Biomedical subjects
R B Rothenberg
Publications and source records attributed to R B Rothenberg.
Methods in epidemiologic research.
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Excess deaths from nine chronic diseases in the United States, 1986.
To assess excess mortality from chronic disease in the United States, state age-adjusted combined mortality rates for nine chronic diseases in 1986 were compared with three "minimum" rates--two calculated from rates actually achieved in states and a third estimated as the mortality remaining after elimination of one risk factor for each disease. Hawaii had the lowest mortality rate of combined diseases (305/100,000); state excesses ranged from 0% to 37%. The sum of lowest disease-specific rates in any state was 284 per 100,000, indicating excesses of between 7% and 41%. A minimum mortality rate of 224 per 100,000 was estimated to result from elimination of one risk factor for each of the nine diseases, indicating state excesses from 26% to 54%, or 524,000 US deaths. Reduction of US mortality from the nine diseases to the risk factor--eliminated rate is estimated to be associated with an increased life expectancy at birth of 4 years.
Application of the Cox model as a predictor of relative risk of coronary heart disease in the Albany Study.
Patients in long term studies of coronary heart disease may have different levels of risk during the course of study. Smoking habits, blood pressure, and obesity may change drastically during this period. The multiple logistic model, the most commonly used model for the analysis of coronary heart disease studies, does not consider survival time in assessment of the dependent covariates and does not account for the censoring which usually occurs in such studies. We propose a Cox model with time-dependent covariates to model the risk of coronary heart disease in the Albany study. The Cox model we fitted evaluates the patients' risk on the basis of the data at the last visit. With this methodology, we can evaluate whether it is advantageous for individuals to modify their risk of disease by their effecting changes in their covariates, that is to stop smoking, lose weight, change diet and so on. The important covariates that explain the risk of coronary heart disease were the same in our model as in the models used in the earlier reports. The estimated relative risks were slightly higher in most cases and lend more support to the need to encourage patients to achieve a better covariate state.
The public health importance of clusters: a note from the Centers for Disease Control.
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Chronic disease in the 1990s.
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Identifying important results from multiple statistical tests.
When many statistical tests are performed simultaneously, the overall chance of a type I error (incorrect rejection of a true null hypothesis) can substantially exceed the nominal error rate used in each individual test. Numerous techniques exist to adjust results of individual tests to control this problem. In general, these techniques apply a more stringent criterion of statistical significance (a smaller P-value) to each individual test than normally needed to maintain the experimentwise type I error. With an analysis that seeks to identify results for further research, however, such a conservative technique may not be appropriate. We present a new approach that uses a mixture of several distributions to model the set of P-values or of test statistics. One component models the results consistent with a failure to reject the null hypothesis, while the other distribution(s) in the mixture represent results inconsistent with the null hypothesis. These latter results may not achieve statistical significance based on a conventional P-value. We illustrate the use of the method on national mortality data and on several data sets analysed previously.
Efficacy of selected diagnostic tests for sexually transmitted diseases.
Direct urethral and cervical smears for gonorrhea in women are useful because of their high specificity. Male rectal smears are less efficacious. Direct tests for candidiasis and trichomoniasis are also specific, but less sensitive than generally thought. Most tests exhibit only moderate month-to-month variability. No association between infection with trichomonads and gonococci was demonstrated. The gonococcal tests all perform best under conditions of high prevalence, such as those that obtain in venereal disease clinics in the United States.
Strategic planning system for control of venereal disease: record keeping in a clinic for treatment of sexually transmitted diseases.
A manual data processing system and a computer-based system that was integrated into the operations of a clinic for treatment of sexually transmitted diseases were developed. The automated system can generate routine management reports and cross-tabulate data for special studies. It is flexible and adaptable to other localities but is not a panacea for clinical problems.
Analysis of routine data describing morbidity from gonorrhea.
A system was developed for the collection, coding, and processing of data from routine reports describing morbidity caused by gonorrhea. These data are coded centrally, and tables that provide information about the age, sex, race, source of care, and geographic and temporal distributions of the population affected by gonorrhea are generated. Applications of the system are described; these include study of distribution of the disease, trends in utilization of facilities, seasonal trends in incidence of the disease, and several features of recidivism in the Denver (Colorado) metropolitan area. This system has potential as a tool for evaluation of disease control efforts in any standard metropolitan statistical area.
Disease transmission by heterosexual men with gonorrhea: an empiric estimate.
In Colorado Springs, Colorado, between January and June 1981, approximately 400 cases of gonorrhea in heterosexual men generated approximately 200 "spread" cases in women. The ratio of spread cases to index cases (0.5) is an empiric measure of the reproductive rate for the disease, i.e., the rate at which an infected person replaces himself. Although a reproductive rate of less than one theoretically should produce extinction of the disease, the rate derived from these data is shown to be a weighted average of the rates in symptomatic men (0.31), subsymptomatic men (0.79), and asymptomatic men (1.30). Approximately 35% of gonorrhea transmitted by men may be attributed to the asymptomatic group, which constitutes 10-15% of the infected population. If the observations in this community are applied to the nation as a whole, we estimate that approximately 1.7 million cases of gonorrhea occurred in 1981, as compared with the 990,864 cases actually occurred in 1981, as compared with the 990,864 cases actually reported. This estimate is close to those usually quoted but differs in gender composition. Whereas the observed male-to-female ratio is 1.48:1, the predicted ratio, based on estimates of reproductive rates in subgroups, is 0.8. This analysis supports the theoretical notion that the endemicity of gonorrhea is maintained by heightened transmission within small groups, and it suggests that underdetection is more important than underreporting in the assessment of the "true" incidence of this infection.
Temporal and social aspects of gonorrhea transmission: the force of infectivity.
Theoretical consideration of the epidemiology of sexually transmitted diseases (STD) suggests that the key determinants of transmission dynamics are the duration of infectiousness and the extent to which subgroups in the population interact sexually. We used two empirical correlates to represent these concepts: (1) the force of infectivity, calculated by summing all the days of potential infectivity (the time between last sexual exposure and treatment of the contact) generated by a given case, and then summing the days for all cases within a given subgroup; (2) self-selection, representing the observed probability that members of a given subgroup select sexual partners from within their own group. Using data gathered in Colorado Springs, Colorado, we estimated that a single group i.e., black, male, heterosexual, military personnel residing in the core areas, generated 27% of the force of infectivity. Subgroups that select greater than 50% of their sexual partners from outside their sociodemographic boundaries generated a rate for the force of infectivity that was 4.5 times higher than the rate for self-selectors. These findings confirm the core group theory and suggest strategies for control of STD.
Ischemic heart disease and hypertension: effect of disease coding on epidemiologic assessment.
During the changeover from the eighth to the ninth revision of the "International Classification of Diseases: Manual of the International Statistical Classification of Diseases, Injuries, and Causes of Death" (ICD), there were several major alterations of coding for the rubrics Ischemic Heart Disease (IHD) and Hypertension (HBP). As expected, these changes caused major discontinuities for IHD and HPB. These discontinuities were not, however, uniform over sex-race groups. When examined by component ICD codes, the discontinuities were found to vary in both magnitude and direction among the groups. In addition to discontinuity, there was a change in the rate of decline for IHD and HBP after the changeover. This rate of decline varied as well by sex-race group. In general, the decline among blacks was slower than among whites. Earlier studies that assessed IHD mortality have used different groupings of ICD codes to obviate the discontinuity, and researchers have observed a similar differential decline. These results should be viewed with caution because of the potential impact of differential coding on sex-race groups. As preparations are made for ICD-10, special attention should be given to the preservation of epidemiologic continuity to provide better assessment of trends in population subgroups.
Epilogue. Establishment of the Center for Chronic Disease Prevention and Health Promotion.
The establishment of the Center for Chronic Disease Prevention and Health Promotion (CCDPHP) at the Centers for Disease Control (CDC) following the Conferences on the State of the Art in Quality Control Measures for Diagnostic Cytology Laboratories is briefly discussed. The CCDPHP is expected to play a major role in the CDC's cancer control program, including participation in establishing effective screening programs and assuring the quality of such methodologies as the Papanicolaou test and mammography.
A controlled trial of disease surveillance strategies.
Active surveillance techniques using routine telephone contacts with providers improved the reporting of measles, rubella, salmonellosis, and hepatitis by a factor of 4.6 among private physicians in Monroe County, New York, and increased reporting for these target diseases from all sources by 51 percent. The timeliness of reporting was not improved by active surveillance. Reporting patterns varied by disease and source of report, suggesting the desirability of various approaches to surveillance based on local resources and priorities. Although reporting rates were higher for diseases among persons from census tracts of low socioeconomic status, physicians providing care to persons living in low-income areas responded no differently to active reporting than did those providing care to patients from middle- and high-income areas.