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PubMed2000

[The power of numbers].

The round figure for the current year has stirred people's minds in anticipation. Numbers have acquired great significance also in today's medical science. The Paris physician Pierre Charles Alexandre Louis (1787-1872) is considered the founding father of the numerical method in medicine. At first the principle of aggregating data from different individuals aroused much resistance and even disgust: Claude Bernard was a leading figure among those who warned that one will never find a mean in nature, and that grouping findings together obscures the true relationship between biological phenomena. True enough, statistical significance is not a characteristic of nature itself. Significant differences or risk reductions do not necessarily imply clinical relevance, and results obtained in a group of patients are rarely applicable to an individual patient in the consultation room. Likewise, the health of a human being cannot be captured in biochemical, radiological or other technical measures, nor in disease-specific scales that reduce well-being to one or two digits. The editors of this journal will remain keen on publishing numerical studies that contribute to evidence-based medicine, but at the same time they will continue to foster the art of reporting illness from the point of view of the sick person.

Clinical Medicine↗
PubMed2000

The clinical burden of prostate cancer in Canada: forecasts from the Montreal Prostate Cancer Model.

OBJECTIVES: The incidence of prostate cancer is increasing, as is the number of diagnostic and therapeutic interventions to manage this disease. We developed a Markov state-transition model--the Montreal Prostate Cancer Model--for improved forecasting of the health care requirements and outcomes associated with prostate cancer. We then validated the model by comparing its forecasted outcomes with published observations for various cohorts of men. METHODS: We combined aggregate data on the age-specific incidence of prostate cancer, the distribution of diagnosed tumours according to patient age, clinical stage and tumour grade, initial treatment, treatment complications, and progression rates to metastatic disease and death. Five treatments were considered: prostatectomy, radiation therapy, hormonal therapies, combination therapies and watchful waiting. The resulting model was used to calculate age-, stage-, grade- and treatment-specific clinical outcomes such as expected age at prostate cancer diagnosis and death, and metastasis-free, disease-specific and overall survival. RESULTS: We compared the model's forecasts with available cohort data from the Surveillance, Epidemiology and End Results (SEER) Program, based on over 59,000 cases of localized prostate cancer. Among the SEER cases, the 10-year disease-specific survival rates following prostatectomy for tumour grades 1, 2 and 3 were 98%, 91% and 76% respectively, as compared with the model's estimates of 96%, 92% and 84%. We also compared the model's forecasts with the grade-specific survival among patients from the Connecticut Tumor Registry (CTR). The 10-year disease-specific survival among the CTR cases for grades 1, 2 and 3 were 91%, 76% and 54%, as compared with the model's estimates of 91%, 73% and 37%. INTERPRETATION: The Montreal Prostate Cancer Model can be used to support health policy decision-making for the management of prostate cancer. The model can also be used to forecast clinical outcomes for individual men who have prostate cancer or are at risk of the disease.

Adult↗
PubMed2000

[Estimated number of HIV-infected individuals aged 15-49 years in Brazil, 1998].

This study estimates the number of HIV-infected individuals from 15 to 49 years of age in Brazil in 1998 based on sentinel population studies in pregnant women, with a selection bias in the sample. A principal components procedure was used to group 44 counties in homogeneous 13 clusters. Two indicators were constructed for each cluster: a) the logarithm of the accumulated AIDS incidence rate among women from 15 to 34 years of age (1996) and b) the logarithm of the growth ratio for the mean AIDS incidence rate for women from 15 to 34 years of age for the period from 1990-1992 to 1993-1996. Taking the log of the proportion of HIV-infected pregnant women as the dependent variable and the two above-mentioned indicators as the independent variables, a regression line was fitted to the aggregate data. Estimation of the model's parameters allowed us to calculate the proportion of infected individuals by macro-region, by age (15-34 and 35-49 years) and gender. The point estimate was 536 thousand HIV-infected adults with a 68% CI (470.689 - 603.305).

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Design and implementation of an outcomes management model.

In today's capitation-based reimbursement environment, acute care staff nurses must coordinate patient care considering the full continuum of care. To do so effectively, staff nurses need tools to accurately predict patient needs, adjust service intensity accordingly, and evaluate the outcomes of the care provided. The design and implementation of a model to support acute care staff nurses in that effort is described. The model's implementation was evaluated, in part, using a ten-item pre- and post-implementation survey. The survey showed that staff nurses who participated in the final educational offering on the model increased significantly their reported use of aggregate data for planning care. To achieve the greatest impact, the model needs to evolve so that it is applied earlier in the care process than at initial hospitalization. Ideally, this should occur during a wellness visit or enrollment in a health plan.

Acute Disease↗
PubMed2000

Surgery for colorectal cancer in elderly patients: a systematic review. Colorectal Cancer Collaborative Group.

BACKGROUND: The effectiveness of surgery for colorectal cancer depends on it being carried out safely, which allows most patients to return to productive lives, with an improved postoperative life expectancy, or at least one that is not diminished by the surgery. Because colorectal cancer is a major cause of morbidity and mortality in elderly people, we have examined how the outcomes of surgery in elderly patients differ from those in younger patients. METHODS: We did a systematic review of published and aggregate data provided by investigators. Studies were identified by computerised and manual searches of published and unpublished reports, scanning references, and contacting investigators. Within each study, outcomes for patients aged 65-74 years, 75-84 years, and 85+ years were expressed in relation to those aged less than 65 years. FINDINGS: From 28 independent studies, and a total of 34,194 patients, we found that elderly patients had an increased frequency of comorbid conditions, were more likely to present with later-stage disease and undergo emergency surgery, and less likely to have curative surgery than younger patients. The incidence of postoperative morbidity and mortality increased progressively with advancing age. Overall survival was reduced in elderly patients, but for cancer specific survival age-related differences were much less striking. INTERPRETATION: The relation between age and outcomes from colorectal cancer surgery is complex and may be confounded by differences in stage at presentation, tumour site, pre-existing comorbidities, and type of treatment received. However, selected elderly patients benefit from surgery since a large proportion survive for 2 or more years, irrespective of their age.

Age Factors↗
PubMed2001

Advancing Antithrombin Therapy in Acute Myocardial Infarction Management: Low Molecular Weight Heparins Plus Fibrinolysis.

Unfractionated heparin (UFH) has been traditionally used as an antithrombotic agent following fibrinolytic therapy for acute myocardial infarction. However, UFH has pharmacokinetic, biophysical, and biological limitations. Although early infarct artery patency has been superior with UFH as compared with placebo, aggregate data has demonstrated only a modest reduction in clinical events. Low molecular weight heparins (LMWHs) are attractive as potential adjunctive therapy to thrombolysis because of their greater bioavailabilty and ease of administration compared with UFH. Initial small trials with LMWHs have demonstrated their apparent safety when used in combination with thrombolytic agents, and a trend toward higher infarct-related artery patency rates. The clinical efficacy of LMWHs compared with UFH is currently being addressed in large-scale randomized clinical trials.

Journal Article↗
PubMed2001

Internet-based program cuts benchmarking tasks.

Practicing by the numbers: The Medical Group Management Association has taken on the task of profiling U.S. physicians, and it's thinking big. The strategy is to entice physician participation with cheap enrollment fees and the promise of aggregated data fast.

Benchmarking↗
PubMedDate not supplied

Residential substance abuse treatment for pregnant and postpartum women and their children: treatment and policy implications.

In FY 1993 and FY 1995, the federal government awarded 27 five-year grants that supported 35 residential treatment projects for substance-abusing pregnant and postpartum women and their children. These projects provided comprehensive culturally and gender-specific treatment. Preliminary aggregated data collected in a national cross-site evaluation of 24 of these projects are encouraging with respect to infant mortality and morbidity, treatment retention and completion rates, and behavioral changes in the participating mothers at six months postdischarge. Local evaluations reflect other benefits of treatment. Cost data are expected to demonstrate the efficiencies and benefits of these projects compared to no treatment.

Adult↗
PubMed2001

Prototypes in category learning: the effects of category size, category structure, and stimulus complexity.

Although research in categorization has sometimes been motivated by prototype theory, recent studies have favored exemplar theory. However, some of these studies focused on small, poorly differentiated categories composed of simple, 4-dimensional stimuli. Some analyzed the aggregate data of entire groups. Some compared powerful multiplicative exemplar models to less powerful additive prototype models. Here, comparable prototype and exemplar models were fit to individual-participant data in 4 experiments that sampled category sets varying in size, level of category structure, and stimulus complexity (dimensionality). The prototype model always fit the observed data better than the exemplar model did. Prototype-based processes seemed especially relevant when participants learned categories that were larger or contained more complex stimuli.

Adult↗
PubMed2001

[Short-term relationships between urban atmospheric pollution and respiratory mortality: time series studies].

Time series studies conducted in the field of air pollution aim at testing and quantifying short-term relations which can exist between daily air pollution levels and daily health effects. The method used for this type of survey has sometimes been misunderstood mainly because individual factors and indoor exposure to air pollutants were not taken into account. The adjustment on these individual confounding factors commonly used in classic epidemiologic studies (case-control studies, cohort studies) is not adequate to times series studies which are based on aggregate data. This is different for those factors that change over time according to the levels of air pollution (meteorological conditions, influenza epidemics, trend of health cases) which, when being analysed, must be taken into account either indirectly through time modelling or directly through non-linear modelling processes. During this last decade, numerous studies using the time series method have been published and have found short-term associations between daily levels of air pollution commonly observed and daily respiratory mortality. The consistency of the numerous results published in the international literature are more arguments in favour of non-confounding short-term relations between air pollution and respiratory mortality.

Adult↗
PubMed2002

A qualitative assessment of one cohort from the University of North Carolina Family Medicine Faculty Development Fellowship.

OBJECTIVES: This project qualitatively assessed the critical components and global impacts for one cohortfrom the part-time faculty development fellowship at the University of North Carolina at Chapel Hill. METHODS: Sixteen individual qualitative in-person interviews were conducted on one complete cohort of faculty development fellows. RESULTS: The data aggregates into four areas of influence. The first two are the critical components of the fellowship: the conditions and the curriculum. The other two are the impacts of the fellowship: the fellows' clarity of career vision and confidence. CONCLUSIONS: Graduates reported that their fellowship vitalized them to pursue their ideal position in academic family medicine.

Adult↗
PubMed2002

One drink to a lifetime of drinking: temporal structures of drinking patterns.

This article presents the proceedings of a symposium at the 2001 Research Society on Alcoholism Meeting in Montreal, Canada. The cochairs were Paul J. Gruenewald and Marcia Russell. The focus of the symposium was on mathematical, methodological, and statistical approaches to the assessment of drinking patterns from short (daily and monthly) to very long periods (the life course) of time. The research presented in the symposium argues that (1) model-based approaches to analyzing drinking patterns can provide comprehensive bases for assessing drinking risks, (2) data acquisition technologies that track daily drinking over long periods of time can illuminate unique features of drinking associated with abuse and dependence, and (3) retrospective data can be used to assess life-course trajectories of drinking associated with chronic problem outcomes. Each of the presentations points toward an integrated approach to understanding acute and chronic risks related to alcohol use. The presentations were (1) Mathematical models of current drinking, by Paul J. Gruenewald and Fred Johnson; (2) Mathematical models of drinking problems, by John Light and Rob Lipton; (3) Patterns of drinking ascertained from daily data aggregated across 24 months, by John Searles; and (4) Cognitive lifetime drinking histories and natural histories of drinking, by Marcia Russell, Paul J. Gruenewald, Fred Johnson, Maurizio Trevisan, Jo Freudenheim, Paola Muti, Ann Marie Carosella, and Thomas H. Nochajski.

Alcohol Drinking↗
PubMed1992

The status quo, regional differences, and trend of the Chinese family structure.

"Based on the 10% machine aggregate data of the fourth census of 1990 and the 1% computer sampling data, this article attempts to analyze the status quo and regional differences of China's family structure and their relationships with the level of social and economic development, and the trend of the Chinese family structure since the 1980s."

Asia↗
PubMed1995

[Non-EC workers in Italy: an overview of the literature and an attempt to test various hypotheses].

"The essay presents an overview of the interpretations offered in scientific literature about causes and effects of non-EC [European Community] immigrants' integration into the Italian labor market....The essay uses the aggregate data of [the] Labor Ministry integrated by local surveys to answer some questions...[concerning] the link between sex, Italian region, place of origin and sector of activity...and the complementarity or competition with [the] Italian labor force." (SUMMARY IN ENG AND FRE)

Acculturation↗
PubMed1992

Interprovincial migration and local public goods.

"The objective of this paper is to test whether fiscally induced migration occurs in Canada; that is, whether interprovincial migration flows are influenced by government tax and expenditure policies. In order to do so, a multinominal logit model of migration is developed in which individuals choose to live in the province where their utility would be highest. The model is estimated using aggregate data for the period 1962-81.... The results indicate that migration is influenced by provincial government spending, trough the magnitude and direction of the effect differs with the type of government spending.... The implication of these results is that intergovernmental transfer payments and provincial natural resource revenues also have the potential to influence migration flows in Canada." (SUMMARY IN FRE)

Americas↗
PubMed1992

An analysis of unmarried population in Tibet.

"This article is intended to analyze the unmarried population above 15 years of age in Tibet based on the 10% machine aggregate data from the 1990 census." Aspects considered include the sex and age composition of the unmarried population, and average and median age at first marriage.

Age Distribution↗