Patients received thalidomide and placebo pills, each
for 12 weeks. The order in which they received the treatments was randomly
assigned. Patients rated the effect of cough on their quality of life, as well
as the severity of their cough, using standardized questionnaires. Changes in
the questionnaire scores after 12 weeks of thalidomide and placebo treatment
were compared. Neither the patients nor the treating physicians were told which
regimen was being administered. Patients received medication to prevent
constipation, a known adverse effect of thalidomide.