The functional comorbidity index had high inter-rater reliability in patients with acute lung injury
1 Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
2 Interdepartmental Division of Critical Care Medicine, University of Toronto, Toronto, Canada
3 Department of Critical Care Medicine, National Institutes of Health, Bethesda, MD, USA
4 Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
5 Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
6 Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
7 Division of Pulmonary and Critical Care Medicine, and Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, MD, USA
8 Mount Sinai Hospital, 600 University Avenue, Room 18-232, Toronto, ON, M5G 1X5, Canada
BMC Anesthesiology 2012, 12:21 doi:10.1186/1471-2253-12-21Published: 13 September 2012
The Functional Comorbidity Index (FCI) was recently developed to predict physical function in acute lung injury patients using comorbidity data. Our objectives were to determine: (1) the inter-rater reliability of the FCI collected using in-patient discharge summaries (primary objective); and (2) the accuracy and predictive validity of the FCI collected using hospital discharge summaries and admission records versus complete chart review (secondary objectives).
For reliability, we evaluated the FCI’s intraclass correlation coefficient (ICC) among trained research staff performing data collection for 421 acute lung injury patients enrolled in a prospective cohort study. For validity and accuracy, we compared the detection of FCI comorbidities across three types of inpatient medical records, and the association of the respective FCI scores obtained with patients’ SF-36 physical function subscale (PFS) scores at 1-year follow-up.
Inter-rater reliability was near-perfect (ICC 0.91; 95% CI 0.89-0.94). Hospital admission records and discharge summaries (vs. complete chart review) significantly underestimated the total FCI score. However, using multivariable linear regression, FCI scores collected using each of the three types of inpatient medical records had similar associations with PFS, suggesting similar predictive value.
Data collection using in-patient discharge summaries represents a reliable and valid method for collecting FCI comorbidity information.