In an analysis of individual patient data, increasing BMI is associated with elevations in both total health care costs and individual health care services, including prescription drug costs and inpatient care, according to findings from a systematic review.
“Our review of the academic literature found strong and consistent evidence that excess weight is associated with higher healthcare costs overall and for major types of healthcare services — inpatient care, outpatient care, and medications — in diverse healthcare settings, Seamus Kent, MSc, a researcher in health economics at the Nuffield Department of Population Health, University of Oxford, told Endocrine Today. “The large healthcare costs associated with excess weight provide further support to calls for greater investment in cost-effective programs designed to reduce weight or prevent weight gain. By providing information on the effects of excess weight on different healthcare services, these results may also be useful for healthcare planning.”
Kent and colleagues analyzed data from 75 studies conducted through September 2016 using individual patient data to estimate associations between BMI and health care costs (median sample size, 11,572); 39 studies were included in cost estimates and sensitivity analyses. For included studies, researchers summarized relative increases in mean costs in comparison with healthy weight reference groups or study-specific reference groups; results were also stratified by inpatient, ambulatory and medication costs.
The researchers observed substantial variation between studies in estimates of average increases in annual costs associated with overweight and obesity for any health care services. Across studies, the median percentage increase in annual total health care costs were 12% for overweight and 36% for obesity.
Researchers found that the greatest estimated increases for overweight and obesity were related to medication costs (18% and 68%, respectively), followed by inpatient costs (12% and 34%, respectively), whereas ambulatory costs were only substantially greater for those with obesity (26%), but not those with overweight (4%).
The estimated percentage increase in total health care costs rose with BMI, the researchers found. Compared with adults of healthy weight, those with class III obesity (BMI 40 kg/m²) experienced an estimated 50% median increase in total health care costs, those with class II obesity (BMI, 35-40 kg/m²) saw a median 45% increase, and those with class I obesity (BMI, 30-35 kg/m²) saw a median 22% increase in total health care costs.
Median estimated percentage increase in total health care costs was also greater for women with obesity vs. men with obesity (50% vs. 40%), but there were no between-sex differences observed for those with overweight, who experienced an estimated 24% increase in total health care costs related to their excess weight.
“Despite the large variations in data and methods used, some clear patterns emerged,” the researchers wrote. “Overweight and obesity were consistently associated with increased health care costs overall and for most major types of health care service. Based on estimates of the prevalence of overweight and obesity in the U.K. and the U.S., the estimated 12% and 36% increases in total annual health care costs for overweight and obesity, respectively, imply that overweight and obesity combined are associated with around 12% of adult health care expenditure in the U.K. and 15% in the U.S.”
Kent noted that few studies have reliably identified the contributions of different health conditions, like diabetes, cardiovascular disease, osteoarthritis, or cancer to the overall higher costs associated with excess weight.
“There also remain concerns that the estimated associations between weight and costs may be underestimated because of underlying health conditions, like chronic obstructive pulmonary disease or cancer, that both reduce weight and increase healthcare costs,” Kent said. “Application of advanced methods using, for example, genetic variation in weight to estimate this relationship, would be valuable.” – by Regina Schaffer
Disclosure: The researchers report no relevant financial disclosures.