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oai:open-archive.highwire.org:amjepid:134/8/7952015-05-11HighWireOUPamjepid:134:8
In Utero Exposure to Steroid Contraceptives and Outcome of Pregnancy
Pardthaisong, Tieng
Gray, Ronald H.
ORIGINAL CONTRIBUTIONS
A cohort study of women who used steroid contraceptives during pregnancy was conducted in Chiang Mai, northern Thailand, between 1984 and 1987 There were 1, 573 pregnancies in which the fetus was exposed to the injectable contraceptive Depo-Provera® (The Upjohn Company, Kalamazoo, Michigan) (830 accidental pregnancies and 743 infants conceived before the mother started use of Depo-Provera), 601 accidental pregnancies in women who were using oral contraceptives, and 2, 578 planned pregnancies with no steroid exposures (controls). Subjects were followed up for interview, and medical records were traced for birth weight Women using Depo-Provera had more risk factors for adverse pregnancy outcomes than did the other groups. The adjusted odds ratios for low birth weight were increased for accidental pregnancies with fetal exposure to Depo-Provera (odds ratio (OR) = 1.5, 95% confidence interval (Cl) 1.2–1.9) or oral contraceptives (OR = 1.5, 95% Cl 1.2–2 0) The higher risk of low birth weight among infants exposed in utero to Depo-Provera or oral contraceptives is due in part to self-selection for adverse outcomes among women with unplanned pregnancies. However, among accidental pregnancies with Depo-Provera, the nsk of low birth weight was significantly increased when conception was estimated to have occurred within 4 weeks of injection. The odds ratios were 1.9 (95% Cl 1.4–3.2) for injection-to-conception intervals of 4 weeks, 1.5 (95% Cl 0.9–2.3) for intervals of 5–8 weeks, and 1.2 (95% Cl 0.7–1.9) for intervals of ≥9 weeks. This trend was highly significant. Thus, the authors conclude that early, high-dose in utero exposures to Depo-Provera may affect fetal growth.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/795
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8042015-05-11HighWireOUPamjepid:134:8
In Utero Exposure to Steroid Contraceptives and Survival During Infancy
Gray, Ronald H.
Pardthaisong, Tieng
ORIGINAL CONTRIBUTIONS
A cohort study was conducted in Chiang Mai, northern Thailand, in 1,431 children of women who had used the injectable contraceptive Depo-Provera® (The Upjohn Company, Kalamazoo, Michigan), 565 children of women who had used oral contraceptives during pregnancy, and a group of 2,307 control infants with no hormonal contraceptive exposures. In follow-up interviews, information was obtained on stillbirths and deaths. Cause of death was ascertained by interview, death certificate, or medical record, and underlying causes of death were ascribed by a panel. The children exposed in utero to Depo-Provera had higher neonatal and infant mortality rates (44.3 and 62.9 per 1,000 live births, respectively) than did the controls (19.8 and 29.1 per 1,000 live births). Mortality in infants exposed in utero to oral contraceptives was intermediate between that in the other two groups. Adjustment by logistic regression showed no significantly increased risk of mortality among infants exposed to oral contraceptives, but the odds ratio for death was significantly increased with Depo-Provera exposures due to accidental pregnancy (odds ratio (OR) = 1.8 (95% confidence interval (CI) 1.1–3.0) for neonatal deaths; OR = 2.0 (95% Cl 1.3–3 2) for infant deaths). Adjustment for low birth weight reduced the risks, suggesting that low birth weight may act as an intermediate determinant of Depo-Provera-associated mortality. Among the accidental pregnancies with Depo-Provera, there was a relation between shorter injection-to-conception intervals, when maternal blood levels of the drug are high, and an increased risk of mortality. The odds ratios for neonatal mortality were 2.5 (95% CI 1.1–5.7), 2.1 (95% Cl 1.0–4.6), and 0.9 (95% CI 0.4–2.4) for injection-to-conception intervals of ≤4, 5–8, and ≥9 weeks, respectively. Adjustment for low birth weight reduced these risks. Chi-square tests for trend were highly significant. Similar associations were also observed between DepoProvera accidental pregnancies and risks of low birth weight. Thus, infants from accidental pregnancies that occur 1–2 months after a 150-mg Depo-Provera injection may be at increased risk for low birth weight and death However, the attributable risk is low, because such pregnancies are uncommon.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/804
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8122015-05-11HighWireOUPamjepid:134:8
Invited Commentary: The Contraceptive Technology Tightrope
Hogue, Carol J. R.
ORIGINAL CONTRIBUTIONS
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/812
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8162015-05-11HighWireOUPamjepid:134:8
The Authors' Response to Hogue
Gray, Ronald H.
Pardthaisong, Tieng
ORIGINAL CONTRIBUTIONS
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/816
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8182015-05-11HighWireOUPamjepid:134:8
Polycystic Ovaries and the Risk of Breast Cancer
Gammon, Marilie D.
Thompson, W. Douglas
ORIGINAL CONTRIBUTIONS
Data from a case-control study that was conducted between 1980 and 1982 were analyzed to investigate the possible association between polycystic ovaries and the risk of breast cancer. The multicenter, population-based study included in-home interviews with 4,730 women with breast cancer and 4, 688 control women aged 20–54 years. The age-adjusted odds ratio for breast cancer among women with a self-reported history of physician-diagnosed polycystic ovaries was 0.52 (95% confidence interval 0.32–0.87). The inverse association was not an artifact of infertility, age at first birth, or surgical menopause. Because women with this syndrome have abnormal levels of certain endogenous hormones, the observation of a low risk of breast cancer in this group may provide new insights into hormonal influences on breast cancer.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/818
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8252015-05-11HighWireOUPamjepid:134:8
Incidence of Surgically Treated Benign Prostatic Hypertrophy and of Prostate Cancer among Blacks and Whites in a Prepaid Health Care Plan
Sidney, Stephen
Quesenberry, Charles P.
Sadler, Marianne C
Guess, Harry A.
Lydick, Eva G.
Cattolica, Eugene V.
ORIGINAL CONTRIBUTIONS
The incidence of surgically treated benign prostatic hypertrophy and of prostate cancer was examined to December 1987 in 14, 897 men (2, 175 blacks and 12,722 whites) who received multiphasic health checkups during 1971–1972 while members of the Kaiser Permanente Medical Care Program (San Francisco-Oakland, California). Prostate cancer incidence was higher in blacks than in whites for all age groups (age-adjusted relative risk (RR) = 1.8, 95% confidence interval (Cl) 1.4–2.3). The incidence of benign prostatic hypertrophy was somewhat higher in blacks than in whites until age 65 years, after which it was higher in whites. In contrast to the risk of prostate cancer, the age-adjusted risk of benign prostatic hypertrophy was the same for blacks as for whites (RR = 1.0, 95% Cl 0.8–1.2).
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/825
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8302015-05-11HighWireOUPamjepid:134:8
Tobacco Smoke Inhalation Pattern, Tobacco Type, and Bladder Cancer in Spain
López-Abente, Gonzalo
González, Carlos A.
Errezola, Manuel
Escolar, Antonio
Izarzugaza, Isabel
Nebot, Manuel
Riboli, Elio
ORIGINAL CONTRIBUTIONS
The association between tobacco smoking and bladder cancer was investigated in a multicenter case-control study conducted in five provinces of Spain between 1983 and 1986. A matched analysis was carried out in males, based on 430 histologically confirmed cases, 405 hospital controls, and 386 population controls, matched by age and place of residence. An increased risk was found for smokers as compared with nonsmokers (odds ratio (OR) = 3.79, 95% confidence interval (Cl) 2.41–5.97), and this increase was significantly associated with the intensity of smoking. Smokers of filtertipped cigarettes had a reduced risk as compared with smokers of non-filter-tipped cigarettes (OR = 0.57, 95% Cl 0.32–1.02). A diminution of risk was also observed for smokers of low-tar and low-nicotine (“light”) cigarettes. Depth of inhalation was strongly associated with illness. No difference was shown in the logistic regression model between smokers of black tobacco and smokers of blond tobacco after controlling for depth of inhalation. Although the number of persons who smoked blond tobacco exclusively was small, the results suggest that it is important to consider inhalation patterns when studying risk variations between smokers of black tobacco and smokers of blond tobacco. The age at which a person started to smoke did not appear to affect risk. An analysis of the decrease in risk associated with years since quitting smoking suggested that different components of cigarette smoke may play a role at different stages of the carcinogenic process.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/830
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8402015-05-11HighWireOUPamjepid:134:8
Micronuclei and Other Nuclear Anomalies in Buccal Smears: A Field Test in Snuff Users
Tolbert, Paige E.
Shy, Carl M.
Allen, James W.
ORIGINAL CONTRIBUTIONS
A revised protocol for the exfoliated cell micronucleus assay was field-tested in a population exposed to a genotoxic agent, snuff, at levels associated with a significant increase in cancer risk. The standard assay involves examination of epithelial smears to determine the prevalence of micronucleated cells, an indication of chromosome breakage or mitotic interference. The assay was revised to increase specificity and to include separate scoring of other nuclear anomalies associated with cytotoxicity and genotoxicity. The modified assay was applied to buccal smears of 38 female snuff users and 15 female nonusers recruited from a North Carolina clinic in 1987. The prevalence of micronucleation was elevated in the snuff users as compared with the nonusers (prevalence ratio = 2.4, 95% confidence interval 1.1–5.2) and, to a lesser extent, at the usual contact site as compared with a distal buccal site in the snuff users (prevalence ratio = 1.5, 95% confidence interval 0.9–2.5). The pattern of relative frequencies of several nuclear anomalies provided strong evidence of a cytotoxic effect, the prevalence ratios ranging from 2 to 13. Nuclear degenerative phenomena can be difficult to distinguish from classical micronuclei; thus, the observed association of indicators of cytotoxcity with exposure introduces the possibility of bias away from the null in micronucleus findings due to differential misclassification. Until methods to better distinguish extranuclear bodies of different origins become available, investigators should use the revised protocol and should focus on agents not thought to be cytotoxic.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/840
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8512015-05-11HighWireOUPamjepid:134:8
Change in Survival from Out-of-Hospital Cardiac Arrest and Its Effect on Coronary Heart Disease Mortality, Minneapolis-St. Paul: The Minnesota Heart Survey
Tillinghast, Stanley J.
Doliszny, Katherine M.
Kottke, Thomas E.
Gomez-Marin, Orlando
Lilja, G. Patrick
Campion, Brian C.
ORIGINAL CONTRIBUTIONS
Emergency medical services with advanced life support systems were implemented in the Minneapolis-St. Paul, Minnesota, area in the mid-1970s. To assess the impact of emergency medical services on coronary heart disease mortality, the authors reviewed ambulance records and hospital emergency room logs for possible out-of-hospital cardiac arrest cases in the period 1972–1982. Potential cases, and their survival to discharge, were validated by hospital record review and were checked against Minnesota death certificates for the year of cardiac arrest and the year following cardiac arrest. Age-adjusted rates of survival to 1 year after cardiac arrest (per 100, 000 population) for survivors of out-of-hospital cardiac arrest aged 30–74 years increased significantly from 1972 to 1982 for men (1.8 vs. 11.7; <it>p</it> < 0.00001) and for women (0.5 vs. 3.5; <it>p</it> < 0.01). Coronary heart disease mortality rates declined in that period by 34 9% for men (from 527.5 per 100, 000 to 343.3 per 100, 000) and by 41.7% for women (from 168.6 per 100,000 to 98.3 per 100,000). The authors estimate that improved survival from out-of-hospital cardiac arrest contributed 5.4% (9.9 of 184.2) of the mortality decline for men and 4.3% (3.0 of 70.3) of the decline for women. This was a significant contribution to the decline in coronary heart disease mortality, but it explains only a small part of it.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/851
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8622015-05-11HighWireOUPamjepid:134:8
The Relation of Physical Activity to Cardiovascular Disease Risk Factors in Mauritians
Zimmet, Paul Z.
Collins, Veronica R.
Dowse, Gary K.
Alberti, K. George M. M.
Tuomilehto, Jaakko
Gareeboo, Hassam
Chitson, Pierrot
the Mauritius Noncommunicable Disease Study Group,
ORIGINAL CONTRIBUTIONS
The authors investigated the relation between physical activity and cardiovascular disease risk factors in a random sample of 4, 658 Asian Indian, Creole, and Chinese adults aged 25–74 years from the island nation of Mauritius. Subjects known to have diabetes were excluded from analyses Subjects were divided into “active” and “inactive” groups on the basis of a combined leisure and occupational physical activity score determined at interview (April 1987). Two-hour plasma glucose concentration and fasting and 2-hour serum insulin concentrations were significantly lower and high density lipoprotein (HDL) cholesterol was significantly higher in active subjects of both sexes. Plasma uric acid and fasting triglyceride levels were also lower among active subjects, but significantly so only in females. Systolic and diastolic blood pressure levels, body mass index (weight (kg)/height (m)2), and waist:hip ratio varied little between the two activity groups. In multiple linear regression analyses, physical activity made an independent negative contribution to the models for 2-hour glucose and insulin in both males and females, as well as for fasting insulin in males. When glucose and insulin were not included, physical activity also made an independent contribution to the models for plasma triglycerides (inversely) in females and HDL cholesterol and HDL cholesterol as a proportion of total cholesterol (positively) in males. The authors have demonstrated improved cardiovascular disease profiles associated with physical activity in Mauritians. The data suggest that much of the effect is modulated via an effect on insulin-glucose metabolism. Promotion of exercise should become an important strategy in the prevention of cardiovascular disease and glucose intolerance in this population.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/862
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8762015-05-11HighWireOUPamjepid:134:8
Is There Clustering of Inflammatory Bowel Disease at Birth?
Ekbom, Anders
Zack, Matthew
Adami, Hans-Olov
Helmick, Charles
ORIGINAL CONTRIBUTIONS
Evidence points to possible cohort effects in inflammatory bowel disease, the possible role of pennatal infection as a risk factor for inflammatory bowel disease, and the occurrence of clusters of Crohn's disease. This evidence suggests the value of searching for birth date clustering among cases of inflammatory bowel disease. The authors looked for clustering by birth date and maternal residence at birth in a population-based series of 845 Crohn's disease patients and 1,330 ulcerative colitis patients born from 1924 through 1957 and diagnosed in the Uppsala Health Care Region, Sweden, until the end of 1983. Over this period, 43% of persons with Crohn's disease had been born within 6 days of another case, compared with 36% of controls simulated to account for monthly variation in births (<it>p</it> = 0.0002). The number of pairs of inflammatory bowel disease cases whose births occurred in the same county (close in space) and whose birth dates were also close in time was statistically significantly greater than expected for most birth dates 23–57 days apart. Results after 1944, when ascertainment was more complete, generally corroborate these findings and suggest some seasonality in the birth dates of ulcerative colitis cases. Results from the entire study penod and after 1944 thus provide evidence for clustering by birth (including seasonality) among Crohn’s disease cases and also, to a lesser extent, among ulcerative colitis cases.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/876
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8872015-05-11HighWireOUPamjepid:134:8
The Role of Home Environment in Infant Diarrhea in Rural Egypt
Wright, Charles E.
Alamy, Mohamed El
DuPont, Herbert L.
Holguin, Alfonso H.
Hsi, Bartholomew P.
Thacker, Stephen B.
Zaki, Ahmed M.
Habib, Mostapha
ORIGINAL CONTRIBUTIONS
In 1982 and 1983, a descriptive environmental survey was conducted in 317 households with newborn infants in rural Bilbeis, Egypt. The incidence of infant diarrhea in these households was ascertained by twice-weekly home visits for a 1-year period (1981–1982). Using univariate and multivanate analyses, the authors identified household factors that were statistically associated with infant diarrhea incidence, including number of children in the house under 4 years of age; number of persons per household; incidence of diarrhea in other family members; having a dirt (vs. concrete) dining room floor; having multiple living areas in the house; having a house or roof in need of repair, using well water rather than tap water for cooking or bathing; the absence of a sewer for waste bathwater; food being left out at room temperature between meals; and having many rodents in the house. Two practices involving interaction with the environment appeared to be protective: butchering of cattle by the family for home consumption, and protection of the infant from flies by a veil during napping. The combined household variables explained 25% of the variance in the total incidence of diarrhea. Categories of variables that accounted for most of the total variance explained by environmental factors are, in decreasing order: house structure (28%), water usage (24%); toilet and bathing area (12%); animal management (11%); food preparation area (10%); hygiene (8%); and wastewater management (6%). This approach may be useful in identifying environmental charactenstics whose change would reduce diarrheal illness among infants.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/887
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/8952015-05-11HighWireOUPamjepid:134:8
Biased Estimation of the Odds Ratio in Case-Control Studies due to the Use of Ad Hoc Methods of Correcting for Missing Values for Confounding Variables
Vach, Werner
Blettner, Mana
ORIGINAL CONTRIBUTIONS
The effects of missing values for a confounding variable are investigated in the setting of case-control studies in which, for simplicity, the effect of one binary risk factor and one categoric confounding variable on disease risk is under investigation. Some ad hoc techniques with which to deal with missing values are examined under different assumptions about the missing-data mechanism. Examples are given to illustrate that the magnitude of the bias that is introduced by applying an inadequate procedure can be large under circumstances that occur frequently in empinc research. This is true even for so-called complete case analysis, i e., when only data on subjects with complete information are used. Appropriate bias corrections are derived. Making use of data on those subjects who are neglected in complete case analysis by creating an additional category always results in biased estimation. An alternative is to allocate these subjects to the cells of the contingency table in an appropnate manner. This approach yields consistent estimates if the data are missing at random. Choosing an appropriate method for dealing with missing values always requires some knowledge of why the data are missing This suggests that investigators should carry out validation studies to understand whether the missing values occur randomly across the study population or occur more frequently in specific subgroups.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/895
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/9082015-05-11HighWireOUPamjepid:134:8
Imputing Nonresponses to Mail-back Questionnaires
Drane, J. Wanzer
ORIGINAL CONTRIBUTIONS
Many mail-back questionnaires are expected at the outset to elicit poor response rates, perhaps as low as 15–30%. Corrections can be designed into such a survey by using either two or three mailouts of the questionnaire at regular intervals. Assuming a trend in responses as a function of the number of mailouts a person receives before filling out and mailing back the questionnaire, responses are imputed for those who do not mail back the questionnaire after the final mailout. Standard errors are derived, and an example is included. The imputation is easily programmed A validation of this method is also included.
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/908
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/9132015-05-11HighWireOUPamjepid:134:8
RE "FETAL LOSS ASSOCIATED WITH TWO SEASONAL SOURCES OF ELECTROMAGNETIC FIELD EXPOSURE"
Klauenberg, B. Jon
LETTERS TO THE EDITOR
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/913
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/9152015-05-11HighWireOUPamjepid:134:8
THE AUTHORS REPLY
Wertheimer, Nancy
Leeper, Ed
LETTERS TO THE EDITOR
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/915
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/9162015-05-11HighWireOUPamjepid:134:8
RE "A MONITORING SYSTEM TO DETECT INCREASED RATES OF CANCER INCIDENCE"
Chen, Rina
LETTERS TO THE EDITOR
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/916
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/9172015-05-11HighWireOUPamjepid:134:8
THE AUTHORS REPLY
Sitter, Randy R.
Hanrahan, Lawrence P.
Anderson, Henry A.
Demets, David
LETTERS TO THE EDITOR
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/917
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/9192015-05-11HighWireOUPamjepid:134:8
RE. VASECTOMY AND PROSTATE CANCER
Comstock, George W.
LETTERS TO THE EDITOR
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/919
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/9202015-05-11HighWireOUPamjepid:134:8
DR ROSENBERG REPLIES
Rosenberg, Lynn
LETTERS TO THE EDITOR
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/920
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Copyright (C) 1991, Oxford University Press
oai:open-archive.highwire.org:amjepid:134/8/9212015-05-11HighWireOUPamjepid:134:8
METTLIN ET AL REPLY
Mettlin, Curtis J.
Natarajan, Nachimuthu
Huben, Robert
LETTERS TO THE EDITOR
Oxford University Press
1991-10-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/134/8/921
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Copyright (C) 1991, Oxford University Press