Apples and oranges: a comparison of costing methods for obesity

The healthcare costs of increased body mass index-evidence from The Trøndelag Health Study

BACKGROUND

Earlier studies have estimated the impact of increased body mass index (BMI) on healthcare costs. Various methods have been used to avoid potential biases and inconsistencies. Each of these methods measure different local effects and have different strengths and weaknesses.

METHODS

In the current study we estimate the impact of increased BMI on healthcare costs using nine common methods from the literature: multivariable regression analyses (ordinary least squares, generalized linear models, and two-part models), and instrumental variable models (using previously measured BMI, offspring BMI, and three different weighted genetic risk scores as instruments for BMI). We stratified by sex, investigated the implications of confounder adjustment, and modelled both linear and non-linear associations.

RESULTS

There was a positive effect of increased BMI in both males and females in each approach. The cost of elevated BMI was higher in models that, to a greater extent, account for endogenous relations.

CONCLUSION

The study provides solid evidence that there is an association between BMI and healthcare costs, and demonstrates the importance of triangulation.

Disease-specific health spending by age, sex, and type of care in Norway: a national health registry study

BACKGROUND

Norway is a high-income nation with universal tax-financed health care and among the highest per person health spending in the world. This study estimates Norwegian health expenditures by health condition, age, and sex, and compares it with disability-adjusted life-years (DALYs).

METHODS

Government budgets, reimbursement databases, patient registries, and prescription databases were combined to estimate spending for 144 health conditions, 38 age and sex groups, and eight types of care (GPs; physiotherapists & chiropractors; specialized outpatient; day patient; inpatient; prescription drugs; home-based care; and nursing homes) totaling 174,157,766 encounters. Diagnoses were in accordance with the Global Burden of Disease study (GBD). The spending estimates were adjusted, by redistributing excess spending associated with each comorbidity. Disease-specific DALYs were gathered from GBD 2019.

RESULTS

The top five aggregate causes of Norwegian health spending in 2019 were mental and substance use disorders (20.7%), neurological disorders (15.4%), cardiovascular diseases (10.1%), diabetes, kidney, and urinary diseases (9.0%), and neoplasms (7.2%). Spending increased sharply with age. Among 144 health conditions, dementias had the highest health spending, with 10.2% of total spending, and 78% of this spending was incurred at nursing homes. The second largest was falls estimated at 4.6% of total spending. Spending in those aged 15-49 was dominated by mental and substance use disorders, with 46.0% of total spending. Accounting for longevity, spending per female was greater than spending per male, particularly for musculoskeletal disorders, dementias, and falls. Spending correlated well with DALYs (Correlation r = 0.77, 95% CI 0.67-0.87), and the correlation of spending with non-fatal disease burden (r = 0.83, 0.76-0.90) was more pronounced than with mortality (r = 0.58, 0.43-0.72).

CONCLUSIONS

Health spending was high for long-term disabilities in older age groups. Research and development into more effective interventions for the disabling high-cost diseases is urgently needed.

Association between the Use of Health Services, Cardiovascular Risk Factors and Metabolic Syndrome in Mexican Adults

Background: The use of health services is a complex behavioral phenomenon affected by multiple factors (availability, distance, cost, quality, attitudes, cultural beliefs, socioeconomic characteristics, and individuals' self-perception of health). Mexico has a segmented health system, and the access to it depends on the labor insertion and the population's ability to pay. Objective: To assess association between use of health services and cardiovascular and metabolic syndrome risk factors among Mexican adults. Methods: Analytical cross-sectional nationally representative study carried out on Mexican adults (≥20-year-old adults of both sexes; n = 4595). Socioeconomic factors, geographic area, health care coverage, information about the use of health services, previous medical diagnoses of diabetes and hypertension, and smoking were assessed. Anthropometrics, triglyceride, total cholesterol, HDL-cholesterol, and glucose plasma levels were measured. Metabolic syndrome (MetS) and cardiovascular risk factors were assessed. Prevalences were expressed in terms of percentages, and significant differences were calculated using χ2 test. Univariate and multivariate analysis was performed to evaluate the association between the use of health services and cardiovascular risk factors and sociodemographic variables. Results: The probability of using health services is higher and more significant in subjects with obesity, diabetes (OR (95% CI): 1.73 (1.49-2.00; p < 0.001), hypertension (OR (95% CI): 1.29 (1.14-1.45; p < 0.001), hypertriglyceridemia (OR (95% CI): 1.30 (1.15-1.46; p < 0.001), and in those with hypercholesterolemia (OR (95% CI): 1.23 (1.03-1.39; p = 0.001). Conclusions: Among health service users, there is a positive significant association between the use of health services and the presence of metabolic syndrome, obesity, diabetes, hypertension, hypertriglyceridemia, and hypercholesterolemia.

Medical costs attributable to overweight and obesity in Japanese individuals

OBJECTIVE

We aimed to reveal the association between body mass index (BMI) and medical costs in the current Japanese population, and to estimate the population attributable fraction (PAF) of medical costs due to overweight and obesity.

METHODS

A generalized linear mixed model with log link function and gamma distribution was used to evaluate the association between BMI and medical costs in 34,537 beneficiaries of the National Health Insurance aged 40-69 years in Chiba City. Medical cost data were obtained from insurance claims submitted between April 2012 and March 2016. PAFs due to overweight (BMI ≥25.0 and <30.0kg/m²) and obesity (BMI ≥30.0kg/m²) were calculated.

RESULTS

Overweight and obesity were significant predictors of excessive medical costs in all age and sex groups. PAF due to overweight and obesity was estimated to be 9.62% (95% confidence interval, 8.52-10.73%). Additionally, PAFs in 40-59-year-old individuals (12.76% in men and 11.63% in women) were greater than those in 60-69-year-old subjects (6.55% in men and 7.80% in women) for both sexes.

CONCLUSIONS

In the Japanese population, overweight and obesity are an excessive financial burden with an estimated PAF of 9.62% of total medical costs.

Body mass index and healthcare costs: a systematic literature review of individual participant data studies

Excess weight is associated with increased total healthcare costs, but it is less well known how the associations between excess weight and costs vary across different types of healthcare service. We reviewed studies using individual participant data to estimate associations between body mass index and healthcare costs, and summarized how annual healthcare costs for overweight (body mass index 25 to <30 kg/m2 ) and obese (≥30 kg/m2 ) individuals compared with those for healthy weight individuals (18.5 to <25 kg/m2 ). EMBASE and MEDLINE were searched from January 1990 to September 2016, and 75 studies were included in the review. Of these, 34 studies presented adequate information to contribute to a quantitative summary of results. Compared with individuals at healthy weight, the median increases in mean total annual healthcare costs were 12% for overweight and 36% for obese individuals. The percentage increases in costs were highest for medications (18% for overweight and 68% for obese), followed by inpatient care (12% and 34%) and ambulatory care (4% and 26%). Percentage increases in costs associated with obesity were higher for women than men. The substantial costs associated with excess weight in different healthcare settings emphasize the need for investment to tackle this major public health problem.

The Impact of Childhood Obesity on Health and Health Service Use

OBJECTIVE

To test the impact of obesity on health and health care use in children, by the use of various methods to account for reverse causality and omitted variables.

DATA SOURCES/STUDY SETTING

Fifteen rounds of the Health Survey for England (1998-2013), which is representative of children and adolescents in England.

STUDY DESIGN

We use three methods to account for reverse causality and omitted variables in the relationship between BMI and health/health service use: regression with individual, parent, and household control variables; sibling fixed effects; and instrumental variables based on genetic variation in weight.

DATA COLLECTION/EXTRACTION METHODS

We include all children and adolescents aged 4-18 years old.

PRINCIPAL FINDINGS

We find that obesity has a statistically significant and negative impact on self-rated health and a positive impact on health service use in girls, boys, younger children (aged 4-12), and adolescents (aged 13-18). The findings are comparable in each model in both boys and girls.

CONCLUSIONS

Using econometric methods, we have mitigated several confounding factors affecting the impact of obesity in childhood on health and health service use. Our findings suggest that obesity has severe consequences for health and health service use even among children.

Economic Burden of Obesity: A Systematic Literature Review

Background: The rising prevalence of obesity represents an important public health issue. An assessment of its costs may be useful in providing recommendations for policy and decision makers. This systematic review aimed to assess the economic burden of obesity and to identify, measure and describe the different obesity-related diseases included in the selected studies. Methods: A systematic literature search of studies in the English language was carried out in Medline (PubMed) and Web of Science databases to select cost-of-illness studies calculating the cost of obesity in a study population aged ≥18 years with obesity, as defined by a body mass index of ≥30 kg/m², for the whole selected country. The time frame for the analysis was January 2011 to September 2016. Results: The included twenty three studies reported a substantial economic burden of obesity in both developed and developing countries. There was considerable heterogeneity in methodological approaches, target populations, study time frames, and perspectives. This prevents an informative comparison between most of the studies. Specifically, there was great variety in the included obesity-related diseases and complications among the studies. Conclusions: There is an urgent need for public health measures to prevent obesity in order to save societal resources. Moreover, international consensus is required on standardized methods to calculate the cost of obesity to improve homogeneity and comparability. This aspect should also be considered when including obesity-related diseases.

Diverse approaches to the health economic evaluation of bariatric surgery: a comprehensive systematic review

BACKGROUND

Health economic evaluations inform healthcare resource allocation decisions for treatment options for obesity including bariatric/metabolic surgery. As an important advance on existing systematic reviews, we aimed to capture, summarize and synthesize a diverse range of economic evaluations on bariatric surgery.

METHODS

Studies were identified by electronic screening of all major biomedical/economic databases. Studies included if they reported any quantified health economic cost and/or consequence with a measure of effect for any type of bariatric surgery from 1995 to September 2015. Study screening, data extraction and synthesis followed international guidelines for systematic reviews.

RESULTS

Six thousand one hundred eighty-seven studies were initially identified. After two levels of screening, 77 studies representing 17 countries (56% USA) were included. Despite study heterogeneity, common themes emerged, and important gaps were identified. Most studies adopted the healthcare system/third-party payer perspective; reported costs were generally healthcare resource use (inpatient/shorter-term outpatient). Out-of-pocket costs to individuals, family members (travel time, caregiving) and indirect costs due to lost productivity were largely ignored. Costs due to reoperations/complications were not included in one-third of studies. Body-contouring surgery included in only 14%. One study evaluated long-term waitlisted patients. Surgery was cost-effective/cost-saving for severely obese with type 2 diabetes mellitus. Study quality was inconsistent.

DISCUSSION

There is a need for studies that assume a broader societal perspective (including out-of-pocket costs, costs to family and productivity losses) and longer-term costs (capture reoperations/complications, waiting, body contouring), and consequences (health-related quality-of-life). Full economic evaluation underpinned by reporting standards should inform prioritization of patients (e.g. type 2 diabetes mellitus with body mass index 30 to 34.9 kg/m(2) or long-term waitlisted) for surgery. © 2016 World Obesity.

Economic Impact of Obesity

Parallel to rising obesity rates is an increase in costs associated with excess weight. Estimates of future direct (medical) and indirect (nonmedical) costs related to obesity suggest rising expenditures that will impose a significant economic burden to individuals and society as a whole. This article reviews research on direct and indirect medical costs and future economic trends associated with obesity and associated comorbidities. Cost disparities associated with subsets of the population experiencing higher than average rates of obesity are explored. Finally, potential solutions with the highest estimated impact are offered, and future directions are proposed.

Health burden and costs of obesity and overweight in Germany: an update

In 2011, Konnopka et al. (Eur J Health Econ 12:345-352, 2011) published a top-down cost of illness study on the health burden, and direct and indirect costs of morbidity and mortality attributable to excess weight (BMI ≥25 kg/m(2)) in Germany in 2002. The objective of the current study was to update the 2002 estimates to the year 2008. To simplify comparisons, we closely followed the methods and assumptions of the original study, using 2008 data for most input parameters (e.g. prevalence, mortality, resource use, costs). Excess weight related deaths increased by 31% (from 36,653 to 47,964) and associated years of potential life lost (from 428,093 to 588,237) and quality adjusted life years lost (from 367,722 to 505,748) by about 37%, respectively. Excess weight caused €16,797 million in total costs in 2008 (+70%), of which €8,647 million were direct costs (corresponding to 3.27% of total German health care expenditures in 2008). About 73% (€12,235 million) of total excess weight related costs were attributable to obesity (BMI ≥30 kg/m(2)). The main drivers of direct costs were endocrinological (44%) and cardiovascular (38%) diseases. Indirect costs amounted to €8,150 million in 2008 (+62%), of which about two-thirds were indirect costs from unpaid work. The great majority of indirect costs were due to premature mortality (€5,669 million). The variation of input parameters (univariate sensitivity analyses) resulted in attributable costs between €8,978 million (-47% compared to base case) and €25,060 million (+49%). The marked increase in excess weight related costs can largely be explained by increases in the prevalence of overweight and obesity, and to a lesser extent from increases in resource consumption, as well as increases in (unit) costs and wages (comprising 5.5% inflation).

Association between childhood obesity and use of regular medications in the UK: longitudinal cohort study of children aged 5-11 years

OBJECTIVES

Increasing rates of childhood obesity have been suggested as a possible cause for the increasing prevalence of chronic conditions among adults and children. Few studies have examined whether obese children are more likely to use medications than normal weight children. We investigate this association in the UK.

DESIGN

A panel study with repeated observations at ages 5, 7 and 11.

SETTING

A general population sample drawn from the Millennium Cohort Study, a UK-based birth cohort.

PARTICIPANTS

A sample of 9667 children.

PRIMARY AND SECONDARY OUTCOME MEASURES

Our primary outcomes were crude and adjusted probabilities of taking any regular medications and the number of medications among overweight and obese children compared with normal weight children. Our secondary outcome was the distribution of medication use by therapeutic classification across body mass index (BMI) groups.

RESULTS

Obese children were more likely to use any medication (marginal effect (ME)=0.02, 95% CI 0.01 to 0.03) and to use more medications (ME=0.08, 95% CI 0.04 to 0.12) than normal weight children. Obese children used more medications for respiratory conditions than those of other BMI groups.

CONCLUSIONS

Obese children are more likely to use regular medications and have comorbid conditions, even at young ages. This suggests that the cost of prescriptions should be considered when evaluating the economic burden of childhood obesity and that preventative strategies to reduce childhood obesity could be cost-effective in the short as well as in the long term. While more research is needed, both clinicians and policymakers should be aware of these findings when planning prevention and treatment strategies.

Association between obesity and prescribed medication use in England

We investigate the association between obesity and use of prescribed medications in England. Data were taken from fourteen rounds of the Health Survey for England (1999-2012), which has measures of current prescribed medication use based on therapeutic classifications in the British National Formulary, and nurse-measured height and weight. We find that obesity has a statistically significant and positive association with use of a range of medicines for managing diseases associated with obesity. The mean probability of using any type of medication is 0.40 in those of normal weight, 0.44 in the overweight, 0.52 in obesity class I and 0.60 in obesity class II/III. Significant positive associations were found between obesity and the use of medication for diseases of the cardiovascular system, gastrointestinal system, respiratory system, and central nervous system, as well as for infections, endocrine system disorders, gynaecological/urinary disorders and musculoskeletal and joint disorders. Use of anti-obesity medication is low, even among those with class II/III obesity.

Sick leave days and costs associated with overweight and obesity in Germany

OBJECTIVE

To analyze the impact of body mass index on sick leave days and related costs in Germany.

METHODS

Cross-sectional analysis of German Socio-Economic Panel data (n = 7990). The relationship between body mass index class and sick leave days was analyzed via analyses of variance (ANOVA) (bivariate) and zero-inflated negative binomial regression models (multivariate).

RESULTS

Body mass index was positively associated with annual sick leave days in the bivariate analysis (P < 0.001). In the fully adjusted zero-inflated negative binomial, overweight women had 3.64, obese women 5.19, and obese men 3.48 excess sick leave days in 2009 (vs normal weight), while excess sick leave days of overweight men were not statistically significant. The extrapolated excess costs in the German working population amount to &OV0556;2.18 billion (base case).

CONCLUSIONS

The absenteeism-related lost productivity costs associated with excess weight are formidable and emphasize the persistent need for health promotion efforts in Germany.

The direct and indirect costs of both overweight and obesity: a systematic review

BACKGROUND

The rising prevalence of overweight and obesity places a financial burden on health services and on the wider economy. Health service and societal costs of overweight and obesity are typically estimated by top-down approaches which derive population attributable fractions for a range of conditions associated with increased body fat or bottom-up methods based on analyses of cross-sectional or longitudinal datasets. The evidence base of cost of obesity studies is continually expanding, however, the scope of these studies varies widely and a lack of standardised methods limits comparisons nationally and internationally. The objective of this review is to contribute to this knowledge pool by examining direct costs and indirect (lost productivity) costs of both overweight and obesity to provide comparable estimates. This review was undertaken as part of the introductory work for the Irish cost of overweight and obesity study and examines inconsistencies in the methodologies of cost of overweight and obesity studies. Studies which evaluated the direct costs and indirect costs of both overweight and obesity were included.

METHODS

A computerised search of English language studies addressing direct and indirect costs of overweight and obesity in adults between 2001 and 2011 was conducted. Reference lists of reports, articles and earlier reviews were scanned to identify additional studies.

RESULTS

Five published articles were deemed eligible for inclusion. Despite the limited scope of this review there was considerable heterogeneity in methodological approaches and findings. In the four studies which presented separate estimates for direct and indirect costs of overweight and obesity, the indirect costs were higher, accounting for between 54% and 59% of the estimated total costs.

CONCLUSION

A gradient exists between increasing BMI and direct healthcare costs and indirect costs due to reduced productivity and early premature mortality. Determining precise estimates for the increases is mired by the large presence of heterogeneity among the available cost estimation literature. To improve the availability of quality evidence an international consensus on standardised methods for cost of obesity studies is warranted. Analyses of nationally representative cross-sectional datasets augmented by data from primary care are likely to provide the best data for international comparisons.

The direct and indirect costs of both overweight and obesity: a systematic review

Background

The rising prevalence of overweight and obesity places a financial burden on health services and on the wider economy. Health service and societal costs of overweight and obesity are typically estimated by top-down approaches which derive population attributable fractions for a range of conditions associated with increased body fat or bottom-up methods based on analyses of cross-sectional or longitudinal datasets. The evidence base of cost of obesity studies is continually expanding, however, the scope of these studies varies widely and a lack of standardised methods limits comparisons nationally and internationally. The objective of this review is to contribute to this knowledge pool by examining direct costs and indirect (lost productivity) costs of both overweight and obesity to provide comparable estimates. This review was undertaken as part of the introductory work for the Irish cost of overweight and obesity study and examines inconsistencies in the methodologies of cost of overweight and obesity studies. Studies which evaluated the direct costs and indirect costs of both overweight and obesity were included.

Methods

A computerised search of English language studies addressing direct and indirect costs of overweight and obesity in adults between 2001 and 2011 was conducted. Reference lists of reports, articles and earlier reviews were scanned to identify additional studies.

Results

Five published articles were deemed eligible for inclusion. Despite the limited scope of this review there was considerable heterogeneity in methodological approaches and findings. In the four studies which presented separate estimates for direct and indirect costs of overweight and obesity, the indirect costs were higher, accounting for between 54% and 59% of the estimated total costs.

Conclusion

A gradient exists between increasing BMI and direct healthcare costs and indirect costs due to reduced productivity and early premature mortality. Determining precise estimates for the increases is mired by the large presence of heterogeneity among the available cost estimation literature. To improve the availability of quality evidence an international consensus on standardised methods for cost of obesity studies is warranted. Analyses of nationally representative cross-sectional datasets augmented by data from primary care are likely to provide the best data for international comparisons.

Variation in the relationship between BMI and survival by socioeconomic status in Great Britain

We investigate the relationship between obesity and survival, and the extent to which this relationship varies by socioeconomic status (SES). The underlying model is based on the "Pathways to health" framework in which SES affects health by modifying the relationship between lifestyles and health. We use data from the British Health and Lifestyle Survey (1984-1985) and the longitudinal follow-up in June 2009, and run parametric Gompertz survival models to investigate the association between obesity and survival, also accounting for interactions between obesity and both age and SES. Generally we find that obesity is negatively associated with survival, and that SES is positively associated with survival, in both men and women. The interactions between obesity and SES predict survival among women but not among men. Obesity compared with normal weight is associated with a reduction in survival of 3.3, 3.2 and 2.8 years in men aged 40, 50 and 60 years, respectively. Corresponding numbers among women in the lowest SES group are 13.1, 9.7 and 6.1 years, respectively; in the highest SES group they are 6.2, 3.1 and 0.1 years, respectively, a difference of approximately 6 years between the highest and lowest SES groups.