Physician decisions to discontinue long-term medications using a two-stage framework: the case of growth hormone therapy.

Background: Physician decisions to discontinue prescription medications for chronic conditions are fundamental determinants of drug use but have been inadequately studied. The decision to stop growth hormone (GH) therapy is an important example because of high cost (approximately $26,000/y for a 48-kg child), complexity of treatment options, and expansion of patient populations.
Aim: The aim of this study was to identify the factors that influence physician recommendations in the process of discontinuing therapy.
Design: A random sample of half of U.S. pediatric endocrinologists (n = 265) was mailed a survey that included case scenarios of GH-deficient adolescents. Decision options involved a 2-stage framework to 1) initiate change in ongoing GH therapy (by discussing discontinuing GH with the family but not yet stopping treatment), and 2) take action to discontinue ongoing GH therapy (by terminating GH or reducing the dose to adult maintenance level).
Main Outcome Measure: Physician recommendations.
Results: The response rate was 83.8%. Physiological indices of growth potential (growth velocity, bone age) significantly influenced discontinuation decisions (both P < 0.001). However, family preference, child's height, and physician attitudes exerted independent effects (each P < 0.05). Treatment price had little influence. Together, these variables accounted for 60% to 70% of the variation in recommendations. Their relative influence differed by stage in the discontinuation process.
Conclusion: The variables in our framework substantially explain discontinuation decisions. The data demonstrate the importance of both physiological and nonphysiological factors. The results suggest that physicians value even small gains as final height approaches, although an additional 20% expenditure may be needed to gain the last 1% to 3% of adult height.