Researchers in Canada have developed a novel clinical tool that uses patients’ overall health status and the risk for intermittent shock events to predict 1- and 2-year mortality in cystic fibrosis (CF), according study results published in European Respiratory Journal.1

Although survival in patients with CF has improved steadily during the past 3 decades, CF remains a life-shortening illness with half of all deaths occurring before the age of 35 years.2 Thus, there is a great need for developing an accurate prediction model for mortality to identify patients who would benefit from expedited referral to a lung transplant program. The researchers sought to develop a clinical tool for predicting 1- and 2-year risk for death using Canadian CF Registry data from 1982 to 2015 and validating it using United Kingdom CF Registry data from 2007 to 2013.1

They found that the combined effect of CF chronic health status and CF intermittent shock risk provided a simple clinical scoring tool for assessing 1-year and 2-year risk for death in an individual person with CF. The Canadian-derived model validated well with the UK data and correctly identified 79% of deaths and 95% of survivors in a single year in the United Kingdom.

In addition, the receiver under the operating curve of the 2-year mortality model was significantly greater than the model that predicted survival based on forced expiratory volume in 1 second <30% predicted (0.95 vs 0.68, respectively; P <.001).

The prediction model has some limitations. For one, although the majority of the predictor variables were obtained in the previous 12 months for the 1-year model or in the 12-month interval 1 year before for the 2-year model, the annual measurements in the Canadian registry do not reflect acute deterioration in health status. The researchers noted that it would be helpful to use encounter-based records in the future. In addition, the study population includes observations over the course of 30 years, during which CF prognosis and treatment have changed considerably.

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“In conclusion, the mortality prediction models provide accurate risks of death over 1-and 2-year time horizons,” the researchers stated.1 “The calculated probability of death may provide physicians and patients with important information with which to access key clinical decisions, such as transplant discussion and referral when the risk of death in the next 2 years is considered high.”

References

1. Stanojevic S, Sykes J, Stephenson AL, Aaron SD, Whitmore GA. Development and external validation of 1- and 2-year mortality prediction models in cystic fibrosis. Eur Respir J. 2019;54(3).

2. Cystic Fibrosis Canada. 2012 Annual Report: The Canadian Cystic Fibrosis Registry. Toronto, Cystic Fibrosis Canada. Available at www.cysticfibrosis.ca/de/action/download?downloads=16&file=dl_Registry+2012 +-+English+FINAL+FOR+WEB.pdf. Published February 2014.