Randomized clinical trials in single patients during a 2-year period

Abstract

Objective: To describe the feasibility of a single patient trial (SPT) service and study the influence of formal SPTs on therapeutic precision.

Design: Descriptive and evaluate study of SPTs. All planned trials were double-blind, randomized, multiple crossover trials. Other key features of individual trials were random assignment of order and assessment of predetermined explicit outcomes. Patients and physicians rated level of confidence in treatment before and after the SPT on visual analog scales.

Setting: Two-year experience (September 1988 to September 1990) of an SPT trial referral service available to physicians in an academic medical center.

Outcome measures: The number of planned and completed SPTs; proportion of completed trials yielding definitive answers; patient- and physician-rated levels of confidence in treatment pre- and post-SPT; time-motion studies to estimate resource consumption (costs) for selected SPTs.

Results: Of 34 completed trials, 17 were judged to give definitive results whereas 17 showed trends only. Results favored active treatment in 16 trials that led to treatment being continued (nine patients) or started (seven patients). Treatment was discontinued (seven patients) or not started (11 patients) based on 18 trial results that demonstrated active treatment was ineffective (seven), harmful (two), or apparently equivalent (nine). Most patients (65%) reported no change in their already high level of confidence in therapy as a result of trials, whereas physicians' confidence levels in therapy either increased or decreased post-SPT depending on the direction of trial results. Patients consistently rated the SPT service as extremely useful. Time-motion estimates indicate that 16.75 staff hours were spent per trial leading to a direct cost estimate of approximately $450 to $500 per trial.

Conclusion: We conclude that an SPT service is feasible, trial costs compare favorably with other conventional services, and clinicians appear to gain confidence and precision from SPTs. When patients or clinicians are uncertain about the value (including the possibility of side effects) of treatment for symptomatic chronic diseases, we believe an SPT can be offered to a patient and will likely yield results that will effect subsequent treatment.