Prevention and Health: from complex life course to simple solutions

__Abstract__ Rede, uitgesproken ter gelegenheid van het aanvaarden van het ambt van hoogleraar Epidemiologische basis van preventieve geneeskunde i.h.b. cardiovasculaire aandoeningen aan het Erasmus MC, faculteit van de Erasmus Universiteit Rotterdam op 3 mei 201

Cardiovascular Disease Prfevention: from meta-analyses to life expectancies

Cardiovascular Disease (CVD) includes dysfunctional conditions of the heart and of the blood vessel system (arteries, veins, and capillaries) that among other functions supply oxygen to all body tissues and organs, including vital life-sustaining areas like the brain and the heart itself. Coronary heart disease and stroke are the principal components of CVD. Cardiovascular disease is the leading cause of mortality and morbidity worldwide. It is on the rise and has become a true pandemic that respect no borders. This thesis presents studies on different areas of the epidemiology of CVD and its prevention. Three specific research questions were investigated: 1. What is the effect of risk factors for cardiovascular disease such as physical inactivity and hypertension, in terms of life expectancy and years lived with and without cardiovascular disease? 2. What is the cost-effectiveness of various strategies for cardiovascu

Development and validation of a clinical and computerised Decision Support System for Management of Hypertension (DSS-HTN) at a Primary Health Care (PHC) setting

Background: Hypertension remains the top global cause of disease burden. Decision support systems (DSS) could provide an adequate and cost-effective m

Determinants and Predictors of Grief Severity and Persistence: The Rotterdam Study

Objective: We aimed to explore correlates and predictors of bereavement severity and persistence (triggered by “loss of a loved one”; referent group partner loss) in the Rotterdam cohort. Method: We used linear regression to examine factors associated with grief severity using a cross-sectional analysis and logistic regression to determine prospective associations. Results: Cross-sectionaly, females, child-lost, higher depressive symptoms, lower education, and difficulties in daily activities were independently associated with a higher bereavement severity. Prospectively (6 years; response rate 71%), the baseline value of the grief severity was the single predictor significantly associated with grief persistence. Discussion: Our results suggest that only grief severity is independently associated with grief persistence. Further studies are needed to confirm ou

Non-steroidal anti-inflammatory drugs and the risk of atrial fibrillation: A population-based follow-up study

Objective: To investigate the association of non-steroidal anti-inflammatory drugs (NSAIDs) and the risk of atrial fibrillation in a prospective community-based follow-up study of elderly individuals with uniform case assessment and data on potential confounders. Design: Data came from the population-based follow-up study, the Rotterdam Study. Participants: The study comprised 8423 participants without atrial fibrillation at baseline. Main outcome measures: Atrial fibrillation was ascertained from ECG assessments as well as medical records. Use of NSAIDs was obtained from automated prescription records by linkage with participating pharmacies. We used Cox proportional hazards models to study the association between NSAID drug use and atrial fibrillation. Use of NSAIDs was included in the model as a time-varying variable. Results: At baseline, the mean age of the study population was 68.5 years (SD: 8.7) and 58% were women. During a mean follow-up of 12.9 years, 857 participants developed atrial fibrillation. Current use of NSAIDs was associated with increased risk compared with never-use (HR 1.76, 95% CI 1.07 to 2.88). Also, recent use (within 30 days after discontinuation of NSAIDs) was associated with an increased risk of atrial fibrillation compared with never-use (HR 1.84, 95% CI 1.34 to 2.51) adjusted for age, sex and several potential confounders. Conclusions: In this study, use of NSAIDs was associated with an increased risk of atrial fibrillation. Further studies are needed to investigate the underlying mechanisms behind this association

Bayesian imputation of time-varying covariates in linear mixed models

Studies involving large observational datasets commonly face the challenge of dealing with multiple missing values. The most popular approach to overcome this challenge, multiple imputation using chained equations, however, has been shown to be sub-optimal in complex settings, specifically in settings with longitudinal outcomes, which cannot be easily and adequately included in the imputation models. Bayesian methods avoid this difficulty by specification of a joint distribution and thus offer an alternative. A popular choice for that joint distribution is the multivariate normal distribution. In more complicated settings, as in our two motivating examples that involve time-varying covariates, additional issues require consideration: the endo- or exogeneity of the covariate and its functional relation with the outcome. In such situations, the implied assumptions of standard methods may be violated, resulting in bias. In this work, we extend and study a more flexible, Bayesian alternative to the multivariate normal approach, to better handle complex incomplete longitudinal data. We discuss and compare assumptions of the two Bayesian approaches about the endo- or exogeneity of the covariates and the functional form of the association with the outcome, and illustrate and evaluate consequences of violations of those assumptions using simulation studies and two real data examples

The relation between non-occupational physical activity and years lived with and without disability

Objectives: The effects of non-occupational physical activity were assessed on the number of years lived with and without disability between age 50 and 80 years. Methods: Using the GLOBE study and the Longitudinal Study of Aging, multi-state life tables were constructed yielding the number of years with and without disability between age 50 and 80 years. To obtain life tables by level of physical activity (low, moderate, high), hazard ratios were derived for different physical activity levels per transition (non-disabled to disabled, non-disabled to death, disabled to non-disabled, disabled to death) adjusted for age, sex and confounders. Results: M

Physical activity and life expectancy with and without diabetes: life table analysis of the Framingham Heart Study

OBJECTIVE: Physical activity is associated with a reduced risk of developing diabetes and with reduced mortality among diabetic patients. However, the effects of physical activity on the number of years lived with and without diabetes are unclear. Our aim is to calculate the differences in life expectancy with and without type 2 diabetes associated with different levels of physical activity. RESEARCH DESIGN AND METHODS: Using data from the Framingham Heart Study, we constructed multistate life tables starting at age 50 years for men and women. Transition rates by level of physical activity were derived for three transitions: nondiabetic to death, nondiabetic to diabetes, and diabetes to death. We used hazard ratios associated with different physical activity levels after adjustment for age, sex, and potential confounders. RESULTS: For men and women with moderate physical activity, life expectancy without diabetes at age 50 years was 2.3 (95% CI 1.2-3.4) years longer than for subjects in the low physical activity group. For men and women with high physical activity, these differences were 4.2 (2.9-5.5) and 4.0 (2.8-5.1) years, respectively. Life expectancy with diabetes was 0.5 (-1.0 to 0.0) and 0.6 (-1.1 to -0.1) years less for moderately active men and women compared with their sedentary counterparts. For high activity, these differences were 0.1 (-0.7 to 0.5) and 0.2 (-0.8 to 0.3) years, respectively. CONCLUSIONS: Moderately and highly active people have a longer total life expectancy and live more years free of diabetes than their sedentary counterparts but do not spend more years with diabetes

Epidemiology and impact of chronic bronchitis in chronic obstructive pulmonary disease

Research on the association between chronic bronchitis and chronic obstructive pulmonary disease (COPD) exacerbations has led to discordant results. Furthermore, the impact of chronic bronchitis on mortality in COPD subjects is unclear. Within the Rotterdam Study, a population-based cohort study of subjects aged ≥45 years, chronic bronchitis was defined as having a productive cough for ≥3 months per year for two consecutive years. Linear, logistic regression and Cox proportional hazard models were adjusted for age, sex and pack-years. Out of 972 included COPD subjects, 752 had no chronic phlegm production (CB-) and 220 had chronic phlegm production, of whom 172 met the definition of chronic bronchitis (CB+). CB+ subjects were older, more frequently current smokers and had more pack-years than CB- subjects. During a median 6.5 years of followup, CB+ subjects had greater decline in lung function (-38 mL·year-1, 95% CI -61.7 - -14.6; p=0.024). CB+ subjects had an increased risk of frequent exacerbations (OR 4.0, 95% CI 2.7-5.9; p<0.001). In females, survival was significantly worse in CB+ subjects compared to CB- subjects. Regarding cause-specific mortality, CB+ subjects had an increased risk of respiratory mortality (hazard ratio 2.16, 95% CI 1.12-4.17; p=0.002). COPD subjects with chronic bronchitis have an increased risk of exacerbations and respiratory mortality compared to COPD subjects without chronic phlegm production

Sugar-containing beverage intake at the age of 1 year and cardiometabolic health at the age of 6 years: The Generation R Study

Background: Consumption of sugar-containing beverages (SCBs) in adults has been associated with an increased risk of metabolic syndrome. Although the effect of SCB on body weight in children is well established, little is known about the cardiometabolic effects in young children. We studied the associations of SCB intake at the age of 1 year with cardiometabolic health at age 6 years. Methods: This study was performed among 2,045 Dutch children from a population based prospective birth cohort. SCB intake was assessed with a semi-quantitative food frequency questionnaire at the age of 13 months and sex-specific tertiles were created. Children visited the research center at the age of 6 years. We created a continuous cardiometabolic risk factor score including: body fat percentage, blood pressure, insulin, HDL-cholesterol and triglycerides. Age-and sex-specific standard deviation (SD) scores were created for all outcomes. Multivariable linear regression was performed with adjustment for socio-demographic and lifestyle variables of mother and child. Results: In the total population, we observed an association between higher SCB intake at 13 months of age and a higher cardiometabolic risk factor score at the age of 6 years (0.13SD (95 % CI 0.01; 0.25), highest vs. lowest tertile) After stratification by sex, we found that boys in the highest tertile of SCB intake had a higher cardiometabolic risk factor score (0.18 SD (95 % CI 0.01; 0.34)), as compared to boys in the lowest tertile of SCB intake. There was no significant association in girls. We did not find associations of SCB intake with the individual cardiometabolic risk factors in the total population, or in the stratified analyses. Conclusion: Higher SCB intake at 1 year of age was associated with a higher cardiometabolic risk factor score at age 6 years in boys, but not in girls. Further research on sex-specific effects of SCBs is needed