Why representativeness should be avoided Rothman, Kenneth J; Gallacher, John E J; Hatch, Elizabeth E
International journal of epidemiology
42, Issue:
4
Journal Article
Socio-economic status (SES) and biological aging are risk factors for dementia, including Alzheimer's disease, however, it is less clear if the associations with SES vary sufficiently across ...different biological age strata. We used data from 331,066 UK Biobank participants aged 38-73 with mean follow-up of 12 years to examine if associations between SES (assessed by educational attainment, employment status and household income) and dementia and Alzheimer's disease are modified by biological age (assessed by leucocyte telomere length: LTL). Diagnosis of events was ascertained through hospital admissions data. Cox regressions were used to estimate hazard ratios HRs. A consistent dose-response relationship was found, with participants in low SES and shorter LTL strata (double-exposed group) reporting 3.28 (95% confidence interval CI 2.57-4.20) and 3.44 (95% CI 2.35-5.04) times higher risks of incident dementia and Alzheimer's disease respectively, compared to those of high SES and longer LTL (least-exposed group). Of interest is a synergistic interaction between SES and LTL to increase risk of dementia (RERI 0.57, 95% CI 0.07-1.06) and Alzheimer's disease (RERI 0.79, 95% CI 0.02-1.56). Our findings that SES and biological age (LTL) are synergistic risk factors of dementia and Alzheimer's disease may suggest the need to target interventions among vulnerable sub-groups.
The urban environment has become the main place that people live and work. As a result it can have profound impacts on our health. While much of the literature has focused on physical health, less ...attention has been paid to the possible psychological impacts of the urban environment. In order to understand the potential relevance and importance of the urban environment to population mental health, we carried out a systematic review to examine the associations between objective measurements of the urban environment and psychological distress, independently of the individual's subjective perceptions of the urban environment.
11 peer-reviewed papers published in English between January 2000 and February 2012 were identified. All studies were cross-sectional. Despite heterogeneity in study design, the overall findings suggested that the urban environment has measurable associations with psychological distress, including housing with deck access, neighbourhood quality, the amount of green space, land-use mix, industry activity and traffic volume. The evidence supports the need for development of interventions to improve mental health through changing the urban environment. We also conclude that new methods for measuring the urban environment objectively are needed which are meaningful to planners. In particular, future work should look at the spatial-temporal dynamic of the urban environment measured in Geographical Information System (GIS) in relation to psychological distress.
•A systematic review examines the associations between objective measurements of the urban environment and psychological distress.•The overall findings suggested that the urban environment has measurable associations with psychological distress.•The evidence supports the need for development of interventions to improve mental health through changing the urban environment.•Future work needs to examine the longitudinal effects of the urban environment measured objectively on psychological distress.•The impact of the urban environment away from home on psychological distress needs to be further explored.
Increased urbanisation and the associated reduced contact of individuals with natural environments have led to a rise in mental disorders, including depression. Residential greenness, a fundamental ...component of urban design, has been shown to reduce the public health burden of mental disorders. The present study investigates the association between residential green exposure and prevalence of major depressive disorders using a large and diverse cross-sectional dataset from the UK Biobank.
In this cross-sectional, observational, associational study, we used baseline data from the UK Biobank cohort of participants aged 37–73 years from across the UK. Environmental exposure data were derived from a modelled and linked built environment database. Residential greenness was assessed with a 0·5 m resolution Normalised Difference Vegetation Index, which is derived from spectral reflectance measurements in remotely sensed colour infrared data and measured within geocoded dwelling catchments. Other environment metrics included street-level movement density, terrain, and fine particulate exposures. A series of logistic models examined associations between residential greenness and odds of major depressive disorder after adjusting for activity-influencing environments and individual covariates.
Of 122 993 participants with data on major depressive disorder, the study analytical sample comprised 94 879 (77·1%) participants recruited across ten UK Biobank assessment centres between April 29, 2009, and Oct 1, 2010. A protective effect of greenness on depression was consistently observed, with 4·0% lower odds of major depressive disorder per interquartile increment in Normalised Difference Vegetation Index greenness (odds ratio 0·960, 95% CI 0·93–0·99; p=0·0044). Interaction analyses indicated that the beneficial effects of greenness were more pronounced among women, participants younger than 60 years, and participants residing in areas with low neighbourhood socioeconomic status or high urbanicity.
The results point to the benefits of well designed green environments on mental health. Further longitudinal studies are needed to decipher causal pathways. In the UK, policies aimed at optimising allocation and design of green spaces might help preserve psychological ecosystem services, thereby, improving the mental wellbeing of populations and enhancing the mental capital of cities.
University of Hong Kong, UK Biobank, and the UK Economic & Social Research Council.
Both physical and psychological health outcomes have been associated with exposure to environmental noise. Noise sensitivity could have the same moderating effect on physical and psychological health ...outcomes related to environmental noise exposure as on annoyance but this has been little tested.
A cohort of 2398 men between 45 and 59 years, the longitudinal Caerphilly Collaborative Heart Disease study, was established in 1984/88 and followed into the mid-1990s. Road traffic noise maps were assessed at baseline. Psychological ill-health was measured in phase 2 in 1984/88, phase 3 (1989/93) and phase 4 (1993/7). Ischaemic heart disease was measured in clinic at baseline and through hospital records and records of deaths during follow up. We examined the longitudinal associations between road traffic noise and ischaemic heart disease morbidity and mortality using Cox Proportional Hazard Models and psychological ill-health using Logistic Regression; we also examined whether noise sensitivity and noise annoyance might moderate these associations. We also tested if noise sensitivity and noise annoyance were longitudinal predictors of ischaemic heart disease morbidity and mortality and psychological ill-health.
Road traffic noise was not associated with ischaemic heart disease morbidity or mortality. Neither noise sensitivity nor noise annoyance moderated the effects of road traffic noise on ischaemic heart disease morbidity or mortality. High noise sensitivity was associated with lower ischaemic heart disease mortality risk (HR = 0.74, 95%CI 0.57, 0.97). Road traffic noise was associated with Phase 4 psychological ill-health but only among those exposed to 56-60dBA (fully adjusted OR = 1.82 95%CI 1.07, 3.07). Noise sensitivity moderated the association of road traffic noise exposure with psychological ill-health. High noise sensitivity was associated longitudinally with psychological ill-health at phase 3 (OR = 1.85 95%CI 1.23, 2.78) and phase 4 (OR = 1.65 95%CI 1.09, 2.50). Noise annoyance predicted psychological ill-health at phase 4 (OR = 2.47 95%CI 1.00, 6.13).
Noise sensitivity is a specific predictor of psychological ill-health and may be part of a wider construct of environmental susceptibility. Noise sensitivity may increase the risk of psychological ill-health when exposed to road traffic noise. Noise annoyance may be a mediator of the effects of road traffic noise on psychological ill-health.
Cathie Sudlow and colleagues describe the UK Biobank, a large population-based prospective study, established to allow investigation of the genetic and non-genetic determinants of the diseases of ...middle and old age.
The health effects of milk and dairy food consumption would best be determined in randomised controlled trials. No adequately powered trial has been reported and none is likely because of the numbers ...required. The best evidence comes, therefore, from prospective cohort studies with disease events and death as outcomes. Medline was searched for prospective studies of dairy food consumption and incident vascular disease and Type 2 diabetes, based on representative population samples. Reports in which evaluation was in incident disease or death were selected. Meta-analyses of the adjusted estimates of relative risk for disease outcomes in these reports were conducted. Relevant case–control retrospective studies were also identified and the results are summarised in this article. Meta-analyses suggest a reduction in risk in the subjects with the highest dairy consumption relative to those with the lowest intake: 0.87 (0.77, 0.98) for all-cause deaths, 0.92 (0.80, 0.99) for ischaemic heart disease, 0.79 (0.68, 0.91) for stroke and 0.85 (0.75, 0.96) for incident diabetes. The number of cohort studies which give evidence on individual dairy food items is very small, but, again, there is no convincing evidence of harm from consumption of the separate food items. In conclusion, there appears to be an enormous mis-match between the evidence from long-term prospective studies and perceptions of harm from the consumption of dairy food items.
BackgroundDisturbed sleep is common throughout the community and is associated with an increase in daytime sleepiness, both of which, in turn are associated with an increased risk of ischaemic ...vascular disease. The hypothesis that sleep disturbances are predictive of dementia, and in particular vascular dementia was tested in a large community-based cohort of older men.MethodsA questionnaire on sleep disturbances was administered to 1986 men aged 55–69 years in the Caerphilly Cohort Study and 10 years later the men were examined clinically for evidence of dementia or cognitive impairment with no dementia (CIND).FindingsApproximately 20% of the men reported disturbed sleep and 30% reported ‘severe’ daytime sleepiness. Ten years later 1225 men (75% of the surviving men in the cohort) were tested and 268 (22%) were found to be cognitively impaired with 93 (7.6%) showing clear evidence of dementia and the remaining 175 (14.3%) showing evidence of CIND. After adjustment for possible confounding, including cognitive function and the taking of sleeping tablets at baseline, sleep disturbances appeared to be predictive of dementia and CIND of vascular origin, while there was no suggestion of prediction of non-vascular cognitive impairment by sleep. Prediction of vascular dementia appeared to be particularly strong for daytime sleepiness, with an adjusted OR of 4.44 (95% CI 2.05 to 9.61). Further adjustments for psychological distress at baseline reduced the size of the relationships, but the ORs remain large, consistent with a direct positive effect of sleep disturbance on vascular dementia.InterpretationSleep disturbances, and in particular severe daytime sleepiness, appear to be strongly predictive of vascular dementia, but have no predictive power for non vascular dementia.
With rapid urbanization, built environment has emerged as a set of modifiable factors of cardiovascular disease (CVD) risks. We conducted a systematic review to synthesize evidence on the ...associations of attributes of urban built environment (e.g. residential density, land use mix, greenness and walkability) with cardiovascular risk factors (e.g. hypertension and arterial stiffness) and major CVD events including mortality. A total of 63 studies, including 31 of cross-sectional design and 32 of longitudinal design conducted across 21 geographical locations and published between 2012 and 2023 were extracted for review. Overall, we report moderately consistent evidence of protective associations of greenness with cardiovascular risks and major CVD events (cross-sectional studies: 12 of 15 on hypertension/blood pressure (BP) and 2 of 3 on arterial stiffness; and longitudinal studies: 6 of 8 on hypertension/BP, 7 of 8 on CVD mortality, 3 of 3 on ischemic heart disease mortality and 5 of 8 studies on stroke hospitalization or mortality reporting significant inverse associations). Consistently, walkability was associated with lower risks of hypertension, arterial stiffness and major CVD events (cross-sectional studies: 11 of 12 on hypertension/BP and 1 of 1 on arterial stiffness; and longitudinal studies: 3 of 6 on hypertension/BP and 1 of 2 studies on CVD events being protective). Sixty-seven percent of the studies were rated as “probably high” risk of confounding bias because of inability to adjust for underlying comorbidities/family history of diseases in their statistical models. Forty-six percent and 14% of the studies were rated as “probably high” risk of bias for exposure and outcome measurements, respectively. Future studies with robust design will further help elucidate the linkages between urban built environment and cardiovascular health, thereby informing planning policies for creating healthy cities.
Later-life depression appears to be different to depression in younger adults. The underlying pathology may also differ. Depression is linked to dementia but whether it is a risk factor or an early ...sign of a developing dementia remains unclear. Neuroinflammation is increasingly recognised in both depression and Alzheimer's Disease.
To investigate the link between depression, inflammation and dementia. We hypothesised that recurrent depression has adverse effects on performance in cognitive tests in middle to older age and that this effect is modified by anti-inflammatory medication.
We identified UK based cohort studies which included individuals aged >50, had medical information, results from detailed cognitive testing and had used reliable measures to assess depression. Individuals with recurrent depression had ≥ 2 episodes of depression. Controls had no history of depression. The presence/absence of inflammatory illness was assessed using a standardised list of inflammatory conditions. Individuals with dementia, chronic neurological and psychotic conditions were excluded.
Logistic and linear regression were used to examine the effect of depression on cognitive test performance and the mediating effect of chronic inflammation.
Unexpectedly in both studies there was evidence that those with recurrent depression performed better in some cognitive tasks (e.g Mill Hill vocabulary) but worse in others (e.g. reaction time). In UK Biobank there was no evidence that anti-inflammatories moderated this effect.
Cross-sectional assessment of cognition.
Although previous recurrent depression has small effects on cognitive test performance this does not appear to be mediated by chronic inflammatory disease.
•We assessed whether recurrent depression affects cognition and if anti-inflammatory medication modifies this effect.•In UK Biobank individuals with recurrent depression were more accurate on a pairs matching task but had slower reaction times.•In Generation Scotland those with recurrent depression had better verbal fluency and worse performance on the digit symbol substitution test.•There was no evidence that these changes were altered in those taking anti-inflammatory medications.