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Biomedical subjects

Lex M Bouter

Publications and source records attributed to Lex M Bouter.

At least 19 recordsLinked to original sources
PubMed2007

Radiographic hip disorders and associated complications in severe cerebral palsy.

We performed a cross-sectional study of 160 adult patients with severe cerebral palsy to study the relationship between radiographic hip disorders (migration and deformity of the femoral head), on the one hand, and complications such as handling problems, seating problems, decubitus ulcers, fractures and contractures, on the other hand. Both migration and deformity were positively related to the need for a special seat in the wheelchair and adduction contractures of the hip. We conclude that migration and deformity of the femoral head, if possible, should be prevented in patients with severe cerebral palsy.

Adult↗
PubMed2007

Cost effectiveness of a pharmacy-based coaching programme to improve adherence to antidepressants.

INTRODUCTION: The efficacy of antidepressants in the treatment of depression has been convincingly demonstrated in randomised trials. However, non-adherence to antidepressant treatment is common. OBJECTIVE: To evaluate, from a societal perspective, the cost effectiveness of a pharmacy-based intervention to improve adherence to antidepressant therapy in adult patients receiving treatment in primary care. METHODS: An economic evaluation was performed alongside a 6-month randomised controlled trial in The Netherlands. Patients who came to 19 pharmacies with a new prescription for a non-tricyclic antidepressant, i.e. those who had not received any prescription for an antidepressant in the past 6 months, were invited to participate. They were then randomly allocated to education and coaching by the pharmacist or to usual care. The coaching programme consisted of three contacts with the pharmacist, with a mean duration of between 13 and 20 minutes, and a take-home video reviewing important facts on depression and antidepressant treatment. The clinical outcome measures were adherence to antidepressant treatment measured using an electronic pill container (eDEM) and improvement in depressive symptoms measured using the Hopkins Symptom Checklist (SCL). Resource use was measured by means of questionnaires. The uncertainty around differences in costs and cost effectiveness between the treatment groups was evaluated using bootstrapping. RESULTS: Seventy patients were randomised to the intervention group and 81 to the usual care group; of these, 40 in the intervention group and 48 in the control group completed all of the follow-up questionnaires. There were no significant differences in adherence, improvements in the SCL depression mean item score and costs over 6 months between the two treatment groups. Mean total costs (2002 values) were 3275 euros in the intervention group and 2961 euros in the control group (mean difference 315 euros; 95% CI -1922, 2416). The incremental cost-effectiveness ratio associated with the pharmacist intervention was 149 euros per 1% improvement in adherence and 2550 euros per point improvement in the SCL depression mean item score. Cost-effectiveness planes and acceptability curves indicated that the pharmacist intervention was not likely to be cost effective compared with usual care. CONCLUSION: In patients starting treatment with antidepressants, there were no significant differences in adherence, severity of depression, costs and cost effectiveness between patients receiving coaching by a pharmacist and patients receiving usual care after 6 months. Considering the resources needed to implement an intervention like this in clinical practice, based on these results, the continuation of usual care is recommended.

Adult↗
PubMed2006

A prediction rule for shoulder pain related sick leave: a prospective cohort study.

BACKGROUND: Shoulder pain is common in primary care, and has an unfavourable outcome in many patients. Information about predictors of shoulder pain related sick leave in workers is scarce and inconsistent. The objective was to develop a clinical prediction rule for calculating the risk of shoulder pain related sick leave for individual workers, during the 6 months following first consultation in general practice. METHODS: A prospective cohort study with 6 months follow-up was conducted among 350 workers with a new episode of shoulder pain. Potential predictors included the results of a physical examination, sociodemographic variables, disease characteristics (duration of symptoms, sick leave in the 2 months prior to consultation, pain intensity, disability, comorbidity), physical activity, physical work load, psychological factors, and the psychosocial work environment. The main outcome measure was sick leave during 6 months following first consultation in general practice. RESULTS: Response rate to the follow-up questionnaire at 6 months was 85%. During the 6 months after first consultation 30% (89/298) of the workers reported sick leave. 16% (47) reported 10 days sick leave or more. Sick leave during this period was predicted in a multivariable model by a longer duration of sick leave prior to consultation, more shoulder pain, a perceived cause of strain or overuse during regular activities, and co-existing psychological complaints. The discriminative ability of the prediction model was satisfactory with an area under the curve of 0.70 (95% CI 0.64-0.76). CONCLUSION: Although 30% of all workers with shoulder pain reported sick leave during follow-up, the duration of sick leave was limited to a few days in most workers. We developed a prediction rule and a score chart that can be used by general practitioners and occupational health care providers to calculate the absolute risk of sick leave in individual workers with shoulder pain, which may help to identify workers who need additional attention. The performance and applicability of our model needs to be tested in other working populations with shoulder pain to enable valid and reliable use of the score chart in everyday practice.

Disability Evaluation↗
PubMed2006

Surgery is more cost-effective than splinting for carpal tunnel syndrome in the Netherlands: results of an economic evaluation alongside a randomized controlled trial.

BACKGROUND: Carpal tunnel syndrome (CTS) is a common disorder, often treated with surgery or wrist splinting. The objective of this economic evaluation alongside a randomized trial was to evaluate the cost-effectiveness of splinting and surgery for patients with CTS. METHODS: Patients at 13 neurological outpatient clinics with clinically and electrophysiologically confirmed idiopathic CTS were randomly allocated to splinting (n = 89) or surgery (n = 87). Clinical outcome measures included number of nights waking up due to symptoms, general improvement, severity of the main complaint, paraesthesia at night and during the day, and utility. The economic evaluation was performed from a societal perspective and involved all relevant costs. RESULTS: There were no differences in costs. The mean total costs per patient were in the surgery group EURO 2,126 compared to EURO 2,111 in the splint group. After 12 months, the success rate in the surgery group (92%) was significantly higher than in the splint group (72%). The acceptability curve showed that at a relatively low ceiling ratio of EURO 2,500 per patient there is a 90% probability that surgery is cost-effective. CONCLUSION: In the Netherlands, surgery is more cost-effective compared with splinting, and recommended as the preferred method of treatment for patients with CTS.

Carpal Tunnel Syndrome↗
PubMed2006

Costs of shoulder pain in primary care consulters: a prospective cohort study in The Netherlands.

BACKGROUND: Shoulder pain is common in primary care, and has an unfavourable outcome in many patients. Information on the costs associated with health care use and loss of productivity in patients with shoulder pain is very scarce. The objective of this study was to determine shoulder pain related costs during the 6 months after first consultation in general practice METHODS: A prospective cohort study consisting of 587 patients with a new episode of shoulder pain was conducted with a follow-up period of 6 months. Data on costs were collected by means of a cost diary during 6 months. RESULTS: 84% of the patients completed all cost diaries. The mean consumption of direct health care and non-health related care was low. During 6 months after first consultation for shoulder pain, the mean total costs a patient generated were 689 euro. Almost 50% of this total concerned indirect costs, caused by sick leave from paid work. A small proportion (12%) of the population generated 74% of the total costs. CONCLUSION: The total costs in the 6 months after first consultation for shoulder pain in primary care, mostly generated by a small part of the population, are not alarmingly high.

Activities of Daily Living↗
PubMed2006

Minimally important change determined by a visual method integrating an anchor-based and a distribution-based approach.

BACKGROUND: Minimally important changes (MIC) in scores help interpret results from health status instruments. Various distribution-based and anchor-based approaches have been proposed to assess MIC. OBJECTIVES: To describe and apply a visual method, called the anchor-based MIC distribution method, which integrates both approaches. METHOD: Using an anchor, patients are categorized as persons with an important improvement, an important deterioration, or without important change. For these three groups the distribution of the change scores on the health status instrument are depicted in a graph. We present two cut-off points for an MIC: the ROC cut-off point and the 95% limit cut-off point. RESULTS: We illustrate our anchor-based MIC distribution method determining the MIC for the Pain Intensity Numerical Rating Scale in patients with low back pain, using two conceivable definitions of minimal important change on the anchor. The graph shows the distribution of the scores of the health status instrument for the relevant categories on the anchor, and also the consequences of choosing the ROC cut-off point or the 95% limit cut-off point. DISCUSSION: The anchor-based MIC distribution method provides a general framework, applicable to all kind of anchors. This method forces researchers to choose and justify their choice of an appropriate anchor and to define minimal importance on that anchor. The MIC is not an invariable characteristic of a measurement instrument, but may depend, among other things, on the perspective from which minimal importance is considered and the baseline values on the measurement instrument under study. A balance needs to be struck between the practicality of a single MIC value and the validity of a range of MIC values.

Health Status Indicators↗
PubMed2006

Quality criteria were proposed for measurement properties of health status questionnaires.

OBJECTIVES: Recently, an increasing number of systematic reviews have been published in which the measurement properties of health status questionnaires are compared. For a meaningful comparison, quality criteria for measurement properties are needed. Our aim was to develop quality criteria for design, methods, and outcomes of studies on the development and evaluation of health status questionnaires. STUDY DESIGN AND SETTING: Quality criteria for content validity, internal consistency, criterion validity, construct validity, reproducibility, longitudinal validity, responsiveness, floor and ceiling effects, and interpretability were derived from existing guidelines and consensus within our research group. RESULTS: For each measurement property a criterion was defined for a positive, negative, or indeterminate rating, depending on the design, methods, and outcomes of the validation study. CONCLUSION: Our criteria make a substantial contribution toward defining explicit quality criteria for measurement properties of health status questionnaires. Our criteria can be used in systematic reviews of health status questionnaires, to detect shortcomings and gaps in knowledge of measurement properties, and to design validation studies. The future challenge will be to refine and complete the criteria and to reach broad consensus, especially on quality criteria for good measurement properties.

Evaluation Studies as Topic↗
PubMed2006

Minimal changes in health status questionnaires: distinction between minimally detectable change and minimally important change.

Changes in scores on health status questionnaires are difficult to interpret. Several methods to determine minimally important changes (MICs) have been proposed which can broadly be divided in distribution-based and anchor-based methods. Comparisons of these methods have led to insight into essential differences between these approaches. Some authors have tried to come to a uniform measure for the MIC, such as 0.5 standard deviation and the value of one standard error of measurement (SEM). Others have emphasized the diversity of MIC values, depending on the type of anchor, the definition of minimal importance on the anchor, and characteristics of the disease under study. A closer look makes clear that some distribution-based methods have been merely focused on minimally detectable changes. For assessing minimally important changes, anchor-based methods are preferred, as they include a definition of what is minimally important. Acknowledging the distinction between minimally detectable and minimally important changes is useful, not only to avoid confusion among MIC methods, but also to gain information on two important benchmarks on the scale of a health status measurement instrument. Appreciating the distinction, it becomes possible to judge whether the minimally detectable change of a measurement instrument is sufficiently small to detect minimally important changes.

Attitude to Health↗
PubMed2006

Do psychological factors predict outcome in both low-back pain and shoulder pain?

BACKGROUND AND OBJECTIVE: Psychological factors are assumed to predict persistent or recurrent musculoskeletal pain. The influence of psychological factors in patients with low-back pain (LBP) or shoulder pain was explored to study whether there is similarity regarding the factors that predict persisting pain and disability. METHODS: Patients presenting in primary care with a new episode of shoulder pain or non-specific (sub)acute low back pain (LBP) were enrolled in a prospective study. In both patient groups, pain catastrophising, distress, somatisation and fear-avoidance beliefs were measured at baseline. Primary outcome measures at 3 months were (1) persistent symptoms, and (2) <30% reduction in functional disability. Multivariate logistic regression analysis was used to study the associations between psychological factors and outcome. RESULTS: A total of 587 patients with shoulder pain and 171 patients with LBP were enrolled in the study. In patients with shoulder pain, most associations of psychological factors with outcome were weak and not significant. Only in patients with longer symptom duration at baseline (>or=3 months) were higher scores on catastrophising significantly associated with persistent symptoms (p = 0.04). In patients with LBP, psychological factors were more strongly associated with poor outcome, although most associations were not significant. CONCLUSION: Psychological factors, with the exception of fear-avoidance beliefs, are more strongly associated with persistent pain and disability in patients with LBP than in those with shoulder pain. This seems to indicate that in a primary care population the influence of psychological factors on outcome may vary across patients with different types of pain.

Adult↗
PubMed2006

When to use agreement versus reliability measures.

BACKGROUND: Reproducibility concerns the degree to which repeated measurements provide similar results. Agreement parameters assess how close the results of the repeated measurements are, by estimating the measurement error in repeated measurements. Reliability parameters assess whether study objects, often persons, can be distinguished from each other, despite measurement errors. In that case, the measurement error is related to the variability between persons. Consequently, reliability parameters are highly dependent on the heterogeneity of the study sample, while the agreement parameters, based on measurement error, are more a pure characteristic of the measurement instrument. METHODS AND RESULTS: Using an example of an interrater study, in which different physical therapists measure the range of motion of the arm in patients with shoulder complaints, the differences and relationships between reliability and agreement parameters for continuous variables are illustrated. CONCLUSION: If the research question concerns the distinction of persons, reliability parameters are the most appropriate. But if the aim is to measure change in health status, which is often the case in clinical practice, parameters of agreement are preferred.

Humans↗
PubMed2006

Lateral epicondylitis in general practice: course and prognostic indicators of outcome.

OBJECTIVE: To investigate the course of lateral epicondylitis and identify prognostic indicators associated with short- and longterm outcome of pain intensity. METHODS: We prospectively followed patients (n = 349) from 2 randomized controlled trials investigating conservative interventions for lateral epicondylitis in primary care. Uni- and multivariate linear regression analyses were used to investigate the association between potential prognostic indicators and pain intensity (0-100 point scale) measured at 1, 6, and 12 months after randomization. Potential prognostic factors were duration of elbow complaints, concomitant neck pain, concomitant shoulder pain, previous elbow complaints, baseline pain scores, age, gender, involvement of dominant side, social class, and work status. The variables "study" and "treatment" were included as covariates in all models. RESULTS: Pain scores at 1 month followup were higher in patients with severe pain, a long duration of elbow complaints, and concomitant shoulder pain. At 12 month followup, the only different prognostic indicator for poor outcome was concomitant neck pain, in place of shoulder pain. Patients from higher social classes reported lower pain scores at 12 month followup than patients from lower social classes. CONCLUSIONS: Lateral epicondylitis seems to be a self-limiting condition in most patients. Long duration of elbow complaints, concomitant neck pain, and severe pain at presentation are associated with poor outcome at 12 months. Our results will help care providers give patients accurate information regarding their prognosis and assist in medical decision-making.

Adult↗
PubMed2006

Predictors of outcome in patients with (sub)acute low back pain differ across treatment groups.

STUDY DESIGN: Prospective study with 6 weeks of follow-up. OBJECTIVE: To examine the predictors of outcome for patients with (sub)acute low back pain (LBP) receiving usual care (UC) or a minimal intervention strategy (MIS) aimed at psychosocial factors. SUMMARY OF BACKGROUND DATA: A randomized controlled trial in general practice showed no differences in average effect between UC and MIS. METHODS: Socio-demographic variables, characteristics of LBP, and psychosocial factors were included as potential predictors of outcome. The outcome clinically important improvement was defined as a reduction of at least 30% on functional disability plus patient perceived recovery. Logistic regression analyses were used to study the associations between predictors and outcome at 6 weeks follow-up. RESULTS: In the UC group (n = 163), the multivariable model included a shorter duration of the LBP episode, few previous episodes, less pain catastrophizing, and good perceived general health. The area under the curve (AUC) of the model was 0.77 (95% confidence interval, 0.70-0.85). In the MIS group (n = 142), the multivariable model included less somatizing symptoms, more solicitous responses by an important other, lower perceived risk for chronic LBP, more fear avoidance beliefs, higher level of education, and shorter duration of the LBP episode. This AUC was 0.78 (95% confidence interval, 0.71-0.86). CONCLUSIONS: As we found two different profiles, our approach may contribute to the important question: what intervention works for whom?

Acute Disease↗
PubMed2006

Clinical heterogeneity was a common problem in Cochrane reviews of physiotherapy and occupational therapy.

BACKGROUND AND OBJECTIVE: To identify the strategies used to deal with the clinical heterogeneity of interventions and multiple outcome measures used in Cochrane reviews on physiotherapy and occupational therapy. METHODS: A search for systematic reviews on physiotherapy and occupational therapy in the Cochrane Library was performed. Data on the method of categorization of interventions, on measures, and on the method of data synthesis were systematically extracted. RESULTS: 52 reviews were identified. In 22 (42%) reviews only one index intervention was evaluated, in the other 30 reviews index interventions were categorized. A large diversity in the number and type of outcome measures was found (median 6.5, range 1-23). In 48% of the reviews one or more primary outcome measures were defined. In 52% of the reviews no quantitative data synthesis was performed, whereas five different methods for qualitative data synthesis were applied in 11 reviews. CONCLUSIONS: Limitation to a few outcome measures and explicit procedures for the categorization of interventions might increase the transparency and reproducibility of systematic reviews on physiotherapy and occupational therapy. Qualitative data synthesis is not often applied, although it is a useful tool to summarize results if a quantitative synthesis is not appropriate. International consensus on a method for qualitative synthesis is clearly needed.

Data Interpretation, Statistical↗
PubMed2006

Does updating improve the methodological and reporting quality of systematic reviews?

BACKGROUND: Systematic reviews (SRs) must be of high quality. The purpose of our research was to compare the methodological and reporting quality of original versus updated Cochrane SRs to determine whether updating had improved these two quality dimensions. METHODS: We identified updated Cochrane SRs published in issue 4, 2002 of the Cochrane Library. We assessed the updated and original versions of the SRs using two instruments: the 10 item enhanced Overview Quality Assessment Questionnaire (OQAQ), and an 18-item reporting quality checklist and flow chart based upon the Quality of Reporting of Meta-analyses (QUOROM) statement. At least two reviewers extracted data and assessed quality. We calculated the percentage (with a 95% confidence interval) of 'yes' answers to each question. We calculated mean differences in percentage, 95% confidence intervals and p-values for each of the individual items and the overall methodological quality score of the updated and pre-updated versions using OQAQ. RESULTS: We assessed 53 SRs. There was no significant improvement in the global quality score of the OQAQ (mean difference 0.11 (-0.28; 0.70 p = 0.52)). Updated reviews showed a significant improvement of 18.9 (7.2; 30.6 p < .01) on the OQAQ item assessing whether the conclusions drawn by the author(s) were supported by the data and/or analysis presented in the SR. The QUOROM statement showed that the quality of reporting of Cochrane reviews improved in some areas with updating. Improvements were seen on the items relating to data sources reported in the abstract, with a significant difference of 17.0 (9.8; 28.7 p = 0.01), review methods, reported in the abstract 35 (24.1; 49.1 p = 0.00), searching methods 18.9 (9.7; 31.6 p = 0.01), and data abstraction 18.9 (11.7; 30.9 p = 0.00). CONCLUSION: The overall quality of Cochrane SRs is fair-to-good. Although reporting quality improved on certain individual items there was no overall improvement seen with updating and methodological quality remained unchanged. Further improvement of quality of reporting is possible. There is room for improvement of methodological quality as well. Authors updating reviews should address identified methodological or reporting weaknesses. We recommend to give full attention to both quality domains when updating SRs.

Bibliometrics↗
PubMed2006

Applicability and clinical relevance of results in randomized controlled trials: the Cochrane review on exercise therapy for low back pain as an example.

STUDY DESIGN: A critical appraisal of the literature. OBJECTIVES: To increase awareness of the importance of applicability and clinical relevance of the results of randomized controlled trials (RCTs) in the field of spinal disorders by formulating a list of items for assessment of applicability and clinical relevance of results of RCTs. SUMMARY OF BACKGROUND DATA: In systematic reviews of randomized controlled trials (RCTs), critical appraisal of methodologic quality is considered important. Less attention has been paid to the assessment of the applicability and the clinical relevance of the results. METHODS: RCTs in an update of the Cochrane review on exercise therapy for low back pain were used. Most of the trials did not score positively on the five Cochrane Back Review Group basic items describing patients: intervention and setting, outcome, effect size, and benefits related to adverse effects. Item 1 was met by 88% of the trials, but item 2 only by 51%, item 3 by 67%, item 4 by 35%, and item 5 by 0%. Subsequently, a more comprehensive list of items for the assessment of applicability and clinical relevance of results of RCTs was developed. These criteria were pilot tested on the RCTs. After pilot testing and a subsequent consensus meeting, the list of items was drafted and circulated among the members of the Editorial Board of the Cochrane Back Review Group. Changes were made in response to comments. RESULTS: The final list consists of 40 items. The items are ordered on two headings: Does the report enable the assessment of applicability? Are the study results clinically relevant? We present examples of informative and noninformative reporting of RCTs in order to illustrate how information on applicability and clinical relevance of results can be assessed. CONCLUSIONS: Authors of RCTs should adequately report on items that are essential to assess the applicability and clinical relevance of results. The presented list of items may help clinicians reading RCTs and authors of systematic reviews to draw more balanced conclusions on applicability and clinical relevance of results.

Humans↗
PubMed2006

Alanine aminotransferase predicts coronary heart disease events: a 10-year follow-up of the Hoorn Study.

Alanine aminotransferase (ALT) is a marker of non-alcoholic fatty liver disease (NAFLD) and predicts incident type 2 diabetes mellitus (DM2). Recently, ALT was shown to be also associated with endothelial dysfunction and carotid atherosclerosis. We studied the predictive value of ALT for all-cause mortality, incident cardiovascular disease (CVD) and coronary heart disease (CHD) events in a population-based cohort of Caucasian men and women aged 50-75 years, at baseline. The 10-year risk of all-cause mortality, fatal and non-fatal CVD and CHD events in relation to ALT was assessed in 1439 subjects participating in the Hoorn Study, using Cox survival analysis. Subjects with prevalent CVD/CHD and missing data were excluded. As compared with the first tertile, the age- and sex-adjusted hazard ratios (95% confidence intervals) for all-cause mortality, CVD events and CHD events were 1.30 (0.92-1.83), 1.40 (1.09-1.81) and 2.04 (1.35-3.10), respectively, for subjects in the upper tertile of ALT. After adjustment for components of the metabolic syndrome and traditional risk factors, the association of ALT and CHD events remained significant for subjects in the third relative to those in the first tertile, with a hazard ratio of 1.88 (1.21-2.92) and 1.75 (1.12-2.73), respectively. In conclusion, the predictive value of ALT for coronary events, seems independent of traditional risk factors and the features of the metabolic syndrome in a population-based cohort. Further studies should confirm these findings and elucidate the pathophysiological mechanisms.

Aged↗
PubMed2006

Reproducibility of the STARD checklist: an instrument to assess the quality of reporting of diagnostic accuracy studies.

BACKGROUND: In January 2003, STAndards for the Reporting of Diagnostic accuracy studies (STARD) were published in a number of journals, to improve the quality of reporting in diagnostic accuracy studies. We designed a study to investigate the inter-assessment reproducibility, and intra- and inter-observer reproducibility of the items in the STARD statement. METHODS: Thirty-two diagnostic accuracy studies published in 2000 in medical journals with an impact factor of at least 4 were included. Two reviewers independently evaluated the quality of reporting of these studies using the 25 items of the STARD statement. A consensus evaluation was obtained by discussing and resolving disagreements between reviewers. Almost two years later, the same studies were evaluated by the same reviewers. For each item, percentages agreement and Cohen's kappa between first and second consensus assessments (inter-assessment) were calculated. Intraclass Correlation coefficients (ICC) were calculated to evaluate its reliability. RESULTS: The overall inter-assessment agreement for all items of the STARD statement was 85% (Cohen's kappa 0.70) and varied from 63% to 100% for individual items. The largest differences between the two assessments were found for the reporting of the rationale of the reference standard (kappa 0.37), number of included participants that underwent tests (kappa 0.28), distribution of the severity of the disease (kappa 0.23), a cross tabulation of the results of the index test by the results of the reference standard (kappa 0.33) and how indeterminate results, missing data and outliers were handled (kappa 0.25). Within and between reviewers, also large differences were observed for these items. The inter-assessment reliability of the STARD checklist was satisfactory (ICC = 0.79 [95% CI: 0.62 to 0.89]). CONCLUSION: Although the overall reproducibility of the quality of reporting on diagnostic accuracy studies using the STARD statement was found to be good, substantial disagreements were found for specific items. These disagreements were not so much caused by differences in interpretation of the items by the reviewers but rather by difficulties in assessing the reporting of these items due to lack of clarity within the articles. Including a flow diagram in all reports on diagnostic accuracy studies would be very helpful in reducing confusion between readers and among reviewers.

Advisory Committees↗