Abstract 12784: 18-Year Trends in Short- and Long-term Stroke Mortality, and the Prognostic Impact of Comorbidity: A Danish Nationwide Cohort Study
Background: No previous study has reported nationwide trends in long-term stroke mortality. We therefore examined 18-year trends in short-term and long-term stroke mortality, and the prognostic impact of comorbidity.
Methods: Using the Danish National Registry of Patients, covering all hospitals in Denmark, we conducted a nationwide population-based cohort study. We identified all 219,354 patients with a first-time hospitalization for stroke between 1994 and 2011. We computed standardized 30-day, 1-year, and 5-year mortality by gender. Comorbidity categories were defined by Charlson Comorbidity Index scores of 0 (none), 1 (moderate), 2 (severe), and 3 or more (very severe). Calendar periods of diagnosis (1994-1998, 1999-2003, 2004-2008, and 2009-2011) and comorbidity categories were compared by means of mortality rate ratios based on Cox regression.
Results: Over time, the 30-day mortality rate adjusted for age, gender, and comorbidity fell by about 45% for ischemic stroke (standardized risk fell from 17.2% in 1994-8 to 10.6% in 2009-11) and by 35% for intracerebral haemorrhage (from 43.2% to 33.8%). The absolute mortality reduction occurred for all levels of comorbidity. Five-year mortality decreased from 56.4% in 1994-1998 to 46.1% in 2004-2008 for ischemic stroke and from 66.1% to 61.0% for intracerebral haemorrhage. When very severe comorbidity was compared with no comorbidity, 30-day and 5-year mortality rates among patients with very severe comorbidity were both approximately 2.5-fold increased for ischemic stroke and 1.7-fold increased for intracerebral hemorrhage.
Conclusions: Short-term and long-term mortality improved considerably between 1994 and 2011 for all types of stroke. Short-term mortality improved regardless of comorbidity burden. However, comorbidity burden was a strong prognostic factor for both short-term and long-term mortality.
- © 2013 by American Heart Association, Inc.