The results of the review were as follows:
The diagnostic procedure consisted of biological tests in 59%, X-rays in 65% and pulmonary function tests in 45% of patients.
Bronchodilators were used in 89% of AECBs, corticosteroids in 24% and others in 25%.
AECB rate was 25.5% for placebo versus 16.1% for NAC (difference: 9.4%; 95% CI: 5.8 - 12.9).
The number of AECBs per patient in a 6-month period was 0.97 (0.80 - 1.13) AECBs with NAC, and 1.53 (1.32 - 1.73;) AECBs with placebo, (p<0.001).
The percentage of days sick per month was 5.3% (95% CI: 2.8 - 8.0) for placebo and 3.6% (95% CI: 1.4 - 5.8) for NAC.
Hospitalisation was 3.5% in the placebo group versus 1.2% in the NAC group, (p=0.054).
Study interruptions due to chest illness or bronchopneumonia were reported in 2.9% of patients in the placebo group and 2.2% in the NAC-treated group.
The death rates were 0.7 in the placebo group and 0.6% in the NAC-treated group.
The rate of satisfactory compliance was 80% in the NAC-treated population.