Dear Editor:
There were two things I found interesting about the special issue on the Podiatric Practice Survey, in the December 1996 JAPMA:
- 1)
- On page 575, how this information was presented to allow comparison of “… practice arrangements and income, assist with answering questions about the practice of podiatric medicine and physician income, and provide colleges of podiatric medicine with student loan indebtedness information so they may analyze student loans as a function of projected future income.”
- 2)
- On page 603, concerning the representativeness of respondents: “These analyses indicated that survey participants were not representative of the total membership.” And “… these findings lend further emphasis to the suggestion that the APMA exercise caution in extrapolating the results of the present survey to the entire membership.” According to the response rate and survey accuracy, “The results of the present survey should be interpreted with caution because of low response rate.”
Over the years, I have seen the results of these surveys used as gospel in telling the public, students, and practitioners what the status of the profession is. My concern is that inaccurate information is being presented, and that the status of income has been inflated. The study stated that younger members did not respond to the survey as frequently as older members. Since younger members tend to have lower incomes, I feel it is reasonable to conclude that the average or even median income is not as high as the survey says it is.
Hopefully, the information about the representativeness of respondents will be included with the survey results given to students, future students, and the general public.
When conducting a survey in the future, I believe a random sampling of the membership would be more accurate.
Author’s Response
Dear Editor:
Dr. Mertzenich’s comments on the survey results are well taken. I hope the following response addresses his comments:
- 1)
- The reference to the article on page 575 accurately reflects the fact that this survey provided unique information on student loan debt not previously available, and provided practice income data that were more recent and comprehensive than previous data.
- 2)
- Our statement that participants were not representative of the total membership is true, but again slightly strong. Some 47% responded in total, and the major problem involved the younger, less experienced members whose the response rate was only 19% (see Table 1, page 578).
- 3)
- Dr. Mertzenich is correct in his assertion that younger members have lower incomes than more experienced members (see Figure 4, page 599). Members with 0-2 years of experience averaged less than $45,000 in net income in 1995 compared with $108,356 for members with 6-9 years of experience.
- 4)
- Provision was made to compensate for the different response rates of experience subgroups when estimating the overall net income of members. Income data were deliberately weighted by experience to estimate the 1995 net income for all members combined ($108,156; Figure 4, page 599). This procedure, in effect, lowered the overall average to reflect the lower response rate from younger members with lower incomes.
- 5)
- The entire membership of the APMA was surveyed in 1996, ie, a “100% sample.” There was no attempt to exclude members or to bias the results in any direction. Indeed, the net income data are lower than they would have been had only members who practiced 30+ hours per week been surveyed, as was the case in the 1992 AACPM survey. Instead, the 1996 survey excluded only those members who categorized themselves as inactive in 1995, the reference year for income data collection.
Survey practitioners are acutely aware of the inherent dangers of reporting imperfect data that can be misinterpreted or used inappropriately, ie, to inflate the income expectations of trainees. If anything, I hope these data serve as a proper caution that student debt is a major, persistent problem (see Figure 1, page 582), and that high earnings require high patient volume (see Figure 2, page 591).
Allan H. Fisher, Jr, PhD
406 New Mark Esplanade Rockville, MD 20850-2735
© 1997 American Podiatric Medical Association