Rehabilitation Applications Based on Behavioral Therapy for People With Knee Osteoarthritis: Systematic Review.

BACKGROUND: The development of digital applications based on behavioral therapies to support patients with knee osteoarthritis (KOA) has attracted increasing attention in the field of rehabilitation. This paper presents a systematic review of research on digital applications based on behavioral therapies for people with KOA. OBJECTIVE: This review aims to describe the characteristics of relevant digital applications, with a special focus on the current state of behavioral therapies, digital interaction technologies, and user participation in design. The secondary aim is to summarize intervention outcomes and user evaluations of digital applications. METHODS: A systematic literature search was conducted using the keywords "Knee Osteoarthritis," "Behavior Therapy," and "Digitization" in the following databases (from January 2013 to July 2023): Web of Science, Embase, Science Direct, Ovid, and PubMed. The Mixed Methods Assessment Tool (MMAT) was used to assess the quality of evidence. Two researchers independently screened and extracted the data. RESULTS: A total of 36 studies met the inclusion criteria and were further analyzed. Behavioral change techniques (BCTs) and cognitive behavioral therapy (CBT) were frequently combined when developing digital applications. The most prevalent areas were goals and planning (n=31) and repetition and substitution (n=27), which were frequently used to develop physical activity (PA) goals and adherence. The most prevalent combination strategy was app/website plus SMS text message/telephone/email (n=12), which has tremendous potential. This area of application design offers notable advantages, primarily manifesting in pain mitigation (n=24), reduction of physical dysfunction (n=21), and augmentation of PA levels (n=12). Additionally, when formulating design strategies, it is imperative to consider the perspectives of stakeholders, especially in response to the identified shortcomings in application design elucidated within the study. CONCLUSIONS: The results demonstrate that "goals and planning" and "repetition and substitution" are frequently used to develop PA goals and PA behavior adherence. The most prevalent combination strategy was app/website plus SMS text message/telephone/email, which has tremendous potential. Moreover, incorporating several stakeholders in the design and development stages might enhance user experience, considering the distinct variations in their requirements. To improve the efficacy and availability of digital applications, we have several proposals. First, comprehensive care for patients should be ensured by integrating multiple behavioral therapies that encompass various aspects of the rehabilitation process, such as rehabilitation exercises and status monitoring. Second, therapists could benefit from more precise recommendations by incorporating additional intelligent algorithms to analyze patient data. Third, the implementation scope should be expanded from the home environment to a broader social community rehabilitation setting.

New global indicator for workers' health: mortality rate from diseases attributable to selected occupational risk factors.

Through sustainable development goals 3 and 8 and other policies, countries have committed to protect and promote workers' health by reducing the work-related burden of disease. To monitor progress on these commitments, indicators that capture the work-related burden of disease should be available for monitoring workers' health and sustainable development. The World Health Organization and the International Labour Organization estimate that only 363 283 (19%) of 1 879 890 work-related deaths globally in 2016 were due to injuries, whereas 1 516 607 (81%) deaths were due to diseases. Most monitoring systems focusing on workers' health or sustainable development, such as the global indicator framework for the sustainable development goals, include an indicator on the burden of occupational injuries. Few such systems, however, have an indicator on the burden of work-related diseases. To address this gap, we present a new global indicator: mortality rate from diseases attributable to selected occupational risk factors, by disease, risk factor, sex and age group. We outline the policy rationale of the indicator, describe its data sources and methods of calculation, and report and analyse the official indicator for 183 countries. We also provide examples of the use of the indicator in national workers' health monitoring systems and highlight the indicator's strengths and limitations. We conclude that integrating the new indicator into monitoring systems will provide more comprehensive and accurate surveillance of workers' health, and allow harmonization across global, regional and national monitoring systems. Inequalities in workers' health can be analysed and the evidence base can be improved towards more effective policy and systems on workers' health.

Par le biais des objectifs de développement durable 3 et 8 ainsi que d'autres mesures, plusieurs pays se sont engagés à protéger et promouvoir la santé des travailleurs en réduisant l'impact des maladies liées au travail. Mais pour évaluer leurs progrès en la matière, il convient de mettre en place des indicateurs estimant l'impact des maladies liées au travail afin de placer le développement durable et la santé des travailleurs sous surveillance. D'après l'Organisation mondiale de la Santé et l'Organisation internationale du Travail, seulement 363 283 (19%) des 1 879 890 décès liés au travail dans le monde en 2016 découlaient de blessures, tandis que 1 516 607 (81%) d'entre eux étaient causés par des maladies. La plupart des systèmes de surveillance qui s'intéressent à la santé des travailleurs ou au développement durable, comme le cadre mondial d'indicateurs pour les objectifs de développement durable, comportent un indicateur relatif à l'impact des accidents de travail. Cependant, rares sont ceux qui possèdent un indicateur concernant l'impact des maladies professionnelles. Pour combler cette lacune, nous dévoilons un nouvel indicateur mondial: le taux de mortalité dû aux maladies attribuables à certains facteurs de risque professionnels classé par maladie, facteur de risque, sexe et catégorie d'âge. Nous exposons le motif politique de l'indicateur, décrivons l'origine des données et les méthodes de calcul, et communiquons et analysons l'indicateur officiel pour 183 pays. Nous fournissons également des exemples de la façon dont l'indicateur peut être utilisé dans des systèmes nationaux de surveillance de la santé des travailleurs et soulignons ses forces et faiblesses. Nous concluons en affirmant que l'intégration de ce nouvel indicateur dans les systèmes de surveillance offrira un suivi plus complet et précis de la santé des travailleurs et ouvrira la voie à une harmonisation des systèmes mondiaux, nationaux et régionaux. Il est possible d'analyser les inégalités en matière de santé des travailleurs et d'en améliorer les bases factuelles afin d'établir des politiques et systèmes plus efficaces dans ce domaine.

A través de los objetivos de desarrollo sostenible 3 y 8 y de otras políticas, los países se han comprometido a proteger y promover la salud de los trabajadores reduciendo la carga de morbilidad relacionada con el trabajo. Para supervisar los avances en el cumplimiento de estos compromisos, debería disponerse de indicadores que reflejen la carga de morbilidad relacionada con el trabajo, a fin de controlar la salud de los trabajadores y el desarrollo sostenible. La Organización Mundial de la Salud y la Organización Internacional del Trabajo estiman que solo 363 283 (19%) de las 1 879 890 muertes relacionadas con el trabajo a nivel mundial en 2016 se debieron a lesiones, mientras que 1 516 607 (81%) muertes se debieron a enfermedades. La mayoría de los sistemas de vigilancia centrados en la salud de los trabajadores o el desarrollo sostenible, como el marco de indicadores mundiales para los objetivos de desarrollo sostenible, incluyen un indicador sobre la carga de las lesiones laborales. No obstante, pocos de estos sistemas cuentan con un indicador sobre la carga de las enfermedades relacionadas con el trabajo. Para subsanar esta carencia, presentamos un nuevo indicador mundial: la tasa de mortalidad por enfermedades atribuibles a factores de riesgo laborales seleccionados, por enfermedad, factor de riesgo, sexo y grupo de edad. Describimos la justificación política del indicador, describimos sus fuentes de datos y métodos de cálculo, e informamos y analizamos el indicador oficial para 183 países. También proporcionamos ejemplos del uso del indicador en los sistemas nacionales de vigilancia de la salud de los trabajadores y destacamos las ventajas y las limitaciones del indicador. Concluimos que la integración del nuevo indicador en los sistemas de vigilancia proporcionará una vigilancia más exhaustiva y precisa de la salud de los trabajadores, y permitirá la armonización entre los sistemas de vigilancia mundiales, regionales y nacionales. Se podrán analizar las desigualdades en la salud de los trabajadores y se podrá mejorar la base de evidencias para lograr políticas y sistemas más eficaces en materia de salud de los trabajadores.

Progress in reducing premature mortality from cancer and cardiovascular disease in the former Soviet Union, 2000-19.

BACKGROUND: A reduction in non-communicable diseases premature mortality by one-third by 2030 is one of the targets of the UN Sustainable Development Goals (SDG3.4). We examined the mortality profiles in the Newly Independent States of the former Soviet Union (NIS) and the European Union (EU) and assessed progress in reductions of premature mortality from cancer, as compared to cardiovascular disease (CVD). METHODS: We used WHO's Global Health Estimates and GLOBOCAN 2020 to examine current mortality profiles and computed the unconditional probabilities of dying at ages 30-70 from CVD and cancer for the years 2000-19 in both sexes, using a linear extrapolation of this trend to predict whether the target of a one-third reduction, as set in 2015, would be met in 2030. RESULTS: CVD was the main cause of premature death in the NIS (43%), followed by cancer (23%), inversely from the EU with 42% cancer and 24% CVD deaths. The NIS achieved major reductions in premature CVD mortality, although the probabilities of death in 2019 remained about five times higher in the NIS compared to the EU. For cancer, mortality reductions in most NIS were quite modest, other than large declines seen in Kazakhstan (44%) and Kyrgyzstan (30%), with both on course to meet the 2030 target. CONCLUSIONS: Limited progress in cancer control in the NIS calls for policy action both in terms of structural changes towards universal health coverage, and scaling up of national cancer control plans, including a shift from opportunistic to evidence-based early detection practices.

Data gaps towards health development goals, 47 low- and middle-income countries.

OBJECTIVE: To assess the availability and gaps in data for measuring progress towards health-related sustainable development goals and other targets in selected low- and middle-income countries. METHODS: We used 14 international population surveys to evaluate the health data systems in the 47 least developed countries over the years 2015-2020. We reviewed the survey instruments to determine whether they contained tools that could be used to measure 46 health-related indicators defined by the World Health Organization. We recorded the number of countries with data available on the indicators from these surveys. FINDINGS: Twenty-seven indicators were measurable by the surveys we identified. The two health emergency indicators were not measurable by current surveys. The percentage of countries that used surveys to collect data over 2015-2020 were lowest for tuberculosis (2/47; 4.3%), hepatitis B (3/47; 6.4%), human immunodeficiency virus (11/47; 23.4%), child development status and child abuse (both 13/47; 27.7%), compared with safe drinking water (37/47; 78.7%) and births attended by skilled health personnel (36/47; 76.6%). Nineteen countries collected data on 21 or more indicators over 2015-2020 while nine collected data on no indicators; over 2018-2020 these numbers reduced to six and 20, respectively. CONCLUSION: Examining selected international surveys provided a quick summary of health data available in the 47 least developed countries. We found major gaps in health data due to long survey cycles and lack of appropriate survey instruments. Novel indicators and survey instruments would be needed to track the fast-changing situation of health emergencies.

Comparing cancer and cardiovascular disease trends in 20 middle- or high-income countries 2000-19: A pointer to national trajectories towards achieving Sustainable Development goal target 3.4.

With the 2030 Sustainable Development Goals (SDG) target of a one-third reduction in noncommunicable diseases (NCDs) less than a decade away, it is timely to assess national progress in reducing premature deaths from the two leading causes of mortality worldwide. We examine trends in the probability of dying ages 30-70 from cardiovascular disease (CVD) and cancer 2000-19 in 10 middle-income (MICs) and 10 high-income (HICs) countries with high quality data. We then predict whether the SDG target will be met in each country for CVD, cancer and for the four main NCDs combined. Downward trends were more evident in HICs relative to the MICs, and for CVD relative to cancer. CVD and cancer declines ranged from 30-60% and 20-30% in HICs over the 20-year period, but progress was less uniform among the MICs. Premature deaths from cancer exceeded CVD in nine of the 10 HICs by 2000 and in all 10 by 2019; in contrast, CVD mortality exceeded cancer in all 10 MICs in 2000 and remained the leading cause in eight countries by 2019. Two of the 10 MICs (Colombia and Kazakhstan) and seven of the HICs (Australia, Chile, Italy, New Zealand, Norway, Slovakia, and the U.K.) are predicted to meet the SDG NCDs target. Whether countries are on course to meet the target by 2030 reflects changing risk factor profiles and the extent to which effective preventative and medical care interventions have been implemented. In addition, lessons can be learned given people living with NCDs are more susceptible to severe COVID-19 illness and death.

A call for standardised age-disaggregated health data.

The 2030 Sustainable Development Goals agenda calls for health data to be disaggregated by age. However, age groupings used to record and report health data vary greatly, hindering the harmonisation, comparability, and usefulness of these data, within and across countries. This variability has become especially evident during the COVID-19 pandemic, when there was an urgent need for rapid cross-country analyses of epidemiological patterns by age to direct public health action, but such analyses were limited by the lack of standard age categories. In this Personal View, we propose a recommended set of age groupings to address this issue. These groupings are informed by age-specific patterns of morbidity, mortality, and health risks, and by opportunities for prevention and disease intervention. We recommend age groupings of 5 years for all health data, except for those younger than 5 years, during which time there are rapid biological and physiological changes that justify a finer disaggregation. Although the focus of this Personal View is on the standardisation of the analysis and display of age groups, we also outline the challenges faced in collecting data on exact age, especially for health facilities and surveillance data. The proposed age disaggregation should facilitate targeted, age-specific policies and actions for health care and disease management.

Patterns and trends in causes of child and adolescent mortality 2000-2016: setting the scene for child health redesign.

The under-5 mortality rate has declined from 93 deaths per 1000 live births in 1990 to 39 per 1000 live births in 2018. This improvement in child survival warrants an examination of age-specific trends and causes of death over time and across regions and an extension of the survival focus to older children and adolescents. We examine patterns and trends in mortality for neonates, postneonatal infants, young children, older children, young adolescents and older adolescents from 2000 to 2016. Levels and trends in causes of death for children and adolescents under 20 years of age are based on United Nations Inter-agency Group for Child Mortality Estimation for all-cause mortality, the Maternal and Child Epidemiology Estimation group for cause of death among children under-5 and WHO Global Health Estimates for 5-19 year-olds. From 2000 to 2016, the proportion of deaths in young children aged 1-4 years declined in most regions while neonatal deaths became over 25% of all deaths under 20 years in all regions and over 50% of all under-5 deaths in all regions except for sub-Saharan Africa which remains the region with the highest under-5 mortality in the world. Although these estimates have great variability at the country level, the overall regional patterns show that mortality in children under the age of 5 is increasingly concentrated in the neonatal period and in some regions, in older adolescents. The leading causes of disease for children under-5 remain preterm birth and infectious diseases, pneumonia, diarrhoea and malaria. For older children and adolescents, injuries become important causes of death as do interpersonal violence and self-harm. Causes of death vary by region.

Thyroid cancer incidence trends by histology in 25 countries: a population-based study.

BACKGROUND: The incidence of thyroid cancer has increased in different populations worldwide in the past 30 years. We present here an overview of international trends of thyroid cancer incidence by major histological subtypes. METHODS: We did a population-based study with data for thyroid cancer incidence collected by the International Agency for Research on Cancer (IARC) for the period 1998-2012. Data were extracted from the Cancer Incidence in Five Continents plus compendium. We selected data for 25 countries that had a population of more than 2 million individuals covered by cancer registration (87 registries in total). Further criteria were that the selected registration areas had to have a proportion of unspecified thyroid cancer of less than 10% and analyses were restricted to individuals aged 20-84 years. We calculated age-specific incidence rates and age-standardised rates per 100 000 person-years for individuals aged 20 to 84 years, and assessed trends by country, sex, and major histological subtype (papillary, follicular, medullary, or anaplastic) based on absolute changes in age-standardised incidence rates between 1998-2002 and 2008-12. FINDINGS: Papillary thyroid cancer was the main contributor to overall thyroid cancer in all the studied countries, and was the only histological subtype that increased systematically in all countries, although with large variability between countries. In women, the age-standardised incidence rate of papillary thyroid cancer during 2008-12 ranged from 4·3-5·3 cases per 100 000 person-years in the Netherlands, the UK, and Denmark, to 143·3 cases per 100 000 women in South Korea. For men during the same period, the age-standardised incidence rates of papillary thyroid cancer per 100 000 person-years ranged from 1·2 cases per 100 000 in Thailand to 30·7 cases per 100 000 in South Korea. In many countries in Asia, the increase in papillary thyroid cancer rates in women was particularly pronounced after the year 2000; rates stabilised since around 2009 in the USA, Austria, Croatia, Germany, Slovenia, Spain, Lithuania, and Bulgaria. Temporal trends for follicular and medullary thyroid cancer did not show consistent patterns across countries, but slight decreases were seen for anaplastic thyroid cancer in 21 of 25 countries between 1998-2002, and 2008-12. In 2008-12, age-standardised rates for the follicular subtype ranged between 0·5 and 2·5 cases per 100 000 women (and between 0·3 and 1·5 per 100 000 men), while those for the medullary subtype were always less than 1 case per 100 000 women or men, and for anaplastic thyroid cancer less than 0·2 cases per 100 000 women or men. INTERPRETATION: In the period from 1998 to 2012, the rapid increases in thyroid cancer incidence were observed only for papillary thyroid cancer, the subtype more likely to be found in a subclinical form and therefore detected by intense scrutiny of the thyroid gland. FUNDING: French Institut National du Cancer, Italian Association for Cancer Research, Italian Ministry of Health.

Effect on longevity of one-third reduction in premature mortality from non-communicable diseases by 2030: a global analysis of the Sustainable Development Goal health target.

BACKGROUND: To curb the rising global burden of non-communicable diseases (NCDs), the UN Sustainable Development Goals (SDGs) include a target to reduce premature mortality from NCDs by a third by 2030. A quantitative assessment of the effect on longevity of meeting this target is one of the many important measures needed to advocate and inform national disease control policies. We did a global analysis to estimate improvements in average expected years lived between 30 and 70 years of age that would result from meeting the SDG target. METHODS: We estimated age-specific mortality in 183 countries in 2015, for the four major NCDs (cardiovascular diseases, cancers, chronic respiratory diseases, and diabetes) and all NCDs combined, using data from WHO Global Health Estimates. We then estimated the potential gains in average expected years lived between 30 and 70 years of age (LE[30-70)) by eliminating all or a third of premature mortality from specific causes of death in countries grouped by World Bank income groups. The feasibility of reducing mortality to the targeted level over 15 years was also assessed on the basis of historical mortality trends from 2000 to 2015. FINDINGS: Reducing a third of premature mortality from NCDs over 15 years is feasible in high-income and upper-middle-income countries, but remains challenging in countries with lower income levels. National longevity will improve if this target is met, corresponding to an average gain in LE[30-70) of 0·64 years worldwide from reduced premature mortality for the four major NCDs and 0·80 years for all NCDs. According to major NCD type, the largest gains attributable to cardiovascular diseases would be in lower-middle-income countries (a gain of 0·45 years), whereas gains attributable to cancer would be in low-income countries (0·33 years). INTERPRETATION: A one-third reduction in premature mortality from the major NCDs in 2015-30 would have substantial effects on longevity. High-level political commitments to effective and equitable national surveillance and prioritised prevention, early detection, and treatment programmes tailored to the major NCD types are needed urgently in lower-resourced settings if this SDG target is to be met by 2030. FUNDING: None.

Cancers attributable to tobacco smoking in France in 2015.

Background: The evidence on the carcinogenicity of tobacco smoking has been well established. An assessment of the population-attributable fraction (PAF) of cancer due to smoking is needed for France, given its high smoking prevalence. Methods: We extracted age- and sex-specific national estimates of population and cancer incidence for France, and incidence rates of lung cancer among never smokers and relative risk (RR) estimates of smoking for various cancers from the American Cancer Prevention Study (CPS II). For active smoking, we applied a modified indirect method to estimate the PAF for lung and other tobacco smoking-related cancer sites. Using the RR estimates for second-hand smoking, the proportion of never smokers living with an ever-smoking partner derived from survey, and marital status data, we then estimated the PAF for lung cancer attributable to domestic passive smoking. Results: Overall in France in 2015, 54 142 and 12 008 cancer cases in males and females, respectively, were attributable to active smoking, accounting for 28 and 8% of all cancer cases observed among adult (30+ years) males and females. Additionally, 36 and 142 lung cancer cases, respectively among male and female never smokers, were attributable to second-hand smoke resulting from their partner's active smoking, corresponding to 4.2 and 6.7% of lung cancer cases which occurred in never smoker males and females, respectively. Conclusions: Tobacco smoking is responsible for a significant number of potentially avoidable cancer cases in France in 2015. More effective tobacco control programmes are critical to reduce this cancer burden.

Benchmarking life expectancy and cancer mortality: global comparison with cardiovascular disease 1981-2010.

Objective To quantify the impact of cancer (all cancers combined and major sites) compared with cardiovascular disease (CVD) on longevity worldwide during 1981-2010.Design Retrospective demographic analysis using aggregated data.Setting National civil registration systems in member states of the World Health Organization.Participants 52 populations with moderate to high quality data on cause specific mortality.Main outcome measures Disease specific contributions to changes in life expectancy in ages 40-84 (LE40-84) over time in populations grouped by two levels of Human Development Index (HDI) values.Results Declining CVD mortality rates during 1981-2010 contributed to, on average, over half of the gains in LE40-84; the corresponding gains were 2.3 (men) and 1.7 (women) years, and 0.5 (men) and 0.8 (women) years in very high and medium and high HDI populations, respectively. Declines in cancer mortality rates contributed to, on average, 20% of the gains in LE40-84, or 0.8 (men) and 0.5 (women) years in very high HDI populations, and to over 10% or 0.2 years (both sexes) in medium and high HDI populations. Declining lung cancer mortality rates brought about the largest LE40-84 gain in men in very high HDI populations (up to 0.7 years in the Netherlands), whereas in medium and high HDI populations its contribution was smaller yet still positive. Among women, declines in breast cancer mortality rates were largely responsible for the improvement in longevity, particularly among very high HDI populations (up to 0.3 years in the United Kingdom). In contrast, losses in LE40-84 were observed in many medium and high HDI populations as a result of increasing breast cancer mortality rates.Conclusions The control of CVD has led to substantial gains in LE40-84 worldwide. The inequality in improvement in longevity attributed to declining cancer mortality rates reflects inequities in implementation of cancer control, particularly in less resourced populations and in women. Global actions are needed to revitalize efforts for cancer control, with a specific focus on less resourced countries.

Future healthy life expectancy among older adults in the US: a forecast based on cohort smoking and obesity history.

BACKGROUND: In the past three decades, the elderly population in the United States experienced increase in life expectancy (LE) and disability-free life expectancy (LE(ND)), but decrease in life expectancy with disability (LE(D)). Smoking and obesity are two major risk factors that had negative impacts on these trends. While smoking prevalence continues to decline in recent decades, obesity prevalence has been growing and is currently at a high level. This study aims to forecast the healthy life expectancy for older adults aged 55 to 85 in the US from 2011 to 2040, in relation to their smoking and obesity history. METHODS: First, population-level mortality data from the Human Mortality Database (HMD) and individual-level disability data from the US National Health Interview Survey (NHIS) were used to estimate the transition rates between different health states from 1982 to 2010, using a multi-state life table (MSLT) model. Second, the estimated transition rates were fitted and projected up to 2040, using a modified Lee-Carter model that incorporates cohort smoking and obesity history from NHIS. RESULTS: Mortality and morbidity for both sexes will continue to decline in the next decades. Relative to 2010, men are expected to have 3.2 years gain in LE(ND) and 0.8 years loss in LE(D). For women, there will be 1.8 years gain in LE(ND) and 0.8 years loss in LE(D). By 2040, men and women are expected to spend respectively 80 % and 75 % of their remaining life expectancy between 55 and 85 disability-free. CONCLUSIONS: Smoking and obesity have independent negative impacts on both the survival and disability of the US older population in the coming decades, and are responsible for the present and future gender disparity in mortality and morbidity. Overall, the US older population is expected to enjoy sustained health improvements and compression of disability, largely due to decline in smoking.

Estimating the Effects of Obesity and Weight Change on Mortality Using a Dynamic Causal Model.

BACKGROUND: A well-known challenge in estimating the mortality risks of obesity is reverse causality attributable to illness-associated and smoking-associated weight loss. Given that the likelihood of chronic and acute illnesses rises with age, reverse causality is most threatening to estimates derived from elderly populations. METHODS: I analyzed data from 12,523 respondents over 50 years old from a nationally representative longitudinal dataset, the Health and Retirement Study (HRS). The effects of both baseline body weight and time-varying weight change on mortality are estimated, adjusting for demographic and socio-economic variables, as well as time-varying confounders including illness and smoking. Body weight is measured by body mass index (BMI). In survival models for mortality, illness and smoking were lagged to minimize bias from reverse causality in estimates of the effect of weight change. Furthermore, because illness both causes and is caused by changes in BMI, I used a marginal structural model (MSM) rather than standard adjustment to control confounding by this and other time-dependent factors. RESULTS: Overall, relative to normal weight, underweight and Class II/III at baseline are associated with hazard ratios that are 2.07 (95% confidence interval (CI): 1.28-3.37) and 1.82 (1.54-2.16) respectively, whereas overweight and Class I obesity do not significantly lower or raise the mortality risks. Furthermore, relative to stable weight change, all types of weight change lead to significantly increased risk of mortality. Specifically, large weight loss results in a mortality risk that is nearly 3.86 (3.26-4.58) times of staying in the stable weight range and small weight loss is about 1.81 (1.55-2.11 ) times riskier. In contrast, large weight gain and small weight gain are associated with hazard ratios that are 1.98 (1.67-2.35) and 1.20 (1.02-1.41) respectively. CONCLUSIONS: Being underweight or severe obese at baseline is associated with excess mortality risk, and weight change tend to raise mortality risk. Both the confounding by illness and by smoking lead to overestimates of the effects of being underweight at baseline and of weight loss, but underestimates the effect of being obese at baseline.

Projecting the effect of changes in smoking and obesity on future life expectancy in the United States.

We estimate the effects of declining smoking and increasing obesity on mortality in the United States over the period 2010-2040. Data on cohort behavioral histories are integrated into these estimates. Future distributions of body mass indices are projected using transition matrices applied to the initial distribution in 2010. In addition to projections of current obesity, we project distributions of obesity when cohorts are age 25. To these distributions, we apply death rates by current and age-25 obesity status observed in the National Health and Nutrition Examination Survey, 1988-2006. Estimates of the effects of smoking changes are based on observed relations between cohort smoking patterns and cohort death rates from lung cancer. We find that changes in both smoking and obesity are expected to have large effects on U.S. mortality. For males, the reductions in smoking have larger effects than the rise in obesity throughout the projection period. By 2040, male life expectancy at age 40 is expected to have gained 0.83 years from the combined effects. Among women, however, the two sets of effects largely offset one another throughout the projection period, with a small gain of 0.09 years expected by 2040.