Table 1.

Recommendations for presentation of survival statistics in national CF registry reports, illustrated using results from the UK Cystic Fibrosis Registry.

1.Present estimated survivor curves and the corresponding median survival age showing 95% CIs, overall (Fig. 2a) and for males and females separately (Fig. 2b), with the following text: What is median age of survival? The estimated median age of survival is an estimate of the age beyond which we expect half of a population of individuals born today with CF in the UK to live. The interpretation of the median survival age of 47 is therefore that in a population of babies born today with CF half would be expected to die before the age of 47 and half would be expected to live beyond age 47. Limitations The estimation of the median age of survival assumes that age-specific mortality rates in the future will be similar to those today. Although it represents the best information available to us currently, it does not take into account recent and future improvements in care and treatment that will impact on survival. The median survival age refers to a population and not an individual; it does not take into account individual features, such as genotype, which impact on survival. 2.Present estimates of median age of survival conditional on survival to a series of ages (Fig. 3), with the following text: What is conditional median age of survival? The estimated median age of survival conditional on survival to age A is the age beyond which we expect 50% of individuals aged A in the present day to live. For example, the median age of survival conditional on survival to age 30 is 55. Therefore we expect 50% of 30 year olds with CF today to live beyond age 55. Limitations The limitations are similar to those for the overall median survival age. Conditional estimates do not take into account an individual's current health status, which is highly informative about their survival prospects.