K. Cheng et al., Randomized controlled trials in cystic fibrosis (1966-1997) categorized bytime, design, and intervention, PEDIAT PULM, 29(1), 2000, pp. 1-7
The improved prognosis of cystic fibrosis (CF) over the last three decades
has been associated with an increased use of a range of treatments, but it
is important that the use of an individual treatment is based on evidence.
Well-designed randomized controlled trials (RCTs) are a robust method for e
valuating the effectiveness of such treatments. We have developed a registe
r of RCTs in CF and have studied when they were performed, their design, an
d what interventions were investigated.
We identified 506 RCTs; 37.5% were identified solely as abstract reports in
conference proceedings. There has been about a 30-fold increase in the num
ber of RCTs in CF since 1966. A high proportion of the RCTs (72.7%) had a s
ample size of 30 or less, and only 8.7% were multicenter trials. Reporting
of study design was poor: in 51.4% the report did not state whether there w
as any blinding in the trial design; 53.6% of studies were of crossover des
ign. The most common interventions studied were antibiotic treatments and p
hysiotherapy, but a number of commonly used therapies had been evaluated on
ly in a small number of patients. Although the number of RCTs of interventi
ons in CF patients has increased over the last 25 years, the sample sizes o
f these trials are generally too small to indicate whether the intervention
was effective, and very few were multicenter. Future RCTs in CF are more l
ikely to provide clinically useful answers if higher numbers of patients ar
e recruited into large, well-designed multicenter trials. This should be a
priority of the organization of future research in CF. (C) 2000 Wiley-Liss,
Inc.