Survival patterns in cyctic fibrosis.

This paper describes the Data Registry System of the Cystic Fibrosis Foundation. 
Through this system an annual up-dated and corrected data base has 
been prepared for cystic fibrosis patients seen at U.S.A. Centers from 
1966 through 1972. From the data base, a large number of 
life table studies are calculated. A study is specified by its 
data base, the observation period, analysis age (age year or year 
since diagnosis), the Centers included, and the condition of patients at 
birth, and possible additional factors such as sex, age at diagnosis, 
or race. The annual rates of mortality are measured by a 
force of mortality technique. Two techniques have been used to appraise 
the mortality of particular groups, graphing the cumulative survival function for 
the group together with the cumulative survival function for a comparative 
group, and calculation of mortality ratios of actual to expected deaths 
(by an applicable standard mortality table). This latter approach lends itself 
readily to tests of significance. For the purpose of calculating mortality 
ratios, two standard tables have been prepared on the basis of 
the 1972 Data Base and the 1966-1972 observations. The first of 
these standard tables is for use with age year studies, and 
the second is for years since diagnosis studies. The paper comments 
on the number of mortality studies by calendar year, by sex, 
by condition at birth, by age at diagnosis, and of survival 
from diagnosis of patients diagnosed in 1966-1972. The calendar year studies 
indicate an improvement trend in the survival experience from 1966 to 
1972 but a change may be occurring. The study by sex 
exhibits a higher female mortality. The 7% of patients who have 
meconium ileus at birth show a significantly higher first-year mortality, and 
a somewhat lower survival rate thereafter even if the first year 
of life experience is excluded. Mortality data for groups specified by 
age at diagnosis are given. For patients diagnosed during 1966-1972, there 
is some indication of better survival than for patients diagnosed prior 
to 1966. The continuation of these mortality studies on an annual 
basis should further our understanding of survival patterns for cystic fibrosis 
patients. 