To estimate incidence and healthcare costs and mortality associated with Clostridioides difficile infection (CDI) among adults <65 years old.

Retrospective cohort study.

First CDI episodes among commercially insured US patients 18–64 years old were identified from a large claims database. CDI+ patients were propensity score−matched (PSM) 1:1 with CDI− controls using clinically relevant variables including comorbidities.

Annual CDI incidence was calculated by age group and year (2015−2019). Healthcare utilization, costs, and mortality were analyzed by age group, acquisition (healthcare and community), and hospitalization status by calculating CDI-excess costs and mortality as the difference between PSM CDI+ and CDI− individuals.

In 50–64- and 18–49-year-olds, respective CDI incidence per 100,000 person-years decreased from 217 and 113 cases in 2015 to 167 and 87 cases in 2019. Most cases (76.5%–86.9%) were community-associated. The costs and mortality analyses included 6,332 matched CDI+/− 50–64-year-olds and 6,667 CDI+/− 18–49-year-olds. Among 50–64-year-olds, mean 2-month healthcare and patients’ out-of-pocket costs were $11,634 and $573 higher, respectively, in the CDI+ versus CDI− group. Among 18–49-year-olds, 2-month costs were $7,826 and $642 higher. Healthcare costs were higher for healthcare- versus community-associated CDI. At the 12-month follow-up, mortality was significantly higher in the CDI+ versus CDI− groups for both 50–64-year-olds (4.2% vs 2.0%; P < .001) and 18–49-year-olds (1.2% vs 0.6%; P < .001). Mortality rates were higher for hospitalized versus nonhospitalized CDI+ patients.

Prevention of CDI among adults 18–64 years old may significantly reduce costs and mortality.

Few data are available to quantify the Clostridioides difficile infection (CDI) burden in US adults depending on Medicaid insurance status; thus, we sought to contribute to this body of information.

Retrospective cohort study to identify adults with codes for CDI from 2011 to 2017 in MarketScan commercial and Medicaid databases (for those aged 25–64 years) and the CMS Medicare database (for those aged ≥65 years). CDI was categorized as healthcare-facility–associated (HCA-CDI) and community-associated CDI (CA-CDI). CDI incidence rates were compared by year, insurer, and age group.

The overall CDI incidence in the elderly was 3.1-fold higher in persons insured by Medicare plus Medicaid than in those insured by Medicare only (1,935 vs 618 per 100,000 person years (PY)), and the CDI incidence was 2.7-fold higher in younger adults with Medicaid compared to commercial insurance (195 vs 73 per 100,000 PY). From 2011 to 2017, HCA-CDI rates declined in the younger Medicaid population (124.0 to 95.2 per 100,000 PY; P < .001) but were stable in those commercially insured (25.9 to 24.8 per 100,000 PY; P = .33). In the elderly HCA-CDI rates declined from 2011 to 2017 in the Medicare-only population (403 to 318 per 100,000 PY; P < .001) and the Medicare plus Medicaid population (1,770 to 1,163 per 100,000 PY; P < .002). Persons with chronic medical conditions and those with immunocompromising conditions insured by Medicaid had 2.8- and 2.7-fold higher CDI incidence compared to the commercially insured population, respectively. The incidence of CDI was lowest in Medicaid and commercially insured younger adults without chronic medical or immunosuppressive conditions (67.5 and 45.6 per 100,000 PY, respectively).

Although HCA-CDI incidence decreased from 2011 to 2017 in elderly and younger adults insured by Medicaid, the burden of CDI remains much higher in low-income adults insured by Medicaid.

To determine the 180-day cumulative incidence of culture-confirmed Staphylococcus aureus infections after elective pediatric surgeries.

Retrospective cohort study utilizing the Premier Healthcare database (PHD).

Inpatient and hospital-based outpatient elective surgical discharges.

Pediatric patients <18 years who underwent surgery during elective admissions between July 1, 2010, and June 30, 2015, at any of 181 PHD hospitals reporting microbiology results.

In total, 74 surgical categories were defined using ICD-9-CM and CPT procedure codes. Microbiology results and ICD-9-CM diagnosis codes defined S. aureus infection types: bloodstream infection (BSI), surgical site infection (SSI), and other types (urinary tract, respiratory, and all other). Cumulative postsurgical infection incidence was calculated as the number of infections divided by the number of discharges with qualifying elective surgeries.

Among 11,874 inpatient surgical discharges, 180-day S. aureus infection incidence was 1.79% overall (1.00% SSI, 0.35% BSI, 0.45% other). Incidence was highest among children <2 years of age (2.76%) and lowest for those 10–17 years (1.49%). Among 50,698 outpatient surgical discharges, incidence was 0.36% overall (0.23% SSI, 0.05% BSI, 0.08% others); it was highest among children <2 years of age (0.57%) and lowest for those aged 10–17 years (0.30%). MRSA incidence was significantly higher after inpatient surgeries (0.68%) than after outpatient surgeries (0.14%; P < .0001). Overall, the median days to S. aureus infection was longer after outpatient surgery than after inpatient surgery (39 vs. 31 days; P = .0116).

These findings illustrate the burden of postoperative S. aureus infections in the pediatric population, particularly among young children. These results underscore the need for continued infection prevention efforts and longer-term surveillance after surgery.

To assess the 180-day incidence of Staphylococcus aureus infections following orthopedic surgeries using microbiology cultures.

Retrospective observational epidemiology study.

National administrative hospital database.

Adult patients with an elective admission undergoing orthopedic surgeries in the inpatient and hospital-based outpatient settings discharged between July 1, 2010, and June 30, 2015.

Patients were identified from 181 hospitals reporting microbiology results to the Premier Healthcare Database. Orthopedic surgeries were defined using International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) procedure and current procedural terminology (CPT) codes. Microbiology cultures and ICD-9/10 diagnosis codes identified surgical site infections (SSIs), bloodstream infections (BSIs), and other infections associated postoperatively (eg, respiratory and urinary tract infections).

Among 359,268 inpatient orthopedic surgical encounters, the S. aureus infection incidence was 1.13%: SSI, 0.68%; BSI, 0.28%; and other types, 0.17%. Among 292,011 outpatient encounters, the S. aureus incidence was 0.78%: SSI, 0.55%; BSI, 0.12%; and other types, 0.11%. Methicillin-resistant S. aureus (MRSA) infections accounted for 46% and 44% in the respective settings. Plastic/hand-limb reattachment and amputation had the highest overall S. aureus incidence in both settings. S. aureus was the most commonly isolated microorganism among culture-confirmed SSIs (48.0%) and BSIs (35.0%), followed by other Enterobacteriaceae (14.0%) for SSIs and Escherichia spp (12.5%) for BSIs.

These findings suggest that S. aureus infections continue to be an important contributor to the burden of postoperative infections after inpatient and outpatient orthopedic procedures.