Invasive Mechanical Ventilation May Improve Cystic Fibrosis Mortality Rates

In-hospital mortality of patients with cystic fibrosis (CF) is decreasing, particularly in patients undergoing invasive mechanical ventilation, according to study results published in Annals of the American Thoracic Society.

Using the United States Nationwide Healthcare Cost and Utilization Project database, researchers identified hospitalized patients with CF who required invasive mechanical ventilation between 2002 and 2014 to assess if mortality among this patient population has decreased over time.

The researchers identified 58,799 hospitalizations of adult patients with CF. Following exclusions, 1711 patient records (2.9% of total adult CF admissions) were available for analysis.

The mortality rate was 44.5% in patients with CF who required hospitalization with invasive mechanical ventilation. Of those who were released from the hospital, 37.4% were discharged home, 23.1% were discharged home with home health care, 20.4% were transferred to a short-term hospital, and 17.8% were transferred to a skilled nursing facility, an intermediate care facility, or another type of facility. Another 1.3% of patients left against medical advice.

Per-year analyses found that the median number of records was 124 with a range of 80 to 199; annual mortality ranged from 29.9% to 55.3%. Generally, mortality decreased during the study period, with an increased probability of survival per hospitalization as the calendar year increased (P =.0029). Each hospital was categorized into 1 of 4 quartiles based on the frequency of hospitalizations for CF requiring invasive mechanical ventilation. Mortality per hospitalization at high-volume hospitals (≥4 CF with invasive mechanical ventilation hospitalizations per year) was 49.0%; comparatively, mortality per hospitalization at low-volume hospitals (≤2 hospitalizations) was 39.1%.

Additional comparisons between the highest and lowest volume hospitals (≥5 admissions per year and ≤1 admission per year, respectively) found that the mortality rate was higher in the highest volume group (60.0% vs 37.8%; P <.001).

Adjusted analyses indicated that female sex (odds ratio [OR], 1.54; 95% CI, 1.14-1.98), acute renal failure (OR, 1.99; 95% CI, 1.32-3.01), and malnutrition (OR 1.44; 95% CI, 1.01-2.06) were associated with increased mortality. Patients between 25 and 32 years of age also had a higher risk for death (OR, 1.54; 95% CI, 1.03-2.30). Compared with private insurance, patients with either Medicare or Medicaid were likely to have decreased mortality rates (OR, 0.68; 95% CI, 0.47-0.99 and OR, 0.64; 95% CI, 0.43-0.96, respectively).

Several study limitations were noted. Billing code data have been shown to contain errors, and diagnoses and procedures may not correlate with patient’s medical records. Additionally, it is unclear what the long-term survival is within this patient population due to a lack of follow-up.

“While the decision to intubate patients with CF remains difficult, our study provides further evidence on outcomes and can help the CF team, family, and patient weigh the risks and benefits of [invasive mechanical ventilation],” the researchers concluded.

Reference

Siuba M, Attaway A, Zein J, et al. Mortality in adults with cystic fibrosis requiring mechanical ventilation: cross-sectional analysis of nationwide events [published online April 26, 2019]. Ann Am Thorac Soc. doi:10.1513/AnnalsATS.201804-268OC