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Maarten Boers

Publications and source records attributed to Maarten Boers.

At least 55 records · Page 3Linked to original sources
PubMed2003

Outcomes from the Patient Perspective Workshop at OMERACT 6.

The objective of the Patient Perspective Workshop at OMERACT 6 was to address the question of assessing the outcomes of intervention in rheumatoid arthritis (RA) from the perspective of those who experience the disease themselves. This was done by reviewing the current state of research in the area, identifying the requirements for the development of valid instruments, delineating a research agenda that can attain these requirements, and motivating participants to undertake the appropriate research. Through a series of meetings and discussion sessions a research agenda emerged that includes: exploring subjective experiences of RA identified by patients as important but not encompassed within the current "core set" of outcome measures (such as a sense of well being, fatigue, and disturbed sleep); clarifying terminology; and empowering patients to be more effective partners in outcomes research. These were supported by the OMERACT plenary session. Specific actions were required by both patient participants and organizers to ensure the nature of the conference, its focus and method of working were understood, and that the patient participants were sufficiently confident to make their contribution.

Arthritis, Rheumatoid↗
PubMed2003

OMERACT 6 Economics Working Group report: a proposal for a reference case for economic evaluation in rheumatoid arthritis.

Standardization of methods for economic evaluation is essential for defining the methodological research agenda that will advance the discipline. Standardization also greatly facilitates the interpretation and comparison of the results of economic analyses. For these reasons, several jurisdictions now require economic evaluation, conducted according to standardized methodological guidelines, as a key ingredient in decision making for reimbursement of health treatments and technologies. The application of these general guidelines, however, can be difficult in the absence of disease-specific information. In the case of rheumatoid arthritis (RA), the recent emergence of innovative, highly effective, but also expensive treatments has created an immediate need to more fully understand the economic implications of RA treatments. With this background, the OMERACT Economics Working Group set out in 1994 to develop an RA-specific reference case for economic evaluation. This report summarizes the OMERACT process leading to specific recommendations on the 12 key elements of a proposed "reference case" for economic evaluation in RA. These elements include: study horizon, duration of therapy, extrapolation beyond trial duration, modeling beyond therapy, synthesis of comparisons where head-to-head trials do not exist, clinical outcome measures, mortality, valuation of health states, resource utilization, discontinuation of therapy, therapeutic sequence, and population risk stratification. Through these efforts, the OMERACT Economics Working Group aims to expedite and enhance the conduct and dissemination of methodological research in economic analyses in the rheumatic diseases.

Arthritis, Rheumatoid↗
PubMed2003

Economic evaluation of programs or interventions in the management of rheumatoid arthritis: defining a consensus-based reference case.

Improvement in the quality of economic evaluation could be documented as a consequence of international and national standardization efforts. One such effort is the recommendation that all economic evaluations in a given field produce findings in a standard format using a reference case. A reference case-based economic evaluation would adhere to specific settings with regard to outcomes, comparators, modeling techniques, and use of costs to facilitate comparisons among economic evaluations performed with the same objective. In the past, the Outcome Measures in Rheumatology Clinical Trials (OMERACT) consensus conference has successfully developed widely used, consensus-based outcome criteria for clinical improvement in rheumatoid arthritis (RA). Present efforts are being directed at the development of recommendations for the type and format of a reference case economic evaluation for newly developed disease modifying antirheumatic drugs (DMARD). This document discusses 13 important elements that experts considered to be relevant for the development of a reference case recommendation for economic evaluations in RA. We provide the rationale for each element and discuss how each element has been addressed in published economic evaluations of DMARD.

Antirheumatic Agents↗
PubMed2003

Repair of erosions in rheumatoid arthritis does occur. Results from 2 studies by the OMERACT Subcommittee on Healing of Erosions.

The committee was charged with determining whether healing of erosions in rheumatoid arthritis (RA) occurs. Two exercises were performed: The first asked the committee members, as a panel of experts, to express agreement or disagreement with the presence of improvement and features of bone reaction to injury in images submitted by members as examples of healing. The second presented panel members with 28 pairs of serial images, 14 chosen to illustrate progression and 14 chosen to illustrate repair. Agreement was tested on 8 items: global judgment on which image in the pair was better, relative size of the erosion in the 2 images, judgment on which image was first, presence and extent of sclerosis, cortication, filling-in, remodeling, and reconstituting normal structure. Our results showed good agreement, among the 15 respondents, on global assessment of which image was better and which image showed the smaller erosion. Correct assignment of sequence was only slightly better than expected by chance (in 65% of the cases). Agreement was poor regarding the presence of morphologic features of bone repair. A majority of a panel of experts agreed on which 2nd images in a set of paired, serial images represented improvement and which showed progression based on global assessment of which was better and on size of erosion. Features of bone repair were not distinctive and did not enable the panel to deduce the correct sequence of the serial images. This study provides evidence that repair of bone damage in RA does occur, resulting in some degree of improvement, which was recognized by a majority of a panel of experts.

Arthritis, Rheumatoid↗
PubMed2003

MCID/Low Disease Activity State Workshop: low disease activity state in rheumatoid arthritis.

The MCID (minimal clinically important difference) module of OMERACT 5 developed a research agenda that led to the conclusion that a state of low disease activity for rheumatoid arthritis (RA) would need to be defined. To develop such a definition the various concepts and terminologies, the process for developing an operational definition, and the availability and design of longitudinal datasets for validation needed to be considered. This article describes the process of the MCID/Low Disease Activity State Workshop at OMERACT 6 to develop such a definition.

Arthritis, Rheumatoid↗
PubMed2003

Deriving an operational definition of low disease activity state in rheumatoid arthritis.

This article summarizes the process proposed to come to a definition of low disease activity in rheumatoid arthritis (RA). The purpose of this definition is to aid the interpretation of trial and longitudinal study results. A conceptual proposal is "a disease activity state that is deemed a useful treatment target by both physicians and patients." An operant definition can be derived by judgmental (opinion-based) or statistical (data-based) approaches, but the first seems more appropriate. Once a few candidate definitions have been selected, their usefulness and prognostic validity can be tested in longitudinal datasets.

Arthritis, Rheumatoid↗
PubMed2003

MCID/Low Disease Activity State Workshop: summary, recommendations, and research agenda.

The OMERACT 6 Minimal Clinically Important Difference/Low Disease Activity Workshop was organized with the aim of meeting the many challenges that exist in determining a low disease activity in rheumatoid arthritis (RA). This article presents an overview of that workshop, including results of the voting, a summary of associated discussions, recommendations, and a proposed research agenda.

Arthritis, Rheumatoid↗
PubMed2002

Contribution of progression of erosive damage in previously eroded joints in early rheumatoid arthritis trials: COBRA trial as an example.

OBJECTIVE: In rheumatoid arthritis (RA) in the context of a drug trial, prevention of erosions in undamaged joints is often considered more important than prevention of progression in already damaged joints, although a clear rationale is lacking. The aim of this study is to evaluate the relative contribution of separate components of the erosion score of the modified Sharp/van der Heijde method in early RA. METHODS: Different aspects of erosive damage were evaluated by their ability to discriminate between the 2 treatments in an early RA trial (the COBRA trial). RESULTS: The contribution of progression of already eroded joints to the total erosion score clearly increased during the 1.5 years of the trial. When the periods 0-28, 28-56, and 56-80 weeks were analyzed separately, the erosion score showed a significant difference between the groups in the first 2 periods (P < 0.0001, P < 0.03, and P < 0.64, respectively). Similar differences were seen in rates of progression in previously eroded joints (P = 0.005, P = 0.003, P = 0.35). On the other hand, rates of progression in newly eroded joints showed no significant difference between the 2 treatment groups in the second and third period (P < 0.0001, P < 0.16, P < 0.87). Analyses on joint and patient level showed analogous results. CONCLUSION: Subanalyses on progression rates in noneroded joints and already eroded joints can provide additional information. However, important information and discriminative strength may be lost when assessment is limited to the development of erosions in undamaged joints.

Antirheumatic Agents↗
PubMed2002

Effectiveness of positron emission tomography in the preoperative assessment of patients with suspected non-small-cell lung cancer: the PLUS multicentre randomised trial.

BACKGROUND: Up to 50% of curative surgery for suspected non-small-cell lung cancer is unsuccessful. Accuracy of positron emission tomography (PET) with 18-fluorodeoxyglucose (18FDG) is thought to be better than conventional staging for diagnosis of this malignancy. Up to now however, there has been no evidence that PET leads to improved management of patients in routine clinical practice. We did a randomised controlled trial in patients with suspected non-small-cell lung cancer, who were scheduled for surgery after conventional workup, to test whether PET with 18FDG reduces number of futile thoracotomies. METHODS: Before surgery (mediastinoscopy or thoracotomy), 188 patients from nine hospitals were randomly assigned to either conventional workup (CWU) or conventional workup and PET (CWU+PET). Patients were followed up for 1 year. Thoracotomy was regarded as futile if the patient had benign disease, explorative thoracotomy, pathological stage IIIA-N2/IIIB, or postoperative relapse or death within 12 months of randomisation. The primary outcome measure was futile thoracotomy. Analysis was by intention to treat. FINDINGS: 96 patients were randomly assigned CWU and 92 CWU+PET. Two patients in the CWU+PET group did not undergo PET. 18 patients in the CWU group and 32 in the CWU+PET group did not have thoracotomy. In the CWU group, 39 (41%) patients had a futile thoracotomy, compared with 19 (21%) in the CWU+PET group (relative reduction 51%, 95% CI 32-80%; p=0.003). INTERPRETATION: Addition of PET to conventional workup prevented unnecessary surgery in one out of five patients with suspected non-small-cell lung cancer.

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PubMed2002

COBRA combination therapy in patients with early rheumatoid arthritis: long-term structural benefits of a brief intervention.

OBJECTIVE: The Combinatietherapie Bij Reumatoide Artritis (COBRA) trial demonstrated that step-down combination therapy with prednisolone, methotrexate, and sulfasalazine (SSZ) was superior to SSZ monotherapy for suppressing disease activity and radiologic progression of rheumatoid arthritis (RA). The current study was conducted to investigate whether the benefits of COBRA therapy were sustained over time, and to determine which baseline factors could predict outcome. METHODS: All patients had participated in the 56-week COBRA trial. During followup, they were seen by their own rheumatologists and were also assessed regularly by study nurses; no treatment protocol was specified. Disease activity, radiologic damage, and functional ability were the primary outcome domains. Two independent assessors scored radiographs in sequence according to the Sharp/van der Heijde method. Outcomes were analyzed by generalized estimating equations on the basis of intent-to-treat, starting with data obtained at the last visit of the COBRA trial (56 weeks after baseline). RESULTS: At the beginning of followup, patients in the COBRA group had a significantly lower mean time-averaged 28-joint disease activity score (DAS28) and a significantly lower median radiologic damage (Sharp) score compared with those in the SSZ monotherapy group. The functional ability score (Health Assessment Questionnaire [HAQ]) was similar in both groups. During the 4-5 year followup period, the time-averaged DAS28 decreased 0.17 points per year in the SSZ group and 0.07 in the COBRA group. The Sharp progression rate was 8.6 points per year in the SSZ group and 5.6 in the COBRA group. After adjustment for differences in treatment and disease activity during followup, the between-group difference in the rate of radiologic progression was 3.7 points per year. The HAQ score did not change significantly over time. Independent baseline predictors of radiologic progression over time (apart from treatment allocation) were rheumatoid factor positivity, Sharp score, and DAS28. CONCLUSION: An initial 6-month cycle of intensive combination treatment that includes high-dose corticosteroids results in sustained suppression of the rate of radiologic progression in patients with early RA, independent of subsequent antirheumatic therapy.

Adult↗
PubMed2002

Determination of the minimal clinically important difference in rheumatoid arthritis joint damage of the Sharp/van der Heijde and Larsen/Scott scoring methods by clinical experts and comparison with the smallest detectable difference.

OBJECTIVE: To assess the minimal clinically important difference (MCID) in joint damage on hand and foot radiographs of patients with early rheumatoid arthritis (RA) as assessed with the Sharp/van der Heijde and Larsen/Scott methods, and to study how the smallest detectable difference (SDD) relates to the MCID for each method. METHODS: The judgments of an international panel of experts on the clinical relevance of progression of joint damage as seen on sets of radiographs obtained at 1-year intervals in 4 clinical settings (early versus late RA and mild versus high disease activity) were used as the external criterion, which was compared with the progression scores as determined by the 2 scoring methods. Progression scores with the highest combined sensitivity and specificity for detecting clinically relevant progression represented the MCID. Subsequently, the sensitivity and specificity of the scoring methods were determined when using the SDD as the threshold for relevant progression, and these were compared with the sensitivity and specificity of the MCID. RESULTS: The panel judged changes in joint damage around the level of the SDD (5.0) of the Sharp/van der Heijde method as minimal clinically important, resulting in satisfactory sensitivity (mean 79%) and specificity (mean 84%) for detecting clinically important progression in the 4 clinical settings when using the SDD as the threshold value. The MCID (mean 2.3) of the Larsen/Scott method was much smaller than its SDD (5.8), and the sensitivity for detecting clinically important progression by applying the SDD as threshold was consequently low (mean 51%), accompanied by high specificity (mean 99%). CONCLUSION: This study suggests that the SDD of the Sharp/van der Heijde method can be used as the MCID, i.e., as the threshold level for individual response criteria. The SDD of the Larsen/Scott method, however, turned out to be too insensitive to use as the threshold for individual clinically relevant change.

Arthritis, Rheumatoid↗
PubMed2002

Association of baseline levels of markers of bone and cartilage degradation with long-term progression of joint damage in patients with early rheumatoid arthritis: the COBRA study.

OBJECTIVE: The known risk factors for radiologic progression in rheumatoid arthritis (RA) are not optimally discriminative in patients with early disease who do not have evidence of radiologic damage. We sought to determine whether urinary C-terminal crosslinking telopeptide of type I (CTX-I) and type II (CTX-II) collagen (markers of bone and cartilage destruction, respectively) are associated with long-term radiologic progression in patients with early RA. METHODS: This was a prospective study of 110 patients with early RA who were participating in the COBRA (Combinatietherapie Bij Reumatoïde Artritis) clinical trial and followup study, a randomized controlled trial comparing the efficacy of oral pulse prednisolone, methotrexate, plus sulfasalazine with sulfasalazine alone. We investigated the relationship between baseline levels of urinary CTX-I and CTX-II and the mean annual progression of joint destruction over a median of 4 years, as measured by changes in the modified Sharp score (average of 2 independent readers). RESULTS: In multivariate logistic regression analysis, baseline urinary CTX-I and CTX-II levels in the highest tertile were the strongest predictors of radiologic progression (Sharp score increase >2 units/year; odds ratio 7.9 and 11.2, respectively), independently of treatment group, erythrocyte sedimentation rate (ESR), Disease Activity Score in 28 joints, rheumatoid factor (RF), and baseline joint damage (Sharp score). The likelihood ratios for a positive test were 3.8 and 8.0 for CTX-I and CTX-II, respectively, which compared favorably with the likelihood ratios for the ESR (3.0), baseline joint damage (1.6), and RF (1.8). When patients were grouped according to the presence (Sharp score >/=4, n = 49) and absence (Sharp score <4, n = 61) of joint damage at baseline, CTX-I and CTX-II levels were predictive only in those without baseline joint damage (odds ratio 14.9 and 25.7, respectively). CONCLUSION: High baseline levels of urinary CTX-I and CTX-II independently predict an increased risk of radiologic progression over 4 years in patients with early RA, especially those without radiologic joint damage. Urinary CTX-I and CTX-II may be useful for identifying individual RA patients at high risk of progression very early in the disease, before erosions can be detected radiographically. Such patients may be in special need of treatments that inhibit bone and cartilage degradation.

Arthritis, Rheumatoid↗
PubMed2002

Prevention or retardation of joint damage in rheumatoid arthritis: issues of definition, evaluation and interpretation of plain radiographs.

This article discusses methodological concepts and challenges underlying the interpretation of changes in plain radiographs of the joints of patients with rheumatoid arthritis. A series of consensus conferences (OMERACT [Outcome Measures in Rheumatology]) has resulted in the formulation and execution of a research agenda to harmonise reading and interpretation of films. This is important in the light of the increasing evidence that drugs can impact on the progression of joint damage. In these conferences, methodological issues have been divided according to applicability tenets summarised in the OMERACT Filter of Truth, Discrimination, and Feasibility. To pass the Filter, a measure must measure what it is supposed to measure (Truth), must discriminate between clinically relevant states (Discrimination) and be feasible in terms of costs and interpretability. 'Truth' issues include the choice of joints, the view and other technical specifications of the radiograph, such as which abnormalities to score, the level of aggregation of the information, culminating in the choice of the scoring system. 'Discrimination' issues include reproducibility and sensitivity to change. The current research agenda includes items such as defining a criterion for 'no relevant progression', comparison between time ordered and randomly ordered reading, further comparison of methods and subscores, and methodology around missing values.

Antirheumatic Agents↗
PubMed2002

The influence of methodologic quality on the conclusion of a landmark meta-analysis on thrombolytic therapy.

OBJECTIVE: We studied the influence of the methodologic quality of individual trials on the outcome of a landmark meta-analysis on thrombolytic therapy in acute myocardial infarction. From each study we extracted the number of patients in both groups who died in hospital or during follow-up. Methodologic quality was assessed using the Delphi list. We first recalculated pooled odds ratios (ORs) and 95% confidence intervals (CIs), on the studies found and compared them with the original results of Yusuf et al. Next we incorporated the results of quality assessment in five different ways in the calculation of the pooled ORs: a) component analysis; b) visual plot; c) quality score as a threshold score; d) quality score as a weighting factor; and e) cumulative pooling. RESULTS AND CONCLUSION: No correlation between quality scores and ORs was found. Studies with a proper description of the different quality components provided an estimate close to the true treatment effect. No major differences were found between the results of the five different methods of incorporating the quality scores into the final conclusion.

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