Predictive validity of disability rating scale in determining functional outcome in patients with severe traumatic brain injury.

BACKGROUND: Most patients with severe traumatic brain injury (TBI) are discharged when they have still not recovered completely. Many such patients are not available for follow up. AIMS: We conducted this study to determine whether the condition at discharge from acute care setting, as assessed with disability rating scale (DRS), correlates with functional outcome at follow up. SETTINGS AND DESIGN: This study was conducted at a Neurosurgical intensive care unit (ICU) of a tertiary care referral center. This was a prospective observational study. MATERIALS AND METHODS: Patients admitted to ICU with a diagnosis of severe TBI were enrolled for the study. On the day of discharge, all patients underwent DRS assessment. A final assessment was performed using Glasgow outcome scale extended (GOSE) at 6 months after discharge from the hospital. STATISTICAL ANALYSIS: The correlation between the DRS scores at the time of discharge with DRS scores and GOSE categories at 6 months after discharge was determined using Spearman's rho correlation coefficient. RESULTS: A total of 88 patients were recruited for the study. The correlation coefficient of DRS at discharge for DRS at 6 months was 0.536 and for GOSE was -0.553. The area under the curve of DRS score at discharge for predicting unfavorable outcome and mortality at 6 months was 0.770 and 0.820, respectively. CONCLUSION: The predictive validity of DRS is fair to good in determining GOSE at follow-up. Pending availability of a more accurate outcome assessment tool, DRS at discharge can be used as a surrogate outcome for GOSE at follow up.