Minimal important change and difference in health outcome: An overview of approaches, concepts, and methods.

OBJECTIVE: To provide an overview of approaches, concepts, and methods used to define and assess minimal important change and difference in health outcome. METHOD: A narrative review of the literature, guided by a conceptual framework. RESULTS: We distinguish between (i) interpretation of health outcome in individuals versus groups, (ii) change within individuals or groups versus difference between change within individuals or groups; and (iii) the responder approach (based on the proportion of patients that obtain a defined response) versus the group average approach (based on the average amount of change in a group). We review approaches, concepts, and methods. CONCLUSION: By bringing together and juxtaposing various approaches, concepts, and methods, we set a precursory step in the direction of consensus building in the field concerned with defining and assessing minimal important change and difference in health outcome. We emphasize the need for conceptual clarification and terminological standardization. We argue that assessing minimal importance of change and difference in health outcome is essentially a value judgment involving a range of considerations and perspectives.

The association of fecal incontinence, constipation, and pelvic pain with the course of lower urinary tract symptoms in community-dwelling men and women.

BACKGROUND: Fecal incontinence, constipation, and pelvic pain are common pelvic floor symptoms (PFS), and frequently coexist with lower urinary tract symptoms (LUTS). However, their association with the longitudinal trajectory of LUTS have not been well described. Our objective was to investigate the association between PFS and the course of LUTS in community-dwelling men and women. METHODS: Men and women aged ≥16 years were invited to participate in a prospective observational cohort study. At baseline, and after 12 and 24 months, participants filled in the International Consultation on Incontinence Modular Questionnaire (ICIQ-MLUTS and ICIQ-FLUTS) for men and women respectively, the Wexner incontinence and constipation scale, and a questionnaire on pelvic pain. Generalized estimating equations were used to examine the association between change scores in defecation problems and pelvic pain, and LUTS change scores. RESULTS: A total of 694 men and 997 women gave informed consent, with 417 men and 566 women included in the analysis. The mean age was 63.2 ± 12.7 years for men and 58.6 ± 14.8 years for women. The study showed minor changes in LUTS scores over the 0-12 and 12-24-month periods. Generalized estimating equations revealed positive associations between changes in constipation and fecal incontinence and LUTS changes in both sexes. For instance, a one-point increase in Wexner constipation score was associated with 0.376 (0.165, 0.587) points higher LUTS change in men and 0.223 (0.109, 0.336) points in women during the 0-12-month follow-up. However, associations between changes in pain and LUTS scores varied across sexes and time periods. CONCLUSIONS: We observed minor changes in LUTS over time and weak associations between PFS and LUTS that sometimes differed between males and females, emphasizing the need for sex-specific considerations. These insights can provide valuable guidance for the development of targeted prevention trials, ultimately aiming to enhance overall pelvic health and patient well-being.

Accuracy of diagnostic tests for acute diverticulitis that are feasible in primary care: a systematic review and meta-analysis.

BACKGROUND: Recognition of acute diverticulitis is important to determine an adequate management strategy. Differentiating it from other gastrointestinal disorders is challenging as symptoms overlap. Clinical tests might assist the clinician with this diagnostic challenge. Previous reviews have focussed on prognostic questions and imaging examinations in secondary care. OBJECTIVE: To evaluate the diagnostic accuracy of clinical tests feasible in primary care for acute diverticulitis in suspected patients. METHOD: We have systematically searched multiple databases for diagnostic accuracy studies of tests feasible in primary care compared to a reference standard in suspected patients. Two reviewers independently selected studies, extracted data, and assessed study quality with the QUADAS-2 tool. We have meta-analysed the results in the case of more than four studies per index test. RESULTS: Seventeen studies were included, all studies were performed in secondary care (median prevalence 48%). Individual signs and symptoms showed a wide range in sensitivity (range 0.00-0.98) and specificity (range 0.08-1.00). Of the four laboratory tests evaluated, CRP >10 mg/l had the highest sensitivity (range 0.89-0.96) with specificity ranging from 0.28 to 0.61. Ultrasound had the highest pooled sensitivity and specificity of 0.92 (95% CI 0.86-0.96) and 0.94 (95% CI 0.88-0.97), respectively. CONCLUSION: None of the studies were performed in primary care. Individual signs and symptoms alone are insufficiently informative for acute diverticulitis diagnosis. CRP showed potential for ruling out and ultrasound had a high diagnostic accuracy. More research is needed about the diagnostic accuracy of these tests in primary care. PROSPERO REGISTRATION NUMBER: CRD42021230622.

Public health care staff during the COVID-19 pandemic: a comparison of job demands and work functioning between temporary and permanent staff.

BACKGROUND: The COVID-19 pandemic posed an enormous challenge on the public health workforce, leading to the hiring of much temporary staff. Temporary staff may experience poorer working conditions compared to permanent staff. From a public health perspective, we need to know how working conditions are experienced when there is an acute pressure on recruiting sufficient public health care staff. This study aimed to investigate differences in job demands and work functioning between temporary and permanent public health care staff, during the fourth wave of the COVID-19 pandemic in the Netherlands and compare it with available pre-pandemic data from the general working population. METHODS: This cross-sectional study included temporary (n = 193) and permanent (n = 98) public health care staff from a municipal health care service in the north of the Netherlands. The participants completed a questionnaire with items about quantitative, cognitive, emotional demands (Copenhagen PsychoSOcial Questionnaire, COPSOQ, range 1-100) and work functioning (Work Role Functioning Questionnaire, WRFQ, range 1-100). The participants' scores were compared to the general working population and differences between temporary and permanent staff were investigated using linear regression analysis. In addition, explorative analyses were conducted with temporary staff stratified by task and permanent staff by department. RESULTS: Permanent staff had relatively high scores on job demands compared to the general working population, whereas temporary staff had relatively low scores. On work functioning, permanent staff had similar scores as the general working population and temporary staff had better scores. Compared to permanent staff, temporary staff had lower, i.e. better, scores on quantitative (regression coefficient (B)=-26.7; 95% Confidence Interval (CI) -30.8 to -22.5), cognitive (B=-24.4; 95% CI -29.0 to -19.9), and emotional demands (B=-11.8; 95% CI -16.0 to -7.7), and better scores on work functioning (B = 7.8; 95% CI 4.5 to 11.3). CONCLUSIONS: Temporary staff experienced lower job demands and reported better work functioning than permanent staff. The acute expansion of the public health workforce did not seem to negatively impact the job demands and work functioning of temporary public health care staff.

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

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.

Towards OPtimal TIming and Method for promoting sUstained adherence to lifestyle and body weight recommendations in postMenopausal breast cancer survivors (the OPTIMUM-study): protocol for a longitudinal mixed-method study.

BACKGROUND: The majority of postmenopausal breast cancer (PMBC) survivors do not adhere to lifestyle recommendations and have excess body weight. In this group, this is associated with poorer health-related quality of life and an increased risk of type II diabetes mellitus, cardiovascular disease, second primary cancers, cancer recurrences, and mortality. Gaining and maintaining a healthy lifestyle and body composition is therefore important. It is unknown when and how sustained adherence to these recommendations can be promoted optimally in PMBC survivors. Therefore, the OPTIMUM study aims to identify the optimal timing and method for promoting sustained adherence to lifestyle and body weight recommendations in PMBC survivors. METHODS: The OPTIMUM-study has a mixed-methods design. To assess optimal timing, a longitudinal observational study will be conducted among approximately 1000 PMBC survivors. The primary outcomes are adherence to lifestyle and body weight recommendations, readiness for change, and need for support. Questionnaires will be administered at 4-6 months after cancer diagnosis (wave 1: during treatment and retrospectively before diagnosis), 1 year after diagnosis (wave 2: after completion of initial treatment), and 1.5 years after diagnosis (wave 3: during follow-up). Wave 2 and 3 include blood sampling, and either wearing an accelerometer for 7 days or completing a 3-day online food diary (randomly assigned at hospital level). To assess the optimal method, behavioural determinants of the primary outcomes will be matched with Behavior Change Techniques using the Behaviour Change Technique Taxonomy. Qualitative research methods will be used to explore perceptions, needs and preferences of PMBC survivors (semi-structured interviews, focus groups) and health care providers (Delphi study). Topics include perceptions on optimal timing to promote adherence; facilitators and motivators of, and barriers towards (sustained) adherence to recommendations; and acceptability of the selected methods. DISCUSSION: The OPTIMUM study aims to gain scientific knowledge on when and how to promote sustained adherence to lifestyle and body weight recommendations among PBMC survivors. This knowledge can be incorporated into guidelines for tailored promotion in clinical practice to improve health outcomes.

Exploring changes in dietary intake, physical activity and body weight during chemotherapy in women with breast cancer: A Mixed-Methods Study.

BACKGROUND: The present study aimed (i) to assess changes in dietary intake (DI), physical activity (PA) and body weight (BW) in breast cancer patients during chemotherapy; (ii) to describe how women explained, experienced and dealt with these potential changes; and (iii) to eventually develop lifestyle intervention strategies tailored to the women's personal needs during chemotherapy. METHODS: A longitudinal parallel mixed-method design was used with quantitative assessment of changes in dietary intake (24-h recall, Appetite, Hunger, Sensory Perception questionnaire), physical activity (Short Questionnaire to Assess Health-enhancing physical activity, Multidimensional Fatigue Inventory) and BW (dual-energy X-ray absorptiometry), in addition to qualitative interviews with 25 women about these potential changes during chemotherapy. RESULTS: Most women who perceived eating less healthily with low energy intake (EI) and being less active before diagnosis continued to do so during chemotherapy, according to quantitative measurements. They struggled to maintain sufficient energy intake. Despite a lower than average reported EI, they unexpectedly gained weight and explained that fatigue made them even more inactive during chemotherapy. Active women usually managed to stay active because exercise was very important to them and made them feel good, although they also suffered from the side-effects of chemotherapy. They found more ways to deal with taste, smell and appetite problems than women with a lower energy intake. CONCLUSIONS: The combination of the quantitative and qualitative data provided more insight into the changes in dietary intake, physical activity and BW during chemotherapy. The women's explanations showed why some women remain active and others need support to deal with changes in lifestyle factors such as healthy nutrition and fatigue.

The Use of the Alcohol Use Disorders Identification Test - Consumption as an Indicator of Hazardous Alcohol Use among University Students.

BACKGROUND: Hazardous drinking among students in higher education is a growing concern. The alcohol use disorders identification test (AUDIT) is the gold standard screening instrument for hazardous drinking in the adult population, for which an abbreviated version has been developed: the -AUDIT-Consumption (AUDIT-C). Currently, there's no gold standard for identifying hazardous drinking among students in higher education and little evidence regarding the concurrent validity of the AUDIT-C as a screening instrument for this group. This study investigated the concurrent validity of the AUDIT-C in a sample of university students and suggests the most appropriate cutoff points. METHODS: Cross-sectional data of health surveys from 5,401 university and university of applied sciences in the Netherlands were used. Receiver operating characteristic (ROC) curves, sensitivity, specificity, and positive and negative predictive values for different cutoff scores of AUDIT-C were calculated for the total sample and for subgroups stratified by age, gender, and educational level. AUDIT-score ≥11 was used as the criterion of hazardous and harmful drinking. RESULTS: Twenty percent of students were hazardous and harmful drinkers. The area under the ROC curve was 0.922 (95% CI 0.914-0.930). At an AUDIT-C cutoff score of ≥7, sensitivity and specificity were both >80%, while other cutoffs showed less balanced results. A cutoff of ≥8 performed better among males, but for other subgroups ≥7 was most suitable. CONCLUSION: AUDIT-C seems valid in identifying hazardous and harmful drinking students, with suggested optimal cutoffs 7 (females) or 8 (males). However, considerations regarding avoiding false-positives versus false-negatives, in relation to the type of intervention following screening, could lead to selecting different cutoffs.

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

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.

Thyroid-stimulating hormone levels in newborns and early life exposure to endocrine-disrupting chemicals: analysis of three European mother-child cohorts.

BackgroundVarious studies have reported interactions between thyroid hormones and early life chemical exposure. Our objective was to analyze the associations between markers of endocrine-disrupting chemical exposure and thyroid function in newborns, determined through heel prick blood spots.MethodsThree European mother-child cohorts (FLEHSI-Belgium, HUMIS-Norway, and the PCB cohort-Slovakia. Total n=1,784) were pooled for the purpose of this study. Data on thyroid-stimulating hormone (TSH) were obtained from national neonatal screening registries, and samples of cord plasma and/or breast milk were collected to determine exposure to various chemicals. Multiple regression models were composed with exposure and cohort as fixed factors, and adjustments were made for a priori defined covariates.ResultsMedian TSH concentrations were 1, 1.10, and 2.76 mU/l for the Belgian, Norwegian, and Slovak cohorts, respectively. For polychlorinated biphenyl (PCB)-153 and dichlorodiphenyldichloroethylene (p,p'-DDE), children in the third exposure quartile had a 12-15% lower TSH at birth. Results remained unchanged after additional adjustment for birth weight and gestational weight gain. No effect on TSH was observed for the other compounds.ConclusionEarly life exposure to PCB-153 and p,p'-DDE impacts newborn TSH levels. Higher exposure levels were associated with 12-15% lower TSH levels.

Client-Related Factors Associated with a "Less than Good" Experience of Midwifery Care during Childbirth in the Netherlands.

BACKGROUND: A "less than good" experience during childbirth can affect a mother's early interaction with her child and may significantly influence a woman's emotional well-being. In this study, we focus on clients who experienced midwifery care provided during childbirth as "less than good" care. The aim of this study was to understand the relationship between client-related factors and the experience of midwifery care during childbirth to improve this care. METHODS: This study was part of the "DELIVER study" where mothers report on the care they received. We used generalized estimation equations to control for correlations within midwife practices. Forward multivariate logistic regression analyses were conducted to model the client-related factors associated with the experienced midwifery care during childbirth. RESULTS: We included the responses of 2,377 women. In the multivariable logistic regression model, odds of reporting "less than good care" were significantly higher for women who experienced an unplanned cesarean birth (OR 2.21 [CI 1.19-4.09]), an instrumental birth (OR 1.55 [CI 1.08-2.23]), and less control during the dilation phase (OR 0.98 [CI 0.97-0.99]) and pushing phase (OR 0.98 [CI 0.97-0.99]). DISCUSSION: Birth-related factors were more likely than maternal characteristics to be associated with the experience of midwifery care during childbirth. We conclude that there is room for midwives to improve their care for women during childbirth particularly in improving the patient centeredness of the care provider, using strategies to enhance sense of control, and focusing on the particular needs of those who experience instrumental vaginal or unplanned cesarean births.

Treatment of acute sciatica with transforaminal epidural corticosteroids and local anesthetic: design of a randomized controlled trial.

BACKGROUND: Transforaminal epidural injections with steroids (TESI) are used increasingly for patients with sciatica. However there is much debate about their safety and effectiveness. It is important to identify patients that benefit most from TESI and only few trials have yet evaluated the effects in patients with acute sciatica. METHODS: We describe a prospective, randomized controlled trial (RCT), with the aim to evaluate the hypothesis that TESI plus Levobupivacaine (TESI-plus) added to oral pain medication is more effective compared to pain medication alone or compared to transforaminal injection with a local anesthetic of short duration among patients with acute sciatica. We will recruit a total of 264 patients with sciatica (<8 weeks) caused by a herniated disc, from two clinical sites. Participants are randomly assigned one of three study groups: 1) oral pain medication (control group), 2) oral pain medication and TESI-plus (intervention group one), 3) oral pain medication and transforaminal epidural injection (TEI) with Levobupivaine and saline solution (intervention group two). Primary outcomes are functional status (Roland-Morris Disability Questionnaire), pain intensity for both leg and back, (100 mm visual analogous scale (VAS)), and global perceived recovery (GPR, reported on a 7-point Likert scale, dichotomized into 'recovered' and 'not recovered'). The secondary outcomes are health-related quality of life (EQ5D-5 L) and patient satisfaction (7-point Likert scale). We will also collect information on healthcare utilization and costs, to perform an economic evaluation. All outcomes are measured at three and six weeks, three and six months after randomization. We defined a minimal clinically relevant difference between groups as a difference between both intervention groups and the control group of 20 points for pain (100-point VAS), four points for functional status (24-point RDQ) and a 20% difference on dichotomized GPR (recovered versus not recovered). DISCUSSION: A clinically relevant outcome in favor of TESI-plus implies that future patients with acute sciatica should be recommended TESI-plus within the first few weeks rather than being treated with pain medication alone in order to relieve pain and improve their functioning. In case of a negative result (no relevant differences in outcome between the three study arms), pain medication will remain the mainstay of treatment in the acute stages of sciatica. TRIAL REGISTRATION: Dutch National trial register: NTR4457 (March, 6th, 2014).

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

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.

Effectiveness of an Intervention to Enhance Occupational Physicians' Guideline Adherence on Sickness Absence Duration in Workers with Common Mental Disorders: A Cluster-Randomized Controlled Trial.

Purpose Evidence-based guidelines in occupational health care improve the quality of care and may reduce sickness absence duration. Notwithstanding that, guideline adherence of occupational physicians (OPs) is limited. Based on the literature on guideline implementation, an intervention was developed that was shown to effectively improve self-reported adherence in OPs. The aim of present study was to evaluate whether this intervention leads to earlier return to work (RTW) in workers with common mental disorders (CMD). Methods In a two-armed cluster randomized controlled trial, 66 OPs were randomized. The trial included 3379 workers, with 1493 in the intervention group and 1886 in the control group. The outcome measures were: time to full RTW, time to first RTW, and total hours of sickness absence. Cox regression analyses and generalized linear mixed model analyses were used for the evaluations. Results The median time to RTW was 154 days among the 3228 workers with CMD. No significant differences occurred in (time to) full RTW between intervention and control group HR 0.96 (95% CI 0.81-1.15) nor for first RTW HR 0.96 (95% CI 0.80-1.15). The mean total hours of sickness absence was 478 h in the intervention group and 483 h in the control group. Conclusions The intervention to enhance OPs' guideline adherence did not lead to earlier RTW in workers with CMD guided by the OPs. Possible explanations are the remaining external barriers for guideline use, and that perceived guideline adherence might not represent actual guideline adherence and improved care.Trail registration: ISRCTN86605310.

Health-based risk neutralization in private disability insurance.

BACKGROUND: Exclusions are used by insurers to neutralize higher than average risks of sickness absence (SA). However, differentiating risk groups according to one's medical situation can be seen as discrimination against people with health problems in violation of a 2006 United Nations convention. The objective of this study is to investigate whether the risk of SA of insured persons with exclusions added to their insurance contract differs from the risk of persons without exclusions. METHODS: A dynamic cohort of 15 632 applicants for private disability insurance at a company insuring only college and university educated self-employed in the Netherlands. Mean follow-up was 8.94 years. Duration and number of SA periods were derived from insurance data to calculate the hazard of SA periods and of recurrence of SA periods. RESULTS: Self-employed with an exclusion added to their insurance policy experienced a higher hazard of one or more periods of SA and on average more SA days than self-employed without an exclusion. CONCLUSION: Persons with an exclusion had a higher risk of SA than persons without an exclusion. The question to what extent an individual should benefit from being less vulnerable to disease and SA must be addressed in a larger societal context, taking other aspects of health inequality and solidarity into account as well.

Prenatal exposure to endocrine disrupting chemicals and birth weight-A prospective cohort study.

Prenatal exposure to endocrine disrupting chemicals may affect fetal development through disruption of hormonal actions and epigenetic modifications, potentially predisposing individuals to later on-set health risks, such as obesity. The objective of this study was to determine associations between biological exposure markers of various endocrine disrupting chemicals and birth weight in a newly established, prospective mother-child cohort in the Netherlands. Birth weight (n = 91) was obtained from birth records, and exposure to dichlorodiphenyldichloroethylene (DDE), three di-2-ethylhexyl phthalate (DEHP) metabolites, polychlorinated biphenyl-153, perfluorooctanesulfonic acid (PFOS), and perfluorooctanoic acid (PFOA) was determined in cord plasma. For DDE, exposure was also measured in breast milk. Linear regression analysis was used to determine associations between compounds and birth weight, which were stratified for gender and adjusted for a priori defined covariates. Increased exposure to DDE was associated with lower birth weight in boys (>95.89 ng L-1, -325.9 g, 95% CI -634.26 to -17.56), whereas in girls a tendency towards a higher birth weight was observed. Lower birth weights for boys were also observed for high exposure to MECPP, and to a certain extent also for PFOA. MEHHP and PFOS exposure on the other hand were associated with higher birth weights in boys. In girls no effects were observed for these compounds. It can be concluded that prenatal exposure to DDE, perfluorinated alkyl acids, and phthalates was associated with changes in birth weight in this population. Associations were gender specific, and appeared to be non-linear. Since the population was relatively small, results should be interpreted with caution.

Insulin-induced changes in skeletal muscle microvascular perfusion are dependent upon perivascular adipose tissue in women.

AIMS/HYPOTHESIS: Obesity increases the risk of cardiovascular disease and type 2 diabetes, partly through reduced insulin-induced microvascular vasodilation, which causes impairment of glucose delivery and uptake. We studied whether perivascular adipose tissue (PVAT) controls insulin-induced vasodilation in human muscle, and whether altered properties of PVAT relate to reduced insulin-induced vasodilation in obesity. METHODS: Insulin-induced microvascular recruitment was measured using contrast enhanced ultrasound (CEU), before and during a hyperinsulinaemic-euglycaemic clamp in 15 lean and 18 obese healthy women (18-55 years). Surgical skeletal muscle biopsies were taken on a separate day to study perivascular adipocyte size in histological slices, as well as to study ex vivo insulin-induced vasoreactivity in microvessels in the absence and presence of PVAT in the pressure myograph. Statistical mediation of the relation between BMI and microvascular recruitment by PVAT was studied in a mediation model. RESULTS: Obese women showed impaired insulin-induced microvascular recruitment and lower metabolic insulin sensitivity compared with lean women. Microvascular recruitment was a mediator in the association between obesity and insulin sensitivity. Perivascular adipocyte size, determined in skeletal muscle biopsies, was larger in obese than in lean women, and statistically explained the difference in microvascular recruitment between obese and lean women. PVAT from lean women enhanced insulin-induced vasodilation in isolated skeletal muscle resistance arteries, while PVAT from obese women revealed insulin-induced vasoconstriction. CONCLUSIONS/INTERPRETATION: PVAT from lean women enhances insulin-induced vasodilation and microvascular recruitment whereas PVAT from obese women does not. PVAT adipocyte size partly explains the difference in insulin-induced microvascular recruitment between lean and obese women.

PortionControl@HOME: results of a randomized controlled trial evaluating the effect of a multi-component portion size intervention on portion control behavior and body mass index.

BACKGROUND: Food portion sizes influence energy intake. PURPOSE: The purpose of this paper is to determine effectiveness of the "PortionControl@HOME" intervention on body mass index and portion control behavior. METHODS: A randomized controlled trial among 278 overweight and obese participants was conducted. PortionControl@HOME aimed to increase: portion size awareness, portion control behavior, portion control cooking skills, and to create a home environment favoring portion control. RESULTS: Intention-to-treat multi-level regression analysis indicated statistically significant effects of the intervention on portion control behavior at 3, 6, and 12 months follow-up. The effect on body mass index was significant only at 3 months follow-up and when outliers (n = 3) were excluded (B = -0.45; 95%CI = -0.88 to -0.04). The intervention effect on body mass index was mediated by portion control behavior. CONCLUSIONS: The intervention improves portion control behavior, which in turn influence body mass index. Once the intervention ceased, sustained effects on body mass index were no longer evident. (Current-Controlled-Trials ISRCTN12363482).

Testing for baseline differences in randomized controlled trials: an unhealthy research behavior that is hard to eradicate.

BACKGROUND: According to the CONSORT statement, significance testing of baseline differences in randomized controlled trials should not be performed. In fact, this practice has been discouraged by numerous authors throughout the last forty years. During that time span, reporting of baseline differences has substantially decreased in the leading general medical journals. Our own experience in the field of nutrition behavior research however, is that co-authors, reviewers and even editors are still very persistent in their demand for these tests. The aim of this paper is therefore to negate this demand by providing clear evidence as to why testing for baseline differences between intervention groups statistically is superfluous and why such results should not be published. DISCUSSION: Testing for baseline differences is often propagated because of the belief that it shows whether randomization was successful and it identifies real or important differences between treatment arms that should be accounted for in the statistical analyses. Especially the latter argument is flawed, because it ignores the fact that the prognostic strength of a variable is also important when the interest is in adjustment for confounding. In addition, including prognostic variables as covariates can increase the precision of the effect estimate. This means that choosing covariates based on significance tests for baseline differences might lead to omissions of important covariates and, less importantly, to inclusion of irrelevant covariates in the analysis. We used data from four supermarket trials on the effects of pricing strategies on fruit and vegetables purchases, to show that results from fully adjusted analyses sometimes do appreciably differ from results from analyses adjusted for significant baseline differences only. We propose to adjust for known or anticipated important prognostic variables. These could or should be pre-specified in trial protocols. Subsequently, authors should report results from the fully adjusted as well as crude analyses, especially for dichotomous and time to event data. Based on our arguments, which were illustrated by our findings, we propose that journals in and outside the field of nutrition behavior actively adopt the CONSORT 2010 statement on this topic by not publishing significance tests for baseline differences anymore.

Effectiveness of a problem-solving based intervention to prolong the working life of ageing workers.

BACKGROUND: An ageing workforce combined with increasing health problems in ageing workers implies the importance of evidence-based interventions to enhance sustainable employability. The aim of this study is to evaluate the effectiveness of the 'Staying healthy at work' problem-solving based intervention compared to business as usual. METHODS: This study was designed as a quasi-experimental trial with a one-year follow-up. Measurements were performed at baseline, three and twelve months. The problem-solving based intervention provides a strategy for increasing the awareness of ageing workers of their role and responsibility in living sustainable, healthy working lives. The primary outcomes were work ability, vitality and productivity. Secondary outcomes were perceived fatigue, psychosocial work characteristics, work attitude, self-efficacy and work engagement. RESULTS: Analyses were performed on the 64 workers in the intervention and 61 workers from the business as usual group. No effects on productivity (OR = 0.83, 95% CI 0.23-3.00) and adverse effects on work ability (B = -1.33, 95% CI -2.45 to -0.20) and vitality (OR = 0.10, 95% CI 0.02-0.46) were found. Positive results were found for the work attitude secondary outcome (B = 5.29, 95% CI -9.59 to -0.99), the self-efficacy persistence subscale (B = 1.45, 95% CI 0.43-2.48) and the skill discretion subscale of the Job Content Questionnaire (B = 1.78, 95% CI 0.74-2.83). CONCLUSION: The results of the problem-solving intervention showed no positive effects on the three outcome measures compared to business as usual. However, effectiveness was shown on three of the secondary outcome measures, i.e. work attitude, self-efficacy and skill discretion. We presume that the lack of positive effects on primary outcomes is due to programme failure and not to theory failure. TRIAL REGISTRATION: The trial is registered with the Dutch Trial Register under number NTR2270 .