A comparison of survival, growth, and pulmonary function in patients with cystic fibrosis in Boston and Toronto

Abstract

Two cystic fibrosis (CF) clinic populations of similar size and age distribution were compared with respect to growth, pulmonary function, and survival. Height and weight measurements were made on 499 patients in Boston (mean ± SD age 15.9 ± 9.6, range 1 month to 45 years) and on 534 patients in Toronto (mean ± SD age 15.2 ± 8.3, range 1 month to 43 years). Males constituted 57% in the Boston group, 58% in Toronto. Pulmonary function test results were recorded for 64% of the Boston patients and 77% of the Toronto patients. Survival curves for the period 1972–1981 generated by the CF Patient Registry were compared. Patients in Boston tended to be shorter than patients in Toronto. This pattern was seen in both sexes in the 10–20 year age groups. Toronto males also weighed more than Boston males. Mean forced expiratory volume in one second (FEV,) was not different in Boston and Toronto CF patients whether expressed as a percent of predicted or in litres by age groups. Median age of survival in Boston was 21 years, in Toronto 30, the two curves showing a marked separation from age 10. Although progressive pulmonary disease is the major cause of mortality in cystic fibrosis, the differences in growth and survival in these two patient groups, with very similar age-specific pulmonary function, suggest further examination of nutritional guidance and intervention in CF, especially regarding the traditional restriction of dietary fat.