220 research outputs found

    Process Evaluation of a Workers' Health Surveillance Program for Meat Processing Workers

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    Objective To evaluate the implementation process of a workers' health surveillance (WHS) program in a Dutch meat processing company. Methods Workers from five plants were eligible to participate in the WHS program. The program consisted of four evaluative components and an intervention component. Qualitative and quantitative methods were used to evaluate seven process aspects. Data were gathered by interviews with stakeholders, participant questionnaires, and from registries of the company and occupational health service. Results Two recruitment strategies were used: open invitation or automatic participation. Of the 986 eligible workers, 305 participated in the program. Average reach was 53 %. Two out of five program components could not be assessed on dose delivered, dose received and fidelity. If components were assessable, 85-100 % of the components was delivered, 66-100 % of the components was received by participants, and fidelity was 100 %. Participants were satisfied with the WHS program (mean score 7.6). Contextual factors that facilitated implementation were among others societal developments and management support. Factors that formed barriers were program novelty and delayed follow-up. Conclusion The WHS program was well received by participants. Not all participants were offered the same number of program components, and not all components were performed according to protocol. Deviation from protocol is an indication of program failure and may affect program effectiveness.</p

    Should we use logistic mixed model analysis for the effect estimation in a longitudinal RCT with a dichotomous outcome variable?

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    Background: Within epidemiology both mixed model analysis and Generalised Estimating Equations (GEE analysis) are frequently used to analyse longitudinal RCT data. With a continuous outcome, both methods lead to more or less the same results, but with a dichotomous outcome the results are totally different. The purpose of the present study is to evaluate the performance of a logistic mixed model analysis and a logistic GEE analysis and to give an advice which of the two methods should be used. Methods: Two real life RCT datasets with and without missing data were used to perform this evaluation. Regarding the logistic mixed model analysis also two different estimation procedures were compared to each other. Results: The regression coefficients obtained from the two logistic mixed model analyses were different from each other, but were always higher then the regression coefficients derived from a logistic GEE analysis. Because this also holds for the standard errors, the corresponding p-values were more or less the same. It was further shown that the effect estimates derived from a logistic mixed model analysis were an overestimation of the ‘real’ effect estimates. Conclusions: &nbsp;Although logistic mixed model analysis is widely used for the analysis of longitudinal RCT data, this article shows that logistic mixed model analysis should not be used when one is interested in the magnitude of the regression coefficients (i.e. effect estimates)

    Effectiveness and Cost-benefit Evaluation of a Comprehensive Workers' Health Surveillance Program for Sustainable Employability of Meat Processing Workers

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    Objective To evaluate the effectiveness of a comprehensive workers' health surveillance (WHS) program on aspects of sustainable employability and cost-benefit. Methods A cluster randomized stepped wedge trial was performed in a Dutch meat processing company from february 2012 until march 2015. In total 305 workers participated in the trial. Outcomes were retrieved during a WHS program, by multiple questionnaires, and from company registries. Primary outcomes were sickness absence, work ability, and productivity. Secondary outcomes were health, vitality, and psychosocial workload. Data were analyzed with linear and logistic multilevel models. Cost-benefit analyses from the employer's perspective were performed as well. Results Primary outcomes sickness absence (OR = 1.40), work ability (B = -0.63) and productivity (OR = 0.71) were better in the control condition. Secondary outcomes did not or minimally differ between conditions. Of the 12 secondary outcomes, the only outcome that scored better in the experimental condition was meaning of work (B = 0.18). Controlling for confounders did not or minimally change the results. However, our stepped wedge design did not enable adjustment for confounding in the last two periods of the trial. The WHS program resulted in higher costs for the employer on the short and middle term. Conclusions Primary outcomes did not improve after program implementation and secondary outcomes remained equal after implementation. The program was not cost-beneficial after 1-3 year follow-up. Main limitation that may have contributed to absence of positive effects may be program failure, because interventions were not deployed as intended

    Diagnostic Imaging in Chiropractic Practice:A Survey of Opinions and Self-Reported Guideline Adherence of Dutch and Belgian Chiropractors

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    Objectives: The purpose of this study was (1) to describe diagnostic imaging in Dutch and Belgian chiropractic practice in general, (2) to estimate adherence to the diagnostic imaging guidelines for patients with low back pain (LBP) via vignettes, and (3) to evaluate factors associated with diagnostic imaging and adherence to the guidelines. Methods: We used a web-based survey to collect sociodemographic data, practice characteristics, amount of imaging, opinions, and indications for requesting imaging from registered Dutch and Belgian chiropractors in 2013. Additionally, adherence to imaging guidelines for LBP was assessed by 6 vignettes in patients with LBP. Multivariable regression analyses were conducted to explore associations between characteristics of chiropractors and the use of imaging. Generalized mixed models were used to explore guidelines adherence and their relationship with chiropractor's characteristics. Results: The overall response rate was 60% (n = 203 out of 340). In total, 83% of chiropractors viewed diagnostic imaging in general as an important part of their practice. It is important to note that Dutch and Belgian chiropractors are not allowed to refer directly for imaging. Chiropractors reported that they would like to have imaging in 42% of their patients. Imaging had already been performed in 37% of patients before the first visit and was ordered by another health care provider (ie, general practitioner or medical specialist). The most common indication for ordering imaging was exclusion of contraindications (73%). The most common reason against imaging was the perceived limited value (45%). Many chiropractors (71%) were familiar with imaging guidelines. Adherence to the imaging guidelines for LBP based upon the vignettes was 66%. Dutch chiropractors and chiropractors with less than 10 years in practice demonstrated better adherence to guidelines and imaging use as compared with Belgian and those with more than 10 years of experience. Conclusions: Most Dutch and Belgian chiropractors reported that imaging in general was important in chiropractic practice. Self-reported indications for ordering diagnostic imaging were in line with the imaging guidelines in the majority of cases. We found some variances between Belgian and Dutch chiropractors and years of experience related to guideline adherence

    The effects of a 25% discount on fruits and vegetables: results of a randomized trial in a three-dimensional web-based supermarket

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    <p>Abstract</p> <p>Background</p> <p>Lowering the price of fruit and vegetables is a promising strategy in stimulating the purchase of those foods. However, the true effects of this strategy are not well studied and it is unclear how the money saved is spent. The aim of this study is to examine the effects of a 25% discount on fruits and vegetables on food purchases in a supermarket environment.</p> <p>Methods</p> <p>A randomized controlled trial with two research conditions was conducted: a control condition with regular prices (n = 52) and an experimental condition with a 25% discount on fruits and vegetables (n = 63). The experiment was carried out using a three-dimensional web-based supermarket, which is a software application in the image of a real supermarket. Data were collected in 2010 in the Netherlands. Participants received a fixed budget and were asked to buy weekly household groceries at the web-based supermarket. Differences in fruit and vegetable purchases, differences in expenditures in other food categories and differences in total calories were analyzed using independent samples t-tests and multiple linear regression models accounting for potential effect modifiers and confounders.</p> <p>Results</p> <p>The purchased amount of fruit plus vegetables was significantly higher in the experimental condition compared to the control condition (Δ984 g per household per week, <it>p </it>= .03) after appropriate adjustments. This corresponds to a 25% difference compared to the control group. Both groups had similar expenditures in unhealthier food categories, including desserts, soda, crisps, candy and chocolate. Furthermore, both groups purchased an equal number of food items and an equal amount of calories, indicating that participants in the discount condition did not spend the money they saved from the discounts on other foods than fruits and vegetables.</p> <p>Conclusion</p> <p>A 25% discount on fruits and vegetables was effective in stimulating purchases of those products and did neither lead to higher expenditures in unhealthier food categories nor to higher total calories purchased. Future studies in real supermarkets need to confirm these findings.</p

    Course of uncomplicated acute gastroenteritis in children presenting to out-of-hours primary care

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    Background The aim of this article is to describe the courses of vomiting, diarrhea, fever, and clinical deterioration, in children with uncomplicated gastroenteritis at presentation. This study was performed as a 7-day prospective follow-up study in an out-of-hours primary care service. The course of vomiting, diarrhea, and fever was analyzed by generalized linear mixed modeling. Because young children ( 90%). Vomiting and fever decreased rapidly, but diarrhea decreased at a somewhat slower pace, especially among children aged 6-12 months. Children who deteriorated during follow-up had a higher frequency of vomiting at presentation and higher frequencies of vomiting and fever during follow-up. Conclusions The frequency of vomiting, not its duration, appears to be the more important predictor of deterioration. When advising parents, it is important to explain the typical symptom duration and to focus on alarm symptoms. Clinicians should be vigilant for children with higher vomiting frequencies at presentation and during follow-up because these children are more likely to deteriorate

    The association between echogenicity and progression of Dupuytren's disease (DD):Birth of an imaging biomarker?

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    BACKGROUND: The shift of focus towards disease-controlling treatments to prevent DD progression at an early stage underlines the need for objective and reliable measurements that can monitor and predict the course of disease. Ultrasound has been studied as a potential tool for this purpose. This study examined to what extent echogenicity of early DD nodules predicts clinical progression.METHODS: Sonographic assessments of Dupuytren's nodules were performed by the same observer on 151 participants as part of an ongoing prospective cohort study on the course of DD. Echogenicity was assessed by determining the greyness of a nodule relative to the surrounding tissue, using ImageJ software. Progression of disease was defined as 1) an increase in total passive extension deficit (TPED) of ≥15 degrees and 2) surgical intervention of the examined ray, both occurring after the sonographic assessment. The associations between echogenicity and time to progression were estimated using Cox-regression models.RESULTS: The association between echogenicity and time to TPED progression showed that for every additional decrease of 1% in relative greyness (darker image) of a nodule, the risk of TPED progression during follow-up increases by 3.4% (hazard ratio [HR] = 0.966, 95% confidence interval [CI]: 0.935-0.966). Similarly, echogenicity was also associated with time to surgical intervention (HR = 0.967, 95% CI: 0.938-0.997), which indicates a higher risk for surgery during follow-up for darker nodules.CONCLUSIONS: These results suggest that echogenicity is predictive of the prognosis of the early stages of DD and might potentially be used as a prognostic imaging biomarker in the future.</p

    Management of people with low back pain:a survey of opinions and beliefs of Dutch and Belgian chiropractors

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    BACKGROUND: Chiropractors commonly provide care to people with low-back pain (LBP). The aim of this survey was to determine the opinions and beliefs of chiropractors regarding the support and management of LBP. We also investigated whether their management is in accordance with the three most commonly recommended approaches to LBP based upon international guidelines (i.e. advice regarding return-to-work, limit bedrest, and stay active). METHODS: A web-based survey was sent out in 2013 to collect data from registered Dutch and Belgian chiropractors. In addition to providing a description of their sociodemographic and practice characteristics, chiropractors were asked to complete six patient vignettes representing people with LBP who typically present to a chiropractor. The respondents indicated which intervention(s) they would recommend or undertake. Based upon these vignettes, we were able to determine whether their management approach adhered to clinical guidelines. Generalized mixed models were used to explore guidelines adherence and their relationship to chiropractors' characteristics. RESULTS: In total, 60% (n = 203/340) of the chiropractors who were invited, chose to participate. Chiropractors reported applying a chiropractic adjustment in 90% of all vignettes, while the advice to exercise varied from one-third in the chronic cases to approximately half of those with acute LBP. More than 75% of the chiropractors would initially treat LBP 1-2 times a week. More than 90% of the chiropractors advised against bedrest. Overall, self-reported adherence to clinical guidelines for all six vignettes was [64.5% (CI 58.7-70.0)]. Adherence in the chronic vignettes [73.4% (CI 66.7-79.2)] was better than in the acute vignettes [55.9% (CI 50.5-61.1)]. Importantly, regarding recommended approaches to LBP, chiropractors more consistently followed guidelines regarding advice to limit bedrest [98.5% (CI 97.3-99.1)] than advice to stay active [77.5% (CI 72.3-81.9)] or return-to-work [59.4% (CI 55.2-63.4)]. Finally, Dutch chiropractors were more likely to adhere to the guidelines than Belgian chiropractors. CONCLUSIONS: Chiropractic adjustments were the most common self-reported treatment modalities supplemented by exercise in the management of LBP patients. Two-thirds of the chiropractors reported adhering to the guidelines regarding management and advice for LBP patients. Practitioners should improve guideline adherence, particularly for acute LBP cases, and when advising on return-to-work

    Analysing outcome variables with floor effects due to censoring: a simulation study with longitudinal trial data

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    ackground: Randomised controlled trials (RCTs) are the gold standard to estimate treatment effects. When patients receive effective treatment over time they may reach the limit of a certain measurement scale. This phenomenon is known as censoring and lead to skewed distributions of the outcome variable with an excess of either low (floor effect) or high values (ceiling effect). Applying traditional methods such as linear mixed models to analyse this kind of longitudinal RCT data may result in bias of the regression parameters. To deal with floor effects due to censoring,&nbsp; a tobit mixed model can be used. The objective of this study was to compare the results of longitudinal linear mixed model analyses with longitudinal tobit mixed model analyses.Methods: First, a simulation study was performed in which several situations of RCTs with floor effects were simulated. Second, data from an empirical RCT was analysed with both methods.Results: Although all analyses underestimated the intervention effects, the tobit mixed model performed much better than the linear mixed model in handling floor effects. However, with an increasing number of follow-up measurements in combination with a strong floor effect estimates from the tobit mixed model were also not accurate.Conclusion: tobit mixed model analysis should be used to estimate treatments effects in longitudinal RCTs with floor effects due to censoring.&nbsp

    Diagnostic accuracy of depression questionnaires in adult patients with diabetes: a systematic review and meta-analysis

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    Importance Comorbid depression is common among patients with diabetes and has severe health consequences, but often remains unrecognized. Several questionnaires are used to screen for depression. A systematic review and meta-analysis regarding the diagnostic accuracy of depression questionnaires in adults with diabetes is unavailable. Objective To conduct a systematic review and meta-analysis to evaluate the diagnostic accuracy of depression questionnaires in adults with type 1 or type 2 diabetes. Data sources PubMed, Embase and PsycINFO were searched from inception to 28 February 2018. Study selection Studies were included when the diagnostic accuracy of depression questionnaires was assessed in a diabetes population and the reference standard was a clinical interview. Data extraction and synthesis Data extraction was performed by one reviewer and checked by another. Two reviewers independently conducted the quality assessment (QUADAS-2). Diagnostic accuracy was pooled in bivariate random effects models. This study is reported according to PRISMA-DTA and is registered with PROSPERO (CRD42018092950). Main Outcome(s) and measure(s) Diagnostic accuracy, expressed as sensitivity and specificity, of depression questionnaires in an adult diabetes population. Results A total 6,097 peer-reviewed articles were screened. Twenty-one studies (N= 5,703 patients) met the inclusion criteria for the systematic review. Twelve different depression questionnaires were identified, of which the CES-D (n=6 studies) and PHQ-9 (n=7 studies) were the most frequently evaluated. Risk of bias was unclear for multiple domains in the majority of studies. In the meta-analyses, five (N= 1,228) studies of the CES-D (≥16), five (N= 1,642) of the PHQ-9 (≥10) and four (N=822) of the algorithm of the PHQ-9 were included in the pooled analysis. The CES-D (≥16) had a pooled sensitivity of 85.0% (95%CI, 71.3-92.8%) and a specificity of 71.6% (95%CI, 62.5-79.2%); the PHQ-9 (≥10) had a sensitivity of 81.5% (95%CI, 57.1-93.5%) and a specificity of 79.7% (95%CI, 62.1-90.4%). The algorithm for the PHQ-9 had a sensitivity of 60.9% (95%CI, 52.3-50 90.8%) and a specificity of 64.0% (95%CI, 53.0-93.9%). Conclusions and relevance This review indicates that the CES-D had the highest sensitivity, whereas the PHQ-9 had the highest specificity, although confidence intervals were wide and overlapping. The algorithm for the PHQ-9 had the lowest sensitivity and specificity. Given the variance in results and suboptimal reporting of studies, further high quality studies are needed to confirm the diagnostic accuracy of these depression questionnaires in patients with diabetes
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