A model for predicting life expectancy of children with cystic fibrosis

Abstract

In this study the authors aimed to produce a model for predicting the life expectancy of children with severe cystic fibrosis (CF) lung disease.The survival of 181 children with severe CF lung disease referred for transplantation assessment 1988±1998 (mean age 11.5 yrs, median survival without transplant 1.9 yrs from date of assessment) were studied. Proportional hazards modelling was used to identify assessment measurements that are of value in predicting longevity.The resultant model included low height predicted forced expiratory volume in one second (FEV1), low minimum oxygen saturation (Sa,O 2 min) during a 12-min walk, high age adjusted resting heart rate, young age, female sex, low plasma albumin, and low blood haemoglobin as predictors for poor prognosis. Extrapolation from the model suggests that a 12-yr old male child with an FEV1 of 30% pred and a Sa,O 2 min of 85% has a 44% risk of death within 2 yrs (95% confidence interval (CI) 35±54%), whilst a female child with the same measurements has a 63% risk of death (95% CI 52±73%) within the same period.The model produced may be of value in predicting the life expectancy of children with severe cystic fibrosis lung disease and in optimizing the timing of lung transplantation.

The effect of prelung transplant clinical status on post-transplant survival of children with cystic fibrosis

“…This formula had been derived from an earlier survival study of children with severe CF lung disease [14].…”

Recommendations on the use of exercise testing in clinical practice

“…In field test studies, the indices most commonly used for patient evaluation are the distance walked, the lowest Sp,O 2 and fC [215]. Some authors have found that V9O 2 ,peak in patients with CF was correlated with 6-MWD, with the correlation coefficient increasing if age, weight, FVC, FEV1 and DL,CO were added to the prediction equation [216,217].…”

Lung Transplantation for Cystic Fibrosis

“…National systems can be structured so as to take into account expert clinician judgment, as was demonstrated during this meeting by descriptions of the British and Canadian systems (7,134,135). It may well be the case, as some have argued, that outcomes for transplantation in the United States are determined to a large part by bureaucratic processes rather than variations in surgical or medical procedures.…”

“…The disadvantage is that by listing children fairly late in the course of their disease, there are inevitably some who will die before receiving organs. In common with most other transplant centers, we use a variety of clinical and physiological data to prognosticate in children referred to us in an attempt to identify the correct time of listing (134,13,15). However, any such survival estimation is inexact in individuals, and occasionally children will die before even being listed.…”

“…The first was designed to identify prognostic markers to determine which children have an expected survival of 2 years or less (134). Although the markers identified in the study are still used by us, we recognize that the treatment of CF has improved over the last 10 years, and our current decisions are adjusted accordingly, with children now being listed with poorer lung function and exercise test results than previously.…”