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PubMedDate not supplied

Environmental correlates of physical activity in a sample of Belgian adults.

PURPOSE: This study investigated the variance in sitting, walking, and moderate and vigorous physical activity explained by neighborhood design and recreational environmental variables above and beyond the variance accounted for by individual demographic variables. DESIGN: Cross-sectional analyses of self-reported survey data. SETTING: A random sample of inhabitants of Ghent, Belgium, aged 18-65 years, was drawn. SUBJECTS: Five hundred twenty-one adults completed questionnaires (52.1% response rate). The average age of the sample was 41 years, and 48.2% were female. MEASURES: A questionnaire developed to assess neighborhood design and recreational environmental variables with a total of 81 items was administered. The environmental questionnaire showed acceptable to good reliability and acceptable validity. The previously validated International Physical Activity Questionnaire (IPAQ) was used to quantify physical activity in the past 7 days. Additional demographic information was also obtained. RESULTS: Regression analyses showed that environmental variables were related to all types of physical activity in both sexes. However, the range of variance explained by the models including demographic and environmental variables was low, only 5% to 13%. Minutes of walking and of moderate-intensity activity were related to quality of sidewalks and accessibility of shopping and public transportation. Vigorous physical activity was related to presence of activity supplies in the home and number of convenient activity facilities outside the home. CONCLUSIONS: Both neighborhood design and recreational environment variables had small but significant associations with multiple types of physical activity in a sample of Belgian adults.

Adolescent↗

PubMedDate not supplied

Review of the studies cited in the DataBase section of the American Journal of Health Promotion.

PURPOSE OF THE REVIEW: To analyze the characteristics of the articles reviewed in the DataBase section of the American Journal of Health Promotion and to summarize this review in tabular format. DATA SOURCES: All 350 entries in the American Journal of Health Promotion DataBase section beginning with issue 1:3 (Winter 1987) through issue 17:3 (January/February 2003) were included in this review. STUDY INCLUSION AND EXCLUSION CRITERIA: Every study summarized in the DataBase section was included. Five duplicate sets of entries existed in the DataBase section. One entry from each set was excluded based upon author consensus. Thus, this review includes 345 unique entries. DATA EXTRACTION METHODS: All data reported in the DataBase section (e.g., sample sizes, measurement tools, study duration), as well as additional data derived directly from the studies (i.e., cross-sectional versus longitudinal study design, unit of analysis, and study topic) were entered in SPSS 11.5 for PC (SPSS, Inc, Chicago, Illinois). DATA SYNTHESIS: Data were synthesized to identify the frequency of entry by research question, research design and internal validity rating, unit of analysis, measurement tool(s), and health topics addressed. MAJOR CONCLUSIONS: The majority of articles included in the DataBase received the highest research design rating, had robust sample sizes, and were of a meaningful duration. Additionally, a wide variety of topics were addressed. Overall, these strengths indicate that a solid foundation of research has been established on many of the most critical issues facing the health promotion field.

Behavioral Research↗

PubMed1998

Comparison of the SimPlate coliform and Escherichia coli test with Petrifilm, three-tube MPN, and VRBA + MUG methods for enumerating coliforms and E. coli in food.

SimPlate for coliforms and Escherichia coli (CEc) is a new method for the detection and quantification of coliforms and E. coli in food. Internal validation of the method was carried out at IDEXX Laboratories (Westbrook, ME) with 180 food samples representing a variety of different food matrices and compared against three-tube MPN (most probable number), VRBA (violet red bile agar) + MUG, and Petrifilm (E. coli count) methods. SimPlate CEc was highly correlated with each of these methods for the quantification of coliform bacteria (r > or = 0.90). An insignificant number of food samples were found to contain E. coli; therefore, no meaningful correlation data could be generated. Four hundred forty-four additional food samples were tested at five collaborating laboratories for the presence of coliforms E. coli using SimPlate CEc and either VRBA + MUG or Petrifilm (E. coli count). Regression analysis of data from SimPlate for CEc versus Petrifilm E. coli count plates generated correlation coefficients (r) of at least 0.89 for total coliforms and at least 0.90 for generic E. coli. Correlation coefficients between SimPlate for CEc and VRBA + MUG data were at least 0.90 for coliforms and at least 0.86 for E. coli. SimPlate for CEc demonstrated better recovery of E. coli than Petrifilm when high populations of bacteria were present. E. coli was not detected in 20 or 50 (40%) raw milk samples tested by the Petrifilm method due to the presence of interfering coliform and noncoliform bacteria. It is concluded that SimPlate for CEc is a suitable alternative for determining numbers of coliform bacteria and E. coli in food.

Bacteriological Techniques↗

PubMed1997

Vocational outcome of intervention for low-back pain.

Practical management guidelines for occupational health physicians are needed for the individual support of employees with low-back pain. In this study the level of evidence regarding the efficacy of intervention with vocational outcome parameters was assessed. In a systematic literature search, 40 randomized clinical trials on different types of intervention were retrieved. Their internal validity and statistical power criteria were assessed. The randomization procedure, blinding of patients, and sample size were problematic in most studies. For patients with acute low-back pain limited or moderate evidence was found for the efficacy of no bed rest, a short period of bed rest, and spinal manipulation. For chronic patients limited evidence was found for the efficacy of antidepressants. For the other types of intervention, studies with sufficient statistical power were lacking. Such studies are needed before more-detailed evidence-based guidelines can be formulated for occupational health care.

Absenteeism↗

PubMed1999

Organizational interventions: facing the limits of the natural science paradigm.

This paper reviews current challenges in the conceptualization, design, and evaluation of organizational interventions to improve occupational health. It argues that attempts to confirm cause-and-effect relationships and allow prediction (maximize internal validity) are often made at the expense of generalizability (external validity). The current, dominant experimental paradigm in the occupational health research establishment, with its emphasis on identifying causal connections, focuses attention on outcome at the expense of process. Interventions should be examined in terms of (i) conceptualization, design and implementation (macroprocesses) and (ii) the theoretical mediating mechanisms involved (microprocesses). These processes are likely to be more generalizable than outcomes. Their examination may require the use of both qualitative and quantitative methodologies. It is suggested that such an approach holds unexplored promise for the healthier design, management, and organization of future work.

Occupational Health↗

PubMed2004

Is job strain a major source of cardiovascular disease risk?

Empirical studies on job strain and cardiovascular disease (CVD), their internal validity, and the likely direction of biases were examined. The 17 longitudinal studies had the highest validity ratings. In all but two, biases towards the null dominated. Eight, including several of the largest, showed significant positive results; three had positive, nonsignificant findings. Six of nine case-control studies had significant positive findings; recall bias leading to overestimation appears to be fairly minimal. Four of eight cross-sectional studies had significant positive results. Men showed strong, consistent evidence of an association between exposure to job strain and CVD. The data of the women were more sparse and less consistent, but, as for the men, most of the studies probably underestimated existing effects. Other elements of causal inference, particularly biological plausibility, corroborated that job strain is a major CVD risk factor. Additional intervention studies are needed to examine the impact of ameliorating job strain upon CVD-related outcomes.

Cardiovascular Diseases↗

PubMed2026

Analysis of end-stage renal disease mediated by cuproptosis-related genes.

OBJECTIVE: The complex pathophysiological mechanism of end-stage renal disease (ESRD) has not been fully understood. Cuproptosis is a newly discovered type of programmed cell death. Therefore, this study attempts to clarify the relationship between cuproptosis-related genes (CRGs) and the phenotype of ESRD. MATERIALS AND METHODS: The National Center for Biological Information Gene Expression Omnibus database was applied to obtain the GSE37171 dataset comprising whole-genome microarray analysis of peripheral blood samples. A 3 : 1 case-control design was employed with 75 ESRD patients and 20 healthy controls who were frequency-matched for age, sex, and ethnicity. Based on differentially expressed genes (DEGs) and genes related to cuproptosis, CRGs were identified. Thereafter, we explored two different subpopulations based on the cuproptosis gene and analyzed their expression and immune infiltration. Genes specific to the CRG cluster were identified through the weighted gene co-expression network analysis algorithm, and the best prediction model was determined and verified by four machine learning methods. RESULTS: The study identified 14 differentially expressed CRGs, among which ATP7B, SLC31A1, LIAS, LIPT1, DLD, MTF1, CDKN2A, DBT, and DLST had relatively high expression levels in the ESRD samples. Compared with the control group, expression levels of FDX1, DLAT, PDHA1, PDHB, and GLS were significantly lower in the ESRD group, and CRGs played a key role in the regulation of immune infiltration in ESRD. Two cuproptosis-related molecular clusters were identified in the ESRD samples. Cluster2 was more correlated with the immune infiltration of ESRD. By analyzing the intersection points between CRG cluster and key genes of ESRD, a total of 888 specific DEGs were identified. Functional differences related to specific DEGs were further explored using gene set variation analysis. Five significant genes (SMC5, USP47, USP53, AGA, and DMXL1) were identified by the support vector machine model as key predictors for ESRD disease risk, achieving an area under the curve (AUC) of 1.00 in internal validation. However, external validation in independent cohorts is required prior to clinical application. Individual gene analysis showed an AUC > 0.81 in discriminating ESRD patients from healthy controls, and the expression of all 5 genes in ESRD patients was significantly lower than in the control group. CONCLUSION: This study clarified the relationship between CRGs and the phenotype of ESRD, analyzed their specific roles in the immune microenvironment, and obtained a predictive model, providing new insights for the study of its potential therapeutic targets.

Humans↗

PubMedDate not supplied

Applying the transtheoretical model to cancer screening behavior.

OBJECTIVE: To provide a comprehensive review of published research on the application of the transtheoretical model (TTM) to cancer screening behavior. METHODS: Studies were categorized by design, given an internal validity rating where appropriate, and rated. RESULTS: Forty-two studies were reviewed. Stage-matched mammography interventions were supported; however, the body of literature was of limited size. Research on the TTM as it applies to other cancer screenings is sparse. CONCLUSIONS: Stage-of-change and decisional balance appear to apply to mammography. More validation research is needed on the application of the TTM to all cancer screening behaviors.

Breast Neoplasms↗

PubMed2003

Screening and interventions for obesity in adults: summary of the evidence for the U.S. Preventive Services Task Force.

BACKGROUND: Obesity poses a considerable and growing health burden. This review examines evidence for screening and treating obesity in adults. DATA SOURCES: MEDLINE and Cochrane Library (January 1994 through February 2003). STUDY SELECTION: Systematic reviews; randomized, controlled trials; and observational studies of obesity's health outcomes or efficacy of obesity treatment. DATA EXTRACTION: Two reviewers independently abstracted data on study design, sample, sample size, treatment, outcomes, and quality. DATA SYNTHESIS: No trials evaluated mass screening for obesity, so the authors evaluated indirect evidence for efficacy. Pharmacotherapy or counseling interventions produced modest (generally 3 to 5 kg) weight loss over at least 6 or 12 months, respectively. Counseling was most effective when intensive and combined with behavioral therapy. Maintenance strategies helped retain weight loss. Selected surgical patients lost substantial weight (10 to 159 kg over 1 to 5 years). Weight reduction improved blood pressure, lipid levels, and glucose metabolism and decreased diabetes incidence. The internal validity of the treatment trials was fair to good, and external validity was limited by the minimal ethnic or gender diversity of volunteer participants. No data evaluated counseling harms. Primary adverse drug effects included hypertension with sibutramine (mean increase, 0 mm Hg to 3.5 mm Hg) and gastrointestinal distress with orlistat (1% to 37% of patients). Fewer than 1% (pooled samples) of surgical patients died; up to 25% needed surgery again over 5 years. CONCLUSIONS: Counseling and pharmacotherapy can promote modest sustained weight loss, improving clinical outcomes. Pharmacotherapy appears safe in the short term; long-term safety has not been as strongly established. In selected patients, surgery promotes large amounts of weight loss with rare but sometimes severe complications.

Adult↗

PubMed2007

Incorporating quality of evidence into decision analytic modeling.

Our objective was to illustrate the effects of using stricter standards for the quality of evidence used in decision analytic modeling. We created a simple 10-parameter probabilistic Markov model to estimate the cost-effectiveness of directly observed therapy (DOT) for individuals with newly diagnosed HIV infection. We evaluated quality of evidence on the basis of U.S. Preventive Services Task Force methods, which specified 3 separate domains: study design, internal validity, and external validity. We varied the evidence criteria for each of these domains individually and collectively. We used published research as a source of data only if the quality of the research met specified criteria; otherwise, we specified the parameter by randomly choosing a number from a range within which every number has the same probability of being selected (a uniform distribution). When we did not eliminate poor-quality evidence, DOT improved health 99% of the time and cost less than 100,000 dollars per additional quality-adjusted life-year (QALY) 85% of the time. The confidence ellipse was extremely narrow, suggesting high precision. When we used the most rigorous standards of evidence, we could use fewer than one fifth of the data sources, and DOT improved health only 49% of the time and cost less than 100,000 dollars per additional QALY only 4% of the time. The confidence ellipse became much larger, showing that the results were less precise. We conclude that the results of decision modeling may vary dramatically depending on the stringency of the criteria for selecting evidence to use in the model.

CD4 Lymphocyte Count↗

PubMed1999

A taxonomy of health networks and systems: bringing order out of chaos.

OBJECTIVE: To use existing theory and data for empirical development of a taxonomy that identifies clusters of organizations sharing common strategic/structural features. DATA SOURCES: Data from the 1994 and 1995 American Hospital Association Annual Surveys, which provide extensive data on hospital involvement in hospital-led health networks and systems. STUDY DESIGN: Theories of organization behavior and industrial organization economics were used to identify three strategic/structural dimensions: differentiation, which refers to the number of different products/services along a healthcare continuum; integration, which refers to mechanisms used to achieve unity of effort across organizational components; and centralization, which relates to the extent to which activities take place at centralized versus dispersed locations. These dimensions were applied to three components of the health service/product continuum: hospital services, physician arrangements, and provider-based insurance activities. DATA EXTRACTION METHODS: We identified 295 health systems and 274 health networks across the United States in 1994, and 297 health systems and 306 health networks in 1995 using AHA data. Empirical measures aggregated individual hospital data to the health network and system level. PRINCIPAL FINDINGS: We identified a reliable, internally valid, and stable four-cluster solution for health networks and a five-cluster solution for health systems. We found that differentiation and centralization were particularly important in distinguishing unique clusters of organizations. High differentiation typically occurred with low centralization, which suggests that a broader scope of activity is more difficult to centrally coordinate. Integration was also important, but we found that health networks and systems typically engaged in both ownership-based and contractual-based integration or they were not integrated at all. CONCLUSIONS: Overall, we were able to classify approximately 70 percent of hospital-led health networks and 90 percent of hospital-led health systems into well-defined organizational clusters. Given the widespread perception that organizational change in healthcare has been chaotic, our research suggests that important and meaningful similarities exist across many evolving organizations. The resulting taxonomy provides a new lexicon for researchers, policymakers, and healthcare executives for characterizing key strategic and structural features of evolving organizations. The taxonomy also provides a framework for future inquiry about the relationships between organizational strategy, structure, and performance, and for assessing policy issues, such as Medicare Provider Sponsored Organizations, antitrust, and insurance regulation.

American Hospital Association↗

PubMedDate not supplied

Therapeutic efficacy and safety of Cimicifuga racemosa for gynecologic disorders.

The reproducible quality of phytopharmaceuticals--herbal medicines--is an essential prerequisite for good efficacy and tolerability in the treatment of functional disorders. In clinical trials and scientific investigations, standardized assessments (i.e., validated, internationally recognized and accepted scales) provide the basis for establishing clinical efficacy and tolerability. Extracts (ethanolic and isopropanolic aqueous, Remifemin) of the rootstock of the herb Cimicifuga racemosa (black cohosh) are active ingredients developed for the treatment of gynecologic disorders, particularly climacteric symptoms. Drug-monitoring and clinical studies documenting experience with C. racemosa rootstock extracts comprise the database of this herbal treatment for menopausal symptoms (e.g., hot flashes, profuse sweating, sleep disturbances, depressive moods). These studies show good therapeutic efficacy and tolerability profiles for C. racemosa. In addition, clinical and experimental investigations indicate that the rootstock of C. racemosa does not show hormone-like activity, as was originally postulated.

Adult↗

PubMed1987

A marketing orientation to modeling the hospital-supplier interface: a probabilistic approach.

The author adopts a marketing orientation to model the hospital-supplier interface. A probabilistic approach using logit models is employed. Internal validity of the models estimated is examined and found to be satisfactory. The implications of the modeling process and findings for both hospitals and linen service contractors are discussed. The study reported is the second in a programmatic inquiry. The results of the first study were reported in the March 1986 issue of this journal.

Bedding and Linens↗

PubMed1999

Chronic venous disorders of the leg: epidemiology, outcomes, diagnosis and management. Summary of an evidence-based report of the VEINES task force. Venous Insufficiency Epidemiologic and Economic Studies.

BACKGROUND: To critically review the classification, epidemiology, outcomes, diagnosis and treatment of chronic venous disorders of the leg (CVDL), to issue evidence-based recommendations, and to identify areas requiring further research. METHODS: Articles identified by an extensive literature search were scored by members of an international task force. Only those articles with a moderate or strong rating for internal validity were retained. RESULTS: A scoring system weighing CVDL severity according to the probability of ulcer occurrence is proposed. Epidemiological data on the frequency of CVDL and its risk factors are reviewed. The following items are evaluated: costs associated with treatment; clinical outcomes related to CVDL and its treatment; available generic and disease-specific measures of quality of life; diagnostic procedures used to detect venous reflux; and efficacy of available treatments. CONCLUSIONS: CVDL is an important public health problem, based on its prevalence, cost and impact on quality of life. High-priority areas for research on CVDL are identified.

Chronic Disease↗

PubMed1999

[A global perspective on evidence-based medicine].

Evidence-based Medicine (EBM) has aroused considerable interest in Spain as a concept. Its original announcement in 1992 proposed a change in the paradigm in both the practice of medicine and how to teach it. That caused some controversy. The progressive improvement of both the quality of literature presentation and common understanding about the internal validity of studies can be attributed to its diffusion. EBM has also helped to disseminate new concepts like the NNT, more intuitive for the clinician. It has also fostered a variety of educational initiatives for the critical appraisal of the literature. Several initiatives for the compilation of sources screened for quality and oriented for application the practitioners' are ongoing, notably the Cochrane Collaboration, often using the features offered by the new technology. EBM has also contributed in some countries to formalize explicit policies to encourage directed clinical research.

Education, Medical↗

PubMed2000

Pooled metaanalysis of radiographic progression: comparison of Sharp and Larsen methods.

Metaanalysis refers to the statistical analysis of results from individual studies for the purpose of integrating the findings. However, numerous biases can threaten the internal validity of metaanalyses. This paper specifically addresses the issue of study heterogeneity in metaanalyses of radiographic progression. It considers the validity of pooling studies that have used either the Sharp score (or its variants) or the Larsen score (or its variants) by examining whether the 2 scoring methods are sufficiently concordant for pooling in terms of content of items, scaling and measurement properties. Despite differences between the Sharp and Larsen methods, they essentially measure the construct of radiographic damage, and as long as the spectrum of radiographic damage in the pooled series is similar, then the scoring methods are robust to pooling. However, where the spectrum of damage is not similar, for example, studies of radiographic progression of early disease compared with late disease, pooling should be exercised with caution.

Arthritis, Rheumatoid↗

PubMedDate not supplied

Liquid chromatographic determination of residual nitrite/nitrate in foods: NMKL collaborative study.

Nitrite and nitrate are used as additives in the food industry to provide color and taste and to control undesirable gas and flavor production by anaerobic bacteria by virtue of their antimicrobial properties. The analytical method that has been widely used to determine nitrite and nitrate involves the use of toxic cadmium. In response to a request from the Nordic Committee on Food Analysis, a study was performed to obtain an alternative chromatographic method to determine residual nitrite and nitrate in meat products. The study was done in 3 stages: (1) comparative evaluation of the performance of 3 liquid chromatographic methods, (2) internal validation of the selected ion chromatographic method, and (3) a collaborative study in which 17 laboratories from European countries participated. Furthermore, the applicability of the method to matrixes other than meat and meat products was demonstrated. The results of the collaborative study show that the European Prestandard prENV 12014-4 is well suited for the determination of nitrite and nitrate in different foods (e.g., meat products, vegetables, baby food, and cheese). The limits of detection for nitrite and nitrate ions are 1 and 10 mg/kg, respectively. Recoveries of residual nitrite/nitrate ranged from 96 to 108%. Repeatability and reproducibility were satisfactory.

Anions↗

PubMed2000

[Basic principles of clinical therapeutic studies--what, how and why?].

Treatment evaluation is one of the most important tasks in medical research. Detailed standards have been developed during the last decades. The efficacy/effectiveness of treatments can only be assessed in comparison to control groups. To guarantee the internal validity of these comparisons, the groups have to be comparable at the beginning of the study. This can be achieved by randomized allocation of patients to treatment. Furthermore, as far as possible patient and physician should be blinded to treatment in order to avoid subjective influences on treatment results. Groups should still be comparable when analysing the trial, thus an analysis according to the principle of intention-to-treat ("as randomized") should be performed. These indispensable principles for design, conduct and analysis of clinical trials are widely accepted and contribute to reliable and credible results.

Humans↗