Trends in the incidence of Clostridioides difficile infection in adults and the elderly insured by Medicaid compared to commercial insurance or Medicare only

Abstract

Objective: 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. Methods: 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. Results: 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). Conclusions: 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.

Clostridioides difficile infection across the lifespan: Estimation using life tables

“…We previously reported higher incidence in younger and elderly persons insured by Medicaid compared to those insured by commercial plans and Medicare only. 3 We hypothesize that persons insured by Medicaid have greater CDI risk due to higher prevalence of many important comorbidities, resulting in greater antibiotic exposure. 3 A number of common comorbidities (eg, diabetes, asthma, chronic kidney disease) are associated with higher infection risk, [6][7][8] and patients with these comorbidities are more likely to be treated with antibiotics, even in the absence of recognized infection.…”

“…We used data from the 2010-2017 Medicare Chronic Condition Warehouse 5% sample for persons aged 65 and older and from the Merative® MarketScan Commercial and Multi-State Medicaid Databases for persons aged 18-64 years, as described previously. 3 The first episode of CDI per person from 2011 to 2017 was identified using International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis code 008.45 and ICD-10-CM diagnosis codes A04.71 and A04.72, as described previously. 3 We also focused on subgroups with chronic conditions known to be at higher risk of CDI and with published life tables available to calculate probability of survival until specific ages, including heart disease (congestive heart failure, valvular disorder, or coronary artery disease), diabetes, and end-stage renal disease with dialysis (see Supplementary Material online for references).…”

“…3 The first episode of CDI per person from 2011 to 2017 was identified using International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis code 008.45 and ICD-10-CM diagnosis codes A04.71 and A04.72, as described previously. 3 We also focused on subgroups with chronic conditions known to be at higher risk of CDI and with published life tables available to calculate probability of survival until specific ages, including heart disease (congestive heart failure, valvular disorder, or coronary artery disease), diabetes, and end-stage renal disease with dialysis (see Supplementary Material online for references). Persons with these conditions were identified as previously described based on coding in the patient's first year of health insurance enrollment (beginning with 2011).…”

“…Persons with these conditions were identified as previously described based on coding in the patient's first year of health insurance enrollment (beginning with 2011). 3 CDI incidence was calculated by dividing the number of patients with codes for CDI by the person years (PY) of observation individually for 2017 and overall from 2011 to 2017 by type of insurer (commercial and Medicaid for those aged <65 years, and Medicare only versus Medicare þ Medicaid in the elderly), sex, and age group. The number of patients with codes for CDI was determined similarly for the 3 chronic conditions of interest from 2012 to 2017 in the commercially insured and Medicare populations, and CDI incidence rates calculated from 2012 to 2017 by condition and sex.…”

The burden of CDI in the United States: a multifactorial challenge

“…The risk for CDI and rCDI is higher among patients who are female, older, have comorbidities (including renal disease, liver disease, rheumatoid arthritis, multiple sclerosis, diabetes, and inflammatory bowel disease), are immunosuppressed, have recently been hospitalized, and have a history of using corticosteroids, proton pump inhibitors, or lipid-lowering therapy [1,20,26,34,[38][39][40][41][42][43][44]. Greater age and the presence of multiple comorbidities are prognostic factors for severe CDI [44].…”