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Biomedical subjects

A Boonen

Publications and source records attributed to A Boonen.

48 records · Page 3Linked to original sources
PubMed1999

Reading radiographs in chronological order, in pairs or as single films has important implications for the discriminative power of rheumatoid arthritis clinical trials.

OBJECTIVE: To determine the influence of reading series of films in chronological order, in pairs with unknown time sequence, or as single films, on precision and sensitivity to change. METHODS: Two studies were performed with 10 and 12 patients fulfilling the American College of Rheumatology criteria. In Study 1, two sets of films with a 1 yr interval were scored in chronological order, in pairs, and as single films. In Study 2, four sets of films, with a 1 yr interval each, were scored in chronological order, as single films and as single-pair (right and left together). All films were scored with the Sharp/van der Heijde method by two independent observers. Data were analysed with a repeated measures ANOVA using a full mixed effects model. Two generalizability (G) coefficients were constructed for reliability and for change. RESULTS: Study 1: the interobserver reliability was similar for the three methods (G(reliability) chronological 0.94, paired 0.88, single 0.93); progression was a mean increase (averaged over patients, observers and methods) from 26 to 37 (P=0.046). The sensitivity for change was greater for the chronological than for the paired and single scoring (G(change) 0.39, 0.22 and 0.24, respectively). Study 2: the interobserver reliability was 0.86 for chronological, 0.76 for single-pair and 0.91 for single readings. Significantly more progression was measured with the chronological compared with the single-paired and single methods (15.9 vs 8.5 and 8.3; P=0.0001). A constant progression was suggested by chronological reading, in contrast to a stabilization in the other two methods after 1 yr. CONCLUSION: Reading films in chronological order is most sensitive to change in a time period up to 3 yr follow-up; this was already present after 1 yr, but even more pronounced with longer follow-up.

Analysis of Variance↗
PubMed1999

Smallest detectable difference in radiological progression.

Omeract IV started a discussion on the development of radiological response criteria in rheumatoid arthritis (RA). Such criteria depend on the definition of what constitutes the minimum clinically important progression of damage. Because such a definition is currently not available, as a first step we have used the concept of random measurement error to determine what is the smallest detectable difference (SDD) in radiological progression between 2 radiographs of a particular patient. Baseline and 12 month radiographs (hands, wrists, feet) of 52 patients representative of the spectrum of radiological progression were selected from a randomized controlled trial of early rheumatoid arthritis (COBRA study) and were read paired and chronologically by 2 observers using the van der Heijde modified Sharp method (0-448 scale) and another 2 observers using the Scott modified Larsen method (0-200). The measurement error of progression was determined using the metric 95% limits of agreement method of Bland and Altman. In the setting of early RA the SDD is 11 modified Sharp score units and 8 modified Larsen score units if there is an equal distribution of baseline damage and progression in the sample and the mean score of the same trained observers is always used. The SDD is 15.5 modified Sharp score units and 11 modified Larsen score units if there is an equal distribution of baseline damage and progression in the sample and the mean score of any 2 trained observers is used. Other SDD were determined depending on the context of measurement. Although this exercise needs repetition in other settings, the SDD is a useful starting point in the development of radiological response criteria.

Adolescent↗
PubMed1999

The responsiveness of generic quality of life instruments in rheumatic diseases. A systematic review of randomized controlled trials.

To review the available evidence that has used generic instruments alone or in comparison with disease specific instruments. A systematic review was carried out using the methods recommended by the Cochrane Collaboration. We used MEDLINE and EMBASE searches and we performed a hand search of the abstracts listed under "quality of life" at American College of Rheumatology (ACR) meetings. Selection was limited to randomized controlled trials (RCT) using generic instruments in populations older than 18 years with any of the following diseases: rheumatoid arthritis, fibromyalgia, osteoporosis, osteoarthritis, systemic lupus erythematosus, and ankylosing spondylitis. Language was restricted to English papers. Studies using only disease-specific instruments were excluded. From 488 articles retrieved, 13 reports of 10 randomized controlled trials were selected. There were 101 abstracts on quality of life in ACR abstract books; 78 abstracts contained data on generic instruments, and of these, 9 described their use in RCT. Despite a substantial increase in the number of papers and abstracts addressing different aspects of generic questionnaires, the majority of the papers were descriptive. The evidence is not yet available to document that any of the generic instruments pass the requirements of the OMERACT Filter.

Adult↗
PubMed1997

Randomised comparison of combined step-down prednisolone, methotrexate and sulphasalazine with sulphasalazine alone in early rheumatoid arthritis.

BACKGROUND: The value of intensive combination therapy in early rheumatoid arthritis is unproven. In a multicentre, double-blind, randomised trial (COBRA), we compared the combination of sulphasalazine (2 g/day), methotrexate (7.5 mg/week), and prednisolone (initially 60 mg/day, tapered in 6 weekly steps to 7.5 mg/day) with sulphasalazine alone. METHODS: 155 patients with early rheumatoid arthritis (median duration 4 months) were randomly assigned combined treatment (76) or sulphasalazine alone (79). Prednisolone and methotrexate were tapered and stopped after 28 and 40 weeks, respectively. The main outcomes were the pooled index (a weighted change score of five disease activity measures) and the Sharp/Van der Heijde radiographic damage score in hands and feet. Independent health-care professionals assessed the main outcomes without knowledge of treatment allocation. FINDINGS: At week 28, the mean pooled index was 1.4 (95% CI 1.2-1.6) in the combined treatment group and 0.8 (0.6-1.0) in the sulphasalazine group (p < 0.0001). At this time, 55 (72%) and 39 (49%) patients, respectively, were improved according to American College of Rheumatology criteria. The clinical difference between the groups decreased and was no longer significant after prednisolone was stopped, and there were no further changes after methotrexate was stopped. At 28 weeks, the radiographic damage score had increased by a median of 1 (range 0-28) in the combined-therapy group and 4 (0-44) in the sulphasalazine group (p < 0.0001). The increases at week 56 (2 [0-43] vs 6 [0-54], p = 0.004), and at week 80 (4 [0-80] vs 12 [0-72], p = 0.01) were also significant. Further analysis suggests that combined therapy immediately suppressed damage progression, whereas sulphasalazine did so less effectively and with a lag of 6 to 12 months. There were fewer withdrawals in the combined therapy than the sulphasalazine group (6 [8%] vs 23 [29%]), and they occurred later. INTERPRETATION: This combined-therapy regimen offers additional disease control over and above that of sulphasalazine alone that persists for up to a year after corticosteroids are stopped. Although confirmatory studies and long-term follow-up are needed, this approach may prove useful in the treatment of early rheumatoid arthritis.

Adult↗
PubMed1996

Clubbing in human immunodeficiency virus infection.

We describe two patients who developed clubbing shortly after HIV seroconversion. None of them had the full syndrome of hypertropic osteoarthropathy. Other causes of clubbing are unlikely. We suggest that clubbing may belong to the spectrum of arthropathies associated with HIV infection.

Adult↗
PubMed1989

Risk factors which determine the long term outcome of Neodymium-YAG laser palliation of colorectal carcinoma.

We have analysed the long term results of YAG laser palliation for incurable colorectal carcinoma in 88 patients. Although initial palliation was achieved in 82%, good palliation could only be maintained in 51% and 41% of patients surviving 6 months and 12 months respectively. The relative inefficacy of YAG laser therapy for palliation of rectal cancer is due to the failure to control extraluminal tumour growth, complications of YAG laser therapy and the poor general condition of these elderly patients. Factors influencing the efficacy of palliation, besides life expectancy, included T classification, and length of the neoplastic stricture. Treatment-related mortality due to perforation was 2.3%. YAG laser therapy, applied as the sole therapeutic modality, is effective for short term palliation of incurable colorectal carcinoma, but is not adequate for long term palliation in most patients. Trials should be conducted to study the effect of combined treatment (e.g. laser + radiotherapy) on palliation.

Aged↗
PubMedDate not supplied

Socioeconomic consequences of ankylosing spondylitis.

Since ankylosing spondylitis usually starts at an early age, the socioeconomic impact of the disease on the patient and on society can be important. Several studies have reported substantial work disability, but there is considerable variation among countries. While withdrawal from work is associated with an older age at diagnosis and manual jobs or a lower educational level, sick leave in those with a paying job is associated with disease activity and physical functioning. The yearly mean total (direct and productivity) costs of AS are US$6,720 per patient in the USA and Euro 9,462 per patient in Europe when the human capital approach is used to calculate the productivity costs. A cost-effectiveness study on spa-therapy in AS shows that the clinical benefits of (expensive) treatments can be reached within acceptable costs.

Cost of Illness↗