A health diary was administered for 28 consecutive days over 3 non-con
secutive months to 53 children and adolescents with Cystic Fibrosis (a
ge 11-17 years). Response rates were 96% for the first, 84% for the se
cond and 58% for the third month. Ill health actions such as missing s
chool or staying in bed, ranged from 0 to 21% of diary days and showed
an apparent seasonal variation being highest in the month of May. Ana
lysis of variance demonstrated significant association between health
actions, use of additional medicines and disease severity although no
such associations were found for worries and concerns and overall asse
ssment of the day. Most were not very bothered by symptoms or complain
ts, the highest visual analogue score on a scale of 0-10 in a single p
atient was 2.4 for coughing. A striking finding was the disparity betw
een perceived vulnerability and subsequent experience with predictions
of common symptoms such as cough and shortness of breath scoring 4-5
times higher than actually experienced. These children and adolescents
were coping very successfully with their disease although the dispari
ty between perceived vulnerability and subsequent experience indicates
some uncertainty about the effects of the disease and/or lack of unde
rstanding about medical therapy.