The Eye-Popping Costs Associated With Sepsis Diagnoses Among Medicare Beneficiaries.

420 www.ccmjournal. org March 2020 • Volume 48 • Number 3 Sepsis is a major cause of morbidity and mortality, yet precisely how much it costs the U.S. healthcare system has not been well characterized. The most recent national estimate from the Health Care Utilization Project (HCUP) was $23.7 billion for hospitalizations with codes for septicemia in 2013 (1). Although this report identified septicemia as the most expensive condition treated in U.S. hospitals, this cost is a significant underestimate of the true costs associated with sepsis given that: 1) many patients have sepsis, severe sepsis, or septic shock without septicemia, 2) sepsis survivors often require skilled nursing care after hospitalization, adding substantial additional costs, and 3) not every hospitalization with septicemia gets coded for septicemia (2). The 2013 HCUP analysis also found that 62% of the costs from septicemia hospitalizations were paid for by Medicare, even though Medicare patients only accounted for 46% of total inpatient costs nationally (1). This likely reflects the higher frequency of sepsis in elderly patients and their more complicated courses compared with younger patients (3). Importantly, the Medicare population has grown much faster than the overall U.S. population in recent years as the “baby boomer” generation has reached Medicare eligibility. Medicare spending has grown in parallel with the increase in the eligible population, accounting for 20% of national health expenditures in 2017 (4). In light of these trends, understanding the burden and costs associated with sepsis among Medicare beneficiaries is of great interest to clinicians, hospital administrators, public health officials, payers, and policy makers. In this issue of Critical Care Medicine, Buchman et al (5) present detailed statistics on the costs and mortality rates associated with hospitalizations with sepsis diagnoses among Medicare beneficiaries between 2012 and 2018. Their data source includes outcomes and costs following hospitalization, including admissions to skilled nursing facilities. This allows for a more comprehensive assessment of sepsis burden compared to most other epidemiologic studies. The study includes a full range of sepsis codes, including the codes for septicemia and the sepsis-specific codes for sepsis, severe sepsis, and septic shock introduced in 2002. The primary findings were as follows. First, the number of inpatient Medicare Part A/B hospitalizations with a sepsis diagnosis code rose from just over 800,000 in 2012 to over 1.1 million in 2018, a rate that outpaced the growth in the Medicare population. Second, the total costs of inpatient admissions with sepsis codes rose from $17.8 to $22.4 billion, whereas the total cost of skilled nursing facility care in the 90 days following sepsis-coded hospitalizations rose from $3.9 to $5.6 billion. Third, when combining care from total inpatient admissions and subsequent skilled nursing facility care among Medicare Part A, B, and Medicare Advantage patients, the total costs rose from $27.6 to $41.5 billion. Finally, 6-month sepsis-associated mortality rates declined over the study period but remained extraordinarily high: approximately 60% for patients with codes for septic shock, 36.4% for severe sepsis, and 30.9% for unspecified sepsis. The numbers presented are eye-popping, yet they still potentially underestimate sepsis burden and costs given the limitations of administrative data for characterizing sepsis epidemiology. Prior work has demonstrated that explicit sepsis codes generally have good positive predictive value (particularly the codes for severe sepsis and septic shock), but they have low sensitivity and tend to be preferentially applied to patients with more severe disease (6). This means that the true burden and costs of sepsis may actually be higher than reported. A potential bias toward applying sepsis codes to the sickest subset of patients may also explain why mortality rates in this study were so much higher than the 90-day mortality rates reported in recent randomized controlled trials of septic shock (generally 20–30%) (7). *See also p. 276.