Papers by Frederick Wolfe
Arthritis & Rheumatism, 1990
Journal of Psychosomatic Research, 2014
Arthritis and Rheumatism, 1998
To provide a single source for the best available estimates of the national prevalence of arthrit... more To provide a single source for the best available estimates of the national prevalence of arthritis in general and of selected musculoskeletal disorders (osteoarthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, the spondylarthropathies, systemic lupus erythematosus, scleroderma, polymyalgia rheumatica/giant cell arteritis, gout, fibromyalgia, and low back pain). The National Arthritis Data Workgroup reviewed data from available surveys, such as the National Health and Nutrition Examination Survey series. For overall national estimates, we used surveys based on representative samples. Because data based on national population samples are unavailable for most specific musculoskeletal conditions, we derived data from various smaller survey samples from defined populations. Prevalence estimates from these surveys were linked to 1990 US Bureau of the Census population data to calculate national estimates. We also estimated the expected frequency of arthritis in the year 2020. Current national estimates are provided, with important caveats regarding their interpretation, for self-reported arthritis and selected conditions. An estimated 15% (40 million) of Americans had some form of arthritis in 1995. By the year 2020, an estimated 18.2% (59.4 million) will be affected. Given the limitations of the data on which they are based, this report provides the best available prevalence estimates for arthritis and other rheumatic conditions overall, and for selected musculoskeletal disorders, in the US population.
Arthritis and Rheumatism, 1995
Objective. Trials of rheumatoid arthritis (RA) treatments report the average response in multiple... more Objective. Trials of rheumatoid arthritis (RA) treatments report the average response in multiple outcome measures for treated patients. It is more clinically relevant to test whether individual patients improve with treatment, and this identifies a single primary efficacy measure. Multiple definitions of improvement are currently in use in different trials. The goal of this study was to promulgate a single definition for use in RA trials.Methods. Using the American College of Rheumatology (ACR) core set of outcome measures for RA trials, we tested 40 different definitions of improvement, using a 3-step process. First, we performed a survey of rheumatologists, using actual patient cases from trials, to evaluate which definitions corresponded best to rheumatologists' impressions of improvement, eliminating most candidate definitions of improvement. Second, we tested 20 remaining definitions to determine which maximally discriminated effective treatment from placebo treatment and also minimized placebo response rates. With 8 candidate definitions of improvement remaining, we tested to see which were easiest to use and were best in accord with rheumatologists' impressions of improvement.Results. The following definition of improvement was selected: 20% improvement in tender and swollen joint counts and 20% improvement in 3 of the 5 remaining ACR core set measures: patient and physician global assessments, pain, disability, and an acutephase reactant. Additional validation of this definition was carried out in a comparative trial, and the results suggest that the definition is statistically powerful and does not identify a large percentage of placebo-treated patients as being improved.Conclusion. We present a definition of improvement which we hope will be used widely in RA trials.
Arthritis and Rheumatism, 1986
Radiologic assessment of progressive joint destruction in rheumatoid arthritis is generally consi... more Radiologic assessment of progressive joint destruction in rheumatoid arthritis is generally considered to be the ultimate standard for evaluation of treatment. We compared alternative radiologic techniques by performing a randomized, controlled trial in which hand films of rheumatoid arthritis patients were read by several skilled observers. The number of joints evaluated (34 versus 18) was found to make relatively little difference, but the number of readers and their experience level was critical. Films should be read in pairs. Joint space narrowing and erosion scores were shown to contribute independent information. Use of recommended techniques can reduce the number of patients required and, thus, can reduce the cost of a clinical trial by more than half and can substantially increase the sensitivity and efficiency of a trial. Therefore, critical selection of the method of assessing study endpoint is of great importance.
Arthritis and Rheumatism, 1992
Objective. To develop and validate revised criteria for global functional status in rheumatoid ar... more Objective. To develop and validate revised criteria for global functional status in rheumatoid arthritis (RA(.Methods. Revised criteria were formulated and tested for criterion and discriminant validity in 325 patients with RA.Results. The revised criteria developed are as follows: class I = able to perform usual activities of daily living (self-care, vocational, and avocational); class II = able to perform usual self-care and vocational activities, but limited in avocational activities; class III = able to perform usual self-care activities but limited in vocational and avocational activities; class IV = limited in ability to perform usual self-care, vocational, and avocational activities. Usual self-care activities include dressing, feeding, bathing, grooming, and toileting; vocational and avocational activities are both patient-desired and age-, and sex-specific. The distribution properties of this classification schema were superior to those of the original Steinbrocker criteria. Mean Health Assessment Questionnaire scores were significantly (P < 0.0001) different between, and increased across, the 4 classes.Conclusion. Although there are limitations inherent in the use of global ordinal scales, the American College of Rheumatology revised criteria will be useful in describing the functional consequences of RA. A more detailed quantitative measure of physical disability should be used, however, for optimal monitoring of patients' clinical status in office practice and clinical research.
Arthritis and Rheumatism, 1995
Objective. To determine the prevalence and characteristics of fibromyalgia in the general populat... more Objective. To determine the prevalence and characteristics of fibromyalgia in the general population.Methods. A random sample of 3,006 persons in Wichita, KS, were characterized according to the presence of no pain, non-widespread pain, and widespread pain. A subsample of 391 persons, including 193 with widespread pain, were examined and interviewed in detail.Results. The prevalence of fibromyalgia was 2.0% (95% confidence interval [95% CI] 1.4, 2.7) for both sexes, 3.4% (95% CI 2.3, 4.6) for women, and 0.5% (95% CI 0.0, 1.0) for men. The prevalence of the syndrome increased with age, with highest values attained between 60 and 79 years (>7.0% in women). Demographic, psychological, dolorimetry, and symptom factors were associated with fibromyalgia.Conclusion. Fibromyalgia is common in the population, and occurs often in older persons. Characteristic features of fibromyalgia–pain threshold and symptoms–are similar in community and clinic populations, but overall severity, pain, and functional disability are more severe in the clinic population.
Arthritis and Rheumatism, 2003
with rheumatoid arthritis (RA), but limited prospective information on the magnitude of their eff... more with rheumatoid arthritis (RA), but limited prospective information on the magnitude of their effects is available. This study was undertaken to evaluate the relative predictive strength and usefulness of a wide range of variables on the risk of mortality in a large, long-term, prospectively studied cohort of patients with RA.
Arthritis and Rheumatism, 1986
The economic impact of chronic illness has important implications for medical practice and health... more The economic impact of chronic illness has important implications for medical practice and health policy. To determine the yearly costs of illness for those who have rheumatoid arthritis, a detailed, self-administered questionnaire was developed. The questionnaire was completed by 940 patients. Direct costs (recorded as charges) include the average annual expenditures by all patients and third party payers for: hospital care ($913), physician costs ($206), other health professional visits ($71), medications ($436), laboratory tests ($217), radiographs ($116), assistive devices ($24), and nontraditional therapies ($22). The total annual medical costs per patient were $2,533. In a multivariate analysis that controlled for age, sex, education, and disease duration, the outpatient costs, inpatient costs, and total costs were all positively related to the Health Assessment Questionnaire Disability Index (P f < 0.01) and global health (P f < 0.01), but were not associated with self-reported pain.
Lancet, 2002
Background Methotrexate is the most frequent choice of disease-modifying antirheumatic therapy fo... more Background Methotrexate is the most frequent choice of disease-modifying antirheumatic therapy for rheumatoid arthritis. Although results of studies have shown the efficacy of such drugs, including methotrexate, on rheumatoid arthritis morbidity measures, their effect on mortality in patients with the disease remains unknown. Our aim was to prospectively assess the effect on mortality of methotrexate in a cohort of patients with rheumatoid arthritis.
Arthritis and Rheumatism, 1997
Objective. To study, for the first time, service utilization and costs in fibromyalgia, a prevale... more Objective. To study, for the first time, service utilization and costs in fibromyalgia, a prevalent syndrome associated with high levels of pain, functional disability, and emotional distress.Methods. Five hundred thirty-eight fibromyalgia patients from 6 rheumatology centers were enrolled in a 7-year prospective study of fibromyalgia outcome. Patients were assessed every 6 months with validated, mailed questionnaires which included questions regarding fibromyalgia symptoms and severity, utilization of services, and work disability.Results. Fibromyalgia patients averaged almost 10 outpatient medical visits per year, and when nontraditional treatments were considered, this number increased to ∼1 visit per month. Patients were hospitalized at a rate of 1 hospitalization every 3 years. In each 6-month study period, patients used a mean of 2.7 fibromyalgia-related drugs. Costs increased over the course of the study. The mean yearly per-patient cost in 1996 dollars was $2,274. However, results were skewed by high utilizers, and many patients used few services and had limited costs. Total costs and utilization were independently associated with the number of selfreported comorbid or associated conditions, functional disability, and global disease severity. Compared with patients with other rheumatic disorders, those with fibromyalgia were more likely to have lifetime surgical interventions, including back or neck surgery, appendectomy, carpal tunnel surgery, gynecologic surgery, abdominal surgery, and tonsillectomy, and were more likely than other rheumatic disease patients to report comorbid or associated conditions. Almost 50% of hospitalizations occurring during the study were related to fibromyalgia-associated symptoms.Conclusion. The average yearly cost for service utilization among fibromyalgia patients is $2,274. Fibromyalgia patients have high lifetime and current rates of utilization of all types of medical services. They report more symptoms and comorbid or associated conditions than patients with other rheumatic conditions, and symptom reporting is linked to service utilization and, to a lesser extent, functional disability and global disease severity.
Arthritis and Rheumatism, 1987
We evaluated methods of grading radiologic progression of osteoarthritis (OA). Sets of radiograph... more We evaluated methods of grading radiologic progression of osteoarthritis (OA). Sets of radiographs were assessed separately by 8 readers who were blinded to the time sequence. Included were radiographs of patients with OA of the hands (24 pairs), hips (40 pairs), and knees (32 pairs). Most films were taken 12–60 months apart. The relative contribution of individual joints (such as particular interphalangeal joints), of observations (such as narrowing or spurs), and of a single joint compartment (such as the medial or lateral compartment of the knee) toward evidence of OA progression was evaluated, as well as the reliability and concordance of scoring, and the sensitivity in detecting change. In assessing OA of the hand, the greatest sensitivity was achieved by reading a single posteroanterior bilateral hand radiograph for narrowing, spurs, and erosions, and scoring 10 joints (second and third distal interphalangeal, second and third proximal interphalangeal, and trapeziometacarpal joints, bilaterally), using a scale of 0–3. In OA of the hip, a single anteroposterior radiograph assessed for joint space narrowing and cyst formation yielded the greatest sensitivity. In OA of the knee, an anteroposterior radiograph, with weight-bearing, assessed for narrowing, spurs, and sclerosis in both the medial and lateral compartments yielded the greatest sensitivity. These techniques will be useful to the investigator in designing experimental studies and to the clinician in determining the rate of disease progression in an individual patient.
Arthritis and Rheumatism, 1988
To assess functional ability in fibromyalgia patients, we examined 28 patients during the perform... more To assess functional ability in fibromyalgia patients, we examined 28 patients during the performance of five standardized work tasks (SWT), and compared their performance to 26 RA patients and 11 healthy community controls. Fibromyalgia patients performed 58.6% and RA patients 62.1% of the work done by normals. Work performance was strongly associated with pretest Stanford Health Assessment Disability Index (HAQ) scores (r = 0.705), but also with pain, global severity, and psychologic status in both RA and fibromyalgia groups. We also examined work status in 176 fibromyalgia patients. Sixty percent were employed, 9.6% considered themselves disabled, but only 6.2% received disability payments (none for the specific diagnosis of fibromyalgia). Thirty percent of patients had changed jobs because of this illness. Functional ability is impaired in Fibromyalgia. SWT and the HAQ disability instrument may be effective in the clinical assessment of fibromyalgia.
Arthritis and Rheumatism, 1986
The Minnesota Multiphasic Personality Inventory (MMPI) scales for Hypochondriasis, Depression, an... more The Minnesota Multiphasic Personality Inventory (MMPI) scales for Hypochondriasis, Depression, and Hysteria were studied in patients with rheumatoid arthritis (RA). The RA patients showed elevated scores on these scales, and these results are similar to those reported in each of 6 published studies. The elevated MMPI scale scores can be explained largely by 5 “disease-related” MMPI statements which met 2 criteria: (a) they were among 11 of the 117 MMPI statements that two-thirds of rheumatologists predicted would be RA-associated; and (b) RA patients and normal subjects differed significantly in their responses to these statements. The responses of RA patients and normal subjects to most other statements in the MMPI Hypochondriasis, Depression, and Hysteria scales were quite similar. In RA patients, responses to “disease-related” statements were correlated with results of measures of disease activity, which indicates that responses to these MMPI items reflect the severity, as well as the presence, of RA. These findings suggest that new criteria are needed for validation of the MMPI as a clinical tool for the recognition of hypochondriasis, depression, and hysteria in a patient who has RA.
Arthritis and Rheumatism, 1993
Objective. To develop a set of disease activity measures for use in rheumatoid arthritis (RA) cli... more Objective. To develop a set of disease activity measures for use in rheumatoid arthritis (RA) clinical trials, as well as to recommend specific methods for assessing each outcome measure. This is not intended to be a restrictive list, but rather, a core set of measures that should be included in all trials.Methods. We evaluated disease activity measures commonly used in RA trials, to determine which measures best met each of 5 types of validity: construct, face, content, criterion, and discriminant. The evaluation consisted of an initial structured review of the literature on the validity of measures, with an analysis of data obtained from clinical trials to fill in gaps in this literature. A committee of experts in clinical trials, health services research, and biostatistics reviewed the validity data. A nominal group process method was used to reach consensus on a core set of disease activity measures. This set was then reviewed and finalized at an international conference on outcome measures for RA clinical trials. The committee also selected specific ways to assess each outcome.Results. The core set of disease activity measures consists of a tender joint count, swollen joint count, patient's assessment of pain, patient's and physician's global assessments of disease activity, patient's assessment of physical function, and laboratory evaluation of 1 acute-phase reactant. Together, these measures sample the broad range of improvement in RA (have content validity), and all are at least moderately sensitive to change (have discriminant validity). Many of them predict other important long-term outcomes in RA, including physical disability, radiographic damage, and death. Other disease activity measures frequently used in clinical trials were not chosen for any one of several reasons, including insensitivity to change or duplication of information provided by one of the core measures (e.g., tender joint score and tender joint count) The committee also proposes specific ways of measuring each outcome.Conclusion. We propose a core set of outcome measures for RA clinical trials. We hope this will decrease the number of outcomes assessed and standardize outcomes assessments. Further, we hope that these measures will be found useful in long-term studies.
American Journal of Medicine, 2004
Arthritis and Rheumatism, 2004
ObjectiveThe risk of lymphoma is increased in patients with rheumatoid arthritis (RA), and sponta... more ObjectiveThe risk of lymphoma is increased in patients with rheumatoid arthritis (RA), and spontaneous reporting suggests that methotrexate (MTX) and anti–tumor necrosis factor (anti-TNF) therapy might be associated independently with an increased risk of lymphoma. However, data from clinical trials and clinical practice do not provide sufficient evidence concerning these issues because of small sample sizes and selected study populations. The objective of this study was to determine the rate of and standardized incidence ratio (SIR) for lymphoma in patients with RA and in RA patient subsets by treatment group. Additionally, we sought to determine predictors of lymphoma in RA.The risk of lymphoma is increased in patients with rheumatoid arthritis (RA), and spontaneous reporting suggests that methotrexate (MTX) and anti–tumor necrosis factor (anti-TNF) therapy might be associated independently with an increased risk of lymphoma. However, data from clinical trials and clinical practice do not provide sufficient evidence concerning these issues because of small sample sizes and selected study populations. The objective of this study was to determine the rate of and standardized incidence ratio (SIR) for lymphoma in patients with RA and in RA patient subsets by treatment group. Additionally, we sought to determine predictors of lymphoma in RA.MethodsWe prospectively studied 18,572 patients with RA who were enrolled in the National Data Bank for Rheumatic Diseases (NDB). Patients were surveyed biannually, and potential lymphoma cases received detailed followup. The SEER (Survey, Epidemiology, and End Results) cancer data resource was used to derive the expected number of cases of lymphoma in a cohort that was comparable in age and sex with the RA cohort.We prospectively studied 18,572 patients with RA who were enrolled in the National Data Bank for Rheumatic Diseases (NDB). Patients were surveyed biannually, and potential lymphoma cases received detailed followup. The SEER (Survey, Epidemiology, and End Results) cancer data resource was used to derive the expected number of cases of lymphoma in a cohort that was comparable in age and sex with the RA cohort.ResultsThe overall SIR for lymphoma was 1.9 (95% confidence interval [95% CI] 1.3–2.7). The SIR for biologic use was 2.9 (95% CI 1.7–4.9) and for the use of infliximab (with or without etanercept) was 2.6 (95% CI 1.4–4.5). For etanercept, with or without infliximab, the SIR was 3.8 (95% CI 1.9–7.5). The SIR for MTX was 1.7 (95% CI 0.9–3.2), and was 1.0 (95% CI 0.4–2.5) for those not receiving MTX or biologics. Lymphoma was associated with increasing age, male sex, and education.The overall SIR for lymphoma was 1.9 (95% confidence interval [95% CI] 1.3–2.7). The SIR for biologic use was 2.9 (95% CI 1.7–4.9) and for the use of infliximab (with or without etanercept) was 2.6 (95% CI 1.4–4.5). For etanercept, with or without infliximab, the SIR was 3.8 (95% CI 1.9–7.5). The SIR for MTX was 1.7 (95% CI 0.9–3.2), and was 1.0 (95% CI 0.4–2.5) for those not receiving MTX or biologics. Lymphoma was associated with increasing age, male sex, and education.ConclusionLymphomas are increased in RA. Although the SIR is greatest for anti-TNF therapies, differences between therapies are slight, and confidence intervals for treatment groups overlap. The increased lymphoma rates observed with anti-TNF therapy may reflect channeling bias, whereby patients with the highest risk of lymphoma preferentially receive anti-TNF therapy. Current data are insufficient to establish a causal relationship between RA treatments and the development of lymphoma.Lymphomas are increased in RA. Although the SIR is greatest for anti-TNF therapies, differences between therapies are slight, and confidence intervals for treatment groups overlap. The increased lymphoma rates observed with anti-TNF therapy may reflect channeling bias, whereby patients with the highest risk of lymphoma preferentially receive anti-TNF therapy. Current data are insufficient to establish a causal relationship between RA treatments and the development of lymphoma.
Arthritis and Rheumatism, 1994
Objective. To evaluate the efficacy and tolerability of oral methotrexate (MTX) in rheumatoid art... more Objective. To evaluate the efficacy and tolerability of oral methotrexate (MTX) in rheumatoid arthritis (RA) in a long-term prospective trial.Methods. One hundred twenty-three patients with RA who completed a 9-month multicenter randomized trial comparing MTX and auranofin enrolled in this 5-year prospective study of MTX.Results. Significant (P = 0.0001) improvement compared with baseline was noted in all clinical disease variables, functional status, and the Westergren erythrocyte sedimentation rate (ESR). “Marked improvement” occurred in 87 (71%) and 85 (69%) of the patients, respectively, in the joint pain/tenderness index and the joint swelling index at the last evaluable visit. Forty-four patients (36%) withdrew during the study. Eight (7%) withdrew due to lack of efficacy, and 8 (7%) due to adverse experiences, including 1 patient with cirrhosis. At 5 years, 64% of patients were still taking MTX and completed the study.Conclusion. This large prospective study of long-term MTX treatment demonstrates sustained clinical response and improvement in the Westergren ESR and functional assessment scores, with an acceptable toxicity profile.
Arthritis and Rheumatism, 2004
ObjectiveAccording to the Centers for Disease Control and Prevention, the 1999 and 2000 incidence... more ObjectiveAccording to the Centers for Disease Control and Prevention, the 1999 and 2000 incidence rates for tuberculosis (TB) in the US population were 6.4 and 5.8, respectively, per 100,000 persons. Recently, reports of TB following infliximab administration have raised questions regarding the rate of TB in patients with rheumatoid arthritis (RA) generally and in those treated with infliximab in clinical practice. We undertook this study to determine the baseline rate of TB in RA prior to the introduction of infliximab and to determine the rate of TB among those currently receiving infliximab.According to the Centers for Disease Control and Prevention, the 1999 and 2000 incidence rates for tuberculosis (TB) in the US population were 6.4 and 5.8, respectively, per 100,000 persons. Recently, reports of TB following infliximab administration have raised questions regarding the rate of TB in patients with rheumatoid arthritis (RA) generally and in those treated with infliximab in clinical practice. We undertook this study to determine the baseline rate of TB in RA prior to the introduction of infliximab and to determine the rate of TB among those currently receiving infliximab.MethodsWe surveyed patients with questionnaires, followed by detailed validation from medical records and physician reports. In study 1, we evaluated 10,782 RA patients in 1998–1999 prior to the widespread use of infliximab. In study 2, we evaluated 6,460 infliximab-treated patients in 2000–2002.We surveyed patients with questionnaires, followed by detailed validation from medical records and physician reports. In study 1, we evaluated 10,782 RA patients in 1998–1999 prior to the widespread use of infliximab. In study 2, we evaluated 6,460 infliximab-treated patients in 2000–2002.ResultsIn study 1, the lifetime rate of TB was 696 per 100,000 patients (95% confidence interval [95% CI] 547–872). Of these cases, 76.8% occurred prior to the onset of RA. During the period of prospective followup, 1 case of TB developed during 16,173 patient-years of followup, yielding a rate of 6.2 cases (95% CI 1.6–34.4) per 100,000 patients. In study 2, the TB incidence rate among infliximab-treated patients was 52.5 cases (95% CI 14.3–134.4) per 100,000 patient-years of exposure. Three of the 4 cases occurred in patients with a history of TB exposure, and no cases occurred in persons with recent TB skin tests or prophylaxis.In study 1, the lifetime rate of TB was 696 per 100,000 patients (95% confidence interval [95% CI] 547–872). Of these cases, 76.8% occurred prior to the onset of RA. During the period of prospective followup, 1 case of TB developed during 16,173 patient-years of followup, yielding a rate of 6.2 cases (95% CI 1.6–34.4) per 100,000 patients. In study 2, the TB incidence rate among infliximab-treated patients was 52.5 cases (95% CI 14.3–134.4) per 100,000 patient-years of exposure. Three of the 4 cases occurred in patients with a history of TB exposure, and no cases occurred in persons with recent TB skin tests or prophylaxis.ConclusionThe rate of TB is not increased in RA patients generally. Among infliximab-treated patients, the rate is 52.5 cases (95% CI 14.3–134.4) per 100,000 patient-years of exposure. A thorough medical history regarding TB, as well as tuberculin testing and radiographic examination (if indicated), should be an essential component of anti–tumor necrosis factor therapy.The rate of TB is not increased in RA patients generally. Among infliximab-treated patients, the rate is 52.5 cases (95% CI 14.3–134.4) per 100,000 patient-years of exposure. A thorough medical history regarding TB, as well as tuberculin testing and radiographic examination (if indicated), should be an essential component of anti–tumor necrosis factor therapy.
Arthritis and Rheumatism, 2000
Objective. To investigate the course of selfreported disability in rheumatoid arthritis (RA) usin... more Objective. To investigate the course of selfreported disability in rheumatoid arthritis (RA) using the major self-report measure of functional impairment, the Health Assessment Questionnaire (HAQ).
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Papers by Frederick Wolfe