The emerging infectious challenge of clostridium difficile-associated disease in Massachusetts hospitals: Clinical and economic consequences

OBJECTIVE. To estimate the clinical and economic burden of Clostridium difficile-associated disease (CDAD) in Massachusetts over 2 years. DESIGN. A retrospective analysis of Massachusetts hospital discharge data from 1999-2003 was conducted. Cases of CDAD in 2000 were identified using code 008.45 from the International Classification of Diseases, Ninth Revision, Clinical Modification; patients were excluded if they had a hospitalization in the prior year during which a diagnosis of CDAD was recorded. Hospitalizations for CDAD during 2001 and 2002 were examined. For primary case patients (ie, those for which CDAD was the principal diagnosis), all inpatient costs were deemed to be related, whereas for secondary case patients, all-patient refined diagnosis-related group assignment, case severity level, and length of stay (LOS) were used to calculate incremental costs attributable to CDAD. Costs were adjusted to the national level and reported in 2005 US dollars. RESULTS. The CDAD cohort consisted of 3,692 patients; 59% were women, and the mean age was 70 years. This group represented 1% of all patients hospitalized in Massachusetts in 2000 (96% of hospitals treated at least 1 case; range, 1-257 cases). Of patients who received a first hospital diagnosis of CDAD in 2000, a total of 28% were primary case patients; their mean LOS was 6.4 days, and the mean cost per stay was $10,212. For secondary case patients, the mean CDAD-related incremental LOS was 2.95 days, and the mean incremental cost per stay was $13,675 per patient. Of patients with CDAD who survived their index stay in 2000, a total of 455 (14%) had at least 1 readmission for CDAD within the subsequent 2 years ( mean number of readmissions, 1.4 per patient; range, 1-7 readmissions), with a mean time to first readmission of 3 months. Over 2 years, a total of 55,380 inpatient-days and $51.2 million were consumed by CDAD management. CONCLUSION. CDAD is widespread in Massachusetts hospitals. Rehospitalization with CDAD, if it occurs, generally happens within a few months and happens multiple times for some patients. Based on this study's findings, a conservative estimate of the annual US cost for CDAD management is $3.2 billion dollars.