Hallie B Murray,1 Brian A Pethica1,2 1EBI, LLC (a Zimmer Biomet company), Parsippany, NJ, USA; 2Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, USA Abstract: During normal fracture repair, healing occurs within a few months. However, for a minority of patients, the processes of bone repair are compromised or interrupted leading to the development of delayed union and nonunion fractures. Noninvasive bone growth stimulators using pulsed electromagnetic field (PEMF) technology are currently in widespread use by patients with impaired fracture healing. This article reports the results of a follow-up study of 1,382 patients treated with PEMF stimulation to evaluate success rates and the relationship between average daily use and the clinical outcomes of therapy as reported by their prescribing physicians. The reported overall success rate for the 1,382 patients was 89.6%. The results were analyzed in audited subsets comparing days of treatment time and average daily use of the electrical bone growth stimulator, using several statistical methods. Linear regression analysis indicated a 6-day reduction in time to heal with each additional hour of average daily use. Survival analysis concluded that the median heal time was reduced by 35%–60%, depending on the different fracture characteristics of patients who complied with the recommended daily use of 10 hours per day. A third statistical analysis indicated that patients treated with the PEMF device for 9 hours or more per day had a significant reduction in time to heal, achieving successful fracture repair an average of 76 days earlier than patients treated with the PEMF device for an average of 3 hours or less per day. Overall, these different methods of statistical analysis indicate that PEMF therapy correlates with an acceleration in the healing of nonunion fractures. Keywords: PEMF, pulsed electromagnetic field, dose–response, nonunion, time to heal