Short-term and long-term increased mortality in elderly patients with burn injury: a national longitudinal cohort study

BACKGROUND: The population of elderly patients with burn injuries is growing. Insight into long-term mortality rates of elderly after burn injury and predictors affecting outcome is limited. This study aimed to provide this information.

METHODS: A multicentre observational retrospective cohort study was conducted in all three Dutch burn centres. Patients aged ≥65 years, admitted with burn injuries between 2009 and 2018, were included. Data were retrieved from electronic patient records and the Dutch Burn Repository R3. Mortality rates and standardized mortality ratios (SMRs) were calculated. Multivariable logistic regression was used to assess predictors for in-hospital mortality and mortality after discharge at 1 year and five-year. Survival analysis was used to assess predictors of five-year mortality.

RESULTS: In total, 682/771 admitted patients were discharged. One-year and five-year mortality rates were 8.1 and 23.4%. The SMRs were 1.9(95%CI 1.5-2.5) and 1.4(95%CI 1.2-1.6), respectively. The SMRs were highest in patients aged 75-80 years at 1 year (SMRs 2.7, 95%CI 1.82-3.87) and five-year in patients aged 65-74 years (SMRs 10.1, 95%CI 7.7-13.0). Independent predictors for mortality at 1 year after discharge were higher age (OR 1.1, 95%CI 1.0-1.1), severe comorbidity, (ASA-score ≥ 3) (OR 4.8, 95%CI 2.3-9.7), and a non-home discharge location (OR 2.0, 95%CI 1.1-3.8). The relative risk of dying up to five-year was increased by age (HR 1.1, 95%CI 1.0-1.1), severe comorbidity (HR 2.3, 95%CI 1.6-3.5), and non-home discharge location (HR 2.1, 95%CI 1.4-3.2).

CONCLUSION: Long-term mortality until five-year after burn injury was higher than the age and sex-matched general Dutch population, and predicted by higher age, severe comorbidity, and a non-home discharge destination. Next to pre-injury characteristics, potential long-lasting systemic consequences on biological mechanisms following burn injuries probably play a role in increased mortality. Decreased health status makes patients more prone to burn injuries, leading to early death.