Variability in physician opinions about the indications for knee arthroplasty.

To determine how much of variability in physician opinion about the indications for knee arthroplasty is due to inconsistency in individual physicians' opinions. We surveyed 201 orthopedic surgeons, 141 rheumatologists, and 455 family physicians. Physicians were asked how 34 patient characteristics affected their decision to perform or refer for knee arthroplasty. Surgeons and referring physicians agreed on how 4 and 2 of 34 patient characteristics affected their decision about knee arthroplasty, respectively. Half of the variability in opinion among physicians could be accounted for by inconsistency in their individual responses to the survey 6 weeks apart (mean intraclass correlation coefficient = 0.49). Although surgeons and referring physicians vary in their opinion, half of the variability could be attributed to individual physician inconsistency.