Temporal trends of medical cost and cost-effectiveness in sepsis patients: a Japanese nationwide medical claims database

Abstract

Background: Sepsis is the leading cause of death worldwide. Although the mortality of sepsis patients has been decreasing over the past decade, the trend of medical costs and cost-effectiveness for sepsis treatment remains insufficiently determined.

Methods: We conducted a retrospective study using the nationwide medical claims database of sepsis patients in Japan between 2010 and 2017. After selecting sepsis patients with a combined diagnosis of presumed serious infection and organ failure, patients over the age of 20 were included in this study. We investigated the annual trend of medical costs during the study period. The primary outcome was the annual trend of the effective cost per survivor, calculated from the gross medical cost and number of survivors per year. Subsequently, we performed subgroup and multiple regression analyses to evaluate the association between the annual trend and medical costs.

Results: Among 50,490,128 adult patients with claims, a total of 1,276,678 patients with sepsis were selected from the database. Yearly gross medical costs to treat sepsis gradually increased over the decade from $3.04 billion in 2010 to $4.38 billion in 2017, whereas the total medical cost per hospitalization declined (rate = - $1075/year, p < 0.0001). While the survival rate of sepsis patients improved during the study period, the effective cost per survivor significantly decreased (rate = - $1806/year [95% CI - $2432 to - $1179], p = 0.001). In the subgroup analysis, the trend of decreasing medical cost per hospitalization remained consistent among the subpopulation of age, sex, and site of infection. After adjusting for age, sex (male), number of chronic diseases, site of infection, intensive care unit (ICU) admission, surgery, and length of hospital stay, the admission year was significantly associated with reduced medical costs.

Conclusions: We demonstrated an improvement in annual cost-effectiveness in patients with sepsis between 2010 and 2017. The annual trend of reduced costs was consistent after adjustment with the confounders altering hospital expenses.

Keywords: Cost-effectiveness; Critical care; Diagnosis procedure combination; Medical cost; Sepsis.

Fig. 1

Temporal change in cost-effectiveness in sepsis patients between 2010 and 2017. The bar plot depicts the relationship between the year of hospital admission on the x-axis and effective cost per survivor on the y-axis. The effective cost per survivor was calculated as follows: the sum of the medical costs of all patients/number of survivors per year. Effective cost per survivor: − $1806/year [95% CI − $2432 to − $1179], p = 0.001. The coefficient was calculated using a linear regression analysis

Fig. 2

Annual change in medical cost according to sex. A Annual changes in adjusted gross medical costs between 2010 and 2017 according to sex. Male: + $115.4 million/year [95% CI $89.5 to $141.0 million], p < 0.0001. Female: + $86.2 million/ year [95% CI $58.8 to $114.0 million], p < 0.0001. B Annual changes in adjusted medical cost per hospitalization between 2010 and 2017 according to sex. Male: − $156/year [95% CI − $163 to − $149], p < 0.0001. Female: − $198/year [95% CI − $206 to − $189], p < 0.0001. The error bars indicate the 95% confidence interval. The coefficient was calculated using a linear regression analysis

Fig. 3

Annual change in medical cost according to age subgroups. A Annual changes in adjusted gross medical costs between 2010 and 2017 according to age subgroups. Adults (20 ≤ age ≤ 64): + $23.0 million /year [95% CI − $15.8 to + $30.3 million], p < 0.0001. Early elderly (65 ≤ age ≤ 74): + $55.3 million/year [95% CI + $40.9 to + $69.8 million], p < 0.0001. Late elderly (75 ≤ age): + $123.2 million/year [95% CI + $76.8 to + $170.0 million], p < 0.0001. B Annual changes in adjusted medical costs per hospitalization between 2010 and 2017 according to age subgroups. Adults (20 ≤ age ≤ 64): − $81/year [95% CI − $91 to − $70], p < 0.0001. Early elderly (65 ≤ age ≤ 74): − $77/year [95% CI − $87 to − $67], p < 0.0001. Late elderly (75 ≤ age): − $81/year [95% CI − $86 to − $75], p < 0.0001. The error bars indicate the 95% confidence interval. The coefficient was calculated using a linear regression analysis

Fig. 4

Annual change in medical costs according to site of infection. A Annual changes in adjusted gross medical costs between 2010 and 2017 according to site of infection. Multiple: + $63.6 million/year [95% CI + $44.7 to + $82.5 million], p < 0.0001. Respiratory: + $65.0 million/year [95% CI + $33.9 to + $96.2 million], p = 0.002. Unknown: + $19.5 million/year [95% CI + $13.0 to + $26.1 million], p < 0.0001. Abdominal: + $23.4 million/year [95% CI + $14.8 to + $32.1 million], p = 0.001. Urogenital: + $15.2 million/year [95% CI + $8.6 to + $21.9 million], p = 0.001. Bone and soft tissue: + $8.3 million/year [95% CI + $6.0 to + $10.6], p < 0.0001. Meninges/brain/spinal cord: + $3.2 million/year [95% CI + $1.7 to + $4.7 million], p = 0.002. Heart: + $2.7 million/year [95% CI + $1.0 to + $4.3 million], p = 0.007. Blood: + $0.36 million/year [95% CI − $0.16 to + $0.89 million], p = 0.14. B Annual changes in adjusted medical costs per hospitalization between 2010 and 2017 according to site of infection. Heart: − $88/year [95% CI − $140 to − $36], p = 0.001. Blood: − $135/year [95% CI − $255 to − $15], p = 0.027. Meninges/brain/spinal cord: − $52/year [95% CI − $92 to − $12], p = 0.010. Unknown: − $96/year [95% CI − $108 to − $83], p < 0.0001. Bone and soft tissue: − $87/year [95% CI − $108 to − $65], p < 0.0001. Abdominal: − $75/year [95% CI − $85 to − $65], p < 0.0001. Multiple: − $130/year [95% CI − $137 to − $122], p < 0.0001. Respiratory: − $111/year [95% CI − $117 to − $105], p < 0.0001. Urogenital: − $101/year [95% CI − $116 to − $86], p < 0.0001. The error bars indicate the 95% confidence interval. The coefficient was calculated using a linear regression analysis