for non-clinical factors, primiparous women identified as high risk at booking made 1.0% more visits than primiparous women identified as low risk at booking (p = 0.196). Multiparous women identified as high risk at booking made 3.5% more visits than their low risk counterparts (p<0.001). High risk-defining criteria during antenatal care led to a 0.3% weekly increase in the number of antenatal visits amongst primiparous women (p <0.001) and a 0.4% weekly increase in the number of antenatal visits amongst multiparous women (p < 0.001). Several notable results, not reported elsewhere in the literature, were revealed by the regression analyses. After all independent variables were controlled for, women who were booked into urban teaching hospitals made 10% fewer antenatal visits than the women who were booked into the urban non-teaching hospitals. Women of Pakistani origin made 9.1% fewer antenatal visits than women of white British origin. Similar results were revealed for women of Indian origin and women from other ethnic groups. Non-smokers made 6.0% more antenatal visits than smokers. The planned pattern of antenatal care, number of carers seen, gestation at first presentation and maternal age also had significant independent impacts on the number of antenatal visits. The study highlights the sizeable impact of non-clinical factors on the antenatal care delivery process and indicates ways in which variations in antenatal care might be reduced.

Antenatal visits and adverse perinatal outcomes : results from a British population-based study

OBJECTIVE The objective of this study was to explore the relationship between the number of antenatal visits made by a representative sample of British women and adverse perinatal outcomes. STUDY DESIGN A total of 20,771 women with a singleton pregnancy were recruited from nine representative maternity units in Northern England and North Wales. A record of each womans antenatal care and the adverse perinatal outcomes of interest were extracted retrospectively from their case notes. Multivariate binomial regression was used to model the probability of adverse outcomes with respect to the absolute number of antenatal visits, after controlling for potentially confounding factors. Separate analyses were performed for primiparae and multiparae, and for low- and high-risk women within each parous group. RESULTS The study revealed an inverse association between the number of antenatal visits and delivery of a low birthweight infant, infant admission to a special care baby unit and perinatal mortality over the 4-14 antenatal visit range, which dissipated at higher levels of antenatal visits. The study also revealed a significant positive association between the number of antenatal visits and delivery by caesarean section (P<0.01). Similar trends in the probabilities of adverse outcomes were observed for low- and high-risk women within each parous group. CONCLUSION Further experimental research is required to ascertain whether a causal relationship exists between antenatal visiting schedules and adverse perinatal outcomes.

Validação da terceira versão do Questionário Alimentar do Dia Anterior (QUADA-3) para escolares de 6 a 11 anos

The aim of this study was to assess the validity of the third version of the Previous Day Food Questionnaire (PDFQ-3) for schoolchildren. PDFQ-3 is a structured instrument with 6 meals and 21 foods. The study included 164 students aged 6 to 11 years in a public school with a full-day school schedule in 2007. Validity was assessed by comparing food items selected on the questionnaire and direct observations of foods eaten in three school meals on the previous day (mid-morning snack, lunch, and mid-afternoon snack). Multivariate logistic regression analysis was used to evaluate the discordance between answers from the questionnaire versus those from observations. Results indicated high sensitivity and specificity for the majority of the food items. Mean values for sensitivity and specificity were 70.5% and 87.1%, respectively, for 12 food items in three combined school meals. Schoolchildren aged 6 to 8 years showed higher discordance between PDFQ-3 and observations, compared to 9-to-11-year-olds. Based on the findings, the PDFQ-3 can generate valid data for the evaluation of previous day food consumption in groups of schoolchildren.

Qualitative analysis of the diet of a probabilistic sample of schoolchildren from Florianópolis, Santa Catarina State, Brazil, using the Previous Day Food Questionnaire

A qualitative evaluation of the diet of a probabilistic sample of 7-10 year old schoolchildren (n=1,232) from Florianópolis (southern Brazil) was carried out by analyzing compliance with recommendations from the Brazilian Food Guidelines. The strengths and limitations of the Previous Day Food Questionnaire (PDFQ) are also presented. Frequencies of intake were defined as how many times per day the food group was reported on the PDFQ. The percentages of schoolchildren who met the minimum recommendations and who ate foods that were not recommended in the guidelines were compared for boys versus girls, private versus public school and by family income level. Although most of the children complied with the guidelines regarding consumption of meat/fish, dry beans, sweets, and eating three meals and two snacks, only 6.5% of the children met the recommendations for cereals, and 15% for fruit and vegetables. The PDFQ was confirmed as a practical and cost-effective method for the evaluation of compliance with health promotion targets.

Cobertura e fatores associados à realização do exame de detecção do câncer de colo de útero em área urbana no Sul do Brasil: estudo de base populacional

This study focused on coverage of screening for cervical cancer and associated factors in women 20 to 59 years of age in Florianópolis, Santa Catarina State, Brazil, in 2009. This was a cross-sectional study using cluster random sampling. Two outcomes were examined: a history of at least one Papanicolaou test and delaying the test (never performed or performed more than three years previously). Among 952 women, 93% (95%CI: 91.5-94.7) had ever had a Pap smear, whereas 14% (95%CI: 11.8-16.2) had delayed the test. According to Poisson regression, both outcomes were associated with marital status, schooling, presence of chronic disease, and consulting a physician for other reasons. Age, income, and hospitalization in the previous year were only associated with ever having a Pap smear. Although test coverage was high, much of the screening was opportunistic. In addition, various social, economic, and demographic disparities influenced the odds of being screened.

Motivational effects of 12-week moderately restrictive diets with or without special attention to the Glycaemic Index of foods.

Low glycaemic index (GI) diets may facilitate weight loss via behavioural and/or endocrine mechanisms. This study investigated whether the outcomes of the Weight Watchers POINTS Weight-Loss System could be improved by encouraging dieters to select low GI, high-carbohydrate foods. Ninety-six women (age 20-72 years; BMI 25-40 kg/m2) were recruited as they started the Weight Watchers POINTS programme for 12 weeks. Weekly classes were randomized so that seven (forty-five women) followed the regular programme while seven others (fifty-one women) followed a revised programme encouraging the selection of low GI foods. Anthropometric and biochemical parameters were measured before and after the 12-week diets. Participants rated hunger and desire to eat using visual analogue scales on 1 d per week, several times per d. Attrition was the same in both groups (32 v. 30 %), as well as many benefits (5 % weight loss, decreases in insulinaemia and blood lipids, waist and hip circumferences, blood pressure). Hunger and desire to eat were rated consistently lower in the low GI group over the 12-week diet. Group differences in subjective sensations were especially large in the afternoon. The 12-week weight management yielded many significant anthropometric and biochemical benefits that were not improved by encouraging dieters to select low GI foods. The subjective benefits (lower hunger and desire to eat) of the low GI diet may be a worthwhile contribution to the motivation of dieters that might affect adherence to the diet over the long term.

Transfusion risk for hepatitis B, hepatitis C and HIV in the state of Santa Catarina, Brazil, 1991-2001

We examined the time trend of residual risk of transfusing blood contaminated with HIV, hepatitis B and hepatitis C, in the largest blood bank of the state of Santa Catarina, Brazil, 1991-2001. The HIV risk was reduced approximately 10 times during the decade of 1990, to 1:48777, but then increased significantly by the end of 2001. A similar time trend was observed for hepatitis B and hepatitis C, although the increase was not significant in this case. Even during the period of lowest risk, the estimates were considerably higher than in developed countries.