COMBINING SINGLE PATIENT (N-OF-1) TRIALS TO ESTIMATE POPULATION TREATMENT EFFECTS AND TO EVALUATE INDIVIDUAL PATIENT RESPONSES TO TREATMENT

When treating individual patients, physicians may fare difficulties us ing the evidence from center-based randomized control trials (RCTs) du e to limitations in these studies' generalizability. Therefore, they o ften perform their own ''informal'' tests of treatment effectiveness. Single patient (''N-of-1'') trials provide a structured design for mor e rigorous assessment of medical treatments of chronic diseases, but a re applied only to the index patient. We present a hierarchical Bayesi an random effects model to combine N-of-1 studies to obtain an estimat e of treatment effectiveness for the population and to use this popula tion information to aid in the evaluation of an individual patient's t rial results. The model's treatment effect estimates are adjustments b etween the population estimate and the individual's observed results. This adjustment is based upon the within-patient and between patient h eterogeneity. We demonstrate this patient-focused method using publish ed data from 23 N-of-1 trial results comparing amitriptyline and place bo for the treatment of fibromyalgia. (C) 1997 Elsevier Science Inc.