Five-Year Risk of Mechanical Ventilation in Community-Dwelling Adults: The Framingham-Intermountain Anticipating Life Support Study

Abstract

Objectives: To develop a quantitative tool for identifying outpatients most likely to require life support with mechanical ventilation within 5 years.

Design: Retrospective cohort study.

Setting: Framingham Heart Study (FHS) 1991 to 2009 and Intermountain Healthcare clinics 2008 to 2013.

Participants: FHS participants (n = 3,666; mean age 74; 58% female) in a derivation cohort and Intermountain Healthcare outpatients aged 65 and older (n = 88,302; mean age 73, 57% female) in an external validation cohort.

Measurements: Information on demographic characteristics and comorbidities collected during FHS examinations to derive a 5-year risk score for receiving mechanical ventilation in an intensive care unit, with external validation using administrative data from outpatients seen at Intermountain Healthcare. A sensitivity analysis investigating model performance for a composite outcome of mechanical ventilation or death was performed.

Results: Eighty (2%) FHS participants were mechanically ventilated within 5 years after a FHS examination. Age, sex, diabetes mellitus, hypertension, atrial fibrillation, alcohol use, chronic pulmonary disease, and hospitalization within the prior year predicted need for mechanical ventilation within 5 years (c-statistic = 0.74, 95% confidence interval (CI) = 0.68-0.80). One thousand seven hundred twenty-five (2%) Intermountain Healthcare outpatients underwent mechanical ventilation. The validation model c-statistic was 0.67 (95% CI = 0.66-0.68). Approximately 1% of individuals identified as low risk and 5% to 12% identified as high risk required mechanical ventilation within 5 years. Sensitivity analysis demonstrated a c-statistic of 0.75 (95% CI = 0.75-0.75) for risk prediction of a composite outcome of mechanical ventilation or death.

Conclusion: A simple risk score using clinical examination data or administrative data may be used to predict 5-year risk of mechanical ventilation or death. Further study is necessary to determine whether use of a risk score enhances advance care planning or improves quality of care of older adults.

Keywords: advance care planning; end-of-life care; mechanical ventilation.