Appendix 1. Differences in Demographic Characteristics Between Respondents and Non-Respondents to the Practice Demographic Survey (PDS) Survey Over Time.
RespondentNon-RespondentP Value
201910,75718,948
Mean Age in years51.84 (9.52)53.97 (9.92)<.0001
Female gender4,659 (43.3%)7,946 (41.9%)0.1094
MD9,645 (89.7%)17,254 (91.1%)0.0002
International Medical Graduate1,841 (17.4%)3,571 (19.1%)0.0003
Under Represented in Medicine1,497 (14.1%)2,451 (13.6%)0.2569
20207,16321,491
Mean Age in years51.41 (9.93)52.01 (10.28)<.0001
Female gender3,218 (44.9%)9,495 (44.2%)0.3359
MD6,387 (89.2%)19,236 (89.5%)0.4168
International Medical Graduate1,344 (19.1%)4,887 (23.1%)<.0001
Under Represented in Medicine1,011 (14.4%)3,479 (16.8%)<.0001
20216,03317,880
Mean Age in years51.92 (10.01)52.14 (10.53)0.1869
Female gender2,721 (45.1%)8,036 (44.9%)0.1869
MD5,318 (88.1%)15,869 (88.8%)0.2016
International Medical Graduate1,246 (20.9%)3,995 (22.6%)0.0164
Under Represented in Medicine802 (13.5%)2,574 (14.9%)0.0215
202210,34921,158
Mean Age in years54.38 (9.92)53.45 (10.74)<.0001
Female gender4,587 (44.3%)9,427 (44.6%)0.4439
MD9,264 (89.5%)18,840 (89.0%)0.3080
International Medical Graduate2,210 (21.7%)4,193 (20.0%)0.0015
Under Represented in Medicine1,463 (14.3%)3,044 (14.6%)0.4439
20239,56720,771
Mean Age in years53.05 (10.13)52.08 (10.66)<.0001
Female gender4,448 (46.5%)9,678 (46.6%)0.0359
MD8,433 (88.1%)18,289 (88.1%)0.8103
International Medical Graduate2,341 (24.9%)4,723 (23.1%)0.0008
Under Represented in Medicine1,648 (17.4%)3,351 (16.5%)0.0633
20247,92818,430
Mean Age in years53.21 (10.49)51.83 (11.00)<.0001
Female gender3,653 (46.1%)8,781 (47.6%)0.0496
MD6,930 (87.4%)15,931 (86.4%)0.0496
International Medical Graduate1,899 (24.3%)4,283 (23.5%)0.1987
Under Represented in Medicine1,217 (15.6%)2,803 (15.5%)0.9334

Although there were some significant year-to-year differences, there was no consistent pattern of bias in the PDS respondents.