TY - JOUR T1 - Defining emergency department episodes by severity and intensity: A 15-year study of Medicare beneficiaries. JF - BMC Health Serv Res Y1 - 2010 A1 - Kaskie, Brian A1 - Maksym Obrizan A1 - Elizabeth A Cook A1 - Michael P Jones A1 - Li Liu A1 - Suzanne E Bentler A1 - Robert B Wallace A1 - John F Geweke A1 - Kara B Wright A1 - Elizabeth A Chrischilles A1 - Claire E Pavlik A1 - Robert L. Ohsfeldt A1 - Gary E Rosenthal A1 - Frederic D Wolinsky KW - Aged KW - Aged, 80 and over KW - Cohort Studies KW - Emergency Service, Hospital KW - Humans KW - Insurance Claim Review KW - Medicare KW - Prospective Studies KW - Severity of Illness Index KW - United States AB -
BACKGROUND: Episodes of Emergency Department (ED) service use among older adults previously have not been constructed, or evaluated as multi-dimensional phenomena. In this study, we constructed episodes of ED service use among a cohort of older adults over a 15-year observation period, measured the episodes by severity and intensity, and compared these measures in predicting subsequent hospitalization.
METHODS: We conducted a secondary analysis of the prospective cohort study entitled the Survey on Assets and Health Dynamics among the Oldest Old (AHEAD). Baseline (1993) data on 5,511 self-respondents >or=70 years old were linked to their Medicare claims for 1991-2005. Claims then were organized into episodes of ED care according to Medicare guidelines. The severity of ED episodes was measured with a modified-NYU algorithm using ICD9-CM diagnoses, and the intensity of the episodes was measured using CPT codes. Measures were evaluated against subsequent hospitalization to estimate comparative predictive validity.
RESULTS: Over 15 years, three-fourths (4,171) of the 5,511 AHEAD participants had at least 1 ED episode, with a mean of 4.5 episodes. Cross-classification indicated the modified-NYU severity measure and the CPT-based intensity measure captured different aspects of ED episodes (kappa = 0.18). While both measures were significant independent predictors of hospital admission from ED episodes, the CPT measure had substantially higher predictive validity than the modified-NYU measure (AORs 5.70 vs. 3.31; p < .001).
CONCLUSIONS: We demonstrated an innovative approach for how claims data can be used to construct episodes of ED care among a sample of older adults. We also determined that the modified-NYU measure of severity and the CPT measure of intensity tap different aspects of ED episodes, and that both measures were predictive of subsequent hospitalization.
PB - 8 VL - 10 U1 - http://www.ncbi.nlm.nih.gov/pubmed/20565949?dopt=Abstract U2 - PMC2903585 U4 - HOSPITALIZATION/emergency department service use/emergency department service use/medicare/predictive validity/predictive validity ER -