552702 research-article2014
APHXXX10.1177/1010539514552702Asia-Pacific Journal of Public HealthLinthicum et al
Article
Economic Burden of Disease-Associated Malnutrition in China
Asia-Pacific Journal of Public Health 2015, Vol. 27(4) 407–417 © 2014 APJPH Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1010539514552702 aph.sagepub.com
Mark T. Linthicum, MPP1, Julia Thornton Snider, PhD1, Rhema Vaithianathan, PhD2, Yanyu Wu, PhD1, Chris LaVallee, MS1, Darius N. Lakdawalla, PhD3, Jennifer E. Benner, BA1, and Tomas J. Philipson, PhD4
Abstract Disease-associated malnutrition (DAM) is a well-recognized problem in many countries, but the extent of its burden on the Chinese population is unclear. This article reports the results of a burden-of-illness study on DAM in 15 diseases in China. Using data from the World Health Organization (WHO), the China Health and Nutrition Survey, and the published literature, mortality and disability-adjusted life years (DALYs) lost because of DAM were calculated; a financial value of this burden was calculated following WHO guidelines. DALYs lost annually to DAM in China varied across diseases, from a low of 2248 in malaria to a high of 1 315 276 in chronic obstructive pulmonary disease. The total burden was 6.1 million DALYs, for an economic burden of US$66 billion (Chinese ¥ 447 billion) annually. This burden is sufficiently large to warrant immediate attention from public health officials and medical providers, especially given that low-cost and effective interventions are available. Keywords burden of illness, disability-adjusted life year, disease-associated malnutrition, malnutrition, quality of life
Introduction Disease-associated malnutrition (DAM) is malnutrition resulting from disease,1 rather than poverty,1-3 and is often associated with increased morbidity and mortality.2,4 DAM arises from a number of disease-related factors, including appetite loss and increased metabolic requirements that can be seen in heart failure, end-stage liver and kidney disease, and solid and hematological cancers.1 Adverse health effects of DAM extend to virtually every organ of the body, with particularly negative consequences, including global muscle loss and physical deconditioning, 1Precision
Health Economics, Los Angeles, CA, USA of Economics, University of Auckland, Auckland, New Zealand 3Schaeffer Center for Health Policy and Economics, University of Southern California, Los Angeles, CA, USA 4Irving B. Harris Graduate School of Public Policy Studies, University of Chicago, Chicago, IL, USA 2Department
Corresponding Author: Julia Thornton Snider, Precision Health Economics, 11100 Santa Monica Blvd, Suite 500, Los Angeles, CA 90025, USA. Email: [email protected]
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Asia-Pacific Journal of Public Health 27(4)
depressed immunity, and increased risk of infection and cognitive decline.1 Studies in highincome countries have documented the effects of DAM on health outcomes, hospitalizations, and medical costs.4-7 This body of research has demonstrated that not only does DAM have a large impact in these specific areas, but it also has been found to exact a large economic burden from the societal perspective.8 Because malnutrition caused by poverty and food scarcity, as opposed to disease, tends to be a greater problem within developing countries, studies of malnutrition in these countries focus on undernutrition in children or women of childbearing age.9,10 However, as China transitions from a developing to an advanced economy and disease patterns shift in tandem from communicable toward chronic diseases, DAM will likely place an increasing burden on population health. Therefore, the objective of this article was to model the economic burden of morbidity and mortality resulting from DAM in China. Since the introduction of broad economic reforms in 1978, the Chinese economy has grown rapidly11 and today is the second largest in the world. According to the World Bank, per capita GDP (in 2011 US dollars) has increased steadily from $186 in 1980 to $5975 in 2012.11 From 1980 to 2011, average life expectancy increased from 67 to 75 years.12 Concurrently, a vast migration to China’s urban centers has occurred as rural residents moved in search of work.13 With this economic and demographic change, China increasingly resembles high-income industrialized countries. Such change brings new public health challenges. Whereas the prevalence of infectious diseases has decreased (eg, malaria-related morbidity decreased more than 4-fold), chronic diseases are now the leading causes of mortality and morbidity in China.14 For example, thyroid cancer incidence has tripled,15 heart disease and diabetes have increased dramatically,14 and the leading causes of death in China are now cancer, stroke, and heart disease.16 As the Chinese population lives longer, thereby increasing the population’s susceptibility to chronic diseases, the impact of DAM on society is likely to increase. As such, it is important for Chinese policy makers and medical professionals to understand the size of the burden from DAM as well as its economic burden on society as a whole. However, no estimate of the burden of DAM in a middle-income Asian economy exists yet. In this study, we used a burden-of-illness modeling approach to estimate the economic value to Chinese society of the health impacts of DAM. Our model measured the burden of DAM in 15 primary diseases: diarrheal diseases, malaria, measles, lower-respiratory infections, other infectious diseases (excluding HIV), protein-energy malnutrition, breast cancer, colorectal cancer, coronary heart disease, chronic obstructive pulmonary disease (COPD), dementia, depression, head and neck cancer, musculoskeletal disorders, and stroke. The first 6 diseases are relevant to DAM in developing countries and are the focus of a previous World Health Organization (WHO) model of DAM.17 The last 9 diseases are relevant to DAM in industrialized countries; they are the focus of prior DAM measurement efforts in Europe.8 Disease burden was expressed through mortality rates and disability-adjusted life years (DALYs). By incorporating both morbidity and mortality from each disease, DALYs represent a burden measure more comprehensive than death counts. Considering the growing elderly population in China and the higher prevalence of both chronic disease and DAM in this age group,14 we explore the distribution of burden from DAM across age groups. In the DAM context, the burden estimate is particularly informative because low-cost solutions such as malnutrition screening18 and the provision of oral nutritional supplements19,20 exist. Thus, if the burden of DAM is quantitatively significant, investments to reduce disease burden are more likely to provide value to society.
Methods We adapted and built on an existing WHO model that quantifies the health burden of DAM, as measured by underweight status, in children and women of childbearing age in developing
Downloaded from aph.sagepub.com by guest on November 15, 2015
409
Linthicum et al
countries.17 Our model used WHO data on death and disability by disease as an input and used relative risk (RR) estimates from the literature to determine the extent to which those deaths and disabilities were attributable to malnutrition. As described above, 15 separate diseases were included. Our model differs from the WHO model in several key aspects, including its multifaceted definition of malnutrition, its inclusion of all ages and genders, the diseases considered, and its inclusion of economic measures of burden. Intuitively, the model’s first inputs were the deaths and DALYs lost as a result of each included disease, drawn from 2004 WHO data. The model then considered the additional risk of mortality or morbidity faced by malnourished patients with that disease and the overall prevalence of malnutrition. Taken together, these factors yielded an estimate of the additional mortality and morbidity caused by malnutrition, by disease group. Finally, an economic valuation of the burden was calculated using the DALY burden, which incorporates both morbidity and mortality. Further details are available in the online Technical Appendix. Although underweight is the most common (and easily measured) metric of undernutrition, malnutrition also arises from deficiencies in specific nutrients that are detectable clinically. As a result, we defined malnutrition as the presence of any of 3 risk factors: underweight (ie, body mass index
APHXXX10.1177/1010539514552702Asia-Pacific Journal of Public HealthLinthicum et al
Article
Economic Burden of Disease-Associated Malnutrition in China
Asia-Pacific Journal of Public Health 2015, Vol. 27(4) 407–417 © 2014 APJPH Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1010539514552702 aph.sagepub.com
Mark T. Linthicum, MPP1, Julia Thornton Snider, PhD1, Rhema Vaithianathan, PhD2, Yanyu Wu, PhD1, Chris LaVallee, MS1, Darius N. Lakdawalla, PhD3, Jennifer E. Benner, BA1, and Tomas J. Philipson, PhD4
Abstract Disease-associated malnutrition (DAM) is a well-recognized problem in many countries, but the extent of its burden on the Chinese population is unclear. This article reports the results of a burden-of-illness study on DAM in 15 diseases in China. Using data from the World Health Organization (WHO), the China Health and Nutrition Survey, and the published literature, mortality and disability-adjusted life years (DALYs) lost because of DAM were calculated; a financial value of this burden was calculated following WHO guidelines. DALYs lost annually to DAM in China varied across diseases, from a low of 2248 in malaria to a high of 1 315 276 in chronic obstructive pulmonary disease. The total burden was 6.1 million DALYs, for an economic burden of US$66 billion (Chinese ¥ 447 billion) annually. This burden is sufficiently large to warrant immediate attention from public health officials and medical providers, especially given that low-cost and effective interventions are available. Keywords burden of illness, disability-adjusted life year, disease-associated malnutrition, malnutrition, quality of life
Introduction Disease-associated malnutrition (DAM) is malnutrition resulting from disease,1 rather than poverty,1-3 and is often associated with increased morbidity and mortality.2,4 DAM arises from a number of disease-related factors, including appetite loss and increased metabolic requirements that can be seen in heart failure, end-stage liver and kidney disease, and solid and hematological cancers.1 Adverse health effects of DAM extend to virtually every organ of the body, with particularly negative consequences, including global muscle loss and physical deconditioning, 1Precision
Health Economics, Los Angeles, CA, USA of Economics, University of Auckland, Auckland, New Zealand 3Schaeffer Center for Health Policy and Economics, University of Southern California, Los Angeles, CA, USA 4Irving B. Harris Graduate School of Public Policy Studies, University of Chicago, Chicago, IL, USA 2Department
Corresponding Author: Julia Thornton Snider, Precision Health Economics, 11100 Santa Monica Blvd, Suite 500, Los Angeles, CA 90025, USA. Email: [email protected]
Downloaded from aph.sagepub.com by guest on November 15, 2015
408
Asia-Pacific Journal of Public Health 27(4)
depressed immunity, and increased risk of infection and cognitive decline.1 Studies in highincome countries have documented the effects of DAM on health outcomes, hospitalizations, and medical costs.4-7 This body of research has demonstrated that not only does DAM have a large impact in these specific areas, but it also has been found to exact a large economic burden from the societal perspective.8 Because malnutrition caused by poverty and food scarcity, as opposed to disease, tends to be a greater problem within developing countries, studies of malnutrition in these countries focus on undernutrition in children or women of childbearing age.9,10 However, as China transitions from a developing to an advanced economy and disease patterns shift in tandem from communicable toward chronic diseases, DAM will likely place an increasing burden on population health. Therefore, the objective of this article was to model the economic burden of morbidity and mortality resulting from DAM in China. Since the introduction of broad economic reforms in 1978, the Chinese economy has grown rapidly11 and today is the second largest in the world. According to the World Bank, per capita GDP (in 2011 US dollars) has increased steadily from $186 in 1980 to $5975 in 2012.11 From 1980 to 2011, average life expectancy increased from 67 to 75 years.12 Concurrently, a vast migration to China’s urban centers has occurred as rural residents moved in search of work.13 With this economic and demographic change, China increasingly resembles high-income industrialized countries. Such change brings new public health challenges. Whereas the prevalence of infectious diseases has decreased (eg, malaria-related morbidity decreased more than 4-fold), chronic diseases are now the leading causes of mortality and morbidity in China.14 For example, thyroid cancer incidence has tripled,15 heart disease and diabetes have increased dramatically,14 and the leading causes of death in China are now cancer, stroke, and heart disease.16 As the Chinese population lives longer, thereby increasing the population’s susceptibility to chronic diseases, the impact of DAM on society is likely to increase. As such, it is important for Chinese policy makers and medical professionals to understand the size of the burden from DAM as well as its economic burden on society as a whole. However, no estimate of the burden of DAM in a middle-income Asian economy exists yet. In this study, we used a burden-of-illness modeling approach to estimate the economic value to Chinese society of the health impacts of DAM. Our model measured the burden of DAM in 15 primary diseases: diarrheal diseases, malaria, measles, lower-respiratory infections, other infectious diseases (excluding HIV), protein-energy malnutrition, breast cancer, colorectal cancer, coronary heart disease, chronic obstructive pulmonary disease (COPD), dementia, depression, head and neck cancer, musculoskeletal disorders, and stroke. The first 6 diseases are relevant to DAM in developing countries and are the focus of a previous World Health Organization (WHO) model of DAM.17 The last 9 diseases are relevant to DAM in industrialized countries; they are the focus of prior DAM measurement efforts in Europe.8 Disease burden was expressed through mortality rates and disability-adjusted life years (DALYs). By incorporating both morbidity and mortality from each disease, DALYs represent a burden measure more comprehensive than death counts. Considering the growing elderly population in China and the higher prevalence of both chronic disease and DAM in this age group,14 we explore the distribution of burden from DAM across age groups. In the DAM context, the burden estimate is particularly informative because low-cost solutions such as malnutrition screening18 and the provision of oral nutritional supplements19,20 exist. Thus, if the burden of DAM is quantitatively significant, investments to reduce disease burden are more likely to provide value to society.
Methods We adapted and built on an existing WHO model that quantifies the health burden of DAM, as measured by underweight status, in children and women of childbearing age in developing
Downloaded from aph.sagepub.com by guest on November 15, 2015
409
Linthicum et al
countries.17 Our model used WHO data on death and disability by disease as an input and used relative risk (RR) estimates from the literature to determine the extent to which those deaths and disabilities were attributable to malnutrition. As described above, 15 separate diseases were included. Our model differs from the WHO model in several key aspects, including its multifaceted definition of malnutrition, its inclusion of all ages and genders, the diseases considered, and its inclusion of economic measures of burden. Intuitively, the model’s first inputs were the deaths and DALYs lost as a result of each included disease, drawn from 2004 WHO data. The model then considered the additional risk of mortality or morbidity faced by malnourished patients with that disease and the overall prevalence of malnutrition. Taken together, these factors yielded an estimate of the additional mortality and morbidity caused by malnutrition, by disease group. Finally, an economic valuation of the burden was calculated using the DALY burden, which incorporates both morbidity and mortality. Further details are available in the online Technical Appendix. Although underweight is the most common (and easily measured) metric of undernutrition, malnutrition also arises from deficiencies in specific nutrients that are detectable clinically. As a result, we defined malnutrition as the presence of any of 3 risk factors: underweight (ie, body mass index
