Study objective: To examine the impact of age on outcome from mechanical ventilation.
Design: Retrospective analysis of a statewide database.
Setting: All acute-care hospitals in New York State.
Patients: All patients, aged 18 years and over, requiring mechanical ventilation during 1990 who could be identified with a mechanical ventilation procedure code (93.92) were studied. Data were obtained in aggregate form (six or more cases) from the New York State Department of Health. This process required a detailed request letter to the Statewide Planning and Cooperative System (SPARCS). Transmission of confidential information was not desired or permitted.
Measurements and results: Age and mortality rate (MR) fit a cuboidal regression model best (MR = -25.55 + 3.98Age - 0.072Age2 + 0.00043Age3, R2 = 0.85). Mortality rates vary significantly across various broad diagnostic groups (p < 0.01, analysis of variance [ANOVA]) and increase as a function of ICU duration (p < 0.01, ANOVA).
Conclusions: Age has an important effect on outcome from mechanical ventilation. Other factors, such as ICU duration and diagnosis, also influence outcome, and age should not be used as a sole criterion in evaluating the potential benefit of mechanical ventilation to an individual patient. Large, existing databases, such as SPARCS, may be useful in studying the application of mechanical ventilation.