Biomedical subjects
Publications and source records attributed to C M Beard.
Maintenance of high autopsy rates is associated with specific benefits, especially for clinical practice and for clinical and epidemiologic research. We have compiled and evaluated (on the basis of related costs and benefits) a comprehensive list of recommendations to resurrect the autopsy and reestablish it as a central contributor to medical practice, teaching, and research.
A population-based case-control study of coronary heart disease (CHD) risk in young women attributable to cigarette smoking, hypertension, diabetes, and steroidal estrogen use was conducted among residents of Rochester, Minnesota. All newly diagnosed cases of CHD (sudden unexpected death [SUD], N = 18; myocardial infarction [MI], N = 90; and angina, N = 133) among female Rochester residents 40 to 59 years of age during the years 1960 through 1982 were identified, and two community control subjects were matched for age and duration of community medical record. The overall adjusted odds ratio (OR) for the association between steroidal estrogen use and definite CHD (MI and SUD) was 0.6 (95% confidence interval [CI] = 0.2 to 1.3). Smoking (OR = 5.1; 95% CI = 2.3 to 11.6), hypertension (OR = 4.8; 95% CI = 2.3 to 10.2), and diabetes (OR = 8.4; 95% CI = 1.6 to 44.5) were strong risk factors for CHD events. If considered causal, cigarette smoking accounted for 64% of all MIs and SUDs in the community, hypertension accounted for 45%, and diabetes accounted for 13%. Although steroidal estrogen exposure reduced CHD among these women by 14%, giving steroidal estrogens to all women in this age group might reduce the population rates of MI by as much as 45%.
The first population-based incident case-control study of temporal arteritis (TA) in the US was conducted using the unique data resources of the Rochester Epidemiology Project. During the period 1950-1985, 88 newly diagnosed cases of biopsy-proven TA were identified among residents of Olmsted County, Minnesota. Cases were each matched to four Olmsted County community controls on age, sex and duration of community medical record. Odds ratios (OR) were calculated for marital status, education, Quetelet index, pregnancy, age at menopause, thyroid disease, diabetes, smoking, hypertension, angina, myocardial infarction, peripheral vascular disease, and stroke. Multivariable conditional logistic regression analysis identified statistically significant adjusted OR for smoking (2.3, 95% CI = 1.3-4.1). Elevated ORs which were not statistically significant were noted for angina, myocardial infarction, and peripheral vascular disease. These data suggest that TA and arteriosclerosis may share a common causal pathway. Alternatively, histopathological misclassification of temporal artery biopsies may have resulted in the observed association. Due to the limited power of this population-based study, multicentre collaboration should be encouraged to more precisely define the epidemiology of TA.
We identified all incident cases of clinically diagnosed Alzheimer's disease among the population of Rochester, MN, with onset from 1965 through 1974. A control (selected from the same community) was matched to each case by age, race, sex, and length of stay in Rochester. We studied 274 case-control pairs. Using the records linkage system available for residents of this community, we abstracted information on the occurrence of head trauma with loss of consciousness (LOC) from the medical records of both cases and controls. There were 5 pairs in which the case suffered an episode of head trauma with LOC but the control did not, and 4 pairs in which the control suffered an episode of head trauma with LOC but the case did not. We failed to detect a statistically significant difference between the 2 groups. This study overcomes many problems encountered in previous case-control studies reporting this association. The sample size was large; severity of head injury was documented in high-quality medical records; data about head injury were recorded before the onset of dementia: equal quality of data were available for cases and controls; and, since the study was population-based, there was no selection bias for cases or controls.
Using the centralized diagnostic data resource for the population of Rochester, Minnesota, we determined the prevalence of medically diagnosed dementia for this community. There were 289 individuals with dementia who were residing in Rochester on January 1, 1975: 208 women and 81 men. The overall age- and sex-adjusted rates per 100,000 population were 342 for all dementias and 227 for Alzheimer's disease. Prevalence rates increased with age for both sexes. Limiting the denominator to persons greater than or equal to 65 years, age-adjusted rates per 100,000 population for men and women were 3,452 and 3,466 (or about 3.5%), respectively, for dementia and 2,007 and 2,675 (2.0 and 2.7%), respectively, for Alzheimer's disease.
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A case-control study was conducted among residents of Rochester, Minn, to assess the influence of prior therapeutic radiation on the risk of primary hyperparathyroidism. Fifty-one cases of surgically proven primary hyperparathyroidism diagnosed from 1975 through 1983 were each matched by age and gender to two control subjects, with radiation exposure documented through preexisting medical records. The overall odds ratio for any prior therapeutic radiation therapy was 1.9 (95% confidence interval, 0.9 to 4.4) and it was 2.3 (95% confidence interval, 0.9 to 5.7) when limited to those with prior head and neck radiation. Among women, the figures were 2.9 (95% confidence interval, 1.1 to 7.5) for any prior therapeutic radiation and 3.4 (95% confidence interval, 1.2 to 10.2) for head and neck exposure. This study confirms the association between primary hyperparathyroidism and prior therapeutic radiation exposure, at least for women in this population.
An earlier report suggested that incidence rates of primary bronchogenic carcinoma had leveled off for men in Olmsted County, MN. Extension of that study to cover 50 years in this midwestern community now shows that lung cancer incidence continues to increase in both sexes, with rates in women approaching those found in men 20 years ago. This increase was seen for all cell types of bronchogenic carcinoma. Because one pathologist reevaluated tissues, changing histologic classifications were not responsible for secular trends; nor were the results influenced by referral bias inasmuch as the study was population based.
Ninety-four Olmsted County, Minnesota residents with temporal arteritis (TA) initially diagnosed between 1950 and 1985 (incidence cohort) were identified. The age- and sex-adjusted incidence of TA per 100,000 population age 50 years or older was 17.0 (95% confidence interval [CI] 13.6-20.5), with a marked increase in incidence with age and a threefold greater incidence in women (23.4, 95% CI 18.2-28.7) than in men (7.4, 95% CI 3.7-11.0). The previously described secular increase in TA incidence in Olmsted County women continued from 1970 through 1985, while TA incidence in men declined in this latter time period. Although the frequency of classic clinical manifestations of TA declined over time, the percentage of patients undergoing biopsy who have positive specimens remained relatively constant (women 41%, men 26%). The incidence rate of temporal artery biopsy also increased for women during this period, but declined for men, suggesting that the differing trends in TA incidence by sex may be partially attributable to a detection bias. Future research in TA etiology and epidemiology should focus on possible causal factors linked to the differential TA incidence by sex.
During the 47-year period 1935 through 1981, 30 cases of malignant bone and joint tumors (in 20 male and 10 female patients) were identified among Olmsted County, Minnesota, residents. The incidence rates per 100,000 population, age-adjusted to the 1970 US total white population, were 1.0 overall, 1.4 for male subjects, and 0.7 for female subjects. Mortality rates, likewise age-adjusted, were 0.7 overall and 1.1 and 0.3 for male and female subjects, respectively. These rates are similar to those from tumor registries, a finding that suggests that reporting of these tumors is relatively complete. The similarity of the incidence and the mortality rates is consistent with the high case-fatality rate. A comparison of the Olmsted County cases with Mayo Clinic referral cases provides some evidence for referral bias, as the referral patients were significantly younger and had significantly more high-grade tumors.
We assessed the risk of occurrence of cancer associated with exposure to metronidazole in the 771 female residents of Rochester, Minnesota, who were treated with metronidazole for vaginal trichomoniasis during the period 1960 through 1969 and were followed up for a total of 12,628 person-years. Standardized morbidity and mortality ratios were determined by using an expected number calculated by applying age-specific incidence rates from Rochester studies and Cancer Surveillance, Epidemiology, and End-Results Reporting (SEER) data to the person-years of follow-up. The overall standardized morbidity ratios for cancer at all sites were 1.4 (Rochester, 1978 through 1983), 1.5 (SEER data for Iowa, 1978 through 1981), and 1.2 (SEER data for Connecticut, 1978 through 1981). By site of the cancers, the standardized morbidity ratios greater than unity were those for malignant lesions of the lung, breast, thyroid, bladder, brain, kidney, nasopharynx, and oral cavity, as well as for multiple myeloma and malignant melanoma; however, the only significantly elevated standardized morbidity ratio was that for bronchogenic carcinoma. After adjustment for smoking status, the standardized morbidity ratio for bronchogenic cancer was 2.5 (95% confidence interval of 1.3 to 4.4). The standardized mortality ratio for cancer at all sites was 1.4 (95% confidence interval of 0.9 to 2.2). The analysis of these data suggests no significant increase in cancer-related morbidity or mortality for women exposed to metronidazole for treatment of vaginal trichomoniasis.
The incidence of anorexia nervosa during a 45-year period (1935 through 1979) was determined for the population of Rochester, Minnesota, from the epidemiology archives at the Mayo Clinic. The medical records of local residents with the diagnosis of anorexia nervosa were the primary source for case ascertainment, although records of those whose diagnoses might have been shielding anorexia nervosa were also screened. Standard criteria for diagnosis were applied. We identified 140 (128 female and 12 male) residents of the community who fulfilled the diagnostic criteria for anorexia nervosa. No significant long-term trend in rates was ascertained. The overall age- and sex-adjusted incidence rate was 7.3 per 100,000 person-years. The highest age-specific incidence rate (56.7 per 100,000 person-years) occurred in female residents 15 to 19 years old. The prevalence rate on Jan. 1, 1980, for Rochester residents with a history of the disease, age- and sex-adjusted to the 1970 US white population, was 113.1 per 100,000 (203.9 for female and 16.9 for male residents).
The incidence of carpal tunnel syndrome in the population of Rochester, Minnesota, from 1961 through 1980 was determined by use of the medical records-linkage system of the Rochester Epidemiology Program Project at the Mayo Clinic; 1,016 patients (1,600 affected hands) were identified. Incidence (cases per 100,000 person-years) was 99 (crude) overall, whereas the age-adjusted rates were 52 for the men, 149 for the women, and 105 for both sexes combined. Age-adjusted incidence rates increased from 88 during the 1961 to 1965 quinquennium to 125 during the 1976 to 1980 quinquennium; these rates probably reflect better recognition rather than a true increase in incidence rates. Age-specific rates generally increased with age in men, whereas in women a peak was reached in the 45 to 54 age group.
As part of a quality assurance program for monitoring medical efficacy of laboratory tests, three registered nurses collected data from the records of over 3000 patients who had plasma parathyroid hormone measurements. At the close of this investigation, medical records were reabstracted to assess the consistency of data collection. Overall agreement between data entries varied from 99.5% to 93.4% to 82% for 1672 numerical entries, 940 interpretative entries, and 50 classification codes, respectively. Statistics for 68 variables showed 3% poor agreement, 10% slight to fair agreement, 15% moderate agreement, 24% substantial agreement, and 48% almost perfect agreement. Since interobserver variability is a potential source of bias, statistical analysis of reabstracted data is a useful way to evaluate data consistency.
From 1967 to 1979, 118 incident cases of idiopathic Parkinson's disease (IPD) and 236 age- and sex-matched controls from Rochester, MN, were identified. Medical records on patients and controls for 40 years preceding the diagnosis of IPD were reviewed. The relative risk (RR) for ever-smoked and IPD was not significantly different from unity (RR = 0.7, 95% confidence interval = 0.4 to 1.2). The mean age at diagnosis of IPD was significantly younger (p = 0.007) in the ever-smokers (68.8 years) compared with never-smokers (73.8 years), although this needs to be interpreted cautiously. It is concluded that smoking had no effect on the development of IPD. Within 5 years after the index date, a new diagnosis of dementia was made more often in cases than in controls (p = 0.01). Relative risk of IPD significantly increased when prior diagnosis of psychoneurosis and psychosomatic illness had been made.
The average annual incidence of Bell's palsy per 100,000 population in Rochester, Minnesota, for 1968 through 1982 was 25.0 for both sexes combined; crude rates for males and females were 22.8 and 26.9, respectively, based on 85 males and 121 females. The relationship between various clinical features, patient characteristics, and the type of recovery was analyzed. In 206 patients, 28 (14%) experienced incomplete recovery and 178 (86%) had complete recovery, based on evidence in the medical records. Using logistic regression, complete facial weakness, non-ear pain, and hypertension were identified as the most important risk factors for incomplete recovery. Patients were divided into two groups for comparison of treatment results; one group (n = 94) was without any of the three identified risk factors, and the other group (n = 112) consisted of patients who had one or more risk factors. Results suggested that among the latter group, those treated with steroids fared better than those in any of the other treatment groups.
A case-control study of sudden unexpected death (SUD) as the initial manifestation of coronary heart disease in women younger than 60 years of age was conducted in Rochester, Minnesota. Risk factors among the 15 SUD cases identified during the years 1960 through 1974 were compared with those in two control groups--a population group of 60 (4 age-matched controls per case) and the 59 cases of myocardial infarction diagnosed in women younger than 60 years of age in Rochester during the same period. By using Miettinen's matched analysis for comparison of SUD cases and matched controls, the relative risks for the accepted coronary heart disease risk factors of ever smoking and hypertension were 8.6 (95% confidence interval [CI], 1.3 to 57.3) and 5.7 (95% CI, 1.2 to 26.9), respectively. In a comparison of SUD cases and myocardial infarction cases by using the Mantel-Haenszel procedure and stratifying by five age groups, the odds ratios were 1.2 for ever smoking and 0.8 for hypertension. Six of the 15 SUD cases had a diagnosis of alcoholism compared with 2 of the 60 controls and 4 of the 59 myocardial infarction cases; thus, the relative risks were 12.0 (95% CI, 3.4 to 41.9) and 4.8 (95% CI, 1.3 to 18.2), respectively. Ever married SUD cases were nulliparous or had fewer children more often than the controls or the myocardial infarction cases. The combination of major psychiatric diagnosis and major tranquilizer use occurred with greater frequency among SUD cases than among controls (relative risk, 2.9; 95% CI, 0.6 to 14.1), whereas comparison of SUD cases and myocardial infarction cases for this variable resulted in a relative risk of 0.7 (95% CI, 0.3 to 1.9).
A study of the incidence of malignant lymphoma in Olmsted County, Minnesota, revealed 91 new cases during the period 1970 through 1977. On the basis of the analyzed data, the overall average annual incidence rate per 100,000 population was 12.2 for males and 14.2 for females. The rates for both sexes combined (unadjusted for age) were 1.5 for Hodgkin's disease, 6.2 for lymphosarcoma, and 5.5 for reticulum cell sarcoma. The incidence rate for Hodgkin's disease decreased insignificantly, whereas that for both lymphosarcoma and reticulum cell sarcoma increased significantly during the period 1970 through 1977 in comparison with rates from the period 1945 through 1969. The largest increase was for rural males, for whom the rates for all three histologic types of lymphoma were substantially higher than those for urban males.