Comorbid illness is associated with survival and length of hospital stay in patients with chronic disability. A prospective comparison of three comorbidity indices.

OBJECTIVES: This study was designed to determine if comorbidity added more information than knowing only the patient's age in predicting survival and length of hospital stay. METHODS: The authors compared the relative predictive validity of three comorbidity indices: the Cumulative Illness Rating Scale, the Charlson Index, and a count of International Classification of Diseases, 9th Revision, Clinical Modification medical diagnoses in relation to survival and length of hospital stays in patients with spinal cord injury. The sample consisted of 330 longitudinally followed spinal-cord injured patients admitted between January 1989 and December 1990 who were followed for an additional 18 months. RESULTS: During the follow-up, 25 (7.5%) patients died and 249 (75.5%) were readmitted to hospital with a median of one admission (range, 1-8). The corresponding lengths of hospital stay ranged from 0 to 548 days, with a median of 7 days. CONCLUSIONS: Patients who died were not significantly older but had higher comorbidity scores. Using patients alive at the end of the follow-up period, linear regression models were fit to the data to determine if comorbidity added more information regarding length of hospital stay than knowing only the patient's age. In the model that included only age as an independent variable, there was a significant relation between age and length of stay (F(1,303) = 5.2; P = 0.012). The R2 value for this model was 0.017. In further models that included age and each of the three comorbidity scores (separately) as the independent variables, the model that included age and the Cumulative Illness Rating Scale yielded the highest R2 value (R2 = 0.062). This study is among the first to compare three different measures of comorbidity and documents that comorbidity provides more information than knowing only the patient's age in relation to survival and length of hospital stay.

Risk assessment for pressure ulcers: an adaptation of the National Pressure Ulcer Advisory Panel risk factors to spinal cord injured patients.

To estimate risk factors for pressure ulcers, we developed quantitative definitions for each of the nine general areas of risk outlined by the 1989 National Pressure Ulcer Advisory Panel (NPUAP) and evaluated each of these factors in a group of spinal cord injured patients by means of a retrospective chart review at a spinal cord injury referral center serving the New England area. All patients (n = 364) admitted to the spinal cord injury service between January 1, 1989 and December 31, 1990 were studied. We identified a pressure ulcer in 81 of 364 patients (22.3 percent). In the univariate analyses, pressure ulcers were associated with Frankel groups A to B with an odds ratio (OR) of 5.7 (95 percent confidence interval 2.8 to 11.9), low albumin with an OR of 4.9 (95 percent confidence interval 2.8 to 8.6), low hemoglobin with an OR of 2.5 (95 percent confidence interval 1.5 to 4.1), age > or = 60 years with an OR of 1.9 (95 percent confidence interval 1.2 to 3.2) and three independent measures of co-morbidity: Cumulative Illness Rating Scale (CIRS) with an OR of 3.7 (95 percent confidence interval 2.1 to 6.3), Charlson Index with an OR of 2.2 (95 percent confidence interval 1.3 to 3.8), and International Classification of Diseases, Ninth Revision, Clinical Modification count with an OR of 4.2 (95 percent confidence interval 2.4 to 7.2). In the logistic regression model, low albumin, CIRS and Frankel grade A to B and history of pressure ulcers were predictors.(ABSTRACT TRUNCATED AT 250 WORDS)