Tasanee Braithwaite

UK health performance: findings of the Global Burden of Disease Study 2010

BACKGROUND The UK has had universal free health care and public health programmes for more than six decades. Several policy initiatives and structural reforms of the health system have been undertaken. Health expenditure has increased substantially since 1990, albeit from relatively low levels compared with other countries. We used data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) to examine the patterns of health loss in the UK, the leading preventable risks that explain some of these patterns, and how UK outcomes compare with a set of comparable countries in the European Union and elsewhere in 1990 and 2010. METHODS We used results of GBD 2010 for 1990 and 2010 for the UK and 18 other comparator nations (the original 15 members of the European Union, Australia, Canada, Norway, and the USA; henceforth EU15+). We present analyses of trends and relative performance for mortality, causes of death, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), and healthy life expectancy (HALE). We present results for 259 diseases and injuries and for 67 risk factors or clusters of risk factors relevant to the UK. We assessed the UKs rank for age-standardised YLLs and DALYs for their leading causes compared with EU15+ in 1990 and 2010. We estimated 95% uncertainty intervals (UIs) for all measures. FINDINGS For both mortality and disability, overall health has improved substantially in absolute terms in the UK from 1990 to 2010. Life expectancy in the UK increased by 4·2 years (95% UI 4·2-4·3) from 1990 to 2010. However, the UK performed significantly worse than the EU15+ for age-standardised death rates, age-standardised YLL rates, and life expectancy in 1990, and its relative position had worsened by 2010. Although in most age groups, there have been reductions in age-specific mortality, for men aged 30-34 years, mortality rates have hardly changed (reduction of 3·7%, 95% UI 2·7-4·9). In terms of premature mortality, worsening ranks are most notable for men and women aged 20-54 years. For all age groups, the contributions of Alzheimers disease (increase of 137%, 16-277), cirrhosis (65%, ?15 to 107), and drug use disorders (577%, 71-942) to premature mortality rose from 1990 to 2010. In 2010, compared with EU15+, the UK had significantly lower rates of age-standardised YLLs for road injury, diabetes, liver cancer, and chronic kidney disease, but significantly greater rates for ischaemic heart disease, chronic obstructive pulmonary disease, lower respiratory infections, breast cancer, other cardiovascular and circulatory disorders, oesophageal cancer, preterm birth complications, congenital anomalies, and aortic aneurysm. Because YLDs per person by age and sex have not changed substantially from 1990 to 2010 but age-specific mortality has been falling, the importance of chronic disability is rising. The major causes of YLDs in 2010 were mental and behavioural disorders (including substance abuse; 21·5% [95 UI 17·2-26·3] of YLDs), and musculoskeletal disorders (30·5% [25·5-35·7]). The leading risk factor in the UK was tobacco (11·8% [10·5-13·3] of DALYs), followed by increased blood pressure (9·0 % [7·5-10·5]), and high body-mass index (8·6% [7·4-9·8]). Diet and physical inactivity accounted for 14·3% (95% UI 12·8-15·9) of UK DALYs in 2010. INTERPRETATION The performance of the UK in terms of premature mortality is persistently and significantly below the mean of EU15+ and requires additional concerted action. Further progress in premature mortality from several major causes, such as cardiovascular diseases and cancers, will probably require improved public health, prevention, early intervention, and treatment activities. The growing burden of disability, particularly from mental disorders, substance use, musculoskeletal disorders, and falls deserves an integrated and strategic response. FUNDING Bill & Melinda Gates Foundation.

New Systematic Review Methodology for Visual Impairment and Blindness for the 2010 Global Burden of Disease Study

Abstract Purpose: To describe a systematic review of population-based prevalence studies of visual impairment (VI) and blindness worldwide over the past 32 years that informs the Global Burden of Diseases, Injuries and Risk Factors Study. Methods: A systematic review (Stage 1) of medical literature from 1 January 1980 to 31 January 2012 identified indexed articles containing data on incidence, prevalence and causes of blindness and VI. Only cross-sectional population-based representative studies were selected from which to extract data for a database of age- and sex-specific data of prevalence of four distance and one near vision loss categories (presenting and best-corrected). Unpublished data and data from studies using rapid assessment methodology were later added (Stage 2). Results: Stage 1 identified 14,908 references, of which 204 articles met the inclusion criteria. Stage 2 added unpublished data from 44 rapid assessment studies and four other surveys. This resulted in a final dataset of 252 articles of 243 studies, of which 238 (98%) reported distance vision loss categories. A total of 37 studies of the final dataset reported prevalence of mild VI and four reported near VI. Conclusion: We report a comprehensive systematic review of over 30 years of VI/blindness studies. While there has been an increase in population-based studies conducted in the 2000s compared to previous decades, there is limited information from certain regions (eg, Central Africa and Central and Eastern Europe, and the Caribbean and Latin America), and younger age groups, and minimal data regarding prevalence of near vision and mild distance VI.

Multiple Deprivation, Vision Loss, and Ophthalmic Disease in Adults:: Global Perspectives

The association between socioeconomic position and morbidity and mortality has long been recognized. We evaluate the evidence for an association between multiple aspects of deprivation and ocular health in a global context. This is a systematic review of studies that evaluated deprivation in the adult population in the context of the major acquired causes of visual loss such as cataract, diabetic eye disease, glaucoma, age-related macular degeneration, and ocular trauma. The search strategy identified relevant studies reported between 1946 and August 2016, with randomized control trials, case-control, cohort, and cross-sectional study designs being selected for inclusion. The studies identified in this review from across the world demonstrate the extent to which the common themes such as low educational attainment and low income may be associated with increased incidence of various sight-threatening conditions and may adversely affect access to specialist assessment and delivery of treatment. Health inequality may always persist, but an increased recognition of the importance of the various impacts of deprivation may empower policy makers to target limited resources to the most vulnerable groups in order to deliver the greatest benefit.

Addressing ethical challenges in the Genetics Substudy of the National Eye Survey of Trinidad and Tobago (GSNESTT).

Background The conduct of international collaborative genomics research raises distinct ethical challenges that require special consideration, especially if conducted in settings that are research-naïve or resource-limited. Although there is considerable literature on these issues, there is a dearth of literature chronicling approaches taken to address these issues in the field. Additionally no previous ethical guidelines have been developed to support similar research in Trinidad and Tobago. Methods A literature review was undertaken to identify strategies used to address common ethical issues relevant to human genetics and genomics research in research-naïve or resource-limited settings. Strategies identified were combined with novel approaches to develop a culturally appropriate, multifaceted strategy to address potential challenges in the Genetics Substudy of the National Eye Survey of Trinidad and Tobago (GSNESTT). Results Regarding the protection of study participants, we report a decision to exclude children as participants; the use of a Community Engagement and Sensitization Strategy to increase the genetic literacy of the target population; the involvement of local expertise to ensure cultural sensitivity and to address potential comprehension barriers in informed consent; and an audit of the informed consent process to ensure valid consent. Concerning the regulation of the research, we report on ethics approvals from relevant authorities; a Materials Transfer Agreement to guide sample ownership and export; and a Sample Governance Committee to oversee data use and data access. Finally regarding the protection of the interests of scientists from the host country, we report on capacity building efforts to ensure that local scientists have access to data collected through the project and appropriate recognition of their contributions in future publications. Conclusion This paper outlines an ethical framework for the conduct of population-based genetics and genomics research in Trinidad and Tobago; highlights common issues arising in the field and strategies to address these.

The National Eye Survey of Trinidad and Tobago (NESTT): Rationale, Objectives and Methodology

ABSTRACT Purpose: This paper describes the rationale, study design and procedures of the National Eye Survey of Trinidad and Tobago (NESTT). The main objective of this survey is to obtain prevalence estimates of vision impairment and blindness for planning and policy development. Methods: A population-based, cross-sectional survey was undertaken using random multistage cluster sampling, with probability-proportionate-to-size methods. Eligible participants aged 5 years and older were sampled from the non-institutional population in each of 120 cluster segments. Presenting distance and near visual acuity were screened in their communities. People aged 40 years and older, and selected younger people, were invited for comprehensive clinic assessment. The interview included information on potential risk factors for vision loss, associated costs and quality of life. The examination included measurement of anthropometrics, blood glucose, refraction, ocular biometry, corneal hysteresis, and detailed assessment of the anterior and posterior segments, with photography and optical coherence tomography imaging. Adult participants were invited to donate saliva samples for DNA extraction and storage. Results: The fieldwork was conducted over 13 months in 2013–2014. A representative sample of 10,651 individuals in 3410 households within 120 cluster segments identified 9913 people who were eligible for recruitment. Conclusion: The study methodology was robust and adequate to provide the first population-based estimates of the prevalence and causes of visual impairment and blindness in Trinidad and Tobago. Information was also gathered on risk factors, costs and quality of life associated with vision loss, and on normal ocular parameters for the population aged 40 years and older.

Prevalence and causes of vision loss in Latin America and the Caribbean in 2015: magnitude, temporal trends and projections

Objective To estimate the prevalence and causes of blindness and vision impairment for distance and near in Latin America and the Caribbean (LAC) in 2015 and to forecast trends to 2020. Methods A meta-analysis from a global systematic review of 283 cross-sectional, population-representative studies from published and unpublished sources from 1980 to 2014 in the Global Vision Database included 17 published and 6 unpublished studies from LAC. Results In 2015, across LAC, age-standardised prevalence was 0.38% in all ages and 1.56% in those over age 50 for blindness; 2.06% in all ages and 7.86% in those over age 50 for moderate and severe vision impairment (MSVI); 1.89% in all ages and 6.93% in those over age 50 for mild vision impairment and 39.59% in all ages and 45.27% in those over 50 for near vision impairment (NVI). In 2015, 117.86 million persons were vision impaired; of those 2.34 million blind, 12.46 million with MSVI, 11.34 million mildly impaired and 91.72 million had NVI. Cataract is the most common cause of blindness. Undercorrected refractive-error is the most common cause of vision impairment. Conclusions These prevalence estimates indicate that one in five persons across LAC had some degree of vision loss in 2015. We predict that from 2015 to 2020, the absolute numbers of persons with vision loss will increase by 12% to 132.33 million, while the all-age age-standardised prevalence will decrease for blindness by 15% and for other distance vision impairment by 8%. All countries need epidemiologic research to establish accurate national estimates and trends. Universal eye health services must be included in universal health coverage reforms to address disparities, fragmentation and segmentation of healthcare

Does blindness count? Disability weights for vision loss

How important is blindness? Is being blind 17% or 60% as bad as being dead? More importantly, why is there such disagreement? These numbers are from disability weights. They were introduced by the Global Burden of Disease (GBD) Study (1990) to give a new population health measure, the disability adjusted life year (DALY). DALYs aimed to capture a societal assessment of the burden of disease resulting from premature mortality and the non-fatal consequences of disease and injury. Their concern was for social justice and the association between the health states resulting from disease, and lost welfare, subjective well-being and quality of life. DALYs differed from quality-adjusted life years, which measure individual preferences for time spent in different health states. DALYs aimed to facilitate a more explicit and consistent comparison of health outcomes for health sector evaluation and resource allocation. DALYs are the sum of years of life lost due to premature mortality and years lived with disability. Calculation of the latter includes the disability weight – a number on a scale from 0 to 1.0. A weight close to 0 indicates a state of minimal impact, and a weight close to 1.0 indicates a state so severe its impact is almost as bad as death. Disability weights are obtained from ordinal measurement of preferences (paired health state comparisons). Advanced modelling transforms these data into weights. To date, eight studies have estimated disability weights for blindness (Table 1), using different approaches. These weights vary from 0.60 in the original GBD study to 0.19 in the 2010 GBD study. This threefold reduction in the recent GBD disability weight reduces the apparent importance of cataract blindness, questioning the validity of the disability weights. Applying the weights from the original and 2010 GBD studies gives very different estimates of the effectiveness of cataract surgery: in one study, from 2599 DALYs averted (disability weight 0.60 for blindness) to just 156 DALYs averted (disability weight 0.033 for moderate distance vision impairment). There are a number of possible explanations for the discrepancy. In our opinion, the most significant is the change from rating ‘disability’ to rating ‘health’. Health, as conceptualized by the World Health Organization, is a multidimensional construct, defined as ‘a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.’ In the original GBD Study, six weights captured ‘loss of well-being’, blindness was assigned a weight of 0.60. These were defined in reference to limitations in ability to perform activities of procreation, occupation, education and recreation or needing assistance with activities of daily living. Fundamentally, this is the measurement of disability. In contrast, the recent GBD Studies framed questions about ‘loss of health’. Although this resulted in only small changes to the disability weights for most disease states, for disabling conditions, including vision and hearing loss, the reduction was dramatic, attributed by some to the change in construct. This is not surprising; blind people often say, ‘I am not sick, I just can’t see!’ A second factor is variability in the description of different effects of the ‘disease’. The original GBD Study (1990) defined blindness as, ‘maximal visual acuity of less than 3/60 with the best possible correction’, resulting in ‘limited ability to perform most activities in all of the following areas: recreation, education, procreation or occupation’. The recent GBD studies defined blindness as, ‘completely blind, which causes great difficulty in some daily activities, worry and anxiety, and great difficulty going outside the home without assistance’ (Table 2). After criticism of some of the GBD 2010 disability weights, including those for vision loss, the GBD 2013 study tested a revised lay definition for some conditions. For example, the revised definition for deafness included a more explicit description of social isolation. When retested, the weight changed dramatically from 0.09 to 0.32, leading to the conclusion that, ‘in some cases, responses are evidently highly sensitive to particular details in these descriptions’. The definition for blindness was not modified in the GBD