What causes health inequality? A systematic review on the relative importance of social causation and health selection.

BACKGROUND: The social gradient in health is one of the most reliable findings in public health research. The two competing hypotheses that try to explain this gradient are known as the social causation and the health selection hypothesis. There is currently no synthesis of the results of studies that test both hypotheses. METHODS: We provide a systematic review of the literature that has addressed both the health selection and social causation hypotheses between 1994 and 2013 using seven databases following PRISMA rules. RESULTS: The search strategy resulted in 2952 studies, of which, we included 34 in the review. The synthesis of these studies suggests that there is no general preference for either of the hypotheses (12 studies for social causation, 10 for health selection). However, both a narrative synthesis as well as meta-regression results show that studies using indicators for socio-economic status (SES) that are closely related to the labor market find equal support for health selection and social causation, whereas indicators of SES like education and income yield results that are in favor of the social causation hypothesis. High standards in statistical modeling were associated with more support for health selection. CONCLUSIONS: The review highlights the fact that the causal mechanisms behind health inequalities are dependent on whether or not the dimension being analyzed closely reflects labor market success. Additionally, further research should strive to improve the statistical modeling of causality, as this might influence the conclusions drawn regarding the relative importance of health selection and social causation.

Understanding how young people transitioning from out-of-home care acquire and develop independent living skills and knowledge: A systematic review of longitudinal studies.

Young people leaving state care often experience hardship in many areas of their life. At a population level, their outcomes in early adulthood are poorer compared to general populations. Effective preparation for leaving care and post-care support systems is vital to improving outcomes. Individual and systemic support for young people to acquire Independent Living Skills (ILS) in the following eight ILS domains have been identified: Financial Management, Knowledge of Accessing Available Supports, Managing Housing, Education Planning, Job Seeking, Health Risk Management, Domestic and Self-help Task, and Managing Relationships. This systematic review aims to identify, summarise, and appraise longitudinal studies that address ILS across these ILS domains to understand better how outcomes could be improved. Seven databases (CINAHL, Embase, ProQuest, PsychINFO, PubMed, Scopus, and Web of Science) were searched on 20th July 2023. In total, twenty-seven studies published between 1994 and 2022 from various countries met the eligibility criteria. The included studies reported on 2-4 waves and adopted different methodological approaches. Study quality was scored using Qualsyst. Study characteristics and details of the interventions are presented in tables. Studies cover overlapping ILS domains, which are mapped in a matrix. Results revealed that nearly three-quarters (74% or 20 out of 27) of studies explored four or fewer of the eight ILS domains. The most frequent ILS domain covered was 'Knowledge of Accessing Available Supports' (19/27 studies). The main conclusion considers the concept of independence as a misnomer, with ILS covering multiple, intersecting, and interdependent domains, which ultimately help and hinder one another. Further research is required to adopt a more comprehensive approach encompassing all the domains to better inform policy, programs, and practice. A limitation is that a meta-analysis was not conducted for this review. This study registered a 'Protocol' with OSF Registries (DOI: 10.17605/OSF.IO/MJ3ZX) on June 5th, 2022.

Trajectories of homelessness and association with mental health and substance use disorders among young people transitioning from out-of-home care in Australia.

BACKGROUND: Researchers have examined sub-groups that may exist among young people transitioning from out-of-home care (OHC) using various theoretical models. However, this population group has not been examined for trajectories of homelessness risk. OBJECTIVES: To examine whether different subtypes of homelessness risk exist among young people transitioning from care and whether these trajectories of homelessness are associated with mental health and substance use disorders. PARTICIPANTS AND SETTING: A retrospective population-based cohort study was conducted from a population of 1018 young people (aged 15-18 years) who transitioned from out-of-home in 2013 to 2014 in the state of Victoria, Australia, with follow-up to 2018. METHODS: Latent Class Growth Analysis was conducted using linked data from homelessness data collections, child protection, mental health information systems, alcohol and drug use, and youth justice information systems. RESULTS: Three sub-groups of young people were identified. The 'moving on' group (88 %) had the lowest levels of homelessness, with the slope of this trajectory remaining almost stable. The 'survivors' (7 %) group started off with a high risk of homelessness, followed by a sharp decrease in homelessness risk over time. The 'complex' (5 %) group started off with a low risk of homelessness but faced sharp increases in the risk of homelessness over time. CONCLUSIONS: Our study demonstrates that subgroups of young people transitioning from care exist with distinct longitudinal trajectories of homelessness, and these classes are associated with different risk factors. Early intervention and different approaches to tackling homelessness should be considered for these three distinct groups before transitioning from care and during the first few years after leaving care.

Defining a threshold above which an adult can be considered to frequently use ambulance services: a retrospective cross-sectional study of emergency calls to an ambulance service in England.

Objective: There is no empirical definition of adult frequent use of ambulance services. This study aimed to define a threshold, and utilise this to explore characteristics of people frequently using services. Methods: This was a retrospective cross-sectional study in a single ambulance service in England. Routinely collected, pseudo-anonymised call- and patient-level data were collected for two months (January and June 2019). Incidents, defined as independent episodes of care, were analysed using a zero-truncated Poisson regression model to determine a suitable frequent-use threshold, with comparisons subsequently made between frequent and non-frequent users. Results: A total of 101,356 incidents involving 83,994 patients were included in the analysis. Two potentially appropriate thresholds were identified: five incidents per month (A); and six incidents per month (B). Threshold A produced 3137 incidents from 205 patients, with five patients likely false-positive identifications. Threshold B produced 2217 incidents from 95 patients, with no false-positive identifications but 100 false-negatives compared to threshold A. Regardless of threshold, frequent users compared to non-frequent users had relatively reduced service use between 08:00 and 15:00, were younger and were more likely to receive lower-priority responses (all p < 0.001). We identified several chief complaints indicative of increased frequent use, including chest pain, psychiatric/suicide attempt and abdominal pains/problems. Conclusions: We suggest a threshold of five incidents per month, with recognition that a small number of patients may be incorrectly identified as using ambulance services frequently. The rationale for this choice is discussed. This threshold may be applicable in wider UK settings and could be used for the routine automated identification of people using ambulance services frequently. The identified characteristics can help inform interventions. Future research should examine applicability of this threshold in other UK ambulance services and countries where patterns and determinants of frequent ambulance use may differ.

Patterns of homelessness and housing instability and the relationship with mental health disorders among young people transitioning from out-of-home care: Retrospective cohort study using linked administrative data.

OBJECTIVES: The study examined the relationship between mental health, homelessness and housing instability among young people aged 15-18 years old who transitioned from out-of-home in 2013 to 2014 in the state of Victoria, Australia with follow-up to 2018. We determined the various mental health disorders and other predictors that were associated with different levels of homelessness risk, including identifying the impact of dual diagnosis of mental health and substance use disorder on homelessness. METHODOLOGY: Using retrospective de-identified linked administrative data from various government departments we identified various dimensions of homelessness which were mapped from the European Topology of Homelessness (ETHOS) framework and associated mental health variables which were determined from the WHO ICD-10 codes. We used ordered logistic regression and Poisson regression analysis to estimate the impact of homelessness and housing instability respectively. RESULTS: A total homelessness prevalence of 60% was determined in the care-leaving population. After adjustment, high risk of homelessness was associated with dual diagnosis of mental health and substance use disorder, intentional self-harm, anxiety, psychotic disorders, assault and maltreatment, history of involvement with the justice system, substance use prior to leaving care, residential and home-based OHC placement and a history of staying in public housing. CONCLUSIONS: There is clearly a need for policy makers and service providers to work together to find effective housing pathways and integrated health services for this heterogeneous group of vulnerable young people with complex health and social needs. Future research should determine longitudinally the bidirectional relationship between mental health disorders and homelessness.

Understanding COVID-19 vaccine hesitancy: A cross-sectional study in Malang District, Indonesia.

Introduction: Vaccine hesitancy could undermine efforts to reduce incidence of coronavirus disease 2019 (COVID-19). Understanding COVID-19 vaccine hesitancy is crucial to tailoring strategies to increase vaccination acceptance. This study aims to investigate the prevalence of and the reasons for COVID-19 vaccine hesitancy in Malang District, Indonesia. Methods: Data come from a cross-sectional study among individuals aged 17-85 years old (N = 3,014). Multivariate ordered logistic regression was used to identify factors associated with postponing or refusing COVID-19 vaccines. The Oxford COVID-19 vaccine hesitancy scale was used to measure vaccine hesitancy. A wide range of reasons for hesitancy, including coronavirus vaccine confidence and complacency, vaccination knowledge, trust and attitude in health workers and health providers, coronavirus conspiracy, anger reaction and need for chaos, populist views, lifestyle, and religious influence, was examined. Results and discussion: The results show that 60.2% of the respondents were hesitant to receive the COVID-19 vaccine. Low confidence and complacency beliefs about the vaccine (OR = 1.229, 95% CI = 1.195-1.264) and more general sources of mistrust within the community, particularly regarding health providers (OR = 1.064, 95% CI = 1.026-1.102) and vaccine developers (OR = 1.054, 95% CI = 1.027-1.082), are associated with higher levels of COVID-19 vaccine hesitancy. Vaccine hesitancy is also associated with anger reactions (OR = 1.019, 95% CI = 0.998-1.040), need for chaos (OR = 1.044, 95% CI = 1.022-1.067), and populist views (OR = 1.028, 95% CI = 1.00-1.056). The findings were adjusted for socio-demographic factors, including age, sex, education, marital status, working status, type of family, household income, religious beliefs, and residency. The results suggest the need for an effective health promotion program to improve community knowledge of the COVID-19 vaccine, while effective strategies to tackle "infodemics" are needed to address hesitancy during a new vaccine introduction program.

Secular Trends in Dementia Free Cognitive Function in Older Adults: A Systematic Review.

BACKGROUND: Although numerous studies have reported a decrease in dementia risk in the last two decades, it is unclear whether dementia-free cognitive function is also changing across generations. OBJECTIVE: The objective was to systematically evaluate the published data on generational differences in cognitive function in the older population. METHODS: Searches were performed on PubMed, Embase, and PsychInfo for articles published in English before 28 June 2021. Included studies were from population-based samples that reported generational differences in cognition in individuals without dementia, aged ≥60 years. RESULTS: 28,101 studies were identified and 15 selected covering the period from 1971 to 2015: including studies from China, Europe, and the USA. The results show generally consistent findings of improvements or stability in dementia free cognitive function in later versus earlier born generations, but not for all cognitive domains. Prevalence of mild cognitive impairment and cognitive impairment no dementia has remained stable in the USA, UK, and China over the last two decades. RESULTS: Prevalence of vascular related mild cognitive impairment has increased in China. Improvements in cognition may only partially be explained by increased educational attainment across generations. CONCLUSION: This review provides evidence for generational effects in dementia-free cognitive function, predominately stability or improvements in performance, in later compared to earlier born individuals across different world regions. There is an urgent need to determine the factors driving such changes and whether they are being experienced in all world regions, particularly low- and middle-income countries where the burden of cognitive impairment is greatest and rising.

Risk of conversion from mild cognitive impairment to dementia in low- and middle-income countries: A systematic review and meta-analysis.

Introduction: With no treatment for dementia, there is a need to identify high risk cases to focus preventive strategies, particularly in low- and middle-income countries (LMICs) where the burden of dementia is greatest. We evaluated the risk of conversion from mild cognitive ompairment (MCI) to dementia in LMICs. Methods: Medline, Embase, PsycINFO, and Scopus were searched from inception until June 30, 2020. The search was restricted to observational studies, conducted in population-based samples, with at least 1 year follow-up. There was no restriction on the definition of MCI used as long as it was clearly defined. PROSPERO registration: CRD42019130958. Results: Ten thousand six hundred forty-seven articles were screened; n = 11 retained. Of the 11 studies, most were conducted in China (n = 7 studies), with only two studies from countries classified as low income. A qualitative analysis of n = 11 studies showed that similar to high-income countries the conversion rate to dementia from MCI was variable (range 6 . 0%-44 . 8%; average follow-up 3 . 7 years [standard deviation = 1 . 2]). A meta-analysis of studies using Petersen criteria (n = 6 studies), found a pooled conversion rate to Alzheimer's disease (AD) of 23 . 8% (95% confidence interval = 15 . 4%-33.4%); approximately one in four people with MCI were at risk of AD in LMICs (over 3 . 0-5 . 8 years follow-up). Risk factors for conversion from MCI to dementia included demographic (e.g., age) and health (e.g., cardio-metabolic disease) variables. Conclusions: MCI is associated with high, but variable, conversion to dementia in LMICs and may be influenced by demographic and health factors. There is a notable absence of data from low-income settings and countries outside of China. This highlights the urgent need for research investment into aging and dementia in LMIC settings. Being able to identify those individuals with cognitive impairment who are at highest risk of dementia in LMICs is necessary for the development of risk reduction strategies that are contextualized to these unique settings.

Non-benzodiazepine hypnotic use for sleep disturbance in people aged over 55 years living with dementia: a series of cohort studies.

BACKGROUND: Sleep disturbance affects around 60% of people living with dementia and can negatively affect their quality of life and that of their carers. Hypnotic Z-drugs (zolpidem, zopiclone and zaleplon) are commonly used to treat insomnia, but their safety and efficacy have not been evaluated for people living with dementia. OBJECTIVES: To estimate the benefits and harms of Z-drugs in people living with dementia with sleep disturbance. DESIGN: A series of observational cohort studies using existing data from (1) primary care linked to hospital admission data and (2) clinical cohort studies of people living with dementia. DATA SOURCES: Primary care study - Clinical Practice Research Datalink linked to Hospital Episode Statistics and Office for National Statistics mortality data. Clinical cohort studies - the Resource Use and Disease Course in Dementia - Nursing Homes (REDIC) study, National Alzheimer's Coordinating Centre (NACC) clinical data set and the Improving Well-being and Health for People with Dementia (WHELD) in nursing homes randomised controlled trial. SETTING: Primary care study - 371 primary care practices in England. Clinical cohort studies - 47 nursing homes in Norway, 34 Alzheimer's disease centres in the USA and 69 care homes in England. PARTICIPANTS: Primary care study - NHS England primary care patients diagnosed with dementia and aged > 55 years, with sleep disturbance or prescribed Z-drugs or low-dose tricyclic antidepressants, followed over 2 years. Clinical cohort studies - people living with dementia consenting to participate, followed over 3 years, 12 years and 9 months, for REDIC, NACC and WHELD, respectively. INTERVENTIONS: The primary exposure was prescription or use of Z-drugs. Secondary exposures included prescription or use of benzodiazepines, low-dose tricyclic antidepressants and antipsychotics. MAIN OUTCOME MEASURES: Falls, fractures, infection, stroke, venous thromboembolism, mortality, cognitive function and quality of life. There were insufficient data to investigate sleep disturbance. RESULTS: The primary care study and combined clinical cohort studies included 6809 and 18,659 people living with dementia, with 3089 and 914 taking Z-drugs, respectively. New Z-drug use was associated with a greater risk of fractures (hazard ratio 1.40, 95% confidence interval 1.01 to 1.94), with risk increasing with greater cumulative dose (p = 0.002). The hazard ratio for Z-drug use and hip fracture was 1.59 (95% confidence interval 1.00 to 2.53) and for mortality was 1.34 (95% confidence interval 1.10 to 1.64). No excess risks of falls, infections, stroke or venous thromboembolism were detected. Z-drug use also did not have an impact on cognition, neuropsychiatric symptoms, disability or quality of life. LIMITATIONS: Primary care study - possible residual confounding because of difficulties in identifying patients with sleep disturbance and by dementia severity. Clinical cohort studies - the small numbers of people living with dementia taking Z-drugs and outcomes not necessarily being measured before Z-drug initiation restricted analyses. CONCLUSIONS: We observed a dose-dependent increase in fracture risk, but no other harms, with Z-drug use in dementia. However, multiple outcomes were examined, increasing the risk of false-positive findings. The mortality association was unlikely to be causal. Further research is needed to confirm the increased fracture risk. Decisions to prescribe Z-drugs may need to consider the risk of fractures, balanced against the impact of improved sleep for people living with dementia and that of their carers. Our findings suggest that when Z-drugs are prescribed, falls prevention strategies may be needed, and that the prescription should be regularly reviewed. FUTURE WORK: More research is needed on safe and effective management strategies for sleep disturbance in people living with dementia. STUDY REGISTRATION: This study is registered as European Union electronic Register of Post-Authorisation Studies (EU PAS) 18006. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 1. See the NIHR Journals Library website for further project information.

WHAT WAS THE PROBLEM?: Poor sleep is common in people living with dementia. It can worsen their own and their carer's quality of life. Sleeping tablets called Z-drugs (zolpidem, zopiclone and zaleplon) are often given to people with dementia. Some studies suggest that Z-drugs may be harmful, but no studies have looked into the effects of Z-drugs for people with dementia. Good sleep is important, but we need to understand if Z-drugs cause harm. WHAT DID WE DO?: Using existing medical records, we compared the quality of life, memory and number of falls, infections, strokes, broken bones and deaths for a group of people living with dementia taking a Z-drug, with those for a group not taking any sleep drug. WHAT DID WE FIND?: Z-drug users were no more likely to suffer falls, infection or stroke, but they were more likely to break a bone. We also found that Z-drug users died earlier, but we could not be sure that this was as a result of taking the Z-drug. Using Z-drugs did not appear to affect quality of life or memory. We talked to carers and health-care practitioners, who told us that decisions about Z-drugs need to balance a range of complicated health and social factors. WHAT DOES THIS MEAN?: We found that people living with dementia who take Z-drugs are more likely to break a bone or to die sooner than similar people with dementia who are not taking Z-drugs. However, we cannot be certain that these problems are caused by Z-drugs, as many other factors can also lead to broken bones and death. Further work is needed to clarify the risk of broken bones, but if sleep problems can be managed in other ways then this may be preferable. Patients and family carers should be involved in decisions about Z-drugs, so that they can balance the possible harms against the benefits.

Prediction of dementia risk in low-income and middle-income countries (the 10/66 Study): an independent external validation of existing models.

BACKGROUND: To date, dementia prediction models have been exclusively developed and tested in high-income countries (HICs). However, most people with dementia live in low-income and middle-income countries (LMICs), where dementia risk prediction research is almost non-existent and the ability of current models to predict dementia is unknown. This study investigated whether dementia prediction models developed in HICs are applicable to LMICs. METHODS: Data were from the 10/66 Study. Individuals aged 65 years or older and without dementia at baseline were selected from China, Cuba, the Dominican Republic, Mexico, Peru, Puerto Rico, and Venezuela. Dementia incidence was assessed over 3-5 years, with diagnosis according to the 10/66 Study diagnostic algorithm. Discrimination and calibration were tested for five models: the Cardiovascular Risk Factors, Aging and Dementia risk score (CAIDE); the Study on Aging, Cognition and Dementia (AgeCoDe) model; the Australian National University Alzheimer's Disease Risk Index (ANU-ADRI); the Brief Dementia Screening Indicator (BDSI); and the Rotterdam Study Basic Dementia Risk Model (BDRM). Models were tested with use of Cox regression. The discriminative accuracy of each model was assessed using Harrell's concordance (c)-statistic, with a value of 0·70 or higher considered to indicate acceptable discriminative ability. Calibration (model fit) was assessed statistically using the Grønnesby and Borgan test. FINDINGS: 11 143 individuals without baseline dementia and with available follow-up data were included in the analysis. During follow-up (mean 3·8 years [SD 1·3]), 1069 people progressed to dementia across all sites (incidence rate 24·9 cases per 1000 person-years). Performance of the models varied. Across countries, the discriminative ability of the CAIDE (0·52≤c≤0·63) and AgeCoDe (0·57≤c≤0·74) models was poor. By contrast, the ANU-ADRI (0·66≤c≤0·78), BDSI (0·62≤c≤0·78), and BDRM (0·66≤c≤0·78) models showed similar levels of discriminative ability to those of the development cohorts. All models showed good calibration, especially at low and intermediate levels of predicted risk. The models validated best in Peru and poorest in the Dominican Republic and China. INTERPRETATION: Not all dementia prediction models developed in HICs can be simply extrapolated to LMICs. Further work defining what number and which combination of risk variables works best for predicting risk of dementia in LMICs is needed. However, models that transport well could be used immediately for dementia prevention research and targeted risk reduction in LMICs. FUNDING: National Institute for Health Research, Wellcome Trust, WHO, US Alzheimer's Association, and European Research Council.

Factors associated with change in self-reported physical activity in the very old: The Newcastle 85+ study.

BACKGROUND: Higher physical activity (PA) has been linked to better health and functioning. Trajectories of PA and associated factors have been studied in older adults aged ≥65, but less is known about influences on PA change in the very old (aged ≥85). OBJECTIVE: To investigate factors associated with self-reported PA and PA change over time in very old adults. METHODS: 845 participants in the Newcastle 85+ Study were followed for health and functioning at 1.5-, 3-, and 5-year follow-up (wave 2 to 4). PA scores (range 0-18) and PA levels (low (PA scores 0-1), medium (2-6) and high (7-18)) were determined using a purpose-designed PA questionnaire. We used linear mixed models (LMM) to investigate factors associated with 5-year change in PA scores. RESULTS: Overall, men had higher mean PA scores than women (up to 2.27 points). The highest proportion of participants (42-48%) had medium levels of PA across the waves. Although most experienced decline-stability in moderate and increases in high PA levels were also observed. The fully adjusted LMM revealed a curvilinear annual decline in PA scores of 0.52 (0.13) (ß (SE), p<0.001), which decelerated by 0.07 (0.02) points (p<0.01) over time. The factors associated with low PA scores at baseline were female gender, higher waist-hip ratio, and no alcohol intake. Better self-rated and cognitive health and having fewer diseases were associated with higher PA scores. None were associated with the rate of change in PA over time. CONCLUSION: We observed a curvilinear trend and deceleration in PA scores decline in the very old. Men and those in better health and who drank alcohol were more physically active at baseline. None of the factors were associated with the rate of PA decline. Investigating those who maintain or increase levels of PA may inform interventions for at risk groups with PA decline.

The reciprocal relationship between material factors and health in the life course: evidence from SHARE and ELSA.

The widely established health differences between people with greater economic resources and those with fewer resources can be attributed to both social causation (material factors affecting health) and health selection (health affecting material wealth). Each of these pathways may have different intensities at different ages, because the sensitivity of health to a lack of material wealth and the degree to which health can influence economic resources may change. We study the relative importance, in terms of explanatory power, of social causation and health selection, comparing the transitions from childhood to adulthood and from adulthood to old age. We use retrospective survey data from ten European countries from the Survey of Health, Ageing and Retirement in Europe (SHARELIFE, n = 18,734) and the English Longitudinal Study of Ageing (ELSA, n = 6117), and structural equations models in a cross-lagged panel design. Material wealth and health depend on their prior status, wealth more so than health. In the transition from childhood to adulthood, social causation and health selection are equally important: the standardized coefficients for men in SHARE are 0.07 and 0.06, respectively, i.e. one standard deviation increase in material wealth in childhood is associated with a 0.07 standard deviation increase in adult health. In the transition from adulthood to old age, social causation is more important than health selection (0.52 vs. 0.01), across gender and data sets. Both pathways contribute to the creation of health inequalities-however, their relative importance changes with age, which is important for understanding how health inequalities develop and how policies can address them.

Retrospective life course data from European countries on how early life experiences determine health in old age and possible mid-life mediators.

The data presented in this article is related to the research paper entitled "The long arm of childhood circumstances on health in old age: Evidence from SHARELIFE" (E. Pakpahan, R. Hoffmann, H. Kröger, 2016) [1]. It presents the distribution of socioeconomic status (SES) and health from childhood until old age in thirteen European countries. In order to capture the characteristics of longitudinal data, which resembles life course data, we divide the data into three schematic periods: childhood (up to 15 years old), adulthood (30 to 60 years old), and old age (61 to 90 years old). This data set contains respondents' life histories, ranging from childhood conditions (such as housing and health) to detailed questions on education, adult SES (working history, income, and wealth) and old age health. The data can be used not only to understand on how early life experiences determine health in old age, but also to recognise the importance of possible mid-life mediators.