Hospital-Onset Clostridioides difficile More Costly for Younger Adults
Costs due to Clostridioides difficile infection (CDI) were highest in younger adults with hospital-onset (HO) CDI and lowest in those with community-associated (CA) CDI treated outside a hospital, according to a study published in Open Forum Infectious Diseases.
Older adults most often experience both health care–associated and CA CDI infections and the resulting morbidity, death, and increased health care costs. Previous research had shown that older adults with fee-for-service Medicare plans experienced higher costs after HO CDI than after CA CDI and estimated that younger adults' attributable health care costs for primary CDI were $26,663 (2014 USD) through propensity score matching to uninfected individuals. Researchers sought to learn more about the economic costs for younger adults experiencing CDI.
“We calculated attributable health care costs in persons aged 25 to 64 years coded for CDI, compared with control persons without CDI, stratified by onset and health care facility association,” explained researchers. “We also calculated attributable costs in persons with health care facility associated (HCFA) and CA CDI hospitalized versus not hospitalized for CDI treatment, to determine the magnitude of costs depending on the site of CDI treatment.”
United States medical claims data for patients covered primarily by employer-sponsored private health plans were pulled from the 2010–2017 Merative Marketscan Commercial database. Patients’ first episodes coded for CDI were analyzed and age, year of CDI, and CDI surveillance were used to match patients with CDI to uninfected individuals. For every patient with CDI, 4 control patients were assigned index dates to match the distribution of CDI case onset dates. Controls and CDI cases were classified according to their location and recent treatment in a health care facility. The study included data from 1 year before and after the CDI index date, with excess individuals randomly excluded to maintain the 4:1 ratio.
Costs included both the sum of patient payments and allowable health plan expenditures and were adjusted to 2017 USD. This study used inverse weighting by the propensity score and two-part models to calculate the attributable costs. Researchers said that variables with an absolute standardized mean difference (SMD) of ≥0.1 between case patients and controls were chosen for inclusion in the propensity score model, with CDI case as the outcome (including age group, sex, and year, regardless of degree of imbalance).
Any residual imbalance was accounted for by including these variables in the two-part model. The costs attributable to CDI were calculated by subtracting the average expected costs among controls from the average expected costs among CDI cases.
Patients with HO CDI experienced the highest crude and attributable costs ($48,225). Costs were lower for patients with HCFA CDI ($43,127) and lowest after CA CDI ($13,105). Hospitalized HCFA patients had the highest costs due to CDI ($71,202), costs were lower in the CA hospitalized group ($36,090), and lowest in the HCFA and CA nonhospitalized patient groups ($15,891 and $3063, respectively).
The study findings suggest that adults aged younger than 65 who have CDI incur higher health care costs than older adults who are insured by traditional Medicare or Medicare Advantage plans. Researchers posited this could be attributed to private insurers reimbursing hospitals and physicians at much higher rates than Medicare does. Additionally, younger individuals are generally healthier than older individuals, which can explain the higher health care costs for CDI in a younger population.
“Given the morbidity and excess health care costs associated with CDI, novel strategies are needed to prevent these infections in younger as well as older adults,” said researchers.
Reference:
Sahrmann JM, Olsen MA, Keller MR, et al. Healthcare costs of Clostridioides difficile infection in commercially insured younger adults. OFID. 2023;10(7): ofad343. doi.org/10.1093/ofid/ofad343
