Abstract
The purpose of this study was to compare patients' and physicians' evaluations of the results of 147 total hip arthroplasties. The patients and physicians independently evaluated pain and over-all satisfaction with the outcome of the procedure using a 10.0-centimeter visual-analog scale. They also answered a questionnaire with which they assessed general health, functional ability, and pain.The mean (and standard deviation) analog rating for pain (with 0.0 centimeters indicating no pain and 10.0 centimeters, severe pain) was 1.7 ± 2.6 centimeters as assessed by the patients and 1.1 ± 1.8 centimeters as assessed by the physicians (p < 0.001, paired t test). The mean analog rating for over-all satisfaction (with 0.0 centimeters indicating poor and 10.0 centimeters, excellent) was 8.6 ± 2.1 centimeters as assessed by the patients and 8.8 ± 1.7 centimeters as assessed by the physicians (p = 0.07, paired t test). There was a marked disparity between the patients' and the physicians' scores when the patients assigned a low score to a particular area. For the thirty patients who rated the pain as more than 4.0 centimeters, the mean analog rating was 6.8 ± 2.1 centimeters according to the patients, while it was 3.6 ± 2.7 centimeters according to the physicians (p < 0.001, linear regression). The mean analog rating for over-all satisfaction according to the nineteen patients who rated this parameter as less than 7.0 centimeters was 3.8 ± 2.0 centimeters, while the mean rating according to the physicians was 6.5 ± 2.8 centimeters (p < 0.001, linear regression). The patients' and physicians' evaluations were similar regarding the results of the total hip arthroplasty when the patients had little or no pain and were satisfied with the result. However, the disparity increased as the patients' ratings for pain increased and their ratings for over-all satisfaction decreased.This study highlights a discrepancy between patients' and physicians' evaluations of the results of total hip arthroplasty. This discrepancy increased when the patient was not satisfied with the outcome. The use of patients' self-administered questionnaires as well as traditional physician-generated assessments may provide a more complete evaluation of the results of total hip arthroplasty.
Traditional methods for the evaluation of the results of a total hip arthroplasty are based on the physician's assessment of the pain and functional ability of the patient. The patient's assessment of the results generally has not been a part of this evaluation. It has been assumed that physicians' evaluations are both accurate and reproducible, but we know of one study1 in which their assessments of various operative procedures have been compared with the patients' assessments. It has also been assumed that physicians and patients concur with regard to the degree of success of the total hip arthroplasty. The purpose of this study was to compare physicians' and patients' evaluations of the results of total hip arthroplasty. The data suggest that a combination of traditional methods of assessment by physicians of patients and patients' self-administered questionnaires will enhance the ability to care for patients who have had a total hip arthroplasty.
*No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study.
†Department of Orthopaedic Surgery, CHS 76-134, University of California at Los Angeles Medical Center, 10833 Le Conte Avenue, Los Angeles, California 90095.
‡Veterans Affairs Health Services Research and Development Service, Department of Medicine, West Los Angeles Veterans Administration Center, 11301 Wilshire Boulevard, Los Angeles, California 90073.
The study group consisted of a consecutive series of 147 patients (147 hips) who were returning for routine follow-up after a total hip arthroplasty that had been performed at the University of California at Los Angeles Medical Center. Both the patients and the physicians evaluated the result of the total hip arthroplasty. The patients completed the evaluation in the waiting area before they saw the physician. Although the physician who performed the operation was aware that the patient was evaluating the result of the total hip arthroplasty, the patient's evaluation was not available for the physician to review. The physician-evaluation forms were completed by the physician who performed the operation or by a resident under the physician's supervision (twenty-eight patients) immediately after completion of the office visit.
The physicians and patients independently evaluated pain and over-all satisfaction with the outcome of the procedure using a 10.0-centimeter visual-analog scale (a ten-centimeter-long horizontal line with 0.0 centimeters indicating no pain or poor satisfaction and 10.0 centimeters indicating severe pain or excellent satisfaction). They also answered a Likert-type questionnaire that provided ordered categorical responses (none, mildly, moderately, extremely, or totally) to assess general health, pain, and functional ability as of the day of the evaluation. Neither the patients nor the physicians were provided with definitions or instructions regarding how to generate the responses to the questionnaire. The patients were also asked to assess their present level of activity as light, moderate, or heavy. Light activity was defined as walking and light housework. Moderate activity was defined as vigorous walking, unlimited housework, or low-impact sports such as golf. Heavy activity was defined as strenuous housework and impact sports such as tennis, jogging, and skiing.
The patients were also asked for their perceptions of their over-all general health, the impact of the total hip arthroplasty on their quality of life, and their functional independence. Finally, the patients were asked if their expectations for the procedure had been met.
All patients who had been followed for a minimum of six months were included in the study. The mean age of the sixty-five male and eighty-two female patients was fifty-four years (range, seventeen to eighty-six years). The mean duration of follow-up was forty-nine months (range, six to 258 months). Fifty-four patients had been followed for less than twenty-four months; fifty-four, for twenty-four to fifty-nine months; twenty-seven, for sixty to 120 months; and twelve, for more than 120 months. There were 110 primary total hip arthroplasties and thirty-seven revisions. The primary diagnosis was osteoarthrosis in eighty-eight patients (60 per cent), rheumatoid arthritis in twenty-one (14 per cent), avascular necrosis in nineteen (13 per cent), congenital dysplasia of the hip in seven (5 per cent), post-traumatic osteoarthrosis in four (3 per cent), and various other diagnoses in eight (5 per cent).
Statistical Analysis
The patients' and physicians' scores on the visual-analog scale were compared with use of the paired t test. The relationship between the mean scores on the analog scale according to the patients and the differences in the scores given by the patients and the physicians were studied with linear regression analysis. The responses of the patients and the physicians to the questionnaire were compared with use of the McNehmar test2.
Demographics
At the time of this assessment, ninety-one patients (62 per cent) were married, twenty-four (16 per cent) were widowed, sixteen (11 per cent) were divorced, thirteen (9 per cent) were single, and three (2 per cent) were separated. Fifty-seven patients (39 per cent) were employed outside the home, fifteen (10 per cent) were homemakers, and seventy-five (51 per cent) were retired. Sixteen patients (11 per cent) had limited activity, 127 (86 per cent) considered their level of daily activity to be moderate or light, and only four (3 per cent) considered their level of activity to be heavy. Fifty-one patients (35 per cent) participated in sports activities or exercised at least once a week.
Patients' Perceptions
One hundred and eighteen patients (80 per cent) thought that their general health was good, very good, or excellent. One hundred and twenty-eight (87 per cent) indicated that their two most important expectations had been met with regard to the total hip arthroplasty. One hundred and five patients (71 per cent) thought that the operation had substantially improved their quality of life, and 110 patients (75 per cent) thought that they were somewhat or substantially more independent than before the operation.
Analysis of Analog Scales
The mean (and standard deviation) analog rating for pain was 1.7 ± 2.6 centimeters as assessed by the patients and 1.1 ± 1.8 centimeters as assessed by the physicians (p < 0.001, paired t test). The mean analog rating for over-all satisfaction was 8.6 ± 2.1 centimeters as assessed by the patients and 8.8 ± 1.7 centimeters as assessed by the physicians (p = 0.07, paired t test).
The disparity between the patients' and the physicians' evaluations increased as the patients' analog rating for pain increased and their satisfaction decreased. Ninety-three patients rated the pain as less than 1.0 centimeter (no or slight pain); their mean score was 0.2 ± 0.3 centimeter, compared with 0.4 ± 0.6 centimeter as assessed by the physicians. Twenty-four patients rated the pain as 1.0 to 4.0 centimeters; their mean score was 2.2 ± 0.8 centimeters, compared with the physicians' rating of 1.4 ± 1.7 centimeters. Pain was given a score of more than 4.0 centimeters by thirty patients; their mean score was 6.8 ± 2.1 centimeters, compared with 3.6 ± 2.7 centimeters according to the physicians. This association reveals that, as the patients' rating for pain increased, the discrepancy between their rating and that of the physicians also became greater (p < 0.001, linear regression).
A similar trend was noted regarding the analog rating for over-all satisfaction. The ninety-six patients who rated their satisfaction as 9.0 to 10.0 centimeters (excellent) had a mean score of 9.7 ± 0.3 centimeters, which differed little from the mean score of the physicians (9.3 ± 0.9 centimeters). Thirty-two patients rated their satisfaction as 7.0 to 8.9 centimeters; their mean rating was 8.0 ± 0.6 centimeters, compared with 8.7 ± 1.3 centimeters as assessed by the physicians. The nineteen patients who rated their satisfaction as less than 7.0 centimeters had a mean rating of 3.8 ± 2.0 centimeters, compared with the physicians' mean score of 6.5 ± 2.8 centimeters. Thus, when the patients' rating for over-all satisfaction decreased, the difference between their rating and that of the physicians increased (p < 0.001, linear regression).
Neither the analog ratings for pain (p = 0.19, one-way analysis of variance) nor those for over-all satisfaction (p = 0.49, one-way analysis of variance) were influenced by the duration of follow-up. The differences between the physicians' and patients' analog ratings for over-all satisfaction (p = 0.39, Student t test) and for pain (p = 0.28, Student t test) were not influenced by the type of total hip arthroplasty (primary or revision).
The physicians tended to assign better ratings than the patients did with regard to general health, walking ability, pain in the thigh, and improvement in the quality of life (Table I). There was also a difference between the patients' rating of pain in the hip and that of the physicians, but it was not significant (p = 0.15).
Over the years, many hip-rating scales have been devised to evaluate the results of total hip arthroplasty. These scoring systems generally were used to evaluate pain and function, and the results were then tabulated by the physician. The present study suggests that physicians and patients may differ in their assessment of the degree of pain and the over-all outcome, especially when the patient is not completely satisfied with the result.
The present study included all patients who had been followed for at least six months after a primary or revision total hip arthroplasty at our institution. In general, studies of the results of total hip arthroplasty are performed after at least two years of follow-up because it is assumed that most total hip arthroplasties will be performing well by this time. For the present study, in which we compared patients' and physicians' evaluations of the result of the total hip arthroplasty, it seemed reasonable to include all patients who had been followed for at least six months. By six months, patients usually have completed physical therapy and are quite active. In addition, most patients consider the hip to have recovered fully by this time4.
Physicians and patients may have different expectations after an operative procedure. The physician may consider a revision total hip arthroplasty to be extremely successful even if the patient has some pain or has a limited level of activity. The physician takes into consideration the number of previous procedures, the quality of the soft tissue and the bone stock, and the age and over-all medical condition of the patient. However, the patient may not be satisfied with anything less than a pain-free hip and may also have unrealistic expectations with respect to the level of activity. However, the differences in this study between the patients' and the physicians' analog ratings for pain and over-all satisfaction with the outcome were not influenced by the duration of follow-up or by whether the operative procedure was a primary or revision total hip arthroplasty. This suggests that orthopaedic surgeons must try to educate patients better with regard to realistic expectations. In addition, the patient's evaluation of the result of the total hip arthroplasty is necessary to attain a more global assessment of the results of the procedure.
In general, orthopaedic surgeons have presumed that they can judge the patient's quality of life after, or the success or failure of, an operative procedure. However, a review of the literature suggests that it may be difficult for the treating physician to analyze the outcome of a particular therapeutic intervention objectively. Haworth et al. compared the evaluations of pain, walking, and function by research occupational therapists with those by physicians after seventy-one total hip arthroplasties. When there was a major disagreement in the ratings between the physicians and the occupational therapists, the physicians assigned better ratings to all three parameters. This finding is in agreement with our data, which also demonstrated that the physicians' ratings of general health, walking ability, pain in the thigh, and improvement in the quality of life tended to be better than those of the patients themselves.
In a study of seventy-five patients who had been managed for hypertension, Jachuck et al. reported that the physicians recorded an improvement in the control of blood pressure for all patients, with no side effects. In contrast, only 48 per cent of the patients thought that they had no side effects and 8 per cent actually felt worse after treatment. In a study comparing physicians' and patients' evaluations of the quality of life of patients who had advanced cancer, Slevin et al. concluded that physicians could not make this assessment adequately.
There are several possible explanations for differences between patients' and physicians' evaluations. First, physicians and patients may have different expectations with regard to the results of the procedure. Second, physicians and patients may have a different definition of what constitutes an excellent outcome. Third, patients may not state their problems clearly for fear of disappointing the physician. Fourth, even if the patients state their problems clearly, the physician still may not comprehend the true nature of the pain and the patient's level of dissatisfaction. Finally, the patient's assessment of the total hip arthroplasty may be influenced by the quality of the patient-physician relationship. Our data do not allow us to estimate the relative contributions of these explanations to the differences that we observed. Additional studies are needed for this purpose.
Patients and physicians may evaluate the results of a total hip arthroplasty from different perspectives, and this may influence their assessment of the success of the procedure. Traditional evaluations of the outcome of total hip arthroplasty have emphasized the physician's assessment of pain and functional status. This study highlights discrepancies between patients' and physicians' evaluations and emphasizes the need to include questionnaires that patients administer to themselves in a complete assessment of the results of total hip arthroplasty.
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