Use of Self-report Activities of Daily Living Questionnaires in Osteoarthritis

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1 Use of Self-report Activities of Daily Living Questionnaires in Osteoarthritis Raye H. Brooks, Leigh F. Callahan, and Theodore Pincus Self-report activities of daily living (ADL) questionnaires and traditional observer-reported physical measures were used to assess clinical status in a clinical trial involving patients with osteoarthritis (OA) of the knee. The observer-reported measures included pain on active motion, pain on passive motion, joint tenderness, joint swelling, joint crepitus, walking time, and observer global assessment. Self-report ADL questionnaires included scales to assess difficulty, dissatisfaction, and pain in eight activities of daily living, as well as a visual analog pain scale and patient global assessment. Significant correlations were seen between the observerreported physical measures and self-report questionnaire measures, indicating that both types of measures detect similar information. In comparisons made four weeks apart, changes in observer-reported physical measures and self-report questionnaire measures were also significantly correlated. Among the eight individual activities within the ADL scales, poorest status was reported for walking, and minimal problems were reported for the two activities involving use of the upper extremities, indicating criterion validity. Self-report ADL questionnaire measures appeared as sensitive as traditional observer-reported measures in detecting changes in clinical status over a four-week period. Self-reported ADL questionnaires appear valid, sensitive, and useful in assessment of clinical status in OA. Raye H. Brooks, BS, Leigh F. Callahan. BS, and Theodore Pincus, MD, are from the Division of Rheumatology and Immunology, Department of Medicine, l anderbilt University School of Medicine, Nashville, Tennessee. These studies lvere supported in part by the Jack C. Massey Foundation. the Robert L\ ood lohiison Foundation, the Arthritis Foundation, NIH General Clinical Research Centers grant /88i$3.50 Osteoarthritis (OA, degenerative joint disease, osteoarthrosis) is a widely prevalent condition [I]. Clinical status in OA has been assessed traditionally using a variety of observer-reported physical measures, including pain on motion, pain at rest, joint tenderness, joint swelling, joint crepitus, and walking time [Z]. The assessment of OA is complex, as the primary clinical problems are pain and loss of functional status, for which the data must be provided by the patient [3-6J. The introduction of questionnaires to assess pain [4-91 and functional capacity in activities of daily living (ADL) [3, has provided new approaches to objective assessment of clinical status in rheumatic diseases. Questionnaires have been found to provide valid and reliable indicators of clinical status. Responses to questions about functional status are predictive of morbidity and mortality in rheumatoid arthritis [17]. In a clinical trial in rheumatoid arthritis, changes in clinical status detected by questionnaires were found comparable to those detected using traditional physical measures [ 141. Most published reports concerning use of questionnaires in rheumatic diseases, as well as most clinical experience, have involved rheumatoid arthritis [ The possibility that questionnaires might be useful in assessment of clinical status in OA appeared attractive, particularly as observerreported physical measures frequently are un- 5M01RR-00095, Parke-Davis Division of Warner-Lambert Corporation, and SIH grant AM Address correspondence to Leigh F. Callahan, Medical Center North. Division of Rheumatology and Immunology. Department of Medicine, Vaiiderbilt University School of Medicine. Nashville, TN Submitted for publication September : accepted December 15, by the Arthritis Hcalth J rnfcssions Associatioil. 23

2 24 Brooks et a1 Vol. 1, No. 1, March 1988 changed from one visit to the next. We have recently incorporated a self-report questionnaire to assess difficulty, dissatisfaction, and pain in ADL into a pilot clinical trial to compare the efficacy of two salicylate preparations, Easprin and Zorprin, in the treatment of OA. In this report, we present results using ADL questionnaire measures and observerreported physical measures in assessing and monitoring OA. PATIENTS AND METHODS Patients During the period of October 1985 through February 1987, a study was conducted to evaluate two salicylate preparations, Easprin and Zorprin, in patients with OA of the knee. All patients seen in Vanderbilt University School of Medicine Rheumatology Clinic with OA of the knee were asked to participate in an eight-week open-label crossover study, if they were between the ages of 50 and 85, had radiographic Stage 2 or 3 OA, and had no major comorbidities. Fewer than five eligible patients declined to participate, generally because of difficulties with transportation. Twenty-two patients were entered into the study, of whom 18 completed a course of one medication and 12 two medications for evaluation. These 18 patients constitute the study population. Observer-reported Physical Measures of Patient Status Seven observer-reported physical measures were included in the protocol to assess OA disease activity [2]: pain on active motion, pain on passive motion, joint tenderness, joint swelling, joint crepitus, 50- foot walking time, and observer global assessment. Pain on active motion, pain on passive motion, joint tenderness, joint swelling, and joint crepitus were all assessed by an observer on a scale of 0 to 4, with 0 for no abnormal finding and 4 for most severe abnormality. The 50-foot walking time involved requesting that the patient walk at a normal pace over a measured 50-foot course [18, 191. An observerreported global assessment of OA of the knee was recorded on a scale of 0 to 10, with 0 representing optimal status and 10 poorest status. Self-report Questionnaire Measures of Patient Status Five self-report questionnaire measures were included: ADL difficulty scale, ADL dissatisfaction scale, ADL pain scale, visual analog pain scale, and patient global assessment scale for functional status [7, 9, 131. The ADL difficulty scale was scored according to the patient s responses to the question: Are you able to,.. [perform eight individual ADL]? Patients rated their capacities according to a four-point scale, analogous to American Rheumatism Association (ARA) functional class [20]: without any difficulty (= l), with some difficulty (=2), with much difficulty (=3), unable to do (=4). The total difficulty score is expressed as the mean score for the eight responses, with a range from 1 to 4 ~31. The ADL dissatisfaction scale was scored according to the patient s response to the question How satisfied are you with your ability to... [perform the same eight individual ADL]? The response options have been modified from the initial report [13] to include four options, as in the ADL difficulty and ADL pain scales: very satisfied (=I), some- what satisfied (= 2), somewhat dissatisfied (= 3), and very dissatisfied (=4). The total dissatisfaction score is the mean score for the eight activities, with a range of 1 to 4. The ADL pain scale included the same eight ADL used in the difficulty and dissatisfaction scales [7]. The patient was asked to respond to the question: How often is it painful for you to... [perform eight individual ADL]? Four response options are presented: never (=I), sometimes (=2), most of the time (=3), and always (=4). The total ADL pain score is the mean score for the eight responses [91. The visual analog pain scale used was a standard 10-cm horizontal scale [6, 9, 10, 21, 221. The patient was asked to indicate severity of pain by placing a mark between terminal points indicating no pain and pain as bad as it can be. The visual analog pain scale is scored from 0 (no pain) to 10 (pain as bad as it can be). Patients were asked to indicate a global assessment of their overall functional status by their response to the question: Which of the following best describes you today? The four response options were: I can do everything I want to do (= 1); I can do most of the things I want to do (=2); I can do some, but not all, of the things I want to do and have many limitations (=3); and I can do hardly any of the things I want to do (=4). Study Design The study design was approved after review by the Vanderbilt University Institutional Review Board for

3 Arthritis Care and Research ADL Self-reports in OA 25 the Protection of Human Subjects. The seven observer-reported physical measures and five selfreport questionnaire measures were recorded at baseline. The patient was then given a four-week supply of either Easprin or Zorprin in a randomized, open-label study, in which the patient and the observer were aware of which medication was being used. The patient was instructed to take two tablets in the morning and two in the evening. After four weeks, the patient was evaluted according to the same measures as had been recorded at baseline. The patient was then given a four-week supply of the other salicylate preparation in a crossover design; that is, if Easprin had been given the first four weeks, Zorprin was given for the next four weeks, or vice versa. After four weeks of use of the second medication, the observer-reported and self-report measures of clinical status were assessed a third time. The same assessor recorded all observer-reported measures at each of the three visits. Three patients were taking Zorprin and none were taking Easprin as their anti-inflammatory or analgesic medication prior to the study. All three patients who had been taking Zorprin were fortuitously randomized initially to Easprin. Therefore, all patients changed their medication at the inception of the study and at four weeks. Among the 18 patients evaluated, 12 completed four weeks of use of each medication, three completed four weeks of Easprin only, and three completed four weeks of Zorprin only. Statistical Methods The data were analyzed using the Statistical Package for the Social Sciences-X (SPSS-X) University of Chicago Version [23] software package. Mean levels at baseline were computed for all measures as well as for the eight individual activities on the ADL scales [9, 131. Pearson product moment correlation coefficients were computed between baseline values for each of the measures with one another. Differences over four weeks in each patient were calculated for each measure of disease status. Simple arithmetic differences were easily applicable to all measures other than the walking time and the visual analog pain scale. There were no established criteria to determine a meaningful change in these measures from one visit to the next. Therefore, prior to data analysis, it was arbitrarily decided that walking time would be considered unchanged if differences were less than one second from the previous recorded value, and the visual analog pain scale would be considered unchanged if differences were less than one centimeter from the previous recorded value. Changes in values over four weeks were computed for each measure to determine a change score. Correlations between change scores for each of the measures with one another were computed. Change scores over four weeks were initially analyzed separately for the 15 courses of Easprin and 15 courses of Zorprin. Patients using either drug showed essentially identical results. As the focus of this study involved the capacity of the various measures to depict changes in clinical status in OA, data for the 30 four-week courses were combined. RESULTS Baseline Measures The mean age of the study population was 65.6 years and mean duration of disease was 6.8 years (Table 1). Two-thirds of the patients were Caucasian, 50% were female, and only 27.3% were married. All 18 patients had pain on active motion, including six with scores of 2 and twelve with scores of 3, yielding a mean score of 2.33 (Table 1). All but one patient had pain on passive motion, with a mean score of All but one patient had joint tenderness, with a mean score of Eight of the 18 patients had joint swelling, with a mean score of Joint crepitus was found in all but one patient, with a mean score of The mean value for 50-foot walking time was 20 seconds, with a range of 10.2 to 57.4 seconds. The mean value for observer global assessment was 5.11 on a scale of 0 for best status to 10 for poorest status. All 18 patients reported some problem on the three ADL scales for difficulty, dissatisfaction, and pain (Table 1). The mean score for the ADL difficulty scale was 1.60, for the ADL dissatisfaction scale is 1.71, and for the ADL pain scale 1.96, on a scale of 1 for no problem to 4 for maximal difficulty, dissatisfaction, or pain. Visual analog pain scores were abnormal in all patients, with a range of 2 to 9 and a mean level of 4.61 on a scale of 0 to 10. In global self-report of functional status, only one patient indicated no limitations, and none indicated incapacitated status; the mean level of self-report global assessment was 2.11 on a scale of 1 to 4. Responses regarding the eight individual activities on the ADL self-report scales were analyzed to better characterize the content validity of these scales

4 ~~ 26 Brooks et aj. Vol. 1, No. 1, March 1988 TABLE 1 Mean Values in Patients with Osteoarthritis of the Knee* Number of Patients with No Abnormality Possible Range Mean Range or Problems Demographic Measures Age (yr) Duration of disease (yr) %) White % Married % Female Observer-Reported Physical Measures Pain on active motion Pain on passive motion Joint tenderness Joint swelling Joint crepitus 50-fOOt walking time Observer global assessment Patient Self-report Questionnaire Measures ADL difficulty scale ADL dissatisfaction scale ADL pain scale Visual analog pain scale Patient global assessment * Clinical status was assessed at baseline for comparison with results four and eight weeks later in 18 patients with osteoarthritis of the knee. (Table 2). The highest scores, indicating poorest clinical status, were reported for the activity of walking on flat ground. Only three patients reported no difficulty, two no dissatisfaction, and one no pain in walking. Progressively lower scores, indicating better clinical status, were reported for bending to pick things up from the floor, getting in and out of a car, getting in and out of bed, dressing oneself, and washing and drying of the body. Most patients reported no problems for the two activities involving essentially only upper extremity function, turning faucets on and off, and lifting a cup to the mouth. Scores among the three scales for each individual activity were generally highest on the pain scale, TABLE 2 Mean Baseline Values in Patients with Osteoarthritis of the Knee for Individual Activities of Daily Living* ADL Difficulty Scale ADL Dissatisfaction Scale ADL Pain Scale Number of Number of Number of Patients with Patients lvith Patients lvith Mean Normal Values Mean Normal \'slues hlean Normal Values Dress oneself 1.33 ( (13) 1.72 (91 In and out of bed ) 1.56 ( (61 Cup to mouth 1.06 (17) 1.06 ( (18) Walk on flat ground 1.94 ( ( (1) Wash and dry body ( (11) Bend to pick up 1.78 ( ( (51 Faucets on and off 1.22 ( ) 1.33 (131 In and out of car 1.78 (5) 1.89 (7) 2.06 (4) * The range of scores for activities of daily living scales is 1 to 1. with 1 indicating normal status and 1 the poorest status. Total numhcr of patients was 18.

5 Arthritis Care and Research ADL Self-reports in OA 27 intermediate on the dissatisfaction scale, and lowest on the difficulty scale, as was seen in patients with rheumatoid arthritis [9]. Correlations at Baseline Between Self-report and Observer-Reported Measures Significant correlations were seen between many of the observer-reported physical measures at baseline, as expected (Table 3). Pain on active motion scores were significantly correlated with walking time and observer global assessment values. Joint tenderness scores were significantly correlated with walking time. Walking time was significantly correlated with observer global assessment values. There were also significant correlations between various self-report questionnaire measures (Table 3). ADL difficulty scale scores were significantly correlated with ADL pain scale scores, although at lower levels than seen in rheumatoid arthritis. ADL pain scale scores were significantly correlated with visual analog pain scale scores and patient global assessment values. In data not depicted in Table 3, pain on passive motion scores were significantly correlated with pain on active motion and joint crepitus scores, and observer global assessment values. Joint swelling scores were significantly correlated with joint tenderness scores but not with values for other measures, possibly because 10 of the 18 patients did not have joint swelling (see Table 1). Joint crepitus scores were significantly correlated with scores for pain on active motion and pain on passive motion, as well as with observer global assessment values. ADL dissatisfaction scale scores were correlated with ADL difficulty scale scores, ADL pain scale scores, and patient global assessment values. Many significant correlations were seen between observer-reported physical measures and patient self-report questionnaire measures (Table 3), notably between ADL difficulty score and ADL pain score with pain on active motion scores. The walking time was also significantly correlated with ADL difficulty and pain scale scores, as well as with patient global assessment values. Observer global assessment values were significantly correlated with ADL pain scale and visual analog pain scale scores. The correlations between the different measures indicate that most appear to be measuring the same phenomenon, although joint tenderness appears to be an exception in being poorly representative of other available measures. Pain on active motion, walking time, and the ADL difficulty and pain scales appear the most broadly representative of all measures studied. The strength of the correlations (r = 0.3 to 0.7) indicates that each measure can account for less than half of the variation of another measure. The correlation between scores for pain on active motion and the ADL pain scale showed the highest correlation (r = 0.77) among all measures. TABLE 3 Correlations Between Observer-Reported Physical Measures and Self-report Questionnaire Measures in Patients with Osteoarthritis of the Knee* Observer-Reported Measures Self-report Measures Obsenrer ADL Pain on Joint \\'alking Global Difficulty ADL \'isual Analog Acti1.e Motion Tenderness Time Assessment Scale Pain Scale Pain Scale ~ Observer-Reported Measures Joint tenderness 0.39 ~ il'alking time 0.62* 0.44t - Obseriw global assessment 0.60* 0.22 O.53t - Self-report Measures ADL difficulty scale 0.61* ADL pain scale 0.77s * O.43t \'isual analog pain scale t 0.28 O.4St ~ Patient global assessment * O.4Zt 0.17 * Correlations are depicted between various observer-reported measures (upper left]. various sr:li-rt.prirt c1ut:sttionnnirt. IiiPdsures (lnxvcv right). ;Ind observer-reported measures md self-report questionnaire measures (icithin box at bottrini]. t P < * P i s P i

6 28 Brooks et al. Vol. 1, No. 1, March 1988 Values of correlations between observer-reported physical measures and self-report questionnaire measures were generally in the same range as values of correlations found between only observerreported physical measures and those between only self-report questionnaire measures. These findings, together with the intuitively reasonable hierarchy among the individual activities within the ADL scales shown in Table 2, indicate content validity for self-report questionnaire measures in the assessment of OA. Assessment of Changes in Clinical Status Over Four Weeks Changes in clinical status over four weeks while patients took either Easprin or Zorprin were analyzed according to the seven observer-reported physical measures and five patient self-report questionnaire measures. Thirty comparisons were available for the 18 patients, including 15 for patients taking Easprin and 15 for patients taking Zorprin over four weeks. As noted above, results were almost identical for patients taking Easprin or Zorprin, and the two data sets were pooled for analysis. In general, about twice as many patients who showed a change in clinical status over the four weeks showed improvement rather than deterioration according to most measures (Table 4). Most comparisons involving observer-reported physical measures indicated the same status at baseline and four weeks later. Pain on active motion remained the same in 73% of patients, pain on passive motion in 63%, joint tenderness and joint swelling in 73%, and joint crepitus in 90% of patients. Only the walking time and observer global assessment were changed in (slightly) more than half of the patients over the four-week period. There was a greater likelihood that a quantitative change in status would be seen over the four-week observation period according to the self-report questionnaire measures (Table 4). Again, about twice as many patients showed evidence of better clinical status than poorer status. The ADL difficulty scale score remained unchanged in 25% of comparisons, the dissatisfaction scale score in 17%, and the ADL pain scale score in only 13%. The visual analog pain scale score was unchanged (that is, within one unit of baseline) in 32% of cases. Patient global assessment was unchanged in 72% of cases, in the range of most observer-reported physical measures. Analyses of changes in scores among the eight individual items within the ADL scales indicated that walking was the single activity most likely to show reported change over four weeks (Table 5). Scores for walking on the ADL difficulty scale were unchanged in 56% of comparisons, scores for dissatisfaction unchanged in 41%, and scores for pain unchanged in 50%. Thus, scores for this single response showed changes in the same range as the highest level of changes among observer-reported measures. The proportion of patients who reported change for other ADL was lower, in an order similar to that seen for the degree of problems at baseline (see Table 2). The two upper extremity activities were least changed, generally reported as normal TABLE 4 Changes Over Four Weeks in Observer-Reported Physical Measures and Patient Self-report Questionnaire Measures in Osteoarthritis of the Knee % Poorer Status % Unchanged Status % Improved Status Observer-Reported Physical Measures Pain on active motion Pain on passive motion Joint tenderness Joint swelling Joint crepitus Walking time Observer global assessment Patient Self-report Questionnaire Measures ADL Difficulty Scale ADL Dissatisfaction Scale ADL Pain Scale Visual analog pain scale Patient global self-assessment

7 Arthritis Care and Research ADL Self-reports in OA 29 TABLE 5 Changes over Four Weeks in Individual Items Within ADL Questionnaire in Patients with Osteoarthritis of the Knee Poorer Status % Unchanged Status O/O Improved Status ADL Difficulty Scale a. Dress oneself b. In and out of bed c. Cup to mouth d. Walk on flat ground e. Wash and dry body f. Bend to pick up g. Faucets on and off h. In and out of car ADL Dissatisfaction Scale a. Dress oneself b. In and out of bed c. Cup to mouth d. Walk on flat ground e. Wash and dry body f. Bend to pick up g. Faucets on and off h. In and out of car ADL Pain Scale a. Dress oneself b. In and out of bed c. Cup to mouth d. Walk on flat ground e. Wash and dry body f. Bend to pick up g. Faucets on and off h. In and out of car both at baseline and four weeks later. These data agah indicate that the ADL questionnaires show criterion validity-that is, differences are most marked for expected activities and least for activities in which they would be unexpected. Correlations were analyzed between change scores, between the magnitude of changes over four weeks for two measures, and for various observerreported physical measures and self-report questionnaires [Table 6). As might be expected, correlations between change scores were generally lower than those seen for baseline measures in Table 3. Nonetheless, almost all correlations were positive-that is, changes in one measure were accompanied by changes in the same direction for another measure, and some were notably high, particularly those involving scores for pain on motion, walking time, the ADL pain scale, and the visual analog pain scale. A curious exception to the positive correlations involved change scores for patient global assessment values, which were poorly correlated with changes in other measures except for ADL pain scale scores. Joint tenderness scores and observer global assess- ment values did not appear as representative as pain on motion scores and walking times among the observer-reported measures. Changes in the ADL and visual analog pain scale scores were more highly correlated with changes in other measures than changes in ADL difficulty scale scores. DISCUSSION These data indicate that ADL self-report questionnaires appear useful to assess and monitor clinical status in OA. At baseline, ADL self-report questionnaire scores were correlated significantly with values for many observer-reported measures, particularly with values for pain on active motion, walking time, and observer global assessment. Changes over four weeks in self-report scores were correlated with changes in values for observer-reported measures. Many of the correlations were surprisingly high, depicting changes not only in the same direction, but of similar magnitude, in two measures over the four-week period.

8 ~ 30 Brooks et al. Vol. 1, No. 1, March 1988 TABLE 6 Correlations Between Change Scores for Observer-Reported Physical Measures and Self-report Questionnaire Measures in Patients with Osteoarthritis of the Knee Over Four Weeks* Observer-Reported Measures Self-report Measures Observer ADL Pain on Joint Walking Global Difficulty ADL Visual Analog Active Motion Tenderness Time Assessment Scale Pain Scale Pain Scale Observer-Reported Measures Joint tenderness Walking time Observer global assessment Self-report Measures ADL difficulty scale ADL pain scale Visual analog pain scale Patient global assessment 0.57* $ * * 0.32t * $ * Correlations are depicted between various observer-reported measures (upper left]. various self-report questionnaire measures (lower right]. and observer-reported measures and self-report questionnaire measures (within box at bottom] t P < * P i s P < Overall, analyses of self-report and observerreported measures indicated that two to four times as many patients showed improved status versus poorer status over four weeks while taking a salicylate drug. However, most observer-reported values were unchanged in the majority of patients over the four-week period. By contrast, most ADL self-report questionnaire scale scores were changed over four weeks. The finding that self-report scores are more likely to differ over a four-week period than physical measures could be interpreted in one of two ways: 1. The ADL self-report questionnaire measures are at least as sensitive to changes in clinical status as the observer-reported measures. 2. The self-report questionnaire measures are less stable than observer-reported physical measures, yielding more measurement variation ( noise ) not necessarily indicative of real changes in clinical status. Although the absence of a gold standard in OA renders it impossible to discriminate absolutely between these two possibilities, there does appear to be strong evidence that differences in self-report scores result from real changes in patient status rather than from measurement variation. The content validity of the ADL questionnaires is evident from several types of analyses, including the following: Significant correlations were seen between baseline self-report and physical measures. Significant correlations were seen between changes over four weeks in these two types of measures. The finding at baseline that the question regarding walking indicated poorest status, whereas questions regarding hand functions in patients with OA of the knee indicated essentially normal status. The fact that the highest levels of improvement were seen for walking, whereas the questions involving hand activities were essentially unchanged (from normal values) over four weeks. These findings would argue strongly against a suggestion that changes in status seen in self-report reflect only measurement error. On the contrary, differences in questionnaire scores appear to reflect real changes rather than noise. It is recognized, nonetheless, that some level of measurement error is associated with self-report, as is the case for all measures in clinical medicine [24]. Data provided by patients are generally regarded as subjective [25], with the implication that such data are likely to have lower reliability (reproducibility) than data derived from physical, radiographic, and laboratory sources. However, recent re-

9 Arthritis Care and Research ADL Self-reports in OA 31 search indicates that self-report questionnaires provide data that appear as reliable as, and often more reliable than, traditional nonpatient-derived measures [14, 161, provided an appropriate format and procedure are used. The observer-reported physical measures of pain on active motion, walking time, and observer global assessment appeared more representative of overall clinical status than other physical measures such as pain on passive motion, joint tenderness, joint swelling, and joint crepitus. Most patients did not show detectable changes over four weeks in scores for pain on active motion, pain on passive motion, joint tenderness, joint swelling, and joint crepitus, although these measures are often included for serial recording in many protocols to assess OA. Only walking time and observer global assessment were changed in about half the patients. The results suggest that measures of pain on active motion, walking time, and observer global assessment are likely to be useful in clinical studies, but little would be lost by omitting pain on passive motion, joint tenderness, joint swelling, and joint crepitus from serial assessment. This study indicates that newer self-report questionnaire methods for assessment have been incorporated to advantage into a standard clinical trial. The findings suggest that such questionnaires might be considered for inclusion in other clinical trials and studies designed to monitor the course of OA. Inclusion of questionnaires could lead to reduction of labor-intensive activity on the part of observers to record measures unlikely to yield meaningful data. Self-report questionnaires may further provide greater sensitivity to changes in clinical status than appears available from traditional observer-reported measures. We thank Drs. Robert Davis, Jean Rowan, and Robert Buchanan at Warner-Lambert, as well as Drs. Howard Fuchs and Nancy Olsen at Vanderbilt for helpful discussions, Ginnie Farley and Carolyn Burnette for assistance in the data processing, and Marilyn LVelch-Fava for editorial help in preparation of the manuscript. REFERENCES 1. Brandt KD: Treatment of osteoarthritis. In McCarty DJ (ed): Arthritis and Allied Conditions, loth ed. Philadelphia, Lea & Febiger, Moskowitz RW: Osteoarthritis-Symptoms and signs. In Moskowitz RW, Howell DS. Goldberg VM, imankin HJ (eds), Osteoarthritis Diagnosis and Management. Philadelphia, Saunders, Katz S, Downs TD, Cash HR: Progress in development of an index of ADL. Gerontologist 10:20-30, Melzack R: The McGill pain questionnaire: Major properties and scoring methods. Pain 1: , Bradley LA, Prokop CK, Gentry WD, et al: Assessment of chronic pain. In Prokop CK, Bradley LA (eds): Medical Psychology: Contributions in Behavioral Medicine. New York, Academic Press, Huskisson EC: Measurement of pain. J Rheumatol 9: , Kazis LE, Meenan RF, Anderson JJ: Pain in the rheumatic diseases: Investigation of a key health status component. Arthritis Rheum 26: , Burckhardt CS: The use of the McGill pain questionnaire in assessing arthritis pain. Pain 19: , Callahan LF, Brooks RH, Summey JA, Pincus T: Quantitative pain assessment for routine care of rheumatoid arthritis patients, using a pain scale based on activities of daily living and a visual analog pain scale. Arthritis Rheum 30: , Fries JF, Spitz P, Kraines RG, Holman HR: Measurement of patient outcomes in arthritis. Arthritis Rheum , Meenan RF, Gertman PM, Mason JH: Measuring health status in arthritis: The arthritis impact measurement scales. Arthritis Rheum 23: , Liang M, Jette A: Measuring functional ability in chronic arthritis. Arthritis Rheum 24:80-85, Pincus T, Sumney JA, Soraci SA, et al: Assessment of patient satisfaction in activities of daily living using a modified Stanford Health Assessment Questionnaire. Arthritis Rheum 26: , Meenan RF, Anderson JJ, Kazis LE, et al: Outcome assessment in clinical trials: Evidence for the sensitivity of a health status measure. Arthritis Rheum , Liang MH, Larson MG, Cullen KE, et a]: Comparative measurement efficiency and sensitivity of five health status instruments for arthritis research. Arthritis Rheum 28: , , Meenan RF, Pincus T: The status of patient status measures. J Rheumatol 14: , Pincus T, Callahan LF, Vaughn WK: Questionnaire, walking time and button test measures of functional capacity as predictive markers for mortality in rheumatoid arthritis. J Rheumatol 14: , DeCeulaer K, Dick WC: The clinical evaluation of antirheumatic drugs. In Kelley WN, Harris ED Jr, Ruddy S, Sledge CB (eds): Textbook of Rheumatology. Philadelphia, WB Saunders, 1981, Pincus T, Callahan LF, Brooks RH: Quantitative nonlaboratory measures to monitor and predict the course of rheumatoid arthritis. In Ehrlich GE (ed): Rehabilitation hfanagement of Rheumatic Conditions 2nd ed. Baltimore, Williams & Wilkins, 1986, Steinbrocker 0, Traeger CH, Batterman RC: Therapeu-

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