Survival estimates for adults with cystic fibrosis born in the United Kingdom between 1947 and 1967
- P A Lewisa,
- S Morisonb,
- J A Dodgeb,
- D Geddesc,
- E C Colesd,
- G Russelle,
- J M Littlewoodf,
- M T Scott (the UK Cystic Fibrosis Survey Management Committee)f
- aSchool of Postgraduate Medicine, University of Bath, Bath, UK, bDepartment of Child Health, Queen’s University, Belfast, UK, cBritish Thoracic Society, London, UK, dDepartment of Medical Computing and Statistics, University of Wales College of Medicine, Cardiff, UK, eRoyal College of Paediatrics and Child Health, London, UK, fCystic Fibrosis Trust, Bromley, Kent, UK
- Dr P A Lewis, School of Postgraduate Medicine, University of Bath, Bath BA2 7AY, UK.
- Received 15 June 1998
- Revision requested 28 September 1998
- Revised 10 December 1998
- Accepted 5 January 1999
Abstract
BACKGROUND The UK has published observed cohort survival figures for subjects with cystic fibrosis born since 1968. Prior to 1968 cohorts cannot be established directly from routine data as cystic fibrosis was classified with a number of unrelated conditions in ICD7. Reported here are interrupted survival curves from 1978 for patients with cystic fibrosis born before 1968.
METHODS Life tables for the three year cohorts born between 1947 and 1967 were constructed by firstly estimating the numbers of patients with cystic fibrosis born in each cohort from live birth data and the disease incidence. The number of the estimated cohort that had survived to 1978 is known, which enables the proportion surviving to 1978 to be calculated. The survival of these cohorts after 1978 can be calculated in the usual way.
RESULTS The survival for each successive cohort was better than that of the previous one, but most of the improvements appear to have taken place up to the age of about 20 years. Only 3% of the 1947–49 cohort survived to 30 years of age compared with 21% for the 1965–67 cohort, and 3% of the 1953–55 cohort survived to 40 years of age. For the later cohorts the mortality rate for those aged between 26 and 30 years appears to be about 50 per 1000 per year.
CONCLUSIONS While the trend in the numbers surviving into later adulthood is upwards, the mortality rates for these ages does not appear to be improving. It is not possible to tell from these data whether the high mortality rates in adulthood will improve with better resourced adult clinics or with improved treatment during childhood.
