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Nynke Smidt

Publications and source records attributed to Nynke Smidt.

At least 19 recordsLinked to original sources
PubMed2006

Health-related quality of life of firefighters and police officers 8.5 years after the air disaster in Amsterdam.

BACKGROUND: In 1992 a cargo aircraft crashed into apartment buildings in Amsterdam. In the troublesome aftermath rumours emerged on potential toxic exposures and health consequences. The aim of this study is to assess the long-term impact of this disaster on the health-related quality of life (HRQoL) of professional assistance workers. METHODS: Historic cohort study, using questionnaires to assess occupational disaster exposure, HRQoL (SF36), and background variables, at on average 8.5 years post-disaster. Participating were the exposed professional firefighters (n = 334) and police officers (n = 834) who reported disaster-related task(s), and their non-exposed colleagues who did not report such tasks (n = 194, and n = 634, respectively). RESULTS: Multivariate logistic regression analysis showed that exposed workers reported a significantly lower physical HRQoL and vitality than non-exposed workers. Exposed police officers also reported a lower mental HRQoL. Among exposed workers, a lower HRQoL was reported significantly more often by workers who had a close one affected by the disaster; by firefighters who rescued people, cleaned-up, or witnessed the immediate disaster scene; and by police officers who supported the injured. Exposed police officers who perceived the disaster as 'not bad' reported a lower HRQoL less often than those to whom it was 'the worst ever'. CONCLUSIONS: This study demonstrates that professional disaster assistance workers are at risk for a lower HRQoL, even after years.

Accidents, Aviation↗
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

Attribution of physical complaints to the air disaster in Amsterdam by exposed rescue workers: an epidemiological study using historic cohorts.

BACKGROUND: In 1992 a cargo aircraft crashed into a residential area of Amsterdam. A troublesome aftermath followed, with rumors on potential toxic exposures and health consequences. Health concerns remained even though no excess morbidity was predicted in retrospective risk evaluations. This study aimed to assess to what extent the rescue workers attribute long-term physical complaints to this disaster, including its aftermath, and to examine associations between such attribution and types of exposure and background variables. METHODS: Historic cohort study that collected questionnaire data on occupational disaster exposure, attribution of physical complaints, and background variables on average 8.5 years post-disaster. For the present study the workers who were exposed to the disaster were selected from the historic cohort, i.e. the professional firefighters (n = 334), police officers (n = 834), and accident and wreckage investigators (n = 241) who performed disaster-related tasks. RESULTS: Across the three occupational groups, a consistent percentage (ranging from 43% to 49%) of exposed workers with long-term physical complaints attributed these to the disaster, including its aftermath. Those with more physical complaints attributed these to a stronger degree. Multivariate logistic regression analyses showed that attribution was significantly more often reported by firefighters who rescued people, and by police officers who reported the identification and recovery of or search for victims and human remains, clean-up, or security and surveillance of the disaster area; who witnessed the immediate disaster scene; who had a close one affected by the disaster; and who perceived the disaster as the worst thing that ever happened to them. Age, sex and educational level were not significantly associated with attribution. CONCLUSION: This study provides further cross-sectional evidence for the role of causal attribution in post-disaster subjective physical health problems. After on average 8.5 years, almost a third (32%) of all the exposed workers, and almost half (45%) of the exposed workers with physical complaints, attributed these complaints to the disaster, including its aftermath. The similarity of the results across the occupational groups suggests a general rather than an occupation-specific attribution process. Longitudinal studies are needed to determine whether causal disaster attribution leads to persistence of post-disaster complaints and health care utilization.

Accidents, Aviation↗
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↗
PubMed2006

Evidence of bias and variation in diagnostic accuracy studies.

BACKGROUND: Studies with methodologic shortcomings can overestimate the accuracy of a medical test. We sought to determine and compare the direction and magnitude of the effects of a number of potential sources of bias and variation in studies on estimates of diagnostic accuracy. METHODS: We identified meta-analyses of the diagnostic accuracy of tests through an electronic search of the databases MEDLINE, EMBASE, DARE and MEDION (1999-2002). We included meta-analyses with at least 10 primary studies without preselection based on design features. Pairs of reviewers independently extracted study characteristics and original data from the primary studies. We used a multivariable meta-epidemiologic regression model to investigate the direction and strength of the association between 15 study features on estimates of diagnostic accuracy. RESULTS: We selected 31 meta-analyses with 487 primary studies of test evaluations. Only 1 study had no design deficiencies. The quality of reporting was poor in most of the studies. We found significantly higher estimates of diagnostic accuracy in studies with nonconsecutive inclusion of patients (relative diagnostic odds ratio [RDOR] 1.5, 95% confidence interval [CI] 1.0-2.1) and retrospective data collection (RDOR 1.6, 95% CI 1.1-2.2). The estimates were highest in studies that had severe cases and healthy controls (RDOR 4.9, 95% CI 0.6-37.3). Studies that selected patients based on whether they had been referred for the index test, rather than on clinical symptoms, produced significantly lower estimates of diagnostic accuracy (RDOR 0.5, 95% CI 0.3-0.9). The variance between meta-analyses of the effect of design features was large to moderate for type of design (cohort v. case-control), the use of composite reference standards and the use of differential verification; the variance was close to zero for the other design features. INTERPRETATION: Shortcomings in study design can affect estimates of diagnostic accuracy, but the magnitude of the effect may vary from one situation to another. Design features and clinical characteristics of patient groups should be carefully considered by researchers when designing new studies and by readers when appraising the results of such studies. Unfortunately, incomplete reporting hampers the evaluation of potential sources of bias in diagnostic accuracy studies.

Clinical Trials as Topic↗
PubMed2006

Epidemiological disaster research: the necessity to include representative samples of the involved disaster workers. Experience from the epidemiological study air disaster Amsterdam-ESADA.

OBJECTIVE: To study whether the methods used to select participants in research on prevalence rates of the health effects of exposure to a disaster may cause bias. This study compared background characteristics, disaster exposure, and complaints reported by (1) police officers who participated in an epidemiological study and underwent a medical examination, and (2) police officers who only participated in an epidemiological study. DESIGN AND SETTING: In 2000, an epidemiological study was started to investigate the health status among police officers who were involved in assistance work related to the air disaster in Amsterdam: the epidemiological study air disaster Amsterdam (ESADA). These police officers were personally invited to participate in the epidemiological study and were additionally offered a medical examination, providing them with the opportunity to have their health checked by a medical doctor. PARTICIPANTS: Of the total group of involved police officers who were invited, 834 (70%) participated in the ESADA: 224 (26.9%) only participated in the study, but 610 (73.1%) also underwent the medical examination. MAIN RESULTS: Police officers who underwent a medical examination significantly more often reported one or more musculoskeletal complaints, skin complaints, general or non-specific complaints, had more often experienced an event with potentially traumatic impact, or had performed one or more potentially traumatic tasks. CONCLUSIONS: The methods of selection of participants are important in research on health effects after disasters and can result in an overestimation of some of the effects, on average, by a factor of 1.5 to 2.

Accidents, Aviation↗
PubMed2006

Systematic review of the efficacy and safety of shock wave therapy for lateral elbow pain.

OBJECTIVE: To determine the efficacy and safety of extracorporeal shock wave therapy (ESWT) for lateral elbow pain. METHODS: Systematic review of randomized controlled trials using Cochrane Collaboration methodology. RESULTS: Nine placebo-controlled trials (1006 participants) and one trial of ESWT versus steroid injection (93 participants) were included. The 9 placebo-controlled trials reported conflicting results, although 11 of 13 pooled analyses found no significant benefit of ESWT over placebo, e.g., weighted mean difference for improvement in pain (on a 100-point scale) from baseline to 4-6 weeks (pooled analysis of 3 trials, 446 participants) was -9.42 (95% CI -20.70 to 1.86). Two pooled results favored ESWT, e.g., relative risk of treatment success (at least 50% improvement in pain with resisted wrist extension at 12 weeks) for ESWT in comparison to placebo (pooled analysis of 2 trials, 192 participants) was 2.2 (95% CI 1.55 to 3.12). However, this finding was not supported by the results of 4 other trials that were unable to be pooled. Steroid injection was more effective than ESWT at 3 months after the end of treatment assessed by a reduction of pain of 50% from baseline [21/25 (84%) vs 29/48 (60%); p < 0.05]. Minimal adverse effects of ESWT were reported. CONCLUSION: Based upon systematic review of 9 placebo-controlled trials, there is "platinum" level evidence that ESWT provides little or no benefit in terms of pain and function in lateral elbow pain. There is "silver" level evidence based upon one trial that steroid injection may be more effective than ESWT.

Clinical Trials as Topic↗
PubMed2005

Epidemiologic study of the autoimmune health effects of a cargo aircraft disaster.

BACKGROUND: In the aftermath of a cargo aircraft crash in Amsterdam in 1992, indications of autoimmune disorders appeared in some of the affected population. METHODS: This epidemiologic study sought to determine the possible long-term autoimmune health effects of the aircraft disaster on professional assistance workers. Exposed professional firefighters (n = 334) and police officers (n = 834) who performed at least 1 disaster-related task and hangar workers who sorted and investigated the wreckage (n = 241) were compared with reference groups of nonexposed colleagues who did not perform any disaster-related tasks (n = 194, n = 634, and n = 104, respectively). Data were collected a mean of 8.5 years after the disaster. Questionnaires were used to assess disaster-related tasks and 11 autoimmune-like symptoms. All serum samples were tested for the presence of antinuclear antibodies, rheumatoid factor, and antineutrophil cytoplasmic and anticardiolipin antibodies. RESULTS: Compared with nonexposed colleagues, exposed workers reported significantly more autoimmune-like symptoms. They reported the following symptoms significantly more often: tingling sensations, myalgia, loss of strength, easily fatigued, and a feeling of sand in the eyes (all groups); infection proneness (firefighters); skin abnormalities and nocturnal transpiration (police officers and hangar workers); and vasculitis-like symptoms and Raynaud discoloring (police officers). In contrast, we found no significant difference between exposed and nonexposed workers in autoantibody prevalence. CONCLUSION: Occupational exposure to the aircraft disaster resulted in an excess of long-term self-reported autoimmune-like symptoms in exposed professional assistance workers, but there was no difference between exposed and nonexposed workers in the prevalence of autoantibodies.

Accidents, Aviation↗
PubMed2005

Epidemiological study air disaster in Amsterdam (ESADA): study design.

BACKGROUND: In 1992, a cargo aircraft crashed into apartment buildings in Amsterdam, killing 43 victims and destroying 266 apartments. In the aftermath there were speculations about the cause of the crash, potential exposures to hazardous materials due to the disaster and the health consequences. Starting in 2000, the Epidemiological Study Air Disaster in Amsterdam (ESADA) aimed to assess the long-term health effects of occupational exposure to this disaster on professional assistance workers. METHODS/DESIGN: Epidemiological study among all the exposed professional fire-fighters and police officers who performed disaster-related task(s), and hangar workers who sorted the wreckage of the aircraft, as well as reference groups of their non-exposed colleagues who did not perform any disaster-related tasks. The study took place, on average, 8.5 years after the disaster. Questionnaires were used to assess details on occupational exposure to the disaster. Health measures comprised laboratory assessments in urine, blood and saliva, as well as self-reported current health measures, including health-related quality of life, and various physical and psychological symptoms. DISCUSSION: In this paper we describe and discuss the design of the ESADA. The ESADA will provide additional scientific knowledge on the long-term health effects of technological disasters on professional workers.

Accidents, Aviation↗
PubMed2005

Quality of reporting of diagnostic accuracy studies.

PURPOSE: To evaluate quality of reporting in diagnostic accuracy articles published in 2000 in journals with impact factor of at least 4 by using items of Standards for Reporting of Diagnostic Accuracy (STARD) statement published later in 2003. MATERIALS AND METHODS: English-language articles on primary diagnostic accuracy studies in 2000 were identified with validated search strategy in MEDLINE. Articles published in journals with impact factor of 4 or higher that regularly publish articles on diagnostic accuracy were selected. Two independent reviewers evaluated quality of reporting by using STARD statement, which consists of 25 items and encourages use of a flow diagram. Total STARD score for each article was calculated by summing number of reported items. Subgroup analyses were performed for study design (case-control or cohort study) by using Student t tests for continuous outcomes and chi(2) tests for dichotomous outcomes. RESULTS: Included were 124 articles published in 2000 in 12 journals: 33 case-control and 91 cohort studies. Only 41% of articles (51 of 124) reported on more than 50% of STARD items, while no articles reported on more than 80%. A flow chart was presented in two articles. Assessment of reporting on individual items of STARD statement revealed wide variation, with some items described in 11% of articles and others in 92%. Mean STARD score (0-25 points available) was 11.9 (range, 3.5-19.5). Mean difference in STARD score between cohort studies and case-control studies was 1.53 (95% confidence interval: 0.24, 2.82). CONCLUSION: Quality of reporting in diagnostic accuracy articles published in 2000 is less than optimal, even in journals with high impact factor. Authors, editors, and reviewers should pay more attention to reporting by checking STARD statement items and including a flow diagram to represent study design and patient flow.

Case-Control Studies↗
PubMed2005

Effectiveness of exercise therapy: a best-evidence summary of systematic reviews.

The purpose of this project was to summarise the available evidence on the effectiveness of exercise therapy for patients with disorders of the musculoskeletal, nervous, respiratory, and cardiovascular systems. Systematic reviews were identified by means of a comprehensive search strategy in 11 bibliographic databases (08/2002), in combination with reference tracking. Reviews that included (i) at least one randomised controlled trial investigating the effectiveness of exercise therapy, (ii) clinically relevant outcome measures, and (iii) full text written in English, German or Dutch, were selected by two reviewers. Thirteen independent and blinded reviewers participated in the selection, quality assessment and data-extraction of the systematic reviews. Conclusions about the effectiveness of exercise therapy were based on the results presented in reasonable or good quality systematic reviews (quality score > or = 60 out of 100 points). A total of 104 systematic reviews were selected, 45 of which were of reasonable or good quality. Exercise therapy is effective for patients with knee osteoarthritis, sub-acute (6 to 12 weeks) and chronic (> or = 12 weeks) low back pain, cystic fibrosis, chronic obstructive pulmonary disease, and intermittent claudication. Furthermore, there are indications that exercise therapy is effective for patients with ankylosing spondylitis, hip osteoarthritis, Parkinson's disease, and for patients who have suffered a stroke. There is insufficient evidence to support or refute the effectiveness of exercise therapy for patients with neck pain, shoulder pain, repetitive strain injury, rheumatoid arthritis, asthma, and bronchiectasis. Exercise therapy is not effective for patients with acute low back pain. It is concluded that exercise therapy is effective for a wide range of chronic disorders.

Chronic Disease↗
PubMed2005

Applied analysis of recurrent events: a practical overview.

STUDY OBJECTIVE: The purpose of this paper is to give an overview and comparison of different easily applicable statistical techniques to analyse recurrent event data. SETTING: These techniques include naive techniques and longitudinal techniques such as Cox regression for recurrent events, generalised estimating equations (GEE), and random coefficient analysis. The different techniques are illustrated with a dataset from a randomised controlled trial regarding the treatment of lateral epicondylitis. MAIN RESULTS: The use of different statistical techniques leads to different results and different conclusions regarding the effectiveness of the different intervention strategies. CONCLUSIONS: If you are interested in a particular short term or long term result, simple naive techniques are appropriate. However, if the development of a particular outcome is of interest, statistical techniques that consider the recurrent events and additionally corrects for the dependency of the observations are necessary.

Adrenal Cortex Hormones↗
PubMed2004

Cost effectiveness of interventions for lateral epicondylitis: results from a randomised controlled trial in primary care.

OBJECTIVE: Lateral epicondylitis is a common complaint, with an annual incidence between 1% and 3% in the general population. The Dutch College of General Practitioners in The Netherlands has issued guidelines that recommend a wait-and-see policy. However, these guidelines are not evidence based. DESIGN AND SETTING: This paper presents the results of an economic evaluation in conjunction with a randomised controlled trial to evaluate the effects of three interventions in primary care for patients with lateral epicondylitis. PATIENTS AND INTERVENTIONS: Patients with pain at the lateral side of the elbow were randomised to one of three interventions: a wait-and-see policy, corticosteroid injections or physiotherapy. MAIN OUTCOME MEASURES AND RESULTS: Clinical outcomes included general improvement, pain during the day, elbow disability and QOL. The economic evaluation was conducted from a societal perspective. Direct and indirect costs (in 1999 values) were measured by means of cost diaries over a period of 12 months. Differences in mean costs between groups were evaluated by applying non-parametric bootstrap techniques. The mean total costs per patient for corticosteroid injections were euro430, compared with euro631 for the wait-and-see policy and euro921 for physiotherapy. After 12 months, the success rate in the physiotherapy group (91%) was significantly higher than in the injection group (69%), but only slightly higher than in the wait-and-see group (83%). The differences in costs and effects showed no dominance for any of the three groups. The incremental cost-utility ratios were (approximately): euro7000 per utility gain for the wait-and-see policy versus corticosteroid injections; euro12000 per utility gain for physiotherapy versus corticosteroid injections, and euro34500 for physiotherapy versus the wait-and-see policy. CONCLUSIONS: The results of this economic evaluation provided no reason to update or amend the Dutch guidelines for GPs, which recommend a wait-and-see policy for patients with lateral epicondylitis.

Adolescent↗
PubMed2004

Tennis elbow.

Explore the source record for details and available documents.

Acupuncture↗
PubMed2003

Tennis elbow.

Explore the source record for details and available documents.

Acupuncture Therapy↗
PubMed2003

Effectiveness of physiotherapy for lateral epicondylitis: a systematic review.

AIM: To evaluate the available evidence of the effectiveness of physiotherapy for lateral epicondylitis of the elbow. METHOD: Randomised controlled trials (RCTs) identified by a highly sensitive search strategy in six databases in combination with reference checking. Two independent reviewers selected RCTs that included a physiotherapy intervention, patients with lateral epicondylitis, and at least one clinically relevant outcome measure. No language restrictions were made. Methodological quality was independently assessed by two blinded reviewers. A best evidence synthesis, including a quantitative and qualitative analysis, was conducted, weighting the studies with respect to their internal validity, statistical significance, clinical relevance, and statistical power. RESULTS: 23 RCTs were included in the review, evaluating the effects of lasertherapy, ultrasound treatment, electrotherapy, and exercises and mobilisation techniques. Fourteen studies satisfied at least 50% of the internal validity criteria. Except for ultrasound, pooling of data from RCTs was not possible because of insufficient data, or clinical or statistical heterogeneity. The pooled estimate of the treatment effects of two studies on ultrasound compared to placebo ultrasound, showed statistically significant and clinically relevant differences in favour of ultrasound. There is insufficient evidence either to demonstrate benefit or lack of effect of lasertherapy, electrotherapy, exercises and mobilisation techniques for lateral epicondylitis. CONCLUSIONS: Despite the large number of studies, there is still insufficient evidence for most physiotherapy interventions for lateral epicondylitis due to contradicting results, insufficient power, and the low number of studies per intervention. Only for ultrasound, weak evidence for efficacy was found. More better designed, conducted and reported RCTs are needed.

Australia↗