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A Boonen

Publications and source records attributed to A Boonen.

At least 19 recordsLinked to original sources
PubMed2003

Disease activity and health status in rheumatoid arthritis: a case-control comparison between Norway and Lithuania.

OBJECTIVE: To compare disease characteristics and health status in patients with rheumatoid arthritis (RA) from two countries, Norway and Lithuania. METHODS: Patients were recruited from the RA registers in Vilnius (Lithuania) and Oslo (Norway). For each patient from Vilnius, a patient matched for age and sex from the Oslo register was selected. Sociodemographic characteristics, disease process, and health status were compared between the patient groups. RESULTS: 201 Lithuanian patients and 201 Norwegian patients were included. Mean (SD) age in both groups was 55.9 (10.0) years, and 83% were women. Patients from Lithuania were less often employed (27% v 42%; p=0.001), had higher disease activity expressed by the disease activity score (DAS28; mean (SD) 5.3 (1.0) v 4.4 (1.4); p<0.001), had worse physical function by the modified Health Assessment Questionnaire (MHAQ; mean (SD) 2.3 (0.8) v 1.6 (0.5); p<0.001), had more often comorbidity (73% v 53%; p<0.001) and they reported worse general health measured by Short Form-36 Health Survey (SF-36; mean (SD) 23.2 (13.5) v 44.5 (21.3); p<0.001). The proportions of patients who had used disease modifying drugs were similar, but the pattern of use differed. CONCLUSION: Important differences in employment, disease activity, physical function, and self reported health status were observed in patients with RA from two northern European countries. Socioeconomic inequalities, differences in disease management, and access to specialised health care, as well as methodological issues regarding instruments and data collection are likely explanations. These data support the view that management of RA should be adapted to country-specific needs.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Direct costs of ankylosing spondylitis and its determinants: an analysis among three European countries.

OBJECTIVE: To assess direct costs associated with ankylosing spondylitis (AS). To determine which variables, including country, predict costs. METHODS: 216 patients with AS from the Netherlands, France, and Belgium participated in a two year observational study and filled in bimonthly economic questionnaires. Disease related healthcare resource use was measured and direct costs were calculated from a societal perspective (true cost estimates) and from a financial perspective (country-specific tariffs). Predictors of costs were assessed using Cox's regression analysis. RESULTS: 209 patients provided sufficient data for cost analysis. Mean annual societal direct costs for each patient were euro;2640, of which 82% were direct healthcare costs. In univariate analysis costs were higher in the Netherlands than in Belgium, but this difference disappeared after adjusting for baseline differences in patients' characteristics among countries. Longer disease duration, lower education, worse physical function, and higher disease activity were predictors of costs. Mean annual direct costs from a financial perspective were euro;2122, euro;1402, and euro;941 per patient in the Netherlands, France, and Belgium, respectively. For each country, costs from a financial perspective were significantly lower than costs from a societal perspective. CONCLUSION: Direct costs for AS are substantial in three European countries but not significantly different after adjusting for baseline characteristics among countries. Worse physical function and higher disease activity are important determinants of costs, suggesting better disease control might reduce the costs of AS. The difference in costs from a societal and financial perspective emphasises the importance of an economic analysis.

Adolescent↗
PubMed2003

Costs of ankylosing spondylitis in three European countries: the patient's perspective.

OBJECTIVE: To assess a patient's out of pocket costs, income loss, time consumption, and quality of life (QoL) due to ankylosing spondylitis (AS) in three European countries and to assess variables predicting these outcomes. METHODS: 216 patients with AS from the Netherlands, France, and Belgium participated in a two year study. Health resource use, days absent from work, time lost, and quality of life (EuroQol) were assessed by bimonthly questionnaires. AS related healthcare and non-healthcare expenditure and income loss were calculated taking into account country-specific regulations. Predictors of costs, time consumption, and QoL were analysed by Cox's regression. RESULTS: 209 patients provided data for cost analysis. Average annual healthcare and non-healthcare expenditure was euro;431 per patient and average annual income loss was euro;1371 per patient. Healthcare costs were highest for Belgian and lowest for French patients, while non-healthcare costs were highest for Dutch patients. A patient's total costs were associated with higher age and worse physical function. On average, patients with AS needed 75 minutes additional time a day because of AS. Worse physical function and higher disease activity predicted time consumption. After adjusting for baseline confounders, QoL was worse in Belgian and French than in Dutch patients. Peripheral arthritis, worse physical function, higher disease activity, and loss of income contributed to worse QoL. CONCLUSION: AS is time consuming and associated with substantial out of pocket costs. Belgian patients incur the highest healthcare payments. Poor physical function increases patient's costs and time consumption. Loss of income is associated with lower QoL.

Adolescent↗
PubMed2002

Ankylosing spondylitis: what is the cost to society, and can it be reduced?

Ankylosing spondylitis is a chronic rheumatic disease leading to functional limitations. This has an important impact on participation in the labour force, with high disease-related work disability. As for cost-of-illness studies, which estimate the costs related to a disease, the cost of lost productivity is the major contributor to the total costs of ankylosing spondylitis. Because of the low prevalence of the disease, the costs related to ankylosing spondylitis are a relatively small part of the costs of all diseases to society. However, given the early and the important long-term functional loss, the lifetime costs and socio-economic impact for the individual patient are likely to be high. Because poor physical function is the major determinant of high direct and productivity costs, new (biological) treatments with effects on long-term functional disability will potentially reduce the economic impact of the disease for society and patients.

Cost of Illness↗
PubMed2002

Work status and productivity costs due to ankylosing spondylitis: comparison of three European countries.

OBJECTIVE: To compare work disability, sick leave, and productivity costs due to ankylosing spondylitis (AS) of three European countries. METHODS: 216 patients with AS from the Netherlands, France, and Belgium participated in a two year observational study. Employment and work disability rates at baseline were adjusted for age and sex. Productivity costs were calculated by both the friction cost method and the human capital approach. The adjusted contributions of country to employment, work disability, and having an episode of sick leave were assessed by logistic regression and the contribution of the country to days of sick leave and costs by Cox proportional hazard analysis. RESULTS: 209 patients completed the two years' follow up with sufficient data for cost analysis. Adjusted employment was 55% in the Netherlands as compared with 72% in both other countries and only in the Netherlands was it lower than expected in the general population. Adjusted work disability was 41%, 23%, and 9% in the Netherlands, France, and Belgium and in all countries was higher than expected in the general population. In those with a paid job, the mean number of days of sick leave per patient per year because of AS was 19 (range 0-130), six (range 0-77), and nine (range 0-60 ) in the Netherlands, France, and Belgium respectively. Applying the friction cost method to those with a paid job resulted in mean costs per patient per year of 1257 euros (range 0-7356), 428 euros (range 0-5979), and 476 euros (range 0-2354) in the Netherlands, France, and Belgium. Applying the human capital approach to the whole group resulted in mean costs per patient per year of 8862 euros (range 0-46 818), 3188 euros (range 0-43 550), and 3609 euros (range 0-34 320) in the three countries, respectively. After adjusting for sociodemographic and disease characteristics, living in the Netherlands, as compared with both other countries, was associated with a higher chance of being work disabled (odds ratio (OR)=3.82; 95% confidence interval (CI) 1.33 to 11.01), but not with the risk of having an episode of sick leave. Similarly, living in the Netherlands contributed independently to the number of days sick leave (OR=0.65; 95% CI 0.43 to 0.97), a higher amount of friction costs (OR=0.63; 95% CI 0.42 to 0.96), and a higher amount of human capital costs (OR=0.46; 95% CI 0.32 to 0.68). CONCLUSION: There are remarkable differences in work status and productivity costs between the three European countries. This has implications for the generalisability of health economic studies.

Adult↗
PubMed2002

Employment perspectives of patients with ankylosing spondylitis.

OBJECTIVES: To assess the labour market position of patients with ankylosing spondylitis (AS) in relation to disease duration and to identify potential factors in relation to withdrawal from the labour force. METHODS: A cross sectional mail survey was conducted among 658 patients with AS. Participation in the labour force was defined as having a paid job. The independent effect of duration of disease was examined by an indirect method of standardisation. A broad variety of risk factors were examined separately and in a combined analysis, including sociodemographic factors, disease related variables, coping styles, and work related factors. Attributable and preventable fractions were calculated from the combined analyses to assess the relative importance of the contributing factors. RESULTS: Probability of participation in the labour force was similarly reduced in patients with AS with different durations of disease. Pacing to cope with limitations was the most relevant factor in increasing the risk of withdrawal from the labour force, accounting for 73% of withdrawals. Coping with limitations by often seeking creative solutions, high disease activity, increased age, and insufficient support from colleagues or management were also positively associated with withdrawal from the labour force. Technical or ergonomic adjustments of the workplace, working in large companies, and coping with dependency style through frequent acceptance were negatively associated. Of these factors, technical or ergonomic adjustment was the most relevant in terms of reducing the risk. CONCLUSION: Sociodemographic factors, disease related factors, coping styles, and work related factors contribute simultaneously to withdrawal from the labour force.

Activities of Daily Living↗
PubMed2002

Ankylosing spondylitis: an overview.

Ankylosing spondylitis (AS) is a complex, potentially debilitating disease that is insidious in onset, progressing to radiological sacroiliitis over several years. Patients with symptomatic AS lose productivity owing to work disability and unemployment, have a substantial use of healthcare resources, and reduced quality of life. The pathogenesis of AS is poorly understood. However, immune mediated mechanisms involving human leucocyte antigen (HLA)-B27, inflammatory cellular infiltrates, cytokines (for example, tumour necrosis factor alpha and interleukin 10), and genetic and environmental factors are thought to have key roles. The detection of sacroiliitis by radiography, magnetic resonance imaging, or computed tomography in the presence of clinical manifestations is diagnostic for AS, although the presence of inflammatory back pain plus at least two other typical features of spondyloarthropathy (for example, enthesitis and uveitis) is highly predictive of early AS. Non-steroidal anti-inflammatory drugs (NSAIDs) effectively relieve inflammatory symptoms and are presently first line drug treatment. However, NSAID treatment has only a symptomatic effect and probably does not alter the disease course. For symptoms refractory to NSAIDs, second line treatments, including corticosteroids and various disease modifying antirheumatic drugs, are employed but are of limited benefit. Emerging biological therapies target the inflammatory processes underlying AS, and thus, may favourably alter the disease process, in addition to providing symptom relief.

Age of Onset↗
PubMed2001

Rhemulatologists' performance in dailiy practice.

OBJECTIVE: To assess rheumatologists' performance for 8 rheumatologic conditions and to explore possible explanatory factors. METHODS: After written informed consent was obtained, 27 rheumatologists (21% of all Dutch rheumatologists) practicing in 16 outpatient departments were each visited by 8 incognito "standardized patients" (SPs). The diagnoses of these 8 cases account for about 23% of all new referred patients in the Netherlands. Results for ordered lab tests as well as real radiographs with corresponding results from a radiologist were simulated. Information from the visits was obtained from the SPs, who completed predefined case-specific checklists, and by collecting data on resource utilization. Feedback was provided. RESULTS: Altogether 254 encounters took place, of which 201 were first visits and 53 were followup visits. SPs were unmasked twice during a visit. There was considerable variation in resource utilization (lab tests and imaging) between cases and between rheumatologists. Mean costs per rheumatologist ranged from US $ 4.67 to $ 65.36 per visit for lab tests and from US $ 33.15 to $ 226.84 per visit for imaging tests. No significant correlations were seen between resource utilization costs and number of years of clinical experience or performance on checklist scores. Rheumatologists with longer experience had lower total item checklist scores (r = -0.47; P < 0.05). CONCLUSION: A considerable variation in resource utilization was found among 27 Dutch rheumatologists. The information obtained is an excellent source for discussion on the appropriateness of care.

Adult↗
PubMed2001

Withdrawal from labour force due to work disability in patients with ankylosing spondylitis.

OBJECTIVE: To investigate withdrawal from the labour force because of inability to work owing to ankylosing spondylitis (AS) and to determine the characteristics of patients with no job because of work disability attributable to AS. METHODS: A postal questionnaire was sent to 709 patients with AS aged 16-60 years followed up by a rheumatologist. Kaplan-Meier survival statistics were used to assess the time lapse between diagnosis and withdrawal from work. Standardised incidence ratios were calculated to compare withdrawal from the labour force in patients with AS and the general population. Determinants of withdrawal were assessed by Cox's proportional hazard regression analysis using variables assumed to be time independent. Cross sectional characteristics of patients without a job owing to disability were further analysed by simple and multiple regression analyses. RESULTS: A total of 658 patients returned the questionnaire. Of 529 patients with a paid job before diagnosis of AS, 5% had left the labour force within the first year after the diagnosis, 13% after 5 years, 21% after 10 years, 23% after 15 years, and 31% after 20 years. Age and sex adjusted risk for withdrawal was 3.1 (95% CI 2.5 to 3.7) times higher than in the general population. In patients with AS, determinants of withdrawal from work were older age at diagnosis, manual work, and coping strategies characterised by limiting or adapting activities. Patients with work disability at the time of the study were older, came from a lower social class, and were more likely to have total hip replacement, peripheral arthritis, or comorbidity. Moreover, they reported worse physical function (BAS-FI), experienced lower quality of life, and more often had extraspinal disease than those with a job. CONCLUSION: Withdrawal from work is 3.1 times higher in patients with AS than expected in the general population. Within patients, higher age at diagnosis, manual work, and unfavourable coping strategies are important determinants of withdrawal. Patients without a job experience a lower quality of life.

Adaptation, Psychological↗
PubMed2001

Employment, work disability, and work days lost in patients with ankylosing spondylitis: a cross sectional study of Dutch patients.

OBJECTIVE: To evaluate employment status, work disability, and work days lost in patients with ankylosing spondylitis (AS). METHODS: A questionnaire was sent to 709 patients with AS aged 16-60. The results of 658 of the patients could be analysed. RESULTS: After adjustment for age, labour force participation was decreased by 15.4% in male patients and 5.2% in female patients compared with the general Dutch population. Work disability (all causes) was 15.7% and 16.9% higher than expected in the general population for male and female patients respectively. In particular, the proportion of those with a partial work disability pension was increased. Patients with a paid job lost 5.0% of work days as the result of having AS, accounting for a mean of 10.1 days of sick leave due to AS per patient per year in addition to the national average of 12.3 unspecified days of sick leave. CONCLUSION: This study on work status in AS provides data adjusted for age and sex, and the differences from the reference population were significant. The impact of AS on employment and work disability is considerable. Work status in patients with AS needs more attention as an outcome measure in future research.

Absenteeism↗
PubMed2001

Minimal clinically important difference in radiological progression of joint damage over 1 year in rheumatoid arthritis: preliminary results of a validation study with clinical experts.

To determine the minimal clinically important difference (MCID) between hand and foot films with a 1 year interval assessed with the Sharp/van der Heijde or Larsen/Scott scoring method. Progression scores of the 2 methods were compared with the opinion of an international expert panel on clinical relevance of radiological joint damage in 4 predefined clinical settings. The expert panel consisted of 3 rheumatologists, who evaluated 46 pairs of hand and foot films, taken with 1 year intervals, of patients with early rheumatoid arthritis. Receiver operating characteristics curves analyzed the accuracy of different threshold values (progression scores) of the 2 scoring methods to detect the presence or absence of clinically important difference, as defined by the expert panel as external criterion. The threshold value with the highest accuracy was subsequently chosen as the score representing the MCID. Five Sharp/van der Heijde units and 2 Larsen/Scott units were the best cutoffs. The accompanying sensitivities ranged from 77% to 100% for the Sharp/van der Heijde method and from 73% to 84% for the Larsen/Scott method for the 4 clinical settings. The specificities were between 78% and 84% for the Sharp/van der Heijde method and between 74% and 94% for the Larsen/Scott method. The smallest progression score that can be detected apart from interobserver measurement error, the smallest detectable difference (SDD), was equal to or larger than the calculated MCID, 5 Sharp/van der Heijde units and 6 Larsen/Scott units in our study, if the mean progression scores of the same 2 observers were used. The SDD is a conservative estimate of the MCID; our panel rated progression at or below this level as clinically significant.

Arthritis, Rheumatoid↗
PubMed2001

Robustness and generalizability of smallest detectable difference in radiological progression.

The smallest detectable difference (SDD) reflects that component of a measure statistically attributable to error from the measurement process itself. As such it is an irreducible component of the inherent variability in measurements in clinical trials and will affect their design, whether randomized or observational. Even though the application of the SDD concept to assaying radiographs in rheumatoid arthritis is relatively new and not well understood, systematic work on the influences of radiographic SDD can be done. This report describes the effects of a number of clinical aspects of the disease and operational aspects of trials on the values of the SDD of radiographic progression data. We show that if conditions affecting SDD are known and kept constant across datasets, the SDD of radiological progression from one study may be generalizable to other studies. However, if any one condition varies, the SDD is distinctly unrobust and cannot be generalized to other studies.

Arthritis, Rheumatoid↗
PubMed2001

Work status and its determinants among patients with ankylosing spondylitis. A systematic literature review.

OBJECTIVE: To evaluate work status and its determinants among patients with ankylosing spondylitis (AS). METHODS: A systematic literature review of original studies published after 1980 in which work status in AS was an outcome. Medline was searched and references of retrieved reports were checked for additional studies. RESULTS: Sixteen full articles and 2 abstracts were identified, describing work status in 14 patient groups. Employment ranged from 34 to 96% after 45 and 5 years disease duration, respectively, and work disability from 3 to 50% after 18 and 45 years disease duration, respectively. Days of sick leave varied from 12 to 46 days per patient per year among those who had a paid job. Determinants of work status were reported in 9 studies. Age, education, and physical function were shown to be associated with work disability, while peripheral joint disease was associated with sick leave. CONCLUSION: Results on work status show considerable variability due to heterogeneity of patient populations studied, but also because of large variation in choices and definitions of endpoints. The absence of data referring to a reference population and failure to adjust results for age and sex are striking. Although standardization in analyzing and reporting data on work status is badly needed, it is clear that work disability and sick leave in AS are substantial.

Cost of Illness↗