Disparities in glaucoma and macular degeneration healthcare utilization among persons living with dementia in the United States.

PURPOSE: Dementia is common among patients with primary open angle glaucoma (POAG) and neovascular age-related macular degeneration (nAMD). This study compares visit frequency, diagnostic test utilization, and treatment patterns for POAG and nAMD among persons with vs. without dementia. METHODS: Optum's de-identified Clinformatics® Data Mart Database (January 1, 2000-June 30, 2022) was used for this study. Two cohorts were created from newly diagnosed POAG or nAMD patients. Within each cohort, an exposure cohort was created of newly diagnosed dementia patients. The primary outcome was the number of visits to an eye care provider. Secondary analyses for the POAG cohort assessed the number of visual field tests, optical coherence tomography (OCT), and glaucoma medication prescription coverage. The secondary analysis for the nAMD cohort included the number of injections performed. Poisson regression was used to determine the relative rates of outcomes. RESULTS: POAG patients with dementia had reduced rates of eye care visits (RR 0.76, 95% CI: 0.75-0.77), lower rates of testing utilization for visual fields (RR 0.66, 95% CI: 0.63-0.68) and OCT (RR 0.67, 95% CI: 0.64-0.69), and a lower rate of glaucoma prescription medication coverage (RR 0.83, 95% CI: 0.83-0.83). nAMD patients with dementia had reduced rates of eye care visits (RR 0.74, 95% CI: 0.70-0.79) and received fewer intravitreal injections (RR 0.64, 95% CI: 0.58-0.69) than those without dementia. CONCLUSIONS: POAG and nAMD patients with dementia obtained less eye care and less monitoring and treatment of their disease. These findings suggest that this population may be vulnerable to gaps in ophthalmic care.

A systematic review of the social impact of diseases in Nordic countries.

BACKGROUND: We review the literature on the social impacts of diseases, defined as the social consequences of having a disease on the people around the patient, such as spouses, caregivers and offspring. The two objectives of this study are to summarise the social outcomes commonly associated with diseases and to compare the social impact across a range of diseases. METHODS: A systematic review of the social impact of disease in Nordic countries was conducted using PubMed, PsycINFO and Google Scholar (PROSPERO registration number CRD42022291796). All articles that met the inclusion criteria were reviewed. We tabulated all outcomes and diseases studied, and synthesised the evidence based on the perspectives of patients, spouse/caregiver and offspring. RESULTS: A total of 135 studies met the eligibility criteria, covering 76 diseases and 39 outcomes. From the patient's perspective, diseases impact divorce and marriage rates, social functioning, likelihood of committing a crime and being a victim of crime. From the caregiver's perspective, diseases affect their health-related quality of life and physical and psychological health. From the offspring's perspective, diseases impact their development, health and social adversities in later life. Diseases generally had negative social impacts, but there were some diseases associated with positive impacts. CONCLUSIONS: The review provides a useful summary and gross comparison of the social impact of different diseases. The social impact of diseases can be large and significant. Thus, it should be considered when policymakers are setting priorities across disease areas.

The economic burden of diseases in the Nordic countries: A systematic review.

BACKGROUND: Economic burden studies can provide insights into the drivers leading to increasing healthcare costs. It can also provide a more holistic view of how diseases impact the welfare of patients and their families. Having concrete estimates of the economic burden across multiple diseases can help policymakers determine which diseases are economically more burdensome. This study aimed to review and summarise comprehensively economic burden studies across multiple diseases in the Nordic countries between 2000 and 2020. METHODS: According to the 2020 PRISMA statement, a systematic literature review was conducted in PubMed, CINAHL, Academic Search Premier and Global Health databases using key terms related to the economic burden of any disease in Denmark, Finland, Greenland, Iceland, Norway and Sweden. Grey literature was also reviewed. RESULTS: A total of 10,050 potential titles and abstracts were identified and screened, and 254 full-text papers that met the inclusion criteria were evaluated by two independent reviewers. Of these, 119 articles were included in a qualitative synthesis. Twenty-nine had clearly defined comparison groups, thus able to attribute the costs to the disease. Large variations concerning methodology and cost components were noted. Across diseases, the economic burden ranged from EUR 1668 per patient annually for chronic obstructive pulmonary disease to EUR 93,041 for multiple sclerosis. However, estimates varied widely, even within each disease. CONCLUSIONS: Our review highlights the need for more comparable economic burden studies. Future studies should focus on applying robust methodology and homogeneous cost-reporting methods to inform policymakers about which diseases are economically more burdensome.

Old vaccines for new infections: Exploiting innate immunity to control COVID-19 and prevent future pandemics.

The COVID-19 pandemic triggered an unparalleled pursuit of vaccines to induce specific adaptive immunity, based on virus-neutralizing antibodies and T cell responses. Although several vaccines have been developed just a year after SARS-CoV-2 emerged in late 2019, global deployment will take months or even years. Meanwhile, the virus continues to take a severe toll on human life and exact substantial economic costs. Innate immunity is fundamental to mammalian host defense capacity to combat infections. Innate immune responses, triggered by a family of pattern recognition receptors, induce interferons and other cytokines and activate both myeloid and lymphoid immune cells to provide protection against a wide range of pathogens. Epidemiological and biological evidence suggests that the live-attenuated vaccines (LAV) targeting tuberculosis, measles, and polio induce protective innate immunity by a newly described form of immunological memory termed "trained immunity." An LAV designed to induce adaptive immunity targeting a particular pathogen may also induce innate immunity that mitigates other infectious diseases, including COVID-19, as well as future pandemic threats. Deployment of existing LAVs early in pandemics could complement the development of specific vaccines, bridging the protection gap until specific vaccines arrive. The broad protection induced by LAVs would not be compromised by potential antigenic drift (immune escape) that can render viruses resistant to specific vaccines. LAVs might offer an essential tool to "bend the pandemic curve," averting the exhaustion of public health resources and preventing needless deaths and may also have therapeutic benefits if used for postexposure prophylaxis of disease.

Estimating health spending associated with chronic multimorbidity in 2018: An observational study among adults in the United States.

BACKGROUND: The rise in health spending in the United States and the prevalence of multimorbidity-having more than one chronic condition-are interlinked but not well understood. Multimorbidity is believed to have an impact on an individual's health spending, but how having one specific additional condition impacts spending is not well established. Moreover, most studies estimating spending for single diseases rarely adjust for multimorbidity. Having more accurate estimates of spending associated with each disease and different combinations could aid policymakers in designing prevention policies to more effectively reduce national health spending. This study explores the relationship between multimorbidity and spending from two distinct perspectives: (1) quantifying spending on different disease combinations; and (2) assessing how spending on a single diseases changes when we consider the contribution of multimorbidity (i.e., additional/reduced spending that could be attributed in the presence of other chronic conditions). METHODS AND FINDINGS: We used data on private claims from Truven Health MarketScan Research Database, with 16,288,894 unique enrollees ages 18 to 64 from the US, and their annual inpatient and outpatient diagnoses and spending from 2018. We selected conditions that have an average duration of greater than one year among all Global Burden of Disease causes. We used penalized linear regression with stochastic gradient descent approach to assess relationship between spending and multimorbidity, including all possible disease combinations with two or three different conditions (dyads and triads) and for each condition after multimorbidity adjustment. We decomposed the change in multimorbidity-adjusted spending by the type of combination (single, dyads, and triads) and multimorbidity disease category. We defined 63 chronic conditions and observed that 56.2% of the study population had at least two chronic conditions. Approximately 60.1% of disease combinations had super-additive spending (e.g., spending for the combination was significantly greater than the sum of the individual diseases), 15.7% had additive spending, and 23.6% had sub-additive spending (e.g., spending for the combination was significantly less than the sum of the individual diseases). Relatively frequent disease combinations (higher observed prevalence) with high estimated spending were combinations that included endocrine, metabolic, blood, and immune disorders (EMBI disorders), chronic kidney disease, anemias, and blood cancers. When looking at multimorbidity-adjusted spending for single diseases, the following had the highest spending per treated patient and were among those with high observed prevalence: chronic kidney disease ($14,376 [12,291,16,670]), cirrhosis ($6,465 [6,090,6,930]), ischemic heart disease (IHD)-related heart conditions ($6,029 [5,529,6,529]), and inflammatory bowel disease ($4,697 [4,594,4,813]). Relative to unadjusted single-disease spending estimates, 50 conditions had higher spending after adjusting for multimorbidity, 7 had less than 5% difference, and 6 had lower spending after adjustment. CONCLUSIONS: We consistently found chronic kidney disease and IHD to be associated with high spending per treated case, high observed prevalence, and contributing the most to spending when in combination with other chronic conditions. In the midst of a surging health spending globally, and especially in the US, pinpointing high-prevalence, high-spending conditions and disease combinations, as especially conditions that are associated with larger super-additive spending, could help policymakers, insurers, and providers prioritize and design interventions to improve treatment effectiveness and reduce spending.

Atypical presentation of invasive myoepithelioma in a pediatric patient.

A 15-year-old girl presented with a mobile lesion with yellowish hue on the posterior lamella of the right lower eyelid adjacent to the punctum. Four years prior, a lesion thought to be a chalazion was excised from the same location. There was subsequent progressive painless enlargement. The patient ultimately underwent an internal excision of the mass. Histopathology demonstrated infiltrative nests and cords of epithelioid and plasmacytoid cells with abundant eosinophilic myxoid-collagenous stroma along with focal infiltration of skeletal muscle with immunohistochemical staining consistent with an invasive myoepithelioma of mixed-cell type. Given concern for invasive disease, the patient underwent subsequent Mohs resection resulting in a 25% full thickness eyelid defect, which was repaired with direct closure of the wedge defect. There has been no recurrence of the disease for 7 months since the Mohs resection. This case illustrates the atypical presentation of an invasive myoepithelioma of the eyelid in a pediatric patient.

Orbital Lipofibromatosis in a Pediatric Patient.

A 10-month-old boy presented with a 3-month history of progressive left lower eyelid swelling. Examination demonstrated left lower eyelid fullness and hyperglobus with a fatty appearing inferior fornix mass. Imaging showed a mass isointense to fat in the left lower eyelid extending posteriorly, surrounding the inferior oblique with complete fatty infiltration, obscuration of the inferior rectus, and adherence to the globe. The patient underwent orbitotomy with biopsy and debulking of the tumor. Surgical pathology showed multiple fragments of adipose tissue with foci of plump and spindle-shaped cells arranged in bundles and fascicles, consistent with lipofibromatosis. This case illustrates a rare presentation of orbital lipofibromatosis in a pediatric patient.

Multimorbidity and care for hypertension, diabetes and HIV among older adults in rural South Africa.

OBJECTIVE: To examine how multimorbidity might affect progression along the continuum of care among older adults with hypertension, diabetes and human immunodeficiency virus (HIV) infection in rural South Africa. METHODS: We analysed data from 4447 people aged 40 years or older who were enrolled in a longitudinal study in Agincourt sub-district. Household-based interviews were completed between November 2014 and November 2015. For hypertension and diabetes (2813 and 512 people, respectively), we defined concordant conditions as other cardiometabolic conditions, and discordant conditions as mental disorders or HIV infection. For HIV infection (1027 people) we defined any other conditions as discordant. Regression models were fitted to assess the relationship between the type of multimorbidity and progression along the care continuum and the likelihood of patients being in each stage of care for the index condition (four stages from testing to treatment). FINDINGS: People with hypertension or diabetes plus other cardiometabolic conditions were more like to progress through the care continuum for the index condition than those without cardiometabolic conditions (relative risk, RR: 1.14, 95% confidence interval, CI: 1.09-1.20, and RR: 2.18, 95% CI: 1.52-3.26, respectively). Having discordant comorbidity was associated with greater progression in care for those with hypertension but not diabetes. Those with HIV infection plus cardiometabolic conditions had less progress in the stages of care compared with those without such conditions (RR: 0.86, 95% CI: 0.80-0.92). CONCLUSION: Patients with concordant conditions were more likely to progress further along the care continuum, while those with discordant multimorbidity tended not to progress beyond diagnosis.

Estimating the distribution of morbidity and mortality of childhood diarrhea, measles, and pneumonia by wealth group in low- and middle-income countries.

BACKGROUND: Equitable access to vaccines has been suggested as a priority for low- and middle-income countries (LMICs). However, it is unclear whether providing equitable access is enough to ensure health equity. Furthermore, disaggregated data on health outcomes and benefits gained across population subgroups are often unavailable. This paper develops a model to estimate the distribution of childhood disease cases and deaths across socioeconomic groups, and the potential benefits of three vaccine programs in LMICs. METHODS: For each country and for three diseases (diarrhea, measles, pneumonia), we estimated the distributions of cases and deaths that would occur across wealth quintiles in the absence of any immunization or treatment programs, using both the prevalence and relative risk of a set of risk and prognostic factors. Building on these baseline estimates, we examined what might be the impact of three vaccines (first dose of measles, pneumococcal conjugate, and rotavirus vaccines), under five scenarios based on different sets of quintile-specific immunization coverage and disease treatment utilization rates. RESULTS: Due to higher prevalence of risk factors among the poor, disproportionately more disease cases and deaths would occur among the two lowest wealth quintiles for all three diseases when vaccines or treatment are unavailable. Country-specific context, including how the baseline risks, immunization coverage, and treatment utilization are currently distributed across quintiles, affects how different policies translate into changes in cases and deaths distribution. CONCLUSIONS: Our study highlights several factors that would substantially contribute to the unequal distribution of childhood diseases, and finds that merely ensuring equal access to vaccines will not reduce the health outcomes gap across wealth quintiles. Such information can inform policies and planning of programs that aim to improve equitable delivery of healthcare services.

Modest improvements in skilled birth attendants at delivery with increased Mutuelles coverage in Rwanda.

Background: We revisit the question of the role health insurance coverage played in increasing use of skilled birth attendants (SBA) at delivery in Rwanda. Previous studies have suggested that enrollment in Mutuelles health insurance increased the odds of using an SBA by up to 163%. Methods: We take advantage of latest Rwanda Demographic Health Survey (NISR M, Macro O. Rwanda Demographic and Health Survey 2010. National Institute of Statistics of Rwanda and Ministry of Health, 2012.) to increase the sample size and extend the time frame of analysis to 5 years (2005-10). We also adopt a stronger matching method, coarsened exact matching, to control for model dependence. Results: We find that although enrollment in Mutuelles insurance increases use of SBAs at delivery, the size of the effect is an order of magnitude lower than previously published (12-18% versus 78-163%). We also find that the effect of education on use of SBA is similar in magnitude to that of Mutuelles insurance enrollment. Conclusions: Our findings lead us to conclude that Mutuelles only had a modest effect on increasing use of SBA at delivery and therefore insurance alone may not be the 'magic bullet' that solves the problem of non-use of SBA at delivery.

Transient Melting and Recrystallization of Semiconductor Nanocrystals Under Multiple Electron-Hole Pair Excitation.

Ultrafast optical pump, X-ray diffraction probe experiments were performed on CdSe nanocrystal (NC) colloidal dispersions as functions of particle size, polytype, and pump fluence. Bragg peak shifts related to heating and peak amplitude reduction associated with lattice disordering are observed. For smaller NCs, melting initiates upon absorption of as few as ∼15 electron-hole pair excitations per NC on average (0.89 excitations/nm3 for a 1.5 nm radius) with roughly the same excitation density inducing melting for all examined NCs. Diffraction intensity recovery kinetics, attributable to recrystallization, occur over hundreds of picoseconds with slower recoveries for larger particles. Zincblende and wurtzite NCs revert to initial structures following intense photoexcitation suggesting melting occurs primarily at the surface, as supported by simulations. Electronic structure calculations relate significant band gap narrowing with decreased crystallinity. These findings reflect the need to consider the physical stability of nanomaterials and related electronic impacts in high intensity excitation applications such as lasing and solid-state lighting.

Prevalence and correlates of frailty in an older rural African population: findings from the HAALSI cohort study.

BACKGROUND: Frailty is a key predictor of death and dependency, yet little is known about frailty in sub-Saharan Africa despite rapid population ageing. We describe the prevalence and correlates of phenotypic frailty using data from the Health and Aging in Africa: Longitudinal Studies of an INDEPTH Community cohort. METHODS: We analysed data from rural South Africans aged 40 and over. We used low grip strength, slow gait speed, low body mass index, and combinations of self-reported exhaustion, decline in health, low physical activity and high self-reported sedentariness to derive nine variants of a phenotypic frailty score. Each frailty category was compared with self-reported health, subjective wellbeing, impairment in activities of daily living and the presence of multimorbidity. Cox regression analyses were used to compare subsequent all-cause mortality for non-frail (score 0), pre-frail (score 1-2) and frail participants (score 3+). RESULTS: Five thousand fifty nine individuals (mean age 61.7 years, 2714 female) were included in the analyses. The nine frailty score variants yielded a range of frailty prevalences (5.4% to 13.2%). For all variants, rates were higher in women than in men, and rose steeply with age. Frailty was associated with worse subjective wellbeing, and worse self-reported health. Both prefrailty and frailty were associated with a higher risk of death during a mean 17 month follow up for all score variants (hazard ratios 1.29 to 2.41 for pre-frail vs non-frail; hazard ratios 2.65 to 8.91 for frail vs non-frail). CONCLUSIONS: Phenotypic frailty could be measured in this older South African population, and was associated with worse health, wellbeing and earlier death.

Amino acid-dependent stability of the acyl linkage in aminoacyl-tRNA.

Aminoacyl-tRNAs are the biologically active substrates for peptide bond formation in protein synthesis. The stability of the acyl linkage in each aminoacyl-tRNA, formed through an ester bond that connects the amino acid carboxyl group with the tRNA terminal 3'-OH group, is thus important. While the ester linkage is the same for all aminoacyl-tRNAs, the stability of each is not well characterized, thus limiting insight into the fundamental process of peptide bond formation. Here, we show, by analysis of the half-lives of 12 of the 22 natural aminoacyl-tRNAs used in peptide bond formation, that the stability of the acyl linkage is effectively determined only by the chemical nature of the amino acid side chain. Even the chirality of the side chain exhibits little influence. Proline confers the lowest stability to the linkage, while isoleucine and valine confer the highest, whereas the nucleotide sequence in the tRNA provides negligible contribution to the stability. We find that, among the variables tested, the protein translation factor EF-Tu is the only one that can protect a weak acyl linkage from hydrolysis. These results suggest that each amino acid plays an active role in determining its own stability in the acyl linkage to tRNA, but that EF-Tu overrides this individuality and protects the acyl linkage stability for protein synthesis on the ribosome.

Morphology, molecular stacking, dynamics and device performance correlations of vacuum-deposited small-molecule organic solar cells.

The "all carbon" organic solar cells (OSCs) based on the homocyclic molecule tetraphenyldibenzoperiflanthene (DBP) as a donor and C60 as an acceptor were comprehensively characterized. The optimized planar-mixed heterojunction device with a DBP:C60 mixture ratio of DBP : C60 (1 : 2) exhibited a power conversion efficiency of 4.47%. To understand why DBP possesses such advantageous characteristics, the correlations of the morphology, molecular stacking, carrier dynamics and performance of DBP:fullerene-based devices have been systematically studied. First, the face-on stacked DBP molecules could enhance both the absorption of light and the charge carrier mobility. Second, DBP : C60 (1 : 2) thin films with optimized domain sizes and partially interconnected acceptor grains led to the most balanced carrier mobility and the lowest bimolecular recombination in devices. Finally, the DBP molecules were found to stack closely using grazing incidence wide-angle X-ray scattering measurements, with a π-π stacking spacing of 4.58 Å, indicating an effective molecular orbital overlap in DBP. The study not only reveals the promising characteristics of DBP as a donor in OSCs but the clear correlations of the thin-film nano-morphology, molecular stacking, carrier mobility and charge recombination found here could also provide insights into the characterization methodology and optimization of the small molecule OSCs.

Discovering Subgroups of Children With High Mortality in Urban Guinea-Bissau: Exploratory and Validation Cohort Study.

BACKGROUND: The decline in global child mortality is an important public health achievement, yet child mortality remains disproportionally high in many low-income countries like Guinea-Bissau. The persisting high mortality rates necessitate targeted research to identify vulnerable subgroups of children and formulate effective interventions. OBJECTIVE: This study aimed to discover subgroups of children at an elevated risk of mortality in the urban setting of Bissau, Guinea-Bissau, West Africa. By identifying these groups, we intend to provide a foundation for developing targeted health interventions and inform public health policy. METHODS: We used data from the health and demographic surveillance site, Bandim Health Project, covering 2003 to 2019. We identified baseline variables recorded before children reached the age of 6 weeks. The focus was on determining factors consistently linked with increased mortality up to the age of 3 years. Our multifaceted methodological approach incorporated spatial analysis for visualizing geographical variations in mortality risk, causally adjusted regression analysis to single out specific risk factors, and machine learning techniques for identifying clusters of multifactorial risk factors. To ensure robustness and validity, we divided the data set temporally, assessing the persistence of identified subgroups over different periods. The reassessment of mortality risk used the targeted maximum likelihood estimation (TMLE) method to achieve more robust causal modeling. RESULTS: We analyzed data from 21,005 children. The mortality risk (6 weeks to 3 years of age) was 5.2% (95% CI 4.8%-5.6%) for children born between 2003 and 2011, and 2.9% (95% CI 2.5%-3.3%) for children born between 2012 and 2016. Our findings revealed 3 distinct high-risk subgroups with notably higher mortality rates, children residing in a specific urban area (adjusted mortality risk difference of 3.4%, 95% CI 0.3%-6.5%), children born to mothers with no prenatal consultations (adjusted mortality risk difference of 5.8%, 95% CI 2.6%-8.9%), and children from polygamous families born during the dry season (adjusted mortality risk difference of 1.7%, 95% CI 0.4%-2.9%). These subgroups, though small, showed a consistent pattern of higher mortality risk over time. Common social and economic factors were linked to a larger share of the total child deaths. CONCLUSIONS: The study's results underscore the need for targeted interventions to address the specific risks faced by these identified high-risk subgroups. These interventions should be designed to work to complement broader public health strategies, creating a comprehensive approach to reducing child mortality. We suggest future research that focuses on developing, testing, and comparing targeted intervention strategies unraveling the proposed hypotheses found in this study. The ultimate aim is to optimize health outcomes for all children in high-mortality settings, leveraging a strategic mix of targeted and general health interventions to address the varied needs of different child subgroups.

Charge carrier dynamics of vapor-deposited small-molecule/fullerene organic solar cells.

Although small-molecule organic solar cells (SMOSCs) have shown increasingly promising prospects as a source of solar power, there have been few studies concerning the photophysics of these systems. Here, we report the time scale and efficiency of charge separation and recombination in a vapor-deposited SMOSC material that produces 5.81% power conversion efficiency. Transient absorption and time-resolved photoluminescence (trPL) studies of thin film blends comprising DTDCTB, a narrow-band gap electron donor, and either C60 or C70 as an electron acceptor show that charge separation occurs in ~100 fs, while charge recombination takes place over sub-ns and ns time scales. trPL indicates a donor electron-hole pair lifetime of ~33 ps in the neat film and reveals that ~20% of donors fail to charge separate in donor-acceptor mixed films, likely owing to some spatially extended donor-rich regions that interact poorly with acceptors. Our results suggest that morphological manipulations of this material could further improve device efficiency.

Visual Function Tests: Visual Fields.

Visual field tests, also known as perimetry tests, are used to assess progression of ophthalmic diseases such as retinitis pigmentosa (RP) by monitoring changes in a patient's visual field (VF). VF loss corresponds to damage at any point in the visual pathway, including the retina, such as in RP. Damage to different parts of this pathway corresponds to characteristic VF defects. Perimetry tests are subjective, as they are functional tests that help physicians identify abnormal fields as well as quantitatively assess VF sensitivity. The results may also be informative of a patient's visual function crucial for performing day-to-day activities. Automated perimetry tests are among the most commonly used, with the most common being automated static perimetry.

Challenges of Treatment Methodologies and the Future of Gene Therapy and Stem Cell Therapy to Treat Retinitis Pigmentosa.

Retinitis pigmentosa (RP) is a heterogeneous group of hereditary retinal degenerations for which there is currently no cure. Studies investigating the use of gene therapy, gene editing, and stem cells as potential treatment strategies have shown promising results in animal models and some early clinical trials. Even still, major barriers still exist, including the ability to develop therapies that can target the wide range of mutational etiologies and phenotypic presentations that encompass RP. Additionally, effective screening and early diagnosis are crucial for maximum therapeutic potential, especially because many therapeutic agents require a baseline level photoreceptor function.

Colloidal InSb nanocrystals.

We report the colloidal synthesis of monodisperse nanocrystals (NCs) of InSb, which is an important member of III-V semiconductor family. Colloidal InSb NC quantum dots showed well-resolved excitonic transitions in the near-infrared spectral range, with the optical band gaps tunable from ∼1.03 eV (1200 nm) to ∼0.71 eV (1750 nm) corresponding to 3.3 and 6.5 nm InSb NCs, respectively. We observed size-tunable band edge photoluminescence that could be significantly enhanced by growing InSb/CdSe or InSb/CdS core-shell nanostructures. Films of InSb NCs capped with S(2-) ions showed ambipolar charge transport.

The health-adjusted dependency ratio as a new global measure of the burden of ageing: a population-based study.

BACKGROUND: The old-age dependency ratio (OADR), which is the ratio of older people (aged ≥65 years) to working age people (aged 20-64 years), is the most common way to assess and compare the burden of population ageing in different countries. However, the relationship between chronological age and dependency varies widely across countries. We therefore present the health-adjusted dependency ratio (HADR), a new measure of ageing burden based on the ageing-related health of the adult population. METHODS: In this population-based study we used health data for diseases and injuries for 2017 from the Global Burden of Disease project and population data for 2017 from the UN's Population Division to identify the number of adults (aged >20 years) in each country who have the same or higher ageing-related disease burden as the global average 65-year-old. We then calculated the HADR as the ratio of adults who were less healthy than the average 65-year-old (dependent population) to those in better health (supporting population) and compared the HADR with the OADR for 188 countries. We also used cross-sectional, bivariate regression analysis to investigate whether the HADR is a more powerful predictor of changes in per capita health-care expenditure than the OADR as a measure of predictive validity. FINDINGS: Many demographically younger populations have an earlier onset of ageing-related disease, and many demographically older populations have a later onset. For instance, Pakistan has an OADR of 0·09 and an HADR of 0·19, and France has an OADR of 0·35 and an HADR of 0·13. Relative to the OADR, the HADR suggests that Asia, western Europe, and North America have a lower ageing burden, whereas central Asia, southern Asia, and Africa have a greater burden. While Japan and countries in western Europe have the highest OADR, Russia, Papua New Guinea, and countries in southeast Europe have the highest HADR. Relative to the OADR, the HADR suggests that there is much less variation in the burden of ageing across countries than has previously been assumed. HADR was also more closely associated with growth in health spending than the OADR. A 0·1 increase in the HADR was associated with a 2·9 percentage points larger growth rate in per capita spending (p=0·0001), and a 0·1-point increase in the OADR was associated with a 1·8 percentage point larger growth rate. INTERPRETATION: The OADR probably overestimates the burden of population ageing in many demographically older countries and underestimates the ageing burden in many demographically younger countries, which implies that the challenges associated with ageing are more universal than previously thought, and that the world cannot easily be divided in a young and an old groups of nations. FUNDING: None.