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At least 595 records · Page 33Linked to original sources

PubMed2003

Effect of trihalomethane exposure on fetal development.

AIMS: To examine the effect of trimester specific and pregnancy average total trihalomethane (TTHM) exposure on infant birth weight, low birth weight, and intrauterine growth retardation in term births, as well as gestational age and preterm delivery in all births. METHODS: Cross sectional analysis of 56 513 singleton infants born to residents of Massachusetts during 1990. City specific aggregate data were used to estimate maternal exposure to TTHM concentration; individual maternal information was used to adjust for confounding. RESULTS: Increased pregnancy average and second trimester TTHM exposure were associated with small for gestational age and reductions in birth weight after adjusting for potential confounding variables. Compared to </=60 micro g/l, pregnancy average TTHM exposure over 80 micro g/l was associated with a 32 g reduction in birth weight. There was a 23 g reduction in birth weight in infants born to mothers exposed to greater than 80 micro g/l TTHM during the second trimester. For each 20 micro g/l increase in TTHM, the estimated reduction in birth was 2.8 g for pregnancy average exposure and 2.6 g for second trimester exposure. An increased risk of small for gestational age births was found for pregnancy average (odds ratio (OR) 1.14; 95% CI 1.02 to 1.26) and second trimester (OR 1.13, 95% CI 1.03 to 1.24) TTHM levels greater than 80 micro g/l. There was no evidence of an association between preterm delivery and increased TTHM levels, but there were slight increases in gestational duration associated with TTHM concentrations. CONCLUSIONS: Maternal exposure to THMs may be associated with fetal growth retardation. Our findings are consistent with most previous work, although we generally found smaller effects of TTHMs on low birth weight and intrauterine growth retardation.

Adolescent↗

PubMed1996

Studies of avoidable factors influencing death: a call for explicit criteria.

OBJECTIVE: To analyse studies evaluating cases of potentially "avoidable" death. DESIGN: The definitions, sources of information, and methods were reviewed with a structured protocol. The different types of avoidable factors,--that is, deficiencies in medical care that may have contributed to death--were categorised. The presence of explicit classifications and standards was examined. basic criteria for quality of the studies were defined and the numbers of studies fulfilling these criteria were assessed. SETTING AND PARTICIPANTS: 65 studies, published during 1988-93 in peer reviewed medical journal for which the title, or abstract, or both indicated that they had analysed potentially avoidable factors influencing death. Studies analysing aggregated data only, were not included. RESULTS: Only one third of the studies fulfilled basic quality criteria,--namely, that the avoidable factors examined should be defined and the sources of information and people responsible for the judgements presented. The definitions used comprised two levels, one stating that there had been errors in management (process) and the other that the errors may have contributed to the deaths (outcome). Only 15% of the studies explicitly defined what type of factors they had looked for and 8% referred to specified standards of care. CONCLUSIONS: Studies of avoidable factors influencing death may have considerable potential as part of a system of improving medical care and reducing avoidable mortality. At present, however, the results from different studies are not comparable, due to differences in materials and methods. There is a need to improve the quality of the studies and to define standardised explicit definitions and classifications.

Cause of Death↗

PubMed2006

Breast density and parenchymal patterns as markers of breast cancer risk: a meta-analysis.

Mammographic features are associated with breast cancer risk, but estimates of the strength of the association vary markedly between studies, and it is uncertain whether the association is modified by other risk factors. We conducted a systematic review and meta-analysis of publications on mammographic patterns in relation to breast cancer risk. Random effects models were used to combine study-specific relative risks. Aggregate data for > 14,000 cases and 226,000 noncases from 42 studies were included. Associations were consistent in studies conducted in the general population but were highly heterogeneous in symptomatic populations. They were much stronger for percentage density than for Wolfe grade or Breast Imaging Reporting and Data System classification and were 20% to 30% stronger in studies of incident than of prevalent cancer. No differences were observed by age/menopausal status at mammography or by ethnicity. For percentage density measured using prediagnostic mammograms, combined relative risks of incident breast cancer in the general population were 1.79 (95% confidence interval, 1.48-2.16), 2.11 (1.70-2.63), 2.92 (2.49-3.42), and 4.64 (3.64-5.91) for categories 5% to 24%, 25% to 49%, 50% to 74%, and > or = 75% relative to < 5%. This association remained strong after excluding cancers diagnosed in the first-year postmammography. This review explains some of the heterogeneity in associations of breast density with breast cancer risk and shows that, in well-conducted studies, this is one of the strongest risk factors for breast cancer. It also refutes the suggestion that the association is an artifact of masking bias or that it is only present in a restricted age range.

Breast Neoplasms↗

PubMed2001

Steps towards constructing a global comparative risk analysis for alcohol consumption: determining indicators and empirical weights for patterns of drinking, deciding about theoretical minimum, and dealing with different consequences.

In order to conduct a comparative risk analysis for alcohol within the Global Burden of Disease Study (GBD 2000), several questions had to be answered. (1) What are the appropriate dimensions for alcohol consumption and how can they be categorized? The average volume of alcohol and patterns of drinking were selected as dimensions. Both dimensions could be looked upon as continuous but were categorized for practical purposes. The average volume of drinking was categorized into the following categories: abstention; drinking 1 (> 0-19.99 g pure alcohol daily for females, > 0-39.99 g for males); drinking 2 (20-39.99 g for females, 40-59.99 g for males), and drinking 3 (> or =40 g for females, > or =60 g for males). Patterns of drinking were categorized into four levels of detrimental impact based on an optimal scaling analysis of key informant ratings. (2) What is the theoretical minimum for both dimensions? A pattern of regular light drinking (at most 1 drink every day) was selected as theoretical minimum for established market economies for all people above age 45. For all other regions and age groups, the theoretical minimum was set to zero. Potential problems and uncertainties with this selection are discussed. (3) What are the health outcomes for alcohol and how do they relate to the dimensions? Overall, more than 60 disease conditions were identified as being related to alcohol consumption. Most chronic conditions seem to be related to volume only (exceptions are coronary heart disease and ischemic stroke), and most acute conditions seem to be related to volume and patterns. In addition, using methodology based on aggregate data, patterns were relevant for attributing harms for men but not women.

Adolescent↗

PubMedDate not supplied

Value and limitation of meta-analysis.

Meta-analysis is a valuable method of aggregating data sets of different trials which are inadequate or unconvincing on their own. There are strict rules on the retrieval and selection of data which are crucial in terms of the validity of a meta-analysis. Many so-called meta-analyses are flawed because of lack of a protocol or non adherence to it. Also underreporting of clinical trials is haunting the validity of meta-analysis. This hidden information is not a random process but is affecting mainly trials with negative results. To avoid this publication bias all clinical trials should enter an international online database.

Humans↗

PubMed2005

An examination of characteristics of lung and colon cancer patients participating in a web-based decision support program. Internet-based decision support programs.

OBJECTIVES: Little is known about the characteristics of cancer patients who employ the Internet as a technique to gather information to assist them in their management. METHODS: To address this issue, aggregate data from individuals with colon (n=7,543), non-small cell lung (n=24,778) and small cell lung (n=13,817) cancers who provided personal clinical information through participation in a proprietary Web-based decision support program (NexProfiler Treatment Option Tools for Cancer; NexCura, Inc., Seattle, Wash., USA) were evaluated for potential differences between specific patient subgroups. RESULTS: Examination of a number of objective (e.g., prior therapy) and subjective (e.g., overall health, activity level) parameters failed to reveal any major differences based on sex, geographical location (US vs. non-US) or newly diagnosed versus recurrent disease (non-small cell lung cancer patients). Several notable findings included: (1) overall >65% of colon cancer patients and >70% of lung cancer patients stated that they 'were interested in learning about clinical trials'; (2) 65-70% of patients with recurrent non-small cell lung cancer stated that their 'general health was good', while >60% noted they had symptoms and >50% declared their activity level to be essentially 'normal'; (3) while almost 80% of small cell lung cancer patients noted symptoms, >60% stated their activity level was 'normal'. CONCLUSION: These data suggest that the population of patients who seek information from Web-based decision support programs share a number of relevant clinical features, yet they appear to represent a unique subset among all individuals with malignant disease. It will be important for oncologists to more fully understand the objectives of this population in order to assist such patients (and their families) in their use of this remarkably powerful, but essentially unregulated, technology.

Activities of Daily Living↗

PubMed1996

Depiction of infarct frequency distribution by computer-assisted image mapping in rat brains with middle cerebral artery occlusion. Comparison of photothrombotic and intraluminal suture models.

BACKGROUND AND PURPOSE: Histopathologic analysis of experimental brain damage has traditionally been performed by measuring areas of infarction and/or selective neuronal alterations on a section-by-section basis in individual animals. For series containing multiple replicate animals, quantitation of tissue injury is typically performed at similar coronal levels throughout an experimental group. A means of facilitating pictorial group comparisons of these histopathologic alterations between different series of replicate studies is highly desirable. METHODS: We introduce a newly designed approach to achieve this goal, based on a linear affine transformation that is used to map corresponding sections at the same anatomic level into a common template to yield a frequency distribution map depicting the aggregate data set. We have applied this approach to compare the histopathologic features of two models of middle cerebral artery (MCA) occlusion in rats: (1) photothrombotically induced permanent distal MCA occlusion in spontaneously hypertensive rats (SHR) and (2) temporary MCA occlusion by intraluminal suture in Wistar rats. RESULTS: The brains of SHR rats with permanent distal MCA occlusion showed a high frequency of infarction involving the dorsolateral and lateral portions of the ipsilateral neocortex, whereas Wistar rats with 90-minute MCA suture occlusion showed a zone of infarction largely concentrated in the dorsolateral portion of the ipsilateral caudoputamen. Infarct frequency distributions for the two animal groups were compared statistically at three corresponding anatomic levels by Fisher's exact test; the resulting statistical parametric maps are shown. CONCLUSIONS: With the use of frequency distribution maps, the pattern of trends within a group can be observed coronally or three-dimensionally. One can directly access data as to numbers of rats with infarction for any point on the map. Studies performed under different experimental conditions can also be compared with one another by means of the generated data sets.

Animals↗

PubMed1989

Pulmonary neuroendocrine cells. Their secretory products and their potential roles in health and chronic lung disease in infancy.

Pulmonary neuroendocrine cells (PNEC) are granulated epithelial cells distributed throughout conducting airways. Among the bioactive products identified within the secretory granules of these cells are potent mitogens and bronchoactive and vasoactive agents. The secretory status of these cells, which are in greatest number in the fetus and newborn, is modulated by neural reflexes and by changes in airway gas composition. The aggregate data suggest roles for PNEC in airway "chemoception" and/or regulation of airway epithelial differentiation. Marked increases in PNEC are observed in bronchopulmonary dysplasia, where airway and alveolar fibrosis, epithelial metaplasia, and airway and vascular smooth muscle hypertrophy contribute to marked pathophysiologic changes in lung function. Considering the biologic effects of PNEC secretory products, particularly gastrin-releasing peptide on airway epithelial cell and fibroblast proliferation, we propose that an increase in PNEC secretory products in the regenerating airway epithelium may contribute to the development of the pathologic alterations in lung structure seen in bronchopulmonary dysplasia. In this proposed scheme, secretion of abnormally large amounts of bronchoactive and vasoactive agents from PNEC (e.g., serotonin, gastrin-releasing peptide) in response to airway hypoxia and hypercapnia may be partially responsible in the genesis of reactive airway disease and pulmonary hypertension seen in this disease.

APUD Cells↗

PubMed2000

Potential cost savings from pill splitting of newer psychotropic medications.

Many of the newer psychotropic medications have a pricing structure in which there are only small cost differences between pills of different strengths, affording an opportunity for cost saving by splitting pills. Twelve newer psychotropic medications were examined. Although savings varied for each drug, aggregate data indicated that splitting pills can produce an annual savings of up to $1.45 billion, which represents about 10 percent of the retail sales of these drugs. Such savings can benefit individuals, state Medicaid programs, community mental health centers, and managed care companies. The authors propose several strategies for encouraging the use of pill splitting.

Cost Control↗

PubMed2001

A self-assessment program for multidisciplinary mental health teams.

OBJECTIVE: The authors describe a self-assessment training program for multidisciplinary mental health teams that was developed in a public multihospital system, the process of implementing the training at a state psychiatric hospital, and a measurement instrument, the Scale for Leadership Assessment and Team Evaluation (SLATE), which they have used for self-assessment of multidisciplinary teams and which is currently being studied. They assessed whether changes in team self-assessments could be seen after the training program. METHODS: A total of 102 mental health professionals from 12 inpatient units representing the disciplines of psychiatry, psychology, nursing, social work, and occupational and activity therapy completed the SLATE before and after participation in a training program that consisted primarily of team self-assessment in the context of treatment planning sessions. The training program included structured feedback, didactics, consultation, and videotaping of sessions. Aggregate data were used to compare mean item scores for the SLATE overall and for its four subscales (team, psychiatrist, participation, and treatment plan) at baseline and after the training. RESULTS: Scores increased significantly for the overall SLATE and for all four subscales, indicating improved team functioning in the areas addressed. The increase in mean score was greatest for the subscale that assessed the leadership of the psychiatrist. CONCLUSIONS: Treatment planning sessions can be used successfully by multidisciplinary mental health teams to examine team functioning in various areas in a self-assessment model. Participation in a training program that included videotaping of sessions, consultation, and structured attention to team functioning was associated with improved ratings of team functioning.

Case Management↗

PubMed1990

Household patterns of older women. Some international comparisons.

Comparative analyses based on aggregate data have shown that the percentage of older women living alone has risen dramatically during recent decades, a pattern repeated in many European and North American countries. This article investigates the correlates of the decision to live alone, using individual-level data from five countries and a parallel analytic approach. The major categories of factors analyzed here are kin availability, financial resources, and disability and health status. Several common patterns of findings emerge for the group of countries considered: Larger kin networks and the presence of severe disabilities reduce the probability of living alone, whereas higher income increases the probability of living alone. Despite these similarities in individual-level correlates, there remain some differences across countries in the levels of single-person households, and these might be attributable to macrolevel forces such as housing and social welfare policies.

Aged↗

PubMed2005

Sexual abuse of vulnerable young and old women: a comparative analysis of circumstances and outcomes.

Aggregated data from 125 substantiated Adult Protective Services cases of sexually abused women were collected during a 5-year period. Women older than 59 years represented 63% of the cases. Regardless of age, the most common types of abuse involved sexualized kissing and fondling and unwelcome sexual interest in the women's body. Most identified perpetrators were older males. Family members were most likely to abuse women living in the community, whereas women living in facilities usually experienced abuse by another resident. Perpetrators were prosecuted and convicted in six cases. About 12% of the women continued to be at risk of further sexual abuse.

Age Factors↗

PubMed2000

Does general practitioner gatekeeping curb health care expenditure?

OBJECTIVES: It is generally assumed that health care systems in which specialist and hospital care is only accessible after referral by a general practitioner (GP) have lower total health care costs. In this study, the following questions were addressed: do health care systems with GPs acting as gatekeepers to specialized care have lower health care expenditure than those with directly accessible specialist care? Does health care expenditure increase more rapidly in countries without a referral system than in those with the GP acting as a gatekeeper? METHODS: Multiple regression analyses on total and ambulatory health care expenditure in 18 OECD countries. RESULTS: Analyses showed only one statistically significant effect (P < 0.05) in countries with gatekeeping GPs: ambulatory care expenditure has increased more slowly than in non-gatekeeping systems. No significant effects of gatekeeping were found on the level of ambulatory care costs, or on the level or growth of total health care expenditure. As in earlier studies, the most important factor influencing aggregate health care costs and their growth is gross national product (GNP), followed by the share of public funding. Relationships that exist at a micro level (such as lower costs with a gatekeeping primary care doctor) did not show up in aggregate data at a macro level. CONCLUSIONS: Gatekeeping systems appear to be better able to contain ambulatory care expenditure. More research is necessary to understand micro level mechanisms and to distinguish the effects of gatekeeping from other structural aspects of health care systems.

Cost Control↗

PubMed1984

Rheumatic disorders in a health survey: how valid and reliable are the reports?

The validity and reliability of interview reports on rheumatic disorders in a Swedish nationwide health survey were studied. Two samples, including altogether 157 individuals, who had reported rheumatic disorders, were medically examined 6 to 24 months after the original interview. The reproducibility of the original interview was studied by the means of two re-interviews. The proportional distribution of rheumatic disorders according to diagnostic group was similar to that in the original interview, in the two re-interviews and at the medical examination. In a subject-to-subject comparison the overall agreement between the medical examination and the lay re-interview was 84% (kappa 0.35) regarding presence of rheumatic disorders, and 57% (kappa 0.41) regarding matching of rheumatic diagnostic groups. In the original interview and the lay re-interview the same individual rheumatic disorder was reported by 38% of the subjects; 58% agreed regarding rheumatic diagnostic groups. The interview reports on rheumatic disorders in the health survey can therefore be considered to have acceptable validity and reliability only with regard to the proportional distribution of groups of rheumatic disorders, based on aggregated data.

Adolescent↗

PubMed2003

Malnutrition and dietary protein: evidence from China and from international comparisons.

Malnutrition, as measured by anthropometric status, is a powerful risk factor for illness and elevated death rates throughout life. Understanding the relative importance of disease, dietary quantity, and dietary quality in causing malnutrition is therefore of major importance in the design of public policy. This paper contributes to the understanding of the relative importance of quantity and quality of diet by utilizing aggregate data to complement previously reported individual-level studies. Three compilations of anthropometric data--one involving subjects from 13 provinces in China, another involving subjects from 64 counties in China, and a third involving 41 populations in 40 countries--are used to examine the relative importance for human growth of inadequacies of dietary energy and protein. The analysis involves regressing average adult heights and weights against estimates of average energy and protein availability (by province, county, or country) and per capita incomes. We use protein availability in part as a marker for overall quality of the diet, while recognizing that protein is far from perfectly correlated with dietary fat or micronutrient availability. The paper discusses issues of both data quality and statistical methodology, and points to relevant resulting caveats to our conclusions. Subject to these limitations, all three analyses suggest that, at the levels of dietary intake in these populations, lower protein intake is related to growth failure whereas lower levels of energy availability are not. The protein effect appears stronger for males than for females.

Adolescent↗

PubMed2006

Surveillance of monthly antimicrobial consumption rates stratified by patient-care area: a tool for triggering and targeting antibiotic policy changes in the hospital.

The profile and temporal trends of antimicrobial use were investigated at a university hospital. Aggregate data were analyzed according to the ATC/DDD methodology. During 1998-2002, hospital-wide antimicrobial use increased by 22%, from 86.97 to 106.24 defined daily doses per 100 bed-days [DDD/100BD]. Pooled usage rates in DDD/100BD, overall percentage increases and annual average increase rates were respectively 109.97, 35.6%, 8.1 for Medical wards, 98.21, 48.7%, 9.1 for Intensive Care Units and 74.46, 34.3%, 5.7 for Hemato-oncology wards. Surgical wards had a fairly constant usage rate (98.36). A shift towards the newer broad-spectrum antibiotics, to the detriment of the older penicillins and cephalosporins, was noted in all hospital areas. Surveillance of antimicrobial consumption using the ATC/DDD system provided a clear picture of its profile. Monthly rates over a sufficient surveillance period allowed the assessment of temporal trends. Stratification of rates according to clinical service allowed areas of concern to be specified and targeted antibiotic policy changes to be initiated.

Anti-Infective Agents↗

PubMed2005

The protease inhibitor PI*S allele and COPD: a meta-analysis.

In many countries, the protease inhibitor (SERPINA1) PI*S allele is more common than PI*Z, the allele responsible for most cases of chronic obstructive pulmonary disease (COPD) due to severe alpha 1-antitrypsin deficiency. However, the risk of COPD due to the PI*S allele is not clear. The current authors located studies that addressed the risk of COPD or measured lung function in individuals with the PI SZ, PI MS and PI SS genotypes. A separate meta-analysis for each genotype was performed. Aggregating data from six studies, the odds ratio (OR) for COPD in PI SZ compound heterozygotes compared with PI MM (normal) individuals was significantly increased at 3.26 (95% confidence intervals (CI): 1.24-8.57). In 17 cross-sectional and case-control studies, the OR for COPD in PI MS heterozygotes was 1.19 (95%CI: 1.02-1.38). However, PI MS genotype was not associated with COPD risk after correcting for smoking. Furthermore, mean forced expiratory volume in one second, a measure of airflow obstruction and a defining feature of COPD, did not differ between PI MS and PI MM individuals. There were not enough cases to summarise the risk of COPD in PI SS homozygotes. In conclusion, the results show that the PI SZ genotype is a significant risk factor for chronic obstructive pulmonary disease. The risk of chronic obstructive pulmonary disease due to the PI MS genotype is not substantially elevated.

Alleles↗

PubMed2000

Ratio of inhaled corticosteroid to bronchodilator treatment and asthma hospitalisation.

BACKGROUND: Previous research based on aggregated data has led to conflicting interpretations of the relationship between the corticosteroid:bronchodilator (C:B) ratio and outcome measures. OBJECTIVES: To assess whether the C:B ratio is associated with hospital contact for asthma at individual patient level. METHODS: The study was a retrospective multivariate analysis, using data from the U.K. General Practice Research Database from 1993 to 1996. The subjects were 3465 asthma-diagnosed patients receiving bronchodilator and corticosteroid medication. The main outcome measures were asthma-related hospital contacts. RESULTS: There was an inverse association between the C:B ratio and hospital contact after controlling for age. The odds ratio for the C:B ratio was 0.87 (95 % CI 0.73-0.98) and 1.04 (95% CI 1.01-1.07) for five-year agebands among patients aged five years and over. There was no systematic relationship between the C:B ratio and hospital contacts for patients aged under five years. CONCLUSION: The results of this study show that higher C:B ratios are associated with lower levels of hospital contacts at patient level, although there are exceptions possibly linked to disease severity. For patients under five years, the ratio may not be a good outcome measure, perhaps owing to the difficulty in diagnosing asthma or poor compliance.

Administration, Inhalation↗