Theophylline for Irreversible Chronic Airflow Limitation: Conduct and Results of n of 1 Trials

Theophylline for Irreversible Chronic Airflow Limitation: Conduct and Results of n of 1 TrialsConduct and Results of n of 1 Trials
Four n of 1 trial patients stopped their n of 1 trials before or on completion of the first treatment period and refused to continue. Of these, three patients in the prior-theophylline-use group chose to remain on theophylline openly (two patients had received theophylline only and one patient had received placebo only), and one patient in the no-prior-theophylline-use group had received theophylline only and chose not to continue the drug. Of the remaining 30 patients, 4 provided diary scores for one pair of theophylline and placebo treatments from which a point estimate on the difference in dyspnea score could be determined. The other 26 patients completed at least two treatment pairs (8 patients, two pairs; 6 patients, three pairs; 12 patients, four pairs) from which CLs on the point estimate could also be determined. Early crossovers to alternate treatments within pairs occurred in six patients, and four patients were treated for a respiratory infection during the n of 1 trials but did not crossover or end the treatment period early.
Seven of 34 patients (21%) undergoing n of 1 trials demonstrated a potentially useful improvement in dyspnea while on theophylline (Table 4) buying antibiotics online buying antibiotics online. In each case, the point estimate on the improvement in mean daily dyspnea score, as measured by the 7-point Likert scale during theophylline therapy, exceeded zero (range, 0.3 to 3.1), and the 90% CLs on the estimates were either removed from zero (five patients) or marginally overlapped zero (two patients). Seven of 18 prior-theophyl-line-use patients (39%) and 1 of 13 no-prior-theophyl-line-use patients (8%) (p = 0.10; Fisher’s exact test) chose either to resume theophylline following a negative n of 1 trial, or to abandon their n of 1 trial in favor of remaining on theophylline, even though they had not received at least one course of both theophylline and placebo treatments.
Table 4—Results of Selected n of 1 Trials

Mean Dyspnea Score* Mean Change (and 90% CLs) in Mean Symptom Score (Theophylline Minus Placebo)!
Pair 1 Pair 2 Pair 3 Pair 4
Patient 1 , 1 Tt P II 1 T P II 1 T P 1 1 T P
1105 6.3 6.0 6.9 6.4 6.7 6.6 ND 0.3 (0.1 and 0.5)
1110 5.4 3.5 5.7 3.0 3.6 4.2 4.6 2.4 1.6 (0.3 and 2.7)
2108 4.4 2.2 5.6 2.1 5.9 2.3 ND 3.1 (2.3 and 3.9)
2206 4.31.2 2.6 2.1 3.1 2.0 ND 1.5 (0.1 and 3.0)
6209 5.8 5.3 5.9 5.5 6.0 5.8 ND 0.4 (0.2 and 0.5)
7208 5.8 4.3 6.5 6.5 6.0 6.2 5.5 4.7 0.5 (-0.1 and 1.2)
7210 5.8 2.1 5.9 5.9 5.0 3.1 ND 1.9 (-0.2 and 3.8)

Category: Airflow Limitation

Tags: irreversible chronic airflow limitations, n of 1 trials, randomized trial, theophylline