Theophylline for Irreversible Chronic Airflow Limitation: OutcomeOur secondary hypothesis that n of 1 trials would lead to less theophylline use than standard practice was also not confirmed in the present study. It was based on the premise that, overall, the biases of single-patient open trials favor false conclusions that the treatment is effective, and our previous randomized study of 26 patients in which 47% (95% CLs, 14%, 80%) fewer n of 1 trial patients than standard practice patients were taking theophylline at 6 months without differences in CRQ scores and the 6-min walk. Patients in our previous study had been on theophylline at the time of recruitment for at least a year, making them more comparable to prior-theophylline-use patients in the present study. Both patient groups were probably “theophylline survivors,” being less sensitive to the drug’s side effects and having a stronger perception that it was relieving symptoms compared to no-prior-theophyl-line-use patients . Flovent inhalers other This inference is supported by our observations of prior-theophylline-use patients versus no-prior-theophylline-use patients of higher theophylline levels at entry, a greater proportion of patients taking theophylline at 1 year, and a larger proportion of patients resuming theophylline following a negative n of 1 trial or prematurely abandoning the n of 1 trial in favor of continuing the drug.
Despite the greater tendency among prior-theo-phylline-use patients to tolerate and remain on theophylline, we found that and fewer n of 1 trial patients than standard practice patients within this stratum were taking theophylline at 3 months (26%) and 6 months (21%), without clinically important changes in CRQ scores and exercise capacity. While the reduction in theophylline use and the lack of changes in quality of life and exercise capacity did not reach statistical significance, given the risks of theophylline and the large number of patients currently on the drug, these findings would be of potential clinical and economic importance if confirmed in a larger sample. We explored this possibility by combining prior-theophylline-use patients in the present trial with patients from our previous trial. We found a statistically and clinically significant reduction in theophylline use (32%) at 6 months among n of 1 patients vs standard practice patients, without significant reductions in the CRQ Physical and Emotional Function scores and the 6-min walk.