Mortality, Health Care Use, and Costs of Clostridioides difficile Infections in Older Adults

Abstract

Objectives: Estimate mortality, cost, and health care resource utilization for Medicare beneficiaries aged ≥65 years who suffered a primary Clostridioides difficile infection (CDI) episode only or any recurrent CDI, and understand how outcomes covary with death.

Design: Retrospective observational claims analysis.

Setting and participants: Patients aged ≥65 years who had an inpatient or outpatient CDI diagnosis claim to Medicare and continuous enrollment in Medicare parts A, B, and D during the 12-month pre- and post-index periods.

Methods: Using 100% Medicare Fee-for-Service claims data for 2009-2017, primary (pCDI, n = 345,893) and recurrent (rCDI: n = 151,596) CDI episodes were identified. Demographic and clinical characteristics, mortality, health care resource utilization, and costs (per patient per month) were summarized for 12 months before and up to 12 months after episode start. Regression models were estimated for hospitalization risk, hospital length of stay (LOS), and cost to adjust for comorbidities.

Results: CDI-associated deaths were almost 10 times higher after recurrent CDI (25.4%) than primary CDI (2.7%). Compared with survivors, decedents were older, had higher Charlson Comorbidity Index scores, and were more likely Black. Adjusting for comorbidities, during follow-up, decedents had higher hospitalization rates [pCDI: odds ratio (OR) = 1.83, P < .001; rCDI: OR = 2.58, P < .001], and recurrent CDI decedents had more intensive care unit use (OR = 2.34, P < .001) compared with survivors. Decedents also had a longer length of stay (pCDI: +3.2 days, P < .001; rCDI: +2.6 days, P < .001), and higher total cost (pCDI: +303%, P < .001; rCDI: +297%, P < .001).

Conclusions and implications: CDI is an important contributing diagnosis to all-cause mortality, particularly for recurrences. Prior to death, older Medicare beneficiaries who experienced CDI received longer, more intensive, and more costly care compared with survivors. Clinicians should be particularly attentive to prevention, identification, and appropriate treatment of CDI in older adults. Better treatments to reduce primary C difficile infection and recurrences in this vulnerable population can lower both mortality and economic burden.

Keywords: Clostridium difficile infection; Medicare; cost; health care resource utilization; recurrent Clostridium difficile infection.