Unwell
Childhood Socioeconomic Status, Telomere Length, and Susceptibility to Upper Respiratory Infection
Sheldon Cohen et al.
Brain, Behavior, and Immunity, forthcoming
Abstract:
Low socioeconomic status (SES) during childhood and adolescence has been found to predict greater susceptibility to common cold viruses in adults. Here, we test whether low childhood SES is associated with shorter leukocyte telomere length in adulthood, and whether telomere length mediates the association between childhood SES and susceptibility to acute upper respiratory disease in adulthood. At baseline, 196 healthy volunteers reported whether they currently owned their home and, for each year of their childhood, whether their parents owned the family home. Volunteers also had blood drawn for assessment of specific antibody to the challenge virus, and for CD8+CD28- T-lymphocyte telomere length (in a subset, n = 135). They were subsequently quarantined in a hotel, exposed to a virus (rhinovirus [RV] 39) that causes a common cold and followed for infection and illness (clinical cold) over 5 post-exposure days. Lower childhood SES as measured by fewer years of parental home ownership was associated with shorter adult CD8+CD28- telomere length and with an increased probability of developing infection and clinical illness when exposed to a common cold virus in adulthood. These associations were independent of adult SES, age, sex, race, body mass, neuroticism, and childhood family characteristics. Associations with infections and colds were also independent of pre-challenge viral-specific antibody and season. Further analyses do not support mediating roles for smoking, alcohol consumption or physical activity but suggest that CD8+CD28- cell telomere length may act as a partial mediator of the associations between childhood SES and infection and childhood SES and colds.
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Mental- and Physical-Health Effects of Acute Exposure to Media Images of the September 11, 2001, Attacks and the Iraq War
Roxane Cohen Silver et al.
Psychological Science, forthcoming
Abstract:
Millions of people witnessed early, repeated television coverage of the September 11 (9/11), 2001, terrorist attacks and were subsequently exposed to graphic media images of the Iraq War. In the present study, we examined psychological- and physical-health impacts of exposure to these collective traumas. A U.S. national sample (N = 2,189) completed Web-based surveys 1 to 3 weeks after 9/11; a subsample (n = 1,322) also completed surveys at the initiation of the Iraq War. These surveys measured media exposure and acute stress responses. Posttraumatic stress symptoms related to 9/11 and physician-diagnosed health ailments were assessed annually for 3 years. Early 9/11- and Iraq War–related television exposure and frequency of exposure to war images predicted increased posttraumatic stress symptoms 2 to 3 years after 9/11. Exposure to 4 or more hr daily of early 9/11-related television and cumulative acute stress predicted increased incidence of health ailments 2 to 3 years later. These findings suggest that exposure to graphic media images may result in physical and psychological effects previously assumed to require direct trauma exposure.
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The Effect of College Education on Health
Kasey Buckles et al.
NBER Working Paper, July 2013
Abstract:
We exploit exogenous variation in college completion induced by draft-avoidance behavior during the Vietnam War to examine the impact of college completion on adult mortality. Our preferred estimates imply that increasing college completion rates from the level of the state with the lowest induced rate to the highest would decrease cumulative mortality by 28 percent relative to the mean. Most of the reduction in mortality is from deaths due to cancer and heart disease. We also explore potential mechanisms, including differential earnings, health insurance, and health behaviors, using data from the Census, ACS, and NHIS.
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The Impact of Neighborhood Socioeconomic Status and Race on the Prescribing of Opioids in Emergency Departments Throughout the United States
Michael Joynt et al.
Journal of General Internal Medicine, forthcoming
Background: Racial and ethnic disparities in opioid prescribing in the emergency department (ED) are well described, yet the influence of socioeconomic status (SES) remains unclear.
Design: We used cross-sectional data from the National Hospital Ambulatory Medical Care Survey between 2006 and 2009 to examine the prescribing of opioids to patients presenting with moderate to severe pain (184 million visits). We used logistic regression to examine the association between the prescribing of opioids, SES, and race. Models were adjusted for age, sex, pain-level, injury-status, frequency of emergency visits, hospital type, and region.
Main measures: Our primary outcome measure was whether an opioid was prescribed during a visit for moderate to severe pain. SES was determined based on income, percent poverty, and educational level within a patient’s zip code.
Results: Opioids were prescribed more frequently at visits from patients of the highest SES quartile compared to patients in the lowest quartile, including percent poverty (49.0 % vs. 39.4 %, P < 0.001), household income (47.3 % vs. 40.7 %, P < 0.001), and educational level (46.3 % vs. 42.5 %, P = 0.01). Black patients were prescribed opioids less frequently than white patients across all measures of SES. In adjusted models, black patients (AOR 0.73; 95 % CI 0.66–0.81) and patients from poorer areas (AOR 0.76; 95 % CI 0.68–0.86) were less likely to receive opioids after accounting for pain-level, age, injury-status, and other covariates.
Conclusions: Patients presenting to emergency departments from lower SES regions were less likely to receive opioids for equivalent levels of pain than those from more affluent areas. Black and Hispanic patients were also less likely to receive opioids for equivalent levels of pain than whites, independent of SES.
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Perceived Neighborhood Social Cohesion and Stroke
Eric Kim, Nansook Park & Christopher Peterson
Social Science & Medicine, forthcoming
Abstract:
Research in the last three decades has shown that negative neighborhood factors such as neighborhood violence, noise, traffic, litter, low neighborhood socioeconomic status, and poor air quality increase the risk of poor health. Fewer studies have examined the potential protective effect that neighborhood factors can have on health, particularly stroke. We examined whether higher perceived neighborhood social cohesion was associated with lower stroke incidence after adjusting for traditional risk and psychological factors that have been linked with stroke risk. Prospective data from the Health and Retirement Study — a nationally representative panel study of American adults over the age of 50 — were used. Analyses were conducted on a subset of 6,740 adults who were stroke-free at baseline. Analyses adjusted for chronic illnesses and relevant sociodemographic, behavioral, and psychosocial factors. Over a four-year follow-up, higher perceived neighborhood social cohesion was associated with a lower risk of stroke. Each standard deviation increase in perceived neighborhood social cohesion was associated with a multivariate-adjusted odds ratio (O.R.) of 0.85 for stroke incidence (95% CI, 0.75-0.97, p <.05). The effect of perceived neighborhood social cohesion remained significant after adjusting for a comprehensive set of risk factors. Therefore, perceived neighborhood social cohesion plays an important role in protecting against stroke.
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Recessions, Healthy No More?
Christopher Ruhm
NBER Working Paper, August 2013
Abstract:
Using data from multiple sources, over the 1976-2009 period, I show that total mortality has shifted over time from strongly procyclical to being essentially unrelated to macroeconomic conditions. The relationship also shows some instability over time and is likely to be poorly measured when using short (less than 15 or 20 year) analysis periods. The secular change in the association between macroeconomic conditions and overall mortality primarily reflects trends in effects for specific causes of death, rather than changes in the composition of total mortality across causes. Deaths due to cardiovascular disease and transport accidents continue to be procyclical (although possibly less so than in the past), whereas strong countercyclical patterns of cancer fatalities and some external sources of death (particularly those due to accidental poisoning) have emerged over time. The changing effect of macroeconomic conditions on cancer deaths may partially reflect the increasing protective influence of financial resources, perhaps because these can be used to obtain sophisticated (and expensive) treatments that have become available in recent years. That observed for accidental poisoning probably has occurred because declines in mental health during economic downturns are increasingly associated with the use of prescribed or illicitly obtained medications that carry risks of fatal overdoses.
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Health and Health Behaviors during the Worst of Times: Evidence from the Great Recession
Erdal Tekin, Chandler McClellan & Karen Jean Minyard
NBER Working Paper, July 2013
Abstract:
While previous studies have shown that recessions are associated with better health outcomes and behaviors, the focus of these studies has been on the relatively milder recessions of the late 20th century. In this paper, we examine if the previously established counter-cyclical pattern in health and heath behaviors is held during the Great Recession. Using data from the Behavioral Risk Factor Surveillance System (BRFSS) between 2005 and 2011 and focusing on a wide range of outcomes capturing health and health behaviors, we show that the association between economic deterioration and these outcomes has weakened considerably during the recent recession. In fact, majority of our estimates indicate that the relationship has practically become zero, though subtle differences exist among various sub-populations. Our results are consistent with the evidence emerging from several recent studies that suggests that the relationship between economic activity and health and health behaviors has become less noticeable in the recent years.
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Safety in Numbers: Are Major Cities the Safest Places in the United States?
Sage Myers et al.
Annals of Emergency Medicine, forthcoming
Study objectives: Many US cities have experienced population reductions, often blamed on crime and interpersonal injury. Yet the overall injury risk in urban areas compared with suburban and rural areas has not been fully described. We begin to investigate this evidence gap by looking specifically at injury-related mortality risk, determining the risk of all injury death across the rural-urban continuum.
Methods: A cross-sectional time-series analysis of US injury deaths from 1999 to 2006 in counties classified according to the rural-urban continuum was conducted. Negative binomial generalized estimating equations and tests for trend were completed. Total injury deaths were the primary comparator, whereas differences by mechanism and age were also explored.
Results: A total of 1,295,919 injury deaths in 3,141 US counties were analyzed. Injury mortality increased with increasing rurality. Urban counties demonstrated the lowest death rates, significantly less than rural counties (mean difference=24.0 per 100,000; 95% confidence interval 16.4 to 31.6 per 100,000). After adjustment, the risk of injury death was 1.22 times higher in the most rural counties compared with the most urban (95% confidence interval 1.07 to 1.39).
Conclusion: Using total injury death rate as an overall safety metric, US urban counties were safer than their rural counterparts, and injury death risk increased steadily as counties became more rural. Greater emphasis on elevated injury-related mortality risk outside of large cities, attention to locality-specific injury prevention priorities, and an increased focus on matching emergency care needs to emergency care resources are in order.
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The Cognitive Effects of Micronutrient Deficiency: Evidence from Salt Iodization in the United States
James Feyrer, Dimitra Politi & David Weil
NBER Working Paper, July 2013
Abstract:
Iodine deficiency is the leading cause of preventable mental retardation in the world today. The condition, which was common in the developed world until the introduction of iodized salt in the 1920s, is connected to low iodine levels in the soil and water. We examine the impact of salt iodization on cognitive outcomes in the US by taking advantage of this natural geographic variation. Salt was iodized over a very short period of time beginning in 1924. We use military data collected during WWI and WWII to compare outcomes of cohorts born before and after iodization, in localities that were naturally poor and rich in iodine. We find that for the one quarter of the population most deficient in iodine this intervention raised IQ by approximately one standard deviation. Our results can explain roughly one decade's worth of the upward trend in IQ in the US (the Flynn Effect). We also document a large increase in thyroid related deaths following the countrywide adoption of iodized salt, which affected mostly older individuals in localities with high prevalence of iodine deficiency.
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Eliminating Malaria in the American South: An Analysis of the Decline of Malaria in 1930s Alabama
Daniel Sledge & George Mohler
American Journal of Public Health, August 2013, Pages 1381-1392
Abstract:
Until the 1930s, malaria was endemic throughout large swaths of the American South. We used a Poisson mixture model to analyze the decline of malaria at the county level in Alabama (an archetypical Deep South cotton state) during the 1930s. Employing a novel data set, we argue that, contrary to a leading theory, the decline of malaria in the American South was not caused by population movement away from malarial areas or the decline of Southern tenant farming. We elaborate and provide evidence for an alternate explanation that emphasizes the role of targeted New Deal–era public health interventions and the development of local-level public health infrastructure. We show that, rather than disappearing as a consequence of social change or economic improvements, malaria was eliminated in the Southern United States in the face of economic dislocation and widespread and deep-seated poverty.
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The health effects of leaving school in a bad economy
Johanna Catherine Maclean
Journal of Health Economics, September 2013, Pages 951–964
Abstract:
This study investigates the lasting health effects of leaving school in a bad economy. Three empirical patterns motivate this study: leaving school in a bad economy has persistent and negative career effects, career and health outcomes are correlated, and fluctuations in contemporaneous economic conditions affect health in the short-run. I draw data from the National Longitudinal Survey of Youth 1979 Age 40 Health Supplement. Members of my sample left school between 1976 and 1992. I find that men who left school when the school-leaving state unemployment rate was high have worse health at age 40 than otherwise similar men, while leaving school in a bad economy lowers depressive symptoms at age 40 among women. A 1 percentage point increase in the school-leaving state unemployment rate leads to a 0.5% to 18% reduction in the measured health outcomes among men and a 6% improvement in depressive symptoms among women.
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Disease Incidence and Mortality Among Older Americans and Europeans
Aida Sole-Auro et al.
RAND Working Paper, July 2013
Abstract:
Recent research has shown a widening gap in life expectancy at age 50 between the U.S. and Europe, as well as large differences in the prevalence of diseases at these ages. Little is known about the processes determining international differences in the prevalence of chronic diseases. Higher prevalence of disease could result from either higher incidence or longer disease-specific survival. This paper uses comparable longitudinal data from 2004 and 2006 for populations aged 50 to 79 from the U.S. and a selected group of European countries to examine age-specific differences in prevalence and incidence of heart disease, stroke, lung disease, diabetes, hypertension, and cancer as well as mortality associated with each disease. Not surprisingly, it finds that Americans have higher disease prevalence. However, incidence of most diseases and survival conditional on disease is higher in Europe at older ages, in particular after age 60. The survival advantage in Europe tends to disappear when we control for co-morbidities but does not suggest a survival advantage in the U.S. Therefore, the origin of the higher disease prevalence at older ages in the U.S. is to be found in higher incidence and prevalence earlier in the life course.
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Neighborhood Socioeconomic Circumstances and the Co-Occurrence of Unhealthy Lifestyles: Evidence from 206,457 Australians in the 45 and Up Study
Xiaoqi Feng & Thomas Astell-Burt
PLoS ONE, August 2013
Background: Research on the co-occurrence of unhealthy lifestyles has tended to focus mainly upon the demographic and socioeconomic characteristics of individuals. This study investigated the relevance of neighborhood socioeconomic circumstance for multiple unhealthy lifestyles.
Method: An unhealthy lifestyle index was constructed for 206,457 participants in the 45 and Up Study (2006–2009) by summing binary responses on smoking, alcohol, physical activity and five diet-related variables. Higher scores indicated the co-occurrence of unhealthy lifestyles. Association with self-rated health, quality of life; and risk of psychological distress was investigated using multilevel logistic regression. Association between the unhealthy lifestyle index with neighborhood characteristics (local affluence and geographic remoteness) were assessed using multilevel linear regression, adjusting for individual-level characteristics.
Results: Nearly 50% of the sample reported 3 or 4 unhealthy lifestyles. Only 1.5% reported zero unhealthy lifestyles and 0.2% had all eight. Compared to people who scored zero, those who scored 8 (the ‘unhealthiest’ group) were 7 times more likely to rate their health as poor (95%CI 3.6, 13.7), 5 times more likely to report poor quality of life (95%CI 2.6, 10.1), and had a 2.6 times greater risk of psychological distress (95%CI 1.8, 3.7). Higher scores among men decreased with age, whereas a parabolic distribution was observed among women. Neighborhood affluence was independently associated with lower scores on the unhealthy lifestyle index. People on high incomes scored higher on the unhealthy lifestyle index if they were in poorer neighborhoods, while those on low incomes had fewer unhealthy lifestyles if living in more affluent areas.
Interpretation: Residents of deprived neighborhoods tend to report more unhealthy lifestyles than their peers in affluent areas, regardless of their individual demographic and socioeconomic characteristics. Future research should investigate the trade-offs of population-level versus geographically targeted multiple lifestyle interventions.
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The cost of uncertain life span
Ryan Edwards
Journal of Population Economics, October 2013, Pages 1485-1522
Abstract:
Much uncertainty surrounds the length of human life. The standard deviation in adult life span is about 15 years in the USA, and theory and evidence suggest that it is costly. I calibrate a utility-theoretic model that shows that 1 year in standard deviation is worth about half a life year. Differences in variance exacerbate health inequalities between and among rich and poor countries. Accounting for the cost of life-span variance appears to amplify recently discovered patterns of convergence in world average human well-being because the component of variance due to infant mortality has exhibited even more convergence than life expectancy.
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Television-Related Injuries to Children in the United States, 1990–2011
Ana De Roo, Thiphalak Chounthirath & Gary Smith
Pediatrics, August 2013, Pages 267 -274
Objective: To investigate the epidemiology of television (TV)-related injuries to children in the United States.
Methods: Using data from the National Electronic Injury Surveillance System, children aged <18 years treated in United States hospital emergency departments for an injury associated with a TV from 1990 through 2011 were investigated.
Results: An estimated 380 885 patients aged <18 years were treated in emergency departments for a TV-related injury during the 22-year study period, which equals an annual average of 17 313 children. The median age of patients was 3 years; children <5 years represented 64.3% of patients, and boys comprised 60.8%. The average annual injury rate was 2.43 (95% confidence interval [CI]: 2.07–2.80) injuries per 10 000 children aged <18 years, with a range of 2.15 (95% CI: 1.64–2.66) to 2.90 (95% CI: 2.31–3.49). Although the overall injury rate was steady, the number and rate of injuries associated with falling TVs increased significantly by 125.5% and 95.3%, respectively, during the study period. In addition, there was a significant 344.1% increase in the number of injuries associated with a TV falling from a dresser/bureau/chest of drawers/armoire during 1995–2011.
Conclusions: The rate of pediatric injuries caused by falling TVs is increasing, which underscores the need for increased prevention efforts. Prevention strategies include public education, provision of TV anchoring devices at the point of sale of TVs, TV anchoring device distribution programs, strengthening of standards for TV stability, and redesign of TVs to improve stability.
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Chronic illness: A revisionist account
David Armstrong
Sociology of Health & Illness, forthcoming
Abstract:
This article challenges the generally accepted thesis that the emergence and dominance of chronic illness over the last half century is due to the receding tide of acute infectious diseases and an ageing population. Instead, through an analysis of contemporary reports in the Journal of the American Medical Association, it is argued that the construct of chronic illness emerged as part of a new focus on the downstream consequences of disease and as a means of transferring what had been seen as the natural processes of ageing and senescence into an explanatory model based on pathological processes. The widely accepted idea of an epidemiological transition in illness prevalence has served to conceal the ways in which medicine has extended its remit and suppressed alternative explanatory frameworks.
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Evidence for Significant Compression of Morbidity In the Elderly U.S. Population
David Cutler, Kaushik Ghosh & Mary Beth Landrum
NBER Working Paper, August 2013
Abstract:
The question of whether morbidity is being compressed into the period just before death has been at the center of health debates in the United States for some time. Compression of morbidity would lead to longer life but less rapid medical spending increases than if life extension were accompanied by expanding morbidity. Using nearly 20 years of data from the Medicare Current Beneficiary Survey, we examine how health is changing by time period until death. We show that functional measures of health are improving, and more so the farther away from death the person is surveyed. Disease rates are relatively constant at all times until death. On net, there is strong evidence for compression of morbidity based on measured disability, but less clear evidence based on disease-free survival.
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Physical and cognitive functioning of people older than 90 years: A comparison of two Danish cohorts born 10 years apart
Kaare Christensen et al.
Lancet, forthcoming
Background: A rapidly increasing proportion of people in high-income countries are surviving into their tenth decade. Concern is widespread that the basis for this development is the survival of frail and disabled elderly people into very old age. To investigate this issue, we compared the cognitive and physical functioning of two cohorts of Danish nonagenarians, born 10 years apart.
Methods: People in the first cohort were born in 1905 and assessed at age 93 years (n=2262); those in the second cohort were born in 1915 and assessed at age 95 years (n=1584). All cohort members were eligible irrespective of type of residence. Both cohorts were assessed by surveys that used the same design and assessment instrument, and had almost identical response rates (63%). Cognitive functioning was assessed by mini-mental state examination and a composite of five cognitive tests that are sensitive to age-related changes. Physical functioning was assessed by an activities of daily living score and by physical performance tests (grip strength, chair stand, and gait speed).
Findings: The chance of surviving from birth to age 93 years was 28% higher in the 1915 cohort than in the 1905 cohort (6•50% vs 5•06%), and the chance of reaching 95 years was 32% higher in 1915 cohort (3•93% vs 2•98%). The 1915 cohort scored significantly better on the mini-mental state examination than did the 1905 cohort (22•8 [SD 5•6] vs 21•4 [6•0]; p<0•0001), with a substantially higher proportion of participants obtaining maximum scores (28—30 points; 277 [23%] vs 235 [13%]; p<0•0001). Similarly, the cognitive composite score was significantly better in the 1915 than in the 1905 cohort (0•49 [SD 3•6] vs 0•01 [SD 3•6]; p=0•0003). The cohorts did not differ consistently in the physical performance tests, but the 1915 cohort had significantly better activities of daily living scores than did the 1905 cohort (2•0 [SD 0•8] vs 1•8 [0•7]; p<0•0001).
Interpretation: Despite being 2 years older at assessment, the 1915 cohort scored significantly better than the 1905 cohort on both the cognitive tests and the activities of daily living score, which suggests that more people are living to older ages with better overall functioning.
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The injured elderly: A rising tide
David Ciesla et al.
Surgery, August 2013, Pages 291–298
Background: Injury remains a public health challenge despite advances in trauma care. Periodic survey of injury epidemiology is essential to the trauma system's continuous performance improvement. We undertook this study to characterize the changes in Florida injury rates during the past 15 years.
Methods: Injured patients were identified with the use of a statewide database over 15 years ending in 2010. Population data were obtained from the U.S. Census. Severe injury was defined by International Classification Injury Severity Scores less than 0.85. Injury rates were expressed in discharges per 100,000 residents. Trends were analyzed by linear regression.
Results: The 1.5 million patient discharges consisted of 5.2% children, 39.7% adults, and 55.1% elderly. The overall injury rate decreased in children by 18% but increased in adults by 2% and in the elderly by 17% during the study period. The proportion of severe injuries decreased in children and the elderly but did not change in adults. Injury patterns changed in all age groups.
Conclusion: Injury in the elderly is increasing at a rate seven times that of adults. In 2010, the elderly accounted for only 17% of the population but 55% of injury-related discharges. These trends have dramatic implications for the design of future trauma systems and health care resource use.
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Long-run trends of human aging and longevity
Holger Strulik & Sebastian Vollmer
Journal of Population Economics, October 2013, Pages 1303-1323
Abstract:
Over the last 200 years, humans experienced a huge increase of life expectancy. These advances were largely driven by extrinsic improvements of their environment (for example, the available diet, disease prevalence, vaccination, and the state of hygiene and sanitation). In this paper, we ask whether future improvements of life expectancy will be bounded from above by human life span. Life span, in contrast to life expectancy, is conceptualized as a biological measure of longevity driven by the intrinsic rate of bodily deterioration. In order to pursue our question, we first present a modern theory of aging developed by bio-gerontologists and show that immutable life span would put an upper limit on life expectancy. We then show for a sample of developed countries that human life span thus defined was indeed constant until the mid-twentieth century but increased since then in sync with life expectancy. In other words, we find evidence for manufactured life span.
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A two-decade comparison of prevalence of dementia in individuals aged 65 years and older from three geographical areas of England: Results of the Cognitive Function and Ageing Study I and II
Fiona Matthews et al.
Lancet, forthcoming
Background: The prevalence of dementia is of interest worldwide. Contemporary estimates are needed to plan for future care provision, but much evidence is decades old. We aimed to investigate whether the prevalence of dementia had changed in the past two decades by repeating the same approach and diagnostic methods as used in the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS) in three of the original study areas in England.
Methods: Between 1989 and 1994, MRC CFAS investigators did baseline interviews in populations aged 65 years and older in six geographically defined areas in England and Wales. A two stage process, with screening followed by diagnostic assessment, was used to obtain data for algorithmic diagnoses (geriatric mental state–automated geriatric examination for computer assisted taxonomy), which were then used to estimate dementia prevalence. Data from three of these areas—Cambridgeshire, Newcastle, and Nottingham—were selected for CFAS I. Between 2008 and 2011, new fieldwork was done in the same three areas for the CFAS II study. For both CFAS I and II, each area needed to include 2500 individuals aged 65 years and older to provide power for geographical and generational comparison. Sampling was stratified according to age group (65–74 years vs ≥75 years). CFAS II used identical sampling, approach, and diagnostic methods to CFAS I, except that screening and assessement were combined into one stage. Prevalence estimates were calculated using inverse probability weighting methods to adjust for sampling design and nonresponse. Full likelihood Bayesian models were used to investigate informative non-response.
Findings: 7635 people aged 65 years or older were interviewed in CFAS I (9602 approached, 80% response) in Cambridgeshire, Newcastle, and Nottingham, with 1457 being diagnostically assessed. In the same geographical areas, the CFAS II investigators interviewed 7796 individuals (14242 approached, 242 with limited frailty information, 56% response). Using CFAS I age and sex specific estimates of prevalence in individuals aged 65 years or older, standardised to the 2011 population, 8•3% (884000) of this population would be expected to have dementia in 2011. However, CFAS II shows that the prevalence is lower (6•5%; 670000), a decrease of 1•8% (odds ratio for CFAS II vs CFAS I 0•7, 95% CI 0•6–0•9, p=0•003). Sensitivity analyses suggest that these estimates are robust to the change in response.
Interpretation: This study provides further evidence that a cohort effect exists in dementia prevalence. Later-born populations have a lower risk of prevalent dementia than those born earlier in the past century.
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Prospective Study of Ultraviolet Radiation Exposure and Mortality Risk in the United States
Shih-Wen Lin et al.
American Journal of Epidemiology, 15 August 2013, Pages 521-533
Abstract:
Geographic variations in mortality rate in the United States could be due to several hypothesized factors, one of which is exposure to solar ultraviolet radiation (UVR). Limited evidence from previous prospective studies has been inconclusive. The association between ambient residential UVR exposure and total and cause-specific mortality risks in a regionally diverse cohort (346,615 white, non-Hispanic subjects, 50–71 years of age, in the National Institutes of Health (NIH)–AARP Diet and Health Study) was assessed, with accounting for individual-level confounders. UVR exposure (averaged for 1978–1993 and 1996–2005) from NASA's Total Ozone Mapping Spectrometer was linked to the US Census Bureau 2000 census tract of participants' baseline residence. Multivariate-adjusted Cox proportional-hazards models were used to estimate hazard ratios and 95% confidence intervals. Over 12 years, UVR exposure was associated with total deaths (n = 41,425; hazard ratio for highest vs. lowest quartiles (HRQ4 vs. Q1) = 1.06, 95% confidence interval (CI): 1.03, 1.09; Ptrend < 0.001) and with deaths (all Ptrend < 0.05) due to cancer (HRQ4 vs. Q1 = 1.06, 95% CI: 1.02, 1.11), cardiovascular disease (HRQ4 vs. Q1 = 1.06, 95% CI: 1.00, 1.12), respiratory disease (HRQ4 vs. Q1 = 1.37, 95% CI: 1.21, 1.55), and stroke (HRQ4 vs. Q1 = 1.16, 95% CI: 1.01, 1.33) but not with deaths due to injury, diabetes, or infectious disease. These results suggest that UVR exposure might not be beneficial for longevity.