Using the literature to quantify the learning curve: a case study.

OBJECTIVES: The aim of this study was to assess whether a literature review of a technology can allow a learning curve to be quantified. METHODS: The literature for fiberoptic intubation was searched for studies reporting information relevant to the learning curve. The Cochrane Library, Medline, Embase, and Science Citation index were searched. Studies that reported a procedure time were included. Data were abstracted on the three features of learning: initial level, rate of learning, and asymptote level. Random effects meta-analysis was performed. RESULTS: Only twenty-one studies gave explicit information concerning the previous experience of the operator(s). There were thirty-two different definitions of procedure time. From four studies of fiberoptic nasotracheal intubation, the mean starting level and time for the 10th procedure was estimated to be 133 seconds (95 percent confidence interval, 113-153) and 71 seconds (95 percent confidence interval, 62-79), respectively. CONCLUSIONS: The review approach allowed learning to be quantified for our example technology. Poor and insufficient reporting constrained formal statistical estimation. Standardized reporting of nondrug techniques with adequate learning curve details is needed to inform trial design and cost-effectiveness analysis.