A system science perspective on burn-out: development of an expert-based causal loop diagram.

Introduction: Burn-out leads to reduced worker well-being, long-term absenteeism, and high costs for employers and society. Determinants at different levels may affect burn-out in an interrelated and dynamic manner. The aim of the present study was to apply a broader systems perspective by exploring and visualizing the complex system of determinants at different levels (living conditions, working conditions, and societal developments) underlying the prevalence of burn-out in the Netherlands. Methods: During three group model building (GMB) sessions with in total eight experts on workers' mental health, a causal loop diagram (CLD) was developed and relevant feedback loops were identified. For the selection of determinants to be included in the CLD a recently published overview of determinants on burn-out at different levels was used. Experts could also add factors that were not listed in the overview. Results: The final CLD consists of 20 factors and depicts a central position of working conditions. Societal developments (e.g., access to mental health care, size of the working population, rougher social climate, etc.) were mostly located at the outside of the CLD and barely integrated in feedback loops. Several reinforcing feedback loops resulting in an increase of the prevalence of burn-out were identified in which the factors (very) high workload, imbalance between work and private life, and insufficient recovery time play an important role. Also, several balancing loops were found that visualize the crucial role of functional support from supervisors to prevent burn-out among workers. Discussion: Applying a broader systems perspective, including determinants at different levels, offers new insights into dynamic feedback loops that contribute to the prevalence of burn-out. Supervisors, amongst others, have a considerable impact on the system underlying the high prevalence of burn-out and may therefore contribute to its prevention. Even though societal developments were less integrated in feedback loops, they might be considered drivers of existing feedback loops. The results from this study confirm that determinants at various levels underly the prevalence of burn-out. To be able to address the diversity of determinants underlying a high prevalence of burn-out, a complex system approach can be helpful.

Short-term effects of an elimination diet and healthy diet in children with attention-deficit/hyperactivity disorder: a randomized-controlled trial.

An Elimination Diet (ED) may be effective in reducing symptoms of Attention-Deficit/Hyperactivity Disorder (ADHD), but has never been compared to an active control condition [i.e., Healthy Diet (HD)]. In a two-armed RCT, a total of N = 165 children (5-12 years) with ADHD were randomized by means of minimization (1:1) to either an ED (N = 84) or HD (N = 81) within two Dutch child and adolescent psychiatry centers. The design included a non-randomized comparator arm including N = 58 children being treated with Care as Usual (CAU). Treatment allocation was unblinded. The primary outcome was a 5-point ordinal measure of respondership based on a combination of parent and teacher ratings on ADHD and emotion regulation, determined after 5 weeks of treatment. Ordinal regression analyses were done on an intention-to-treat basis. Fewer ED (35%) than HD (51%) participants showed a partial to full response, despite overall good-to-excellent treatment adherence (> 88%) and comparable high parental prior believes. A younger age and higher problem severity predicted a better respondership. CAU-preferring participants responded more often favorably (56%) compared to ED-but not HD-participants. Small-to-medium improvements in physical health (blood pressure, heart rate, and somatic complaints) were found in response to ED/HD versus decrements in response to CAU (74% received psychostimulants). The lack of superiority of the ED versus HD suggests that for the majority of children, dietary treatment response is not rooted in food-allergies/-sensitivities. The comparable results for treatment with HD and CAU are remarkable given that CAU participants were probably 'easier to treat' than HD (and ED) participants with proportionally fewer with a (suboptimal/non-response to) prior treatment with medication (4% versus 20%). Further assessment of long-term effects is needed to evaluate the potential place of dietary treatment within clinical guidelines. The trial is closed and registered in the Dutch trial registry, number NL5324 ( https://www.onderzoekmetmensen.nl/en/trial/25997 ).

A two arm randomized controlled trial comparing the short and long term effects of an elimination diet and a healthy diet in children with ADHD (TRACE study). Rationale, study design and methods.

BACKGROUND: Food may trigger Attention-Deficit/Hyperactivity Disorder (ADHD) symptoms. Therefore, an elimination diet (ED) might be an effective treatment for children with ADHD. However, earlier studies were criticized for the nature of the control group, potential confounders explaining the observed effects, unsatisfactory blinding, potential risks of nutritional deficiencies and unknown long term and cost-effectiveness. To address these issues, this paper describes the rationale, study design and methods of an ongoing two arm randomized controlled trial (RCT) comparing the short (5 week) and long term (1 year) effects of an elimination diet and a healthy diet compared with care as usual (CAU) in children with ADHD. METHODS: A total of N = 162 children (5-12 years) with ADHD will be randomized to either an ED or a healthy diet. A comparator arm including N = 60 children being solely treated with CAU (e.g. medication) is used to compare the effects found in both dietary groups. The two armed RCT is performed in two youth psychiatry centers in the Netherlands, with randomization within each participating center. The primary outcome measure is response to treatment defined as a ≥ 30% reduction on an ADHD DSM-5 rating scale (SWAN) and/or on an emotion dysregulation rating scale (SDQ: dysregulation profile). This is assessed after 5 weeks of dietary treatment, after which participants continue the diet or not. Secondary outcome measures include the Disruptive Behavior Diagnostic Observational Schedule (DB-DOS), parent and teacher ratings of comorbid symptoms, cognitive assessment (e.g. executive functions), school functioning, physical measurements (e.g. weight), motor activity, sleep pattern, food consumption, nutritional quality of the diet, adherence, parental wellbeing, use of health care resources and cost-effectiveness. Assessments take place at the start of the study (T0), after five weeks (T1), four months (T2), eight months (T3) and 12 months of treatment (T4). T0, T1 and T4 assessments take place at one of the psychiatric centers. T2 and T3 assessments consist of filling out online questionnaires by the parents only. DISCUSSION: This RCT will likely contribute significantly to clinical practice for ADHD by offering insight into the feasibility, nutritional quality, (cost-)effectiveness and long term effects of dietary treatments for ADHD. TRIAL REGISTRATION: www.trialregister.nl, NTR5434. Registered at October 11th, 2015.

Adhering to the 2017 Dutch Physical Activity Guidelines: A Trend over Time 2001-2018.

Recently, new physical activity (PA) guidelines were adopted in the Netherlands consisting of two components: (1) addressing duration of moderate and vigorous PA, (2) bone and muscle strengthening activities. The aim of this study is to retrospectively assess the long-term trend in fulfilling the criteria of the new PA guidelines and to gain insight into which activities contribute to changes over time. Data were available for 2001-2018 of a nationally representative sample of approximately 7000 Dutch citizens aged 12 years and over using the Short Questionnaire to Assess Health-enhancing physical activity (SQUASH). Multiple logistic regression analysis was performed by age, sex, and level of education. Overall, a positive trend was found from 39.9% adherence in 2001 to 46.0% in 2018. Adherence levels among adolescents decreased and increased among adults and seniors. Intermediate and higher educated groups showed positive trends over time whereas a stable trend was observed among lower educated. Activities contributing most to changes over time were sports, leisure time walking, and strenuous occupational activities. In the period 2001-2018, though an increasing trend was found, less than half of the population was sufficiently active. Special effort is necessary to reach adolescents, seniors, and lower educated groups in PA promotion programs.

Do generations differ in sports participation and physical activity over the life course? Evidence from multiple datasets.

Generational differences in health-related factors will affect forecasts of future disease patterns and health care needs. We studied whether participation in sports activity and being physically active are different between 10-year generations over a part of their life course. We used three different datasets on Dutch adults: a cohort study running for 20 years, the Doetinchem Cohort Study (DCS), multiple yearly databases (2001-2015) from the Netherlands health interview study (HIS), and a retrospective cohort study on life time sports careers, the Sports Participation Monitor (SPM). Based on a different questionnaire in each study, frequencies of weekly sport participation and being physically active according to recommended levels were determined by generation and sex. All data sets showed that self-reported sport participation has been increasing with every 10-year generation already for many decades. Especially for those generations born in the 1930s up to the 1960s, sport participation is higher compared to their predecessors. For instance at age 50, 43% of those born in the 1940s engaged in sports activities compared to 55% of those born in the 1950s (DCS data). Physical activity according to recommended levels showed no systematic differences by generation. In conclusion, favourable generation-specific trends in participation in sports activities are found: recent generations are doing better than the older generations. It is unclear whether this also reflects higher levels of physical activity or lower levels of inactivity. Future research may reveal whether these developments also hold for other countries, and whether these developments continue for the younger generations.

Dietary patterns within educational groups and their association with CHD and stroke in the European Prospective Investigation into Cancer and Nutrition-Netherlands cohort.

Higher-educated people often have healthier diets, but it is unclear whether specific dietary patterns exist within educational groups. We therefore aimed to derive dietary patterns in the total population and by educational level and to investigate whether these patterns differed in their composition and associations with the incidence of fatal and non-fatal CHD and stroke. Patterns were derived using principal components analysis in 36 418 participants of the European Prospective Investigation into Cancer and Nutrition-Netherlands cohort. Self-reported educational level was used to create three educational groups. Dietary intake was estimated using a validated semi-quantitative FFQ. Hazard ratios were estimated using Cox Proportional Hazard analysis after a mean follow-up of 16 years. In the three educational groups, similar 'Western', 'prudent' and 'traditional' patterns were derived as in the total population. However, with higher educational level a lower population-derived score for the 'Western' and 'traditional' patterns and a higher score on the 'prudent' pattern were observed. These differences in distribution of the factor scores illustrate the association between education and food consumption. After adjustments, no differences in associations between population-derived dietary patterns and the incidence of CHD or stroke were found between the educational groups (P interaction between 0·21 and 0·98). In conclusion, although in general population and educational groups-derived dietary patterns did not differ, small differences between educational groups existed in the consumption of food groups in participants considered adherent to the population-derived patterns (Q4). This did not result in different associations with incident CHD or stroke between educational groups.

Maternal fish consumption during pregnancy and BMI in children from birth up to age 14 years: the PIAMA cohort study.

PURPOSE: This study aimed to investigate the association between maternal fish consumption during pregnancy and BMI in children and the development of this association between birth and 14 years of age, taking into account relevant mother and child covariates. METHODS: The study population consisted of 3684 Dutch children born in 1996-1997 who participated in the PIAMA birth cohort study. Maternal fish consumption during pregnancy and the child's body weight and height (up to 11 times) were reported by questionnaire. Generalized estimating equations were used to investigate whether BMI of children differed according to maternal fish consumption during pregnancy. RESULTS: The crude overall association between maternal fish consumption during pregnancy and BMI in children was non-significant (P = 0.17), but differed by the child's age (P interaction = 0.03). Children of mothers who consumed fish ≥1×/week during pregnancy (n = 909) had statistically significant lower mean BMI z scores than children of mothers who never consumed fish (n = 1025) at the ages 4, 7, 8.5, and 11.5 years. Adjustment for maternal covariates (particularly pre-pregnancy BMI) attenuated the differences, which remained statistically significant at the age of 7 years only (mean difference in BMI z score: -0.14 95 % CI -0.25; -0.03). Additional adjustment for child covariates hardly affected the results. CONCLUSIONS: In a population with relatively low fish consumption, higher fish consumption by pregnant women seems rather an indicator for more healthy maternal characteristics in general than a causal factor for the lower BMI in their children.

Food supply and actions to improve dietary behaviour of students - a comparison between secondary schools participating or not participating in the 'Healthy School Canteen Program'.

OBJECTIVE: (i) To identify determinants of participation in the 'Healthy School Canteen Program', a programme that encourages schools to set up their canteen in a way that promotes healthy dietary behaviour. (ii) To compare food supply and actions between participating and non-participating schools. (iii) To investigate what reasons schools have to increase attention for nutrition in the curriculum. DESIGN: A cross-sectional study based on information from questionnaires performed in 2010/2011. SETTING: All secondary schools (age group 12-18 years) in the Netherlands (n 1145). SUBJECTS: Response was 33 % (n 375). Analyses included all schools with a canteen in which food is offered (28 %, n 325). RESULTS: None of the investigated determinants was associated with participation. Participating schools offered significantly (P < 0·001) more of eleven inventoried healthy foods (e.g. sandwiches, (butter)milk, fruit, light soft drinks, yoghurt and salad) than non-participating schools. However, there was no difference in the number of less healthy products offered (e.g. candy bars, cakes and regular soft drinks). Participating schools reported more often that they took actions to improve dietary behaviour and more often had a policy on nutrition. Participating schools more often increased attention for nutrition in the curriculum in recent years than non-participating schools (57 % v. 43 %, P = 0·01). Reported reasons were similar and included media attention, eating behaviour of students and 'overweight'. CONCLUSIONS: Schools that participate in the programme seemed to offer more healthy products in their canteens and took more actions to improve dietary behaviour than non-participating schools. However, at all schools less healthy foods were also available.

Early life factors and adult mammographic density.

PURPOSE: Early life factors have shown to be related to breast cancer risk. The pathophysiological link could be mammographic density, a strong risk factor for breast cancer. Mammary gland development already starts in utero and early life factors might affect the number of mammary cells at risk. In this study, we investigated the association between early life factors and mammographic density in adulthood. METHODS: The study was conducted within 2,588, mainly postmenopausal women of the Prospect-European Prospective Investigation into Cancer and Nutrition cohort. This ongoing study recruited breast cancer screening participants who filled out extensive questionnaires. Information on the early life factors birth weight, gestational age, maternal and paternal age, multiple births, birth rank, exposure to parental smoking, and leg length as a proxy for growth at childhood was obtained using questionnaires. Generalized linear models and linear regression models were used to study the relation between early life factors and mammographic density. Analyses were adjusted for potential confounders. RESULTS: Women who had an older mother (p = 0.06) or father (p = 0.002) at birth tended to have a higher mammographic density. Furthermore, greater leg length seemed to be related to higher mammographic density, although not statistically significantly (p = 0.16). After adjustment for confounders, none of the early life factors showed any statistically significant relationship with mammographic density in adulthood. CONCLUSION: Although we cannot exclude small effects that go undetected due to measurement error in recall of early life factors, the results suggest that mammographic density is not a major pathway in any observed relationship between these early life events and breast cancer risk.

Changes in school environment, awareness and actions regarding overweight prevention among Dutch secondary schools between 2006-2007 and 2010-2011.

BACKGROUND: Schools can be an important setting for the prevention of overweight. This nation-wide survey investigated changes in the obesogenity of the school environment, the awareness of schools regarding overweight, school health policy, and actions taken by schools to prevent overweight. METHODS: In 2006/2007 and 2010/2011, questionnaires were sent to all Dutch secondary schools, (n = 1250 and n = 1145, response rate 44% and 33% respectively, repeated data for 187 schools). RESULTS: The percentage of schools with vending machines for soft drinks (~90%) and sweets (~80%) remained fairly stable, whereas slightly more schools indicated to have a canteen (87%-91%). The food supply was reported to be healthier in 2010/2011 compared to 2006/2007. Canteens and/or vending machines offered more often fresh fruits (+8%), sandwiches (+11%), water (+11%) and salad (+7%) and less often sugar sweetened soft drinks (-10%). However, unfavorable changes such as an increase in the supply of pizza slices (+13%) and milk and yoghurt drinks with added sugar (+12%) were also reported. Between 2006/2007 and 2010/2011, the presence of water coolers increased (12% versus 33%) as well as facilities for physical activity (67% versus 77%). However, more schools had vending places of unhealthy foods in the vicinity (73% versus 85%). Compared to 2006/2007, a higher percentage of schools indicated that they have taken actions to stimulate healthy eating behavior (72% versus 80%) or to prevent overweight (34% versus 52%) in 2010/2011. Less schools indicated that they expect to pay more attention to overweight prevention in the near future (56% versus 43%), but none of them expected to pay less attention. CONCLUSIONS: Several aspects of the school environment changed in a positive way. However, schools should be encouraged to contribute to the prevention of overweight, or to continue to do so.

The association between dietary energy density and type 2 diabetes in Europe: results from the EPIC-InterAct Study.

BACKGROUND: Observational studies implicate higher dietary energy density (DED) as a potential risk factor for weight gain and obesity. It has been hypothesized that DED may also be associated with risk of type 2 diabetes (T2D), but limited evidence exists. Therefore, we investigated the association between DED and risk of T2D in a large prospective study with heterogeneity of dietary intake. METHODOLOGY/PRINCIPAL FINDINGS: A case-cohort study was nested within the European Prospective Investigation into Cancer (EPIC) study of 340,234 participants contributing 3.99 million person years of follow-up, identifying 12,403 incident diabetes cases and a random subcohort of 16,835 individuals from 8 European countries. DED was calculated as energy (kcal) from foods (except beverages) divided by the weight (gram) of foods estimated from dietary questionnaires. Prentice-weighted Cox proportional hazard regression models were fitted by country. Risk estimates were pooled by random effects meta-analysis and heterogeneity was evaluated. Estimated mean (sd) DED was 1.5 (0.3) kcal/g among cases and subcohort members, varying across countries (range 1.4-1.7 kcal/g). After adjustment for age, sex, smoking, physical activity, alcohol intake, energy intake from beverages and misreporting of dietary intake, no association was observed between DED and T2D (HR 1.02 (95% CI: 0.93-1.13), which was consistent across countries (I(2) = 2.9%). CONCLUSIONS/SIGNIFICANCE: In this large European case-cohort study no association between DED of solid and semi-solid foods and risk of T2D was observed. However, despite the fact that there currently is no conclusive evidence for an association between DED and T2DM risk, choosing low energy dense foods should be promoted as they support current WHO recommendations to prevent chronic diseases.

Longitudinal changes in weight in relation to smoking cessation in participants of the EPIC-PANACEA study.

PURPOSE: We assessed the association between smoking cessation and prospective weight change in the European population of the European Prospective Investigation into Cancer and Nutrition-Physical Activity, Nutrition, Alcohol, Cessation of smoking, Eating out of home And obesity (EPIC-PANACEA) project. METHODS: The study involved more than 300,000 healthy volunteers, recruited between 1992 and 2000 in 9 European countries, who provided data on anthropometry and smoking habits at baseline and after a follow-up of 5 years on average. Adjusted mixed-effects linear regression models were used to obtain sex-specific summary estimates of the association between the change in smoking status and the annual change in weight. RESULTS: Smoking cessation tends to be followed by weight gain; when compared to stable smokers, annual weight gain was higher in men (0.44 kg (95%CI: 0.36; 0.52)) and women (0.46 kg (95%CI: 0.41; 0.52)) who stopped smoking during follow-up. When smokers who stopped smoking at least 1 year before recruitment were compared to never smokers, no major differences in annual weight gain were observed. The excess weight gain following smoking cessation appears to mainly occur in the first years following the cessation. CONCLUSIONS: When considering the benefits of smoking cessation, such findings strengthen the need for promoting cessation offering information on weight gain control and support to weight-concerned smokers in order to remove a barrier to quitting.

Quantification of the energy gap in young overweight children. The PIAMA birth cohort study.

BACKGROUND: Overweight develops gradually as a result of a long term surplus on the balance between energy intake and energy expenditure. Aim of this study was to quantify the positive energy balance responsible for excess body weight gain (energy gap) in young overweight children. METHODS: Reported data on weight and height were used of 2190 Dutch children participating in the PIAMA birth cohort study. Accumulated body energy was estimated from the weight gain observed between age 2 and age 5-7. Energy gap was calculated as the difference in positive energy balance between children with and without overweight assuming an energy efficiency of 50%. RESULTS: Ten percent of the children were overweight at the age of 5-7 years. For these children, median weight gain during 4-years follow-up was 13.3 kg, as compared to 8.5 kg in the group of children who had a normal weight at the end of the study. A daily energy gap of 289-320 kJ (69-77 kcal) was responsible for the excess weight gain or weight maintenance in the majority of the children who were overweight at the age of 5-7 years. The increase in daily energy requirement to maintain the 4.8 kilograms excess weight gain among overweight children at the end of the study was approximately 1371 kJ. CONCLUSIONS: An energy gap of about 289-320 kJ per day over a number of years can make the difference between normal weight and overweight in young children. Closing the energy gap in overweight children can be achieved by relatively small behavior changes. However, much more effort is required to lose the excess weight gained.

Physical activity and gain in abdominal adiposity and body weight: prospective cohort study in 288,498 men and women.

BACKGROUND: The protective effect of physical activity (PA) on abdominal adiposity is unclear. OBJECTIVE: We examined whether PA independently predicted gains in body weight and abdominal adiposity. DESIGN: In a prospective cohort study [the EPIC (European Prospective Investigation into Cancer and Nutrition)], we followed 84,511 men and 203,987 women for 5.1 y. PA was assessed by a validated questionnaire, and individuals were categorized into 4 groups (inactive, moderately inactive, moderately active, and active). Body weight and waist circumference were measured at baseline and self-reported at follow-up. We used multilevel mixed-effects linear regression models and stratified our analyses by sex with adjustments for age, smoking status, alcohol consumption, educational level, total energy intake, duration of follow-up, baseline body weight, change in body weight, and waist circumference (when applicable). RESULTS: PA significantly predicted a lower waist circumference (in cm) in men (ß = -0.045; 95% CI: -0.057, -0.034) and in women (ß = -0.035; 95% CI: -0.056, -0.015) independent of baseline body weight, baseline waist circumference, and other confounding factors. The magnitude of associations was materially unchanged after adjustment for change in body weight. PA was not significantly associated with annual weight gain (in kg) in men (ß = -0.008; 95% CI: -0.02, 0.003) and women (ß = -0.01; 95% CI: -0.02, 0.0006). The odds of becoming obese were reduced by 7% (P < 0.001) and 10% (P < 0.001) for a one-category difference in baseline PA in men and women, respectively. CONCLUSION: Our results suggest that a higher level of PA reduces abdominal adiposity independent of baseline and changes in body weight and is thus a useful strategy for preventing chronic diseases and premature deaths.

Dietary intake of folate and riboflavin, MTHFR C677T genotype, and colorectal adenoma risk: a Dutch case-control study.

We investigated the associations between dietary intake of folate and vitamin B2, MTHFR C677T genotype, and colorectal adenomas in a Dutch case-control study. Data of cases with at least one histologically confirmed colorectal adenoma (n = 768) and controls with no history of any type of colorectal polyp (n = 709) were included. Dietary intake was assessed using a food-frequency questionnaire. Multivariable models included age and, if appropriate, dietary folate and calcium intake. The adjusted odds ratio (OR) and 95% confidence interval (CI) for the highest compared with the lowest sex-specific tertile of intake were 1.32 (95% CI, 1.01-1.73) for folate and 0.51 (95% CI, 0.36-0.73) for vitamin B2. Folate seemed to be a risk factor, especially when vitamin B2 intake was low; vitamin B2 was inversely associated with adenomas, especially with relatively high folate intake. No association was observed between MTHFR C677T genotype and colorectal adenomas. The inverse association between vitamin B2 intake and colorectal adenoma risk seemed to be more pronounced among those with the MTHFR TT genotype. We conclude that this study does not provide evidence for a decreased colorectal adenoma risk for subjects with high dietary intake of folate. It suggests, however, an inverse association between vitamin B2 and colorectal adenomas, which may be more relevant for those with the MTHFR TT genotype.