Table 1: Lessons learned from collecting cost data from physicians - Two-method comparison.

Technique applied			Lesson learned
Criteria	Delphi Panel N = 16	Online Survey N = 14
Recruitment	Contacted physicians’ medical specialty organization and randomly selected 20 physicians who met the study criteria using the random function in Excel. 80% of physicians invited agreed to participate in the Delphi panel.	Contacted the medical education director of their hospital and sent an online invitation to all physicians who met the study criteria. Less than 15% of physicians accepted the invitation to participate in the study.	Physicians have a stronger association with their medical specialty organization and are more likely to participate if they are selected personally than if invited via their hospital email.
Data collection	Each participant received an electronic survey, at least 3 follow-up phone calls, and a personalized interview to review responses. 100% of questions were answered.	Each participant received an online invitation with detailed instructions, and 3 electronic reminders. 20% of questions were answered; most questions were left blank or incomplete.	Physicians are unfamiliar with cost structures and financial questions about their practices. The Delphi panel proved to be more effective in collecting valid and complete information.
Time	Total time dedicated to each participant ranged from 60-180 minutes, from recruitment and data verification.	Minimum time was spent interacting with physicians. Researchers used online automatic reminders.	Physicians are unlikely to have dedicated time to complete questionnaires. Researchers need to plan time to guide physicians through questions, explain possible scenarios, and gather the financial data needed.
Cost	An incentive of $500 per physician was offered to participate.	No incentive was offered to physicians to participate in the study. Physicians receive institutional incentives from their medical associations	Physicians respond positively to an economic incentive, which may have guaranteed dedicated time to participate in the study.
Response rate	Of those selected for the study, 100% of participants completed the survey and the subsequent rounds of data collection.	Less than 15% of participants initiated the survey, and less than 10% finished the survey.	There is a direct relationship between time spent in contact with participating physicians and the response rate.
Quality of information	High quality. Each participant was individually guided on data collection and all responses were verified.	Low quality.	Physicians rely on office support to handle the financial aspect of their practices. Without guidance from the research team, physicians are unfamiliar with the costs associated with their practices.