Severe sepsis in managed care: analysis of incidence, one-year mortality, and associated costs of care

Abstract

Objective: To determine severe sepsis (SS) incidence, hospital mortality, 1-year mortality, and costs associated with care in a sample of enrollees in a nationally representative individual practice association (IPA)-network managed care organization (MCO).

Methods: This was a retrospective analysis of administrative claims data for commercial (not managed Medicare) members. We identified MCO members hospitalized for SS between July 1995 and December 1998. SS cases were identified by a combination of ICD-9-CM codes for infection and organ dysfunction. Enrollment information, physician, facility, and pharmacy claims were analyzed. Subjects with continuous enrollment were followed for 1 full year of observation. Costs were health plan payments to providers, after subtraction of member cost-share amounts.

Results: The incidence rate was 0.91 cases of SS per 1,000 enrollees, increasing with age. The mean age of SS patients was 50 years, and 53% were male. Approximately 63% received surgical intervention. Mortality was 21% during the first hospitalization and 36.1% at 1 year. During follow-up, 47.1% of survivors were rehospitalized. Mean index hospitalization length of stay and costs were 16 days and 26,820 dollars, with 1-year inpatient and outpatient costs totaling 48,996 dollars. Mean outpatient costs per survivor were 8,363 dollars, and mean per-patient-per-month (PPPM) outpatient costs were 906 dollars. Total follow-up costs including rehospitalization were similar for nonsurvivors compared with survivors (7,710 dollars versus 8,522 dollars, P=0.274), but PPPM costs were higher for nonsurvivors (1,760 dollars versus 699 dollars, P<0.001).

Conclusions: Incidence, hospital, and 1-year mortality rates were lower in this population compared with literature reports and were associated with a lower average age in this managed care population. Mean SS hospitalization costs were high, and nearly one half of survivors required rehospitalization within 1 year. Study results suggest the need to evaluate SS interventions for improvement in health outcomes and cost outcomes, particularly in postsurgical patients.