Factors affecting medical decision-making in patients with osteoarthritis of the hip: allocation of surgical priority.

Purpose: The purpose was to determine (1) how well doctors' assessments of patients matched the patients'own self assessments and (2) what doctors looked for in terms of patient factors (such as pain and dysfunction, radiographic evidence) that influenced their decisions to allocate priority for hip replacement.

Method: Data collected independently from patients and surgeons after consultation were used to investigate medical decision-making. Patients were 74 consecutive patients who were offered total hip replacement in an orthopaedic outpatient department at a single hospital. Main measures were (1) assignment to priority group; (2) surgeons' ratings of patient pain, function, stoicism and predicted benefit; (3) patients' pain ratings, function (Arthritis Impact Measurement Scale) and timed walk, and predicted benefit; (4) hip radiographs were assessed independently using composite grading scores.

Results: Surgeon- and patient-rated current pain and function were reasonably correlated; predicted benefit from surgery in pain and function were not, although surgeons predicted greater benefit. High priority for surgery was associated with higher surgeon-rated patient pain and function, by higher pain ratings by patients, more severe radiographic abnormalities, by being female and over 70. Some patients with relatively low pain scores and low levels of dysfunction were offered hip replacements.

Conclusions: Doctors made reasonable estimates of patients' pain and function by direct history taking and examination. There was no systematic underestimation of patients' pain, in contrast to previous studies. Doctors' estimate plus radiological changes account for most of the priority differences. Patients' and surgeons' expectation of improvement, relatively unrelated to severity of pain and dysfunction, in the absence of agreed minimal clinical criteria, may drive surgical demand. There was a wide range in measures of pain and function. Introduction of formal measurement of pain and function, and setting formal clinical criteria, could assist medical decision-making.