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Biomedical subjects

D F Stroup

Publications and source records attributed to D F Stroup.

54 records · Page 3Linked to original sources

Persistence of influenza A by continuous close-contact transmission: the effect of non-random mixing.

The interaction of two populations has variable effects on the nature and duration of epidemic activity, depending on the transmissibility of the virus, the susceptibility of the population, migration, birth and death rates, and the initial number of cases. Under circumstances where transmission stops in a single population (the infectious contact number is less than or equal to one), transmission may continue indefinitely when two populations interact under many different parameter combinations. A mass-action model was constructed using difference equations for two populations that included parameters for migration between populations and variable transmissibility between and within these populations. The limitations of extrapolating the model to actual conditions in human populations result from assumptions inherent in these models, such as fractional infection of individuals.

Disease Outbreaks↗

Detection of aberrations in the occurrence of notifiable diseases surveillance data.

The detection of unusual patterns in the occurrence of diseases and other health events presents an important challenge to public health surveillance. This paper discusses three analytic methods for identifying aberrations in underlying distributions. The methods are illustrated on selected infectious diseases included in the National Notifiable Diseases Surveillance System of the Centers for Disease Control. Results suggest the utility of such an analytic approach. Further work will determine the sensitivity of such methods to variations in the occurrence of disease. These methods are useful for evaluating and monitoring public health surveillance data.

Centers for Disease Control and Prevention, U.S.↗

Vibrio gastroenteritis in Louisiana: a prospective study among attendees of a scientific congress in New Orleans.

The incidence of diarrhea associated with infection by Vibrio species was investigated among attendees at the 1986 Interscience Conference on Antimicrobial Agents and Chemotherapy held in New Orleans. Twelve percent of respondents reported diarrhea; the risk of diarrhea was significantly higher in those who ate raw or cooked oysters (relative risk = 1.5, P = .005). At least one Vibrio species was recovered from 51 (11%) of 479 persons submitting stool specimens; however, only 15 (29%) of those with a positive stool culture also reported diarrhea. Of the five Vibrio species identified, V. parahaemolyticus was most common and was most strongly associated with diarrhea. V. cholerae serogroup O1 was not isolated despite the occurrence of a cholera outbreak during the same time period in Louisiana. Cultures of raw and cooked seafood served in local restaurants yielded five different Vibrio species. Although asymptomatic passage of Vibrio organisms was common among persons eating seafood, the risk of Vibrio gastroenteritis was low.

Adult↗

Hepatitis A outbreak on a floating restaurant in Florida, 1986.

In April and May 1986, the largest reported foodborne outbreak of hepatitis A in Florida state history occurred among patrons and employees of a floating restaurant. A total of 103 cases (97 patrons and six employees) were identified. The exposure period lasted 31 days (March 20-April 19), making this the most prolonged hepatitis A outbreak to occur in a restaurant that to date has been reported to the Centers for Disease Control. The exposure period was divided into time intervals (peak, early, late, and total) for calculation of food-specific attack rates. The authors showed that green salad was an important vehicle of transmission for each phase of the exposure period, with the highest adjusted odds ratio for the three-day peak exposure interval (March 28-30), 6.8 (p = 0.001). Non-salad pantry items and mixed bar drinks were also identified as vehicles of transmission; both were more important during the early interval of the exposure period than during the late interval. Two of six infected employees worked in the pantry and may have sequentially infected patrons. Though rare, this outbreak suggests that hepatitis A infection among employees may allow for transmission to patrons for prolonged periods of time. Prevention of such outbreaks requires prompt reporting of ill patrons with rapid identification of infected employees and correction of food handling practices.

Adolescent↗

The science of public health surveillance.

Improved public health surveillance can lead to earlier implementation of prevention and control measures. Better surveillance data lead to a more rational establishment of priorities. More timely and accurate data facilitate earlier epidemic detection and control. With better surveillance data, the impact of intervention activities and other public health programs can be evaluated more accurately. In this paper we describe how to improve the science of surveillance in terms of data collection, analysis, and dissemination and its application to public health practice. We then discuss the potential benefits and costs of such efforts and suggest methods for evaluating alternative approaches. The argument for science in surveillance, on the other hand, may be subject to excess. Surveillance is not an end unto itself, but rather a tool. This tool should be refined and modified to adapt to the goals of a particular public health program. It is the development of methods to apply creative ideas to surveillance, and the rigorous assessment of the process, that will benefit from the application of scientific principles.

Data Interpretation, Statistical↗

A nurse-associated epidemic of cardiac arrests in an intensive care unit.

Review of 2219 admissions to an intensive care unit at a large urban hospital from 1983 to 1985 revealed an epidemic of cardiac arrests during the evening shift from January 1984 to March 1985. Of the 88 evening-shift cardiac arrests during this time, one specific nurse (Nurse 14) was the care giver for 57 (65%). Eight of ten epidemic-period patients who experienced shift-specific circadian recurrences of cardiac arrests were patients of Nurse 14. No therapeutic intervention and no other health care provider was as strongly associated with evening-shift cardiac arrests as was Nurse 14. Multiple logistic regression analysis demonstrated that when risk of cardiac arrest was adjusted for age, sex, severity of illness, and postoperative status, patients of Nurse 14 were 47.5 times more likely to experience arrest than were other nurses' patients. An expert determined that, compared with other nurses, the cardiac arrests among Nurse 14's patients were more likely to be consistent with unexplained hyperkalemia, to be unexpected in timing, and to be inconsistent with the clinical course. The epidemic ceased when Nurse 14 left employment at the intensive care unit in March 1985. Epidemiologic surveillance of adverse outcomes in health care settings is recommended.

Data Interpretation, Statistical↗

Application of multiple time series analysis to the estimation of pneumonia and influenza mortality by age 1962-1983.

We employed multiple time series analysis to estimate the impact of influenza on mortality in different age groups, using a procedure for updating estimates as current data become available from national mortality data collected from 1962 to 1983. We compared mortality estimates that resulted from a multivariate model for epidemic forecasting with those obtained from univariate models. We found more accurate prediction of deaths from all age groups using the multivarate model. While the univariate models show an adequate fit to the data, the multivariate model often enables earlier detection of epidemics. Additionally, the multivariate approach provides insight into relationships among different age groups at different points in time. For both models, the largest excess mortality due to pneumonia and influenza during influenza epidemics occurred among those 65 years of age and older. Although multiple time series models appear useful in epidemiologic analysis, the complexity of the modelling process may limit routine application.

Adolescent↗

Occupational risk of Lyme disease in endemic areas of New York State.

Although Lyme disease (LD) is the most common tick-borne disease in the United States, little is known about the frequency of and risk factors for infection with Borrelia burgdorferi in occupational groups. In 1986, we recruited primarily outdoor workers from six employee groups in southeastern New York where LD is endemic. Of 414 participants who completed questionnaires and had blood samples tested for antibodies against B. burgdorferi by ELISA and Western immunoblot, 27 (6.5%) were seropositive, but only 14 of the 27 reported previous symptoms of LD. Persons who spent more than 30 hours per week outdoors during leisure were 2.5 times more likely to be seropositive than those who did not (p = .02). Those with a history of outdoor employment were twice as likely to be seropositive as those without such a history, although this finding was not statistically significant (p = .70). However, the seroprevalence rate for the employees was 5.9 times higher than the rate for a comparison group of anonymous blood donors from the same region of New York (p less than .001). These results suggest that there was a relatively high rate of seropositivity for the employee groups and that infection was frequently asymptomatic and associated with outdoor exposure.

Adolescent↗

Public health surveillance for chronic conditions: a scientific basis for decisions.

In this paper we investigate the important contribution of multiple public health surveillance systems to policy in chronic disease control and prevention. We show that, typically, surveillance for chronic diseases relies on multiple data sources, often created for another purpose. We also define the concept of burden for chronic conditions based on data from multiple sources. An example from a state illustrates a model for combining data for use in policy development. These applications illustrate the central role of statistical methods in ensuring the appropriate use of data from multiple surveillance systems.

Cardiovascular Diseases↗

The prevention of ankle sprains in sports. A systematic review of the literature.

To assess the published evidence on the effectiveness of various approaches to the prevention of ankle sprains in athletes, we used textbooks, journals, and experts in the field of sports medicine to identify citations. We identified 113 studies reporting the risk of ankle sprains in sports, methods to provide support, the effect of these interventions on performance, and comparison of prevention efforts. The most common risk factor for ankle sprain in sports is history of a previous sprain. Ten citations of studies involving athletes in basketball, football, soccer, or volleyball compared alternative methods of prevention. Methods tested included wrapping the ankle with tape or cloth, orthoses, high-top shoes, or some combination of these methods. Most studies indicate that appropriately applied braces, tape, or orthoses do not adversely affect performance. Based on our review, we recommend that athletes with a sprained ankle complete supervised rehabilitation before returning to practice or competition, and those athletes suffering a moderate or severe sprain should wear an appropriate orthosis for at least 6 months. Both coaches and players must assume responsibility for prevention of injuries in sports. Methodologic limitations of published studies suggested several areas for future research.

Ankle Injuries↗

[Improving the quality of reports of meta-analyses of randomized controlled trials: the QUOROM Statement].

BACKGROUND: The Quality of Reporting of Meta-analyses (QUOROM) Conference was convened to address standards for improving the quality of reporting of meta-analyses of clinical randomised controlled trials (RCTs). METHODS: The QUOROM group consists of 30 clinical epidemiologists, clinicians, statisticians, editors, and researchers. In conference, the group was asked to identify items they thought should be included in a checklist of standards. Whenever possible, checklist items were guided by research evidence suggesting that failure to adhere to the item proposed could lead to biased results. A modified Delphi technique was used in assessing candidate items. RESULTS: The conference resulted in the QUOROM statement, a checklist, and a flow diagram. The checklist describes our preferred way to present the abstract, introduction, methods, results, and discussion sections of a report of a meta-analysis. it is organized into 21 headings and subheadings regarding searches, selection, validity assessment, data abstraction, study characteristics, and quantitative data synthesis, and in the results with 'trial flow', study characteristics, and quantitative data synthesis; research documentation was identified for eight of the 18 items. The flow diagram provides information about both the numbers of RCTs identified, included, and excluded and the reasons for exclusion of trials. INTERPRETATION: We hope this report will generate further thought about ways to improve the quality of reports of meta-analyses of RCTs and that interested readers, reviewers, researchers, and editors will use the QUOROM statement and generate ideas for its improvement.

Meta-Analysis as Topic↗

Epidemiologic field investigations by the Centers for Disease control and Epidemic Intelligence Service, 1946-87.

The epidemiologic field investigation is an important tool used by the Centers for Disease Control (CDC) to provide assistance to State, local, and international public health agencies. The Epidemic Intelligence Service (EIS) of the CDC is an ongoing program that gives physicians and other health professionals opportunities to learn and practice epidemiology. In the period 1946-87, EIS Officers and other professional staff based at CDC headquarters participated in 2,900 epidemiologic field investigations requested by State, local, and international public health agencies. Nearly two-thirds of the investigations involved infectious disease problems, while 13 percent involved noninfectious conditions; for 21.1 percent, the etiology of the problem was unknown when the investigation was initiated. Among the specific subcategories, bacterial causes were the most common, accounting for 864 (29.8 percent) of all investigations. During this 41-year period, an increasing proportion of the field epidemiologic investigations involved public health problems of noninfectious etiology. Trends in the types of investigations done probably represent the influence of such factors as CDC's priorities, organizational structure, and budget; the size of the EIS Program; national health initiatives; and the States' needs and programs.

Centers for Disease Control and Prevention, U.S.↗

The reporting of race and ethnicity in the National Notifiable Diseases Surveillance System.

The authors used 1987 data from the Epidemiologic Surveillance Project (ESP) of the Centers for Disease Control to examine the completeness of race-ethnicity reporting in the National Notifiable Diseases Surveillance System. And, to the extent possible, they used ESP to assess racial and ethnic disparities in the occurrence of selected notifiable infectious diseases. For the 30 reporting areas (29 States and the District of Columbia) that provided data to ESP for all of calendar year 1987, approximately 60 percent of case reports were accompanied by specified race-ethnicity for affected persons. This percentage varied widely by disease and State. In general, non-Hispanic whites had morbidity rates (cases per 100,000 population per year) that were among the lowest compared with rates for other groups, and Native Americans commonly had rates that were among the highest. The ranking of morbidity rates among blacks, Hispanics, and Asians and Pacific Islanders varied by disease, although the last group had strikingly higher rates for malaria and tuberculosis. The age distribution of persons with cases was often lower among minority groups than among non-Hispanic whites, but the authors were unable to calculate age-specific or age-adjusted rates. Potential biases that limit interpretation of the findings are reviewed. Efforts to eliminate racial-ethnic disparities in the occurrence of infectious diseases would be aided by effective surveillance data. For the ESP to meet its potential in this regard, however, substantial improvements in the reporting of race-ethnicity for notifiable diseases are needed.

Adolescent↗

Public health surveillance in child-care settings.

To investigate the potential contribution of public health surveillance systems to the health of children and workers in out-of-home child-care settings, we review existing public health surveillance practice in the United States. We identify issues that are of particular concern for surveillance in child-care settings. We propose a framework for developing public health surveillance systems that uses sentinel child-care sites, notifiable disease surveillance, modification of existing surveillance systems, and population surveys. Successful surveillance in these settings depends on the active participation of child-care providers, public health practitioners, and clinicians in (a) the selection of high priority diseases and injuries for surveillance; (b) the development of practical case definitions; (c) the augmentation of current surveillance systems to include disease and injury related to child care; and (d) the implementation, assessment, dissemination, and evaluation of new approaches for surveillance in child-care settings.

Child↗

Race and ethnicity in public health surveillance: criteria for the scientific use of social categories.

Public health surveillance is the cornerstone of public health practice. The uses of surveillance include the identification of patterns of health among population subgroups. The assessment of race and ethnicity in public health surveillance is fundamental to the reduction of preventable excesses in poor health among racial and ethnic populations. We review the use of race and ethnic variables in national public health surveillance systems in the United States. One barrier to the use of race and ethnicity in public health surveillance is the lack of scientific consensus on the nature of race and ethnicity and the measurement of these variables. Differences in terminology, data collection procedures, perceptions of group identity, and changing demographics of the U.S. population present particular challenges for surveillance. We propose criteria for any useful variables collected through surveillance. Application of these criteria to race and ethnicity suggests that race as assessed in surveillance is not primarily associated with biological characteristics, but it is more like ethnicity--a matter of self-perceived membership in population groups. Regular evaluation of surveillance systems will contribute to the usefulness of information on race and ethnicity in the improvement of the health of minority populations.

Data Collection↗

[Improving the quality of reports on randomized controlled trials. Recommendations of the CONSORT Study Group].

This summary corresponds to the translation into Spanish of the Special Communication published in the Journal of the American Medical Association in August 1996, along with the editorial published in the same issue "How to report Randomized Controlled Trials. The Consort Statement". It describes the Consolidated Standards for Preparation of Controlled Clinical Trials, prepared by a work group made up of members of the SORT Group and of the Asilomar Work Group, along with the director of a magazine and the author of the report on a clinical trial. The work was carried out by means of a Delphi process and the result was a check list and a process diagram. The check list is made up of 21 items that mainly refer to methods, results and discussions on the report of a controlled clinical trial, identifying the necessary information in order to be able to evaluate the internal and external value of the report, judging the improvement to be positive for the patient, the editors and the reviewers of the magazines.

Delphi Technique↗