Development of prediction models for upper and lower respiratory and gastrointestinal tract infections using social network parameters in middle-aged and older persons -The Maastricht Study.

The ability to predict upper respiratory infections (URI), lower respiratory infections (LRI), and gastrointestinal tract infections (GI) in independently living older persons would greatly benefit population and individual health. Social network parameters have so far not been included in prediction models. Data were obtained from The Maastricht Study, a population-based cohort study (N = 3074, mean age (±s.d.) 59.8 ± 8.3, 48.8% women). We used multivariable logistic regression analysis to develop prediction models for self-reported symptomatic URI, LRI, and GI (past 2 months). We determined performance of the models by quantifying measures of discriminative ability and calibration. Overall, 953 individuals (31.0%) reported URI, 349 (11.4%) LRI, and 380 (12.4%) GI. The area under the curve was 64.7% (95% confidence interval (CI) 62.6-66.8%) for URI, 71.1% (95% CI 68.4-73.8) for LRI, and 64.2% (95% CI 61.3-67.1%) for GI. All models had good calibration (based on visual inspection of calibration plot, and Hosmer-Lemeshow goodness-of-fit test). Social network parameters were strong predictors for URI, LRI, and GI. Using social network parameters in prediction models for URI, LRI, and GI seems highly promising. Such parameters may be used as potential determinants that can be addressed in a practical intervention in older persons, or in a predictive tool to compute an individual's probability of infections.

The Healthy Primary School of the Future: study protocol of a quasi-experimental study.

BACKGROUND: Unhealthy lifestyles in early childhood are a major global health challenge. These lifestyles often persist from generation to generation and contribute to a vicious cycle of health-related and social problems. This design article presents a study evaluating the effects of two novel healthy school interventions. The main outcome measure will be changes in children's body mass index (BMI). In addition, lifestyle behaviours, academic achievement, child well-being, socio-economic differences, and societal costs will be examined. METHODS: In close collaboration with various stakeholders, a quasi-experimental study was developed, for which children of four intervention schools (n = 1200) in the southern part of the Netherlands are compared with children of four control schools (n = 1200) in the same region. The interventions started in November 2015. In two of the four intervention schools, a whole-school approach named 'The Healthy Primary School of the Future', is implemented with the aim of improving physical activity and dietary behaviour. For this intervention, pupils are offered an extended curriculum, including a healthy lunch, more physical exercises, and social and educational activities, next to the regular school curriculum. In the two other intervention schools, a physical-activity school approach called 'The Physical Activity School', is implemented, which is essentially similar to the other intervention, except that no lunch is provided. The interventions proceed during a period of 4 years. Apart from the effectiveness of both interventions, the process, the cost-effectiveness, and the expected legal implications are studied. Data collection is conducted within the school system. The baseline measurements started in September 2015 and yearly follow-up measurements are taking place until 2019. DISCUSSION: A whole-school approach is a new concept in the Netherlands. Due to its innovative, multifaceted nature and sound scientific foundation, these integrated programmes have the potential to form a template for primary schools worldwide. The effects of this approach may extend further than the outcomes associated with well-being and academic achievement, potentially impacting legal and cultural aspects in our society. TRIAL REGISTRATION: The study protocol was registered in the database ClinicalTrials.gov on 14-06-2016 with the reference number NCT02800616 .

Cognitive hostility predicts all-cause mortality irrespective of behavioural risk at late middle and older age.

BACKGROUND: Most but not all evidence supports hostility-related attributes to increase mortality risk. However, studies usually include single attributes, their effects have been studied predominantly in younger populations, and behavioural pathways explaining the mortality effect seem to differ by age. We examined the relationship between all-cause mortality and cognitive hostility, anger, aggression and rebelliousness, and their independence of health behaviours in a late middle-aged and older population. METHODS: Data were derived from the longitudinal Dutch Study of Medical Information and Lifestyles in the city of Eindhoven, in the Southeast of the Netherlands study among 2679 late middle-aged and older Dutch people. Psychological characteristics were self-reported in 2004/2005, and mortality was monitored from 2005 to 2010. Cox regression analyses were used to calculate the mortality risk by each unique psychological variable with additional adjustments for the other psychological variables and for health behaviours. Baseline adjustments included age, sex, educational level and prevalent morbidity. RESULTS: Cognitive hostility was associated with all-cause mortality, independent of health behaviours (on a scale ranging from 6 to 30, the hazard ratio (HR) was 1.05; 95% confidence interval [95% CI): 1.01-1.09]. Anger, aggression and rebelliousness were not associated with mortality risk. CONCLUSIONS: In diminishing excess mortality risks, hostile cognitions might be acknowledged separately and additionally to the risk posed by unhealthy lifestyles.

Personality and health as predictors of income decrease in old age: findings from the longitudinal SMILE study.

BACKGROUND: There is much evidence for the influence of low socio-economic status on poor health. It is, however, also important to study the ways in which people attain and retain their socio-economic status and the factors that predict changes in socio-economic status, such as a decrease in income. Such mobility also occurs in older populations, in which financial and health-related changes are very common, especially after retirement. METHODS: Three years of follow-up data from 1443 Dutch men and women aged 55 years and older who participated in the Study on Medical Information and Lifestyles Eindhoven (SMILE) were gathered. Logistic regression analyses were used to study the independent effects of physical and mental dysfunction and severity of chronic diseases and adverse personality factors on decrease in income. RESULTS: Social anxiety (OR = 1.62, 95% CI: 1.09-2.40), physical dysfunction (OR = 1.71, 95% CI: 1.07-2.74) and severe diseases (OR = 1.37, 95% CI: 1.05-1.78) were significant predictors of decrease in income. These contributions were independent of each other, and remained robust after controlling for other confounding factors, such as gender, age and educational level and change in employment status. Mental dysfunction and other personality characteristics, such as hostility and mastery, did not contribute to decrease in income. CONCLUSION: Social anxiety and poor physical health are relevant factors associated with decrease in income in old age. The findings suggest that these factors are important in retaining one's socio-economic status. Future longitudinal research is necessary to further disentangle the mechanisms and pathways related to socio-economic health inequalities along the life-course.

Measuring rebelliousness and predicting health behaviour and outcomes: an investigation of the construct validity of the Social Reactivity Scale.

The Social Reactivity Scale is a questionnaire measure of individual differences in rebelliousness. The associations between rebelliousness, health behaviours and health outcomes were examined in two Dutch samples by means of cross-sectional survey data. We found moderate support for the reliability and construct validity of the scale. Findings were suggestive of rebelliousness, first, being associated with low control beliefs, second, being related to hostility and, third, also heightening the risk of engaging in unhealthy behaviours and that of poor health (perhaps through deliberately rejecting health education messages). Findings thus contribute to the ongoing emergence of an empirically viable theoretical construct.

Cognitive functioning in healthy older adults aged 64-81: a cohort study into the effects of age, sex, and education.

The objective of this study was to determine a possible differential effect of age, education, and sex on cognitive speed, verbal memory, executive functioning, and verbal fluency in healthy older adults. A group of 578 healthy participants in the age range of 64-81 was recruited from a large population study of healthy adults (Maastricht Aging Study). Even in healthy individuals in this restricted age range, there is a clear, age-related decrease in performance on executive functioning, verbal fluency, verbal memory, and cognitive speed tasks. The capacity to inhibit information is affected most. Education had a substantial effect on cognitive functioning: participants with a middle or high level of education performed better on cognitive tests than did participants with a low level of education. Women performed better than men on verbal memory tasks. Therefore, education and sex must be taken into account when examining an older individual's cognitive performance.

[Intelligence, socio-economic status and hospital admissions of young adults]. / Intelligentie, sociaaleconomische status en ziekenhuisopnamen van jongvolwassenen.

OBJECTIVE: To determine whether socio-economic differences in hospital admissions of adolescents and young adults are related to differences in intelligence. DESIGN: . Retrospective cohort study. METHODS: The data were derived from a group of 10,231 young adults and adolescents who were followed for a total of 47,212 person years with regard to their hospital admissions. Intelligence was measured in the first year of secondary school by 2 non-verbal intelligence tests for fluid intelligence. Data from hospital admissions were matched to a large-scale educational and occupational cohort. Data were analysed with Cox proportional hazards analysis. RESULTS: Intelligence was not found to be related to hospital admissions. However, a low occupational and educational level of the young adults or their parents, was strongly related to heightened risk for hospital admissions. In particular, the low socio-economic status of a respondent was associated with heightened risk for hospital admissions due to accidents (relative risk: 3.49; 95% confidence interval: 1.91-6.39). CONCLUSION: The small extent to which the socio-economic differences in hospital admissions seem to be based upon fluid intelligence, at least in adolescents and young adults, as well as the heightened risks of hospital admissions in lower socio-economic status groups and the associated high costs for health care legitimise further study of the determinants of these differences.

Prevalence of primitive reflexes and the relationship with cognitive change in healthy adults: a report from the Maastricht Aging Study.

OBJECTIVES: Primitive reflexes (PR) generally disappear early in life but may reappear later, in which case they are often associated with chronic neurological conditions, such as dementia or Parkinson's disease. Studies have shown that the presence of PRs may be indicative of both the severity and rate of progression of these diseases and may be the result of disinhibition of cortical networks. The association between PRs and cognitive function in usual ageing is unclear. We investigated whether the occurrence, amplitude, and persistence of four nociceptive (glabbelar tap, palmomental, pollicomental, and snout reflexes), three prehensile reflexes (suck, palmar grasp, and rooting), and two other reflexes (mouth open finger-spread and nuchocephalic reflexes) were related to performance in specific cognitive domains in normal ageing individuals. METHODS: Four-hundred and seventy normal aging participants (25-82 years) in the Maastricht Aging Study (MAAS), were included in the study. They were neurologically and cognitively screened at baseline and were retested after 3 (only individuals aged 50 years and older at baseline) and 6 years. RESULTS: The prevalence of most PRs increased with age: 47% of men aged 25-45 years had at least one PR, compared with 73% of men aged 65-85 year (p = 0.002). In women these percentages were 51 and 75, respectively (p=0.008). The prevalence, amplitude, and persistence of PRs were unrelated to cognition at baseline or at the 3- or 6-year follow-up. CONCLUSIONS: The prevalence of particularly nociceptive reflexes rises substantially with increasing age in normal individuals. However, the presence of PRs cannot be considered to be a marker of cognitive decline in normal aging individuals.

Effectiveness and cost-effectiveness of a minimal psychological intervention to reduce non-severe depression in chronically ill elderly patients: the design of a randomised controlled trial [ISRCTN92331982].

BACKGROUND: Depression is a prevalent disorder in chronically ill elderly persons. It may decrease quality of life, and increase functional disability, medical costs, and healthcare utilisation. Because patients may slip into a downward spiral, early recognition and treatment of depression is important. Depression can be treated with antidepressants or psychological interventions; the latter can also be applied by trained paraprofessionals. In this paper, we describe the design of the DELTA study (Depression in Elderly with Long-Term Afflictions). The first objective of the DELTA study is to evaluate the effectiveness and cost-effectiveness of a minimal psychological intervention (MPI) to reduce depression in chronically ill elderly patients. The second objective is to evaluate whether a potential effect of the MPI may differ between types of chronic illnesses. The tailor-made intervention is administered by nurses, who are trained in the principles of cognitive behavioural therapy and self-management. METHODS/DESIGN: DELTA is a two-armed randomised controlled trial, comparing MPI to usual care. A total number of 180 patients with diabetes mellitus type II (DM) and 180 patients with chronic obstructive pulmonary disease (COPD), who in addition suffer from non-severe depression, will be included in the study. In our study, non-severe depression is defined as having minor depression, mild major depression or moderate major depression. The primary outcome measure is depression using the Beck Depression Inventory. Secondary outcome measures include quality of life, daily functioning, self-efficacy, autonomy, and participation. In the economic evaluation, cost-effectiveness and cost-utility ratios will be calculated. Furthermore, a process evaluation will be carried out. Analyses will include both univariate and multivariate techniques and according to the intention to treat principle. The economic evaluation will be done from a societal perspective and data of the process evaluation will be analysed using descriptive techniques. DISCUSSION: A total number of 361 patients has been included in the study. All interventions have been administered and follow-up data will be complete in September 2006. Preliminary results from the process evaluation indicate that patients' satisfaction with the intervention is high. If this intervention proves to be effective, implementation of the DELTA intervention is considered and anticipated.

Low control beliefs, classical coronary risk factors, and socio-economic differences in heart disease in older persons.

The objective of this study was to examine whether it is through their low control beliefs that low socio-economic status groups have higher risks of heart disease, and to examine whether this mechanism is more substantial than and independent of the mechanism via classical coronary risk factors. In a population-based prospective cohort study, participants were selected from 27 general practices in the north-eastern part of The Netherlands. In 1993, there were 3888 men and women, 57 years and older, who were without prevalent heart disease. During the 5-year follow-up period, 287 cases of incident heart disease (acute myocardial infarction and/or congestive heart failure) were registered (7%). Persons with a low socio-economic status had higher risks of heart disease (RR = 1.45 (95% CI: 1.06 - 1.99)) compared with their high status counterparts. On average, 4 percent of the socio-economic differences were accounted for by the classical coronary risk factors (e.g. smoking, hypertension) compared with 30 percent by the control beliefs. The contribution of the latter was largely independent of the former. Our findings support the hypothesis that socio-economic inequalities in heart disease-at least in middle-aged and older persons-may be based upon differences in control beliefs, more than upon differences in smoking rates and other classical risk factors.

[More social exclusion of chronically ill patients with lower incomes]. / Meer sociale uitsluiting van chronisch zieken bij een lager inkomen.

OBJECTIVE: To determine whether income is connected with the variation in the social exclusion of chronically ill patients. DESIGN: Descriptive. METHOD: In 223 chronically ill patients that had been detected via patients' associations, general practitioners and outpatient clinics, a structured interview was administered during a home visit 4 times during a period of 7 months (October 2003-April 2004). Due to dropouts, the actual number of patients interviewed at each of the 4 times was 223, 176, 143 and 105, respectively. Social exclusion was measured with the aid of the 'Autonomy outside the home' subscale of the 'Impact on participation and autonomy' questionnaire. The possible total score varied from 5 (little social exclusion) to 25 (much social exclusion). In order to explain a possible effect of income, various other patient characteristics were added to the analysis model: type of primary disease (rheumatism, multiple sclerosis, pulmonary emphysema, other), duration of the primary disease, comorbidity, educational level, whether or not the patient was employed or engaged in volunteer work, whether or not the patient lived together with a partner, the self-rated health, physical functioning, social functioning, mental functioning, and the subjective pain. The data were analysed by means of multilevel repeated regression analysis. RESULTS: A low income was associated with social exclusion at all 4 times of measurement. The regression coefficient of income was -1.47 (95% CI: -2.28- -0.65), indicating that the score on the scale for social exclusion decreased by 1.47 for every euro 544,- (= 1 x SD) increase in net monthly income. This relationship could not be explained by the other patient characteristics, not even by a low educational level. CONCLUSION: The supportive care intended for the prevention of social exclusion of chronically ill patients should be concentrated sufficiently on those who have too little income to organise such care for themselves.

Serum cholesterol, precursors and metabolites and cognitive performance in an aging population.

The present study investigated if a causal relation exists between serum concentrations of precursors and metabolites of cholesterol and cognitive performance in a healthy aging population. Cognitive function addressing four domains of 144 individuals (30-80 years) was tested at baseline and after 6 years of follow-up. Serum concentrations of different sterols related to cholesterol were measured. Serum levels of lathosterol and lanosterol correlated negatively with cognitive performance on the Word Learning tests for verbal learning and memory. This was observed at baseline and follow-up and was independent of age, sex and educational level. Furthermore, the levels of lathosterol and lanosterol at baseline correlated with performance on the Stroop test and Word Learning tests over the 6-year follow-up period. Serum levels of 27-hydroxycholesterol and 24S-hydroxycholesterol showed inconsistent correlations, while cholesterol, desmosterol, sitosterol and campesterol were not related to cognitive performance.Thus, relative high serum ratios of the cholesterol precursors lanosterol and lathosterol, indicative for a high rate of endogenous cholesterol synthesis, are associated with relatively low memory performance in this aging population.

Combination of serum markers related to several mechanisms in Alzheimer's disease.

Alzheimer's disease (AD) probably involves several pathobiochemical mechanisms and this may be reflected by changes in different serum components. The present study investigated whether the combined analysis of serum molecules related to different mechanisms improves the discrimination of AD patients from healthy controls. Serum of patients with AD was analyzed for a broad spectrum of marker molecules, including 11 inflammatory proteins, 12 sterol intermediates and phytosterols, 2 brain-specific proteins and 4 constituents involved in homocysteine homeostasis. The serum molecule concentrations were combined in a logistic regression model, using a forward stepwise inclusion mode. The results showed that the combination of interleukin-6 (IL-6) receptor, protein alpha1 fraction, cysteine and cholesterol concentrations improved the discrimination between AD patients and healthy controls compared to the single markers. In conclusion, the results of this study have shown that the complex pathology in AD is reflected in a pattern of altered serum concentrations of several marker molecules related to several pathobiochemical mechanisms.

Head size and cognitive ability in nondemented older adults are related.

In a cross-sectional analysis of 818 healthy older individuals (aged 50 to 81 years), head size was found to be related to performance on tests measuring intelligence, global cognitive functioning, and speed of information processing, but not memory. These relations were not confounded by educational level, socioeconomic background, or height. Large head/brain size may protect elderly people against cognitive deterioration, supporting a reserve hypothesis of brain aging.

Inflammation markers in relation to cognition in a healthy aging population.

The relation between serum inflammatory protein levels and cognitive performance was investigated in a healthy population. Individuals were tested during 6 years of follow-up. Serum concentrations of 10 inflammatory proteins were correlated to cognitive speed (Letter-Digit Coding Test, LDCT), attention and information processing (Stroop) and memory (Word Learning). Haptoglobin levels at baseline correlated negatively with cognitive performance on the Stroop and Word Learning Recall test over the 6 years follow-up period. C-reactive protein (CRP) levels at baseline correlated negatively with performance on the Word Learning tests over the 6 years follow-up period. Thus, relatively high concentrations of haptoglobin and C-reactive protein may be indicative for impaired cognitive performance.

Predictors of attrition in a longitudinal cognitive aging study: the Maastricht Aging Study (MAAS).

A large sample of older participants of the Maastricht Aging Study (MAAS) were compared to drop-outs at the 3-year follow-up with respect to socio-demographic, health, and cognitive characteristics. In addition, the impact of selective drop-out on measures of cognitive change was examined. To this end, hypothetical scores were estimated for drop-outs by using single and multiple imputation methods. Of the initial sample of 539 subjects, aged 49 years and older at baseline, 116 (22 %) did not return for the follow-up (n = 32 had died, n = 84 refused participation). Drop-outs who refused to participate in the follow-up were more often women, had lower educational levels, and had lower baseline scores on neurocognitive tests. Follow-up drop-outs who had died were more often men, older, and had a poorer performance on cognitive tests than the follow-up participants. Although follow-up participants and drop-outs differed in terms of socio-demographic and cognitive characteristics, attrition appeared to have little effect on the estimates of cognitive change.

Educational level of spouses and risk of mortality: the WHO Kaunas-Rotterdam Intervention Study (KRIS).

BACKGROUND: A 9.5-year follow-up of the Kaunas-Rotterdam Intervention Study (KRIS) provided the opportunity of investigating whether the educational level of wives was associated with their husbands' risk of mortality and coronary heart disease (CHD), independently of the educational level of the husbands themselves. METHODS: The data represent populations consisting of 2452 Lithuanian men and 3365 Dutch men. These men were extensively screened for cardiovascular risk factors in the period 1972-1974. During the follow-up 303 Kaunasians and 350 Rotterdammers died. We used the Cox proportional hazards and the logistic regression models to analyse the data. RESULTS: We found that men whose spouses had little education apparently had an increased risk of all-cause mortality, even when their own educational level was taken into account. The relative risks (RR) were 1.57 in Kaunas and 2.15 in Rotterdam. The results for fatal and non-fatal myocardial infarctions were compatible with this finding, especially in Rotterdam. The prevalence of smoking was higher among men whose wives had primary schooling only. Nonetheless, adjusting the effect of the wife's educational level on her husband's mortality risk for all coronary risk factors in the husband only partially explained the association. CONCLUSIONS: The spouse's educational level appears to have independent effects on a man's risk of mortality in both eastern and western European communities. The results strongly suggest that including characteristics of the socioeconomic status of an individual's spouse would improve studies of socioeconomic differences in health.

Differences in mortality and coronary heart disease between Lithuania and The Netherlands: results from the WHO Kaunas-Rotterdam Intervention Study (KRIS).

BACKGROUND: A 9.5-year follow-up of the Kaunas-Rotterdam Intervention Study (KRIS) provided an opportunity to compare mortality patterns and rates in a population from Lithuania, one of the former republics of the Soviet Union, with a population from the Netherlands. These populations consisted of 2452 and 3365 males, respectively, aged 45-60 years. In 1972-1974, these males were extensively screened for cardiovascular risk factors, using uniform methods. METHODS AND RESULTS: During the follow-up, 303 males in Kaunas (Lithuania) and 350 males in Rotterdam (the Netherlands) died. Using Cox proportional hazards and logistic regression analysis, it was found that all-cause mortality rates during follow-up were 30% higher in Kaunas; this was mainly due to higher mortality rates from external causes (relative risk = 6.69), stomach cancer (RR = 2.78), stroke (RR = 2.30) and infectious diseases (RR = 12.43). The risk of fatal and non-fatal coronary heart disease (CHD) was, however, smaller in Kaunas (RR = 0.72). This lower risk closely corresponded with the Lithuanian risk profile which could be described by less smoking, lower cholesterol levels, and higher physical activity. As Lithuanians had a more advantageous cardiovascular risk profile, the higher Lithuanian all-cause mortality rates could not be explained by this risk profile. CONCLUSIONS: The results provide evidence for geographical differences in mortality and morbidity between Lithuania and the Netherlands. Population-specific health behaviours were shown to be involved in differences in the risk of CHD. The lower CHD rates in Eastern European communities in the 1970s, in this study confirmed for Lithuania, suggests that the apex of the CHD epidemic had not yet reached the Lithuanian population.