Assessing and using comorbidity measures in elderly veterans with lower extremity amputations.

Area of Science:

• Health Services Research
• Geriatric Medicine
• Epidemiology

Background:

• Understanding comorbidity in older veterans with lower extremity amputations is crucial for patient outcomes and care quality.
• Comorbidities significantly impact resource utilization and facility-level assessments in this population.

Purpose of the Study:

• To evaluate if combining outpatient and inpatient administrative data enhances comorbidity prevalence estimates.
• To determine if integrated data sources improve models predicting 1-year mortality.
• To compare the Charlson/Deyo and Elixhauser comorbidity measures.

Main Methods:

• Retrospective cohort study of 2,375 veterans with lower extremity amputations.
• Analysis included frequencies, cross-tabulations, and logistic regression.
• Comorbidity prevalence, 1-year mortality rates, and standardized mortality ratios (SMRs) were assessed using Charlson/Deyo and Elixhauser measures.

Main Results:

• Integrating multiple data sources significantly increased comorbidity prevalence estimates for both measures.
• The Elixhauser measure yielded higher prevalence estimates than Charlson/Deyo but did not improve mortality prediction models.
• Standardized mortality ratios varied geographically but were independent of comorbidity measure or data source.

Conclusions:

• Merging outpatient and inpatient data may reduce undercoding of comorbidities but does not enhance mortality prediction.
• The Elixhauser comorbidity measure provides more complete coding for conditions relevant to lower extremity amputations (e.g., diabetes, peripheral vascular disease) compared to Charlson/Deyo.