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S D Stellman

Publications and source records attributed to S D Stellman.

At least 73 records · Page 4Linked to original sources
PubMed1987

Workshop on guidelines to the epidemiology of weak associations. Confounding.

The magnitude of confounding is examined in nine case studies of two "weak" relationships: between artificial sweeteners and bladder cancer, and between oral contraceptives and cervical dysplasia. Confounding had little or no influence on the results of any published study. The responsible epidemiologist must always consider the possibility of confounding, no less when associations are weak than when they are strong. Identification of potentially confounding variables is an integral part of good epidemiologic practice. Rarely, however, does confounding itself, especially from unidentified sources, live up to its reputation for introducing seriously spurious associations. An investigator is more likely to be led astray by undetected biases than by pure confounding.

Contraceptives, Oral↗
PubMed1986

Estimation of exposure to Agent Orange and other defoliants among American troops in Vietnam: a methodological approach.

Two pivotal problems in determining whether exposure to herbicides has caused disease in Vietnam veterans or their offspring are definition of which troops were exposed and extent of exposure. The DoD HERBS tape is the most complete publicly available record of herbicide spraying in Vietnam. It contains about 17,000 records consisting of coordinates of spray missions, dates, chemical agent, quantity and area sprayed, and mission purpose. We have developed a set of discrete and continuous indexes of probability of exposure to herbicides for individual veterans. These probability indexes are based on HERBS tape spray data and on locations and dates of service derived from a place-and-date matrix completed by the veteran. They can take into account a conservative estimate of environmental persistence of herbicide by using first-order exponential decay kinetics with an estimated half-life of dioxin. Mean values for the continuous exposure probability indexes were significantly greater among veterans judged to be exposed according to self-reported job titles and specific military experiences than among men judged unlikely to have been exposed. Probabilistic exposure indexes based on HERBS tape for classification of likely exposure to herbicides in South Vietnam during 1965-1971 appear to be well suited for comparative classification of veterans and hence for use in epidemiologic studies.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1986

Artificial sweetener use and one-year weight change among women.

Weight change over a 1-year period was examined in a highly homogeneous group of 78,694 women ages 50-69 enrolled in a prospective mortality study. Artificial sweetener usage increased with relative weight and decreased with age. Users were significantly more likely than nonusers to gain weight, regardless of initial weight. Average weight gains or losses by artificial sweetener users differed by less than 2 pounds from gains or losses among nonusers. These results were not explicable by differences in food consumption patterns. The data do not support the hypothesis that long-term artificial sweetener use either helps weight loss or prevents weight gain.

Aged↗
PubMed1986

Smoking habits and tar levels in a new American Cancer Society prospective study of 1.2 million men and women.

In 1982 the American Cancer Society (ACS) enrolled over 1.2 million American men and women in a prospective mortality study of cancer and other causes in relation to environmental and life-style factors. Biennial follow-up is planned through 1988. At the time of enrollment, 23.6% of the men and 20.0% of the women were current smokers of cigarettes. Compared with a similar ACS study of 1 million subjects enrolled 23 years earlier, among men the proportion of current smokers was halved and that of ex-smokers doubled, while among women the proportion of ever-smokers increased by 10% and that of ex-smokers quadrupled. Most smokers of filter cigarettes had smoked nonfiltered cigarettes earlier in life. The median year for switching to filters was 1964, the year of the first Surgeon General's report. More than one-third of male smokers' and one-half of female smokers' current brands had tar yields below 12 mg; less than 9% of male smokers' and 4% of female smokers' current brands had tar yields of 20.2 mg or more (nonfilters). The study population differed in many respects from the general U.S. population; the study population had, for example, a much higher average educational level. Nevertheless, distributions of smoking habits changed a few percentage points after adjustment to the educational level of the general population.

Adult↗
PubMed1984

Cancer mortality among woodworkers.

The mortality experience of 10,322 men employed in woodworking industries was compared with that of 406,798 nonwoodworkers. All subjects were enrolled in an American Cancer Society study and followed prospectively from 1959 through 1972. Age-adjusted rates of death from all causes and from all cancers were not higher in the woodworker group, but excess rates were observed for cancers of the lung, stomach, and bladder, as well as nonmelanoma skin cancer and possibly leukemia. Woodworkers experienced significantly decreased rates of colon-rectum cancer and coronary heart disease. The elevated cancer rates could not be explained by cigarette smoking habits. If anything, there is evidence to suggest a possible interaction between employment in woodworking trades and heavy cigarette smoking, in increasing the risk of lung and bladder cancer.

Adult↗
PubMed1980

Artificial sweetener use and bladder cancer: a case-control study.

In a case-control study of 302 male and 65 female bladder cancer patients and an equal number of other patients matched to them in age, sex, hospital, and hospital-room status, no association was found between use of artificial sweeteners or diet beverages and bladder cancer. No dose-response was observed with respect to quantity or duration of use of the two combined. No evidence was found to suggest that artificial sweeteners or diet beverages promote the tumorigenic effect of tobacco smoking. Artificial sweetener and diet beverage use strongly reflected socioeconomic status among controls with various diagnoses.

Female↗
PubMed1980

Cervix cancer and cigarette smoking: a case-control study.

The association between cervix cancer and cigarette smoking was examined among 332 white cases and 1725 white controls. Cases were of lower socioeconomic status (SES) and smoked more than controls. After adjustment for both age and SES, no significant association was observed between cervix cancer and cigarette smoking. Many variables related both to cigarette smoking and to known risk factors for cervix cancer are sources of confounding and inadequate control for these variations may cause an overestimation of the effect of smoking.

Adult↗
PubMed1979

Impact of long-term filter cigarette usage on lung and larynx cancer risk: a case-control study.

A case-control study was conducted among 1.034 white male and female hospital patients with histologically proved lung cancer (Kreyberg type l) or larynx cancer. After adjustment for duration of the smoking habit, inhalation, and butt length, relative risks of developing lung or larynx cancer were consistently lower among long-term smokers of filter cigarettes than among smokers of nonfilter cigarettes, irrespective of quantity smoked. Relative risks in all groups declined with increased years of smoking cessation. The observed risk reduction among current smokers of filter cigarettes was consistent with that expected, considering that these persons had smoked the older high-tar nonfilter cigarettes for a large proportion of their lives.

Adult↗
PubMed1978

The epidemiology of breast cancer in 785 United States Caucasian women.

A retrospective case-control hospital study of 785 Caucasian breast cancer patients and 2,231 age-stratified controls was conducted in New York City from 1969-1975. Patients were grouped by pre- peri- and postmenopausal status at diagnosis for the analysis to make a distinctive separation for variables showing a pre- and postmenopausal differential. Demographic characteristics were similar for cases and controls. Previously recorded hormone-related risk variables for this disease were largely confirmed for pre- and perimenopausal women, i.e., late age at first birth (greater than 25), premenstrual symptoms of breast swelling and premenopausal chills and flushes. Mother's history of breast cancer was also found to be a risk variable. Nulliparity was a risk factor only perimenopausally. No risk was foun for absolute height, weight or for obesity (Quetelet Index), prior breast diseases or previous usage of exogenous hormones of any type and no "protective" effect was found for multiparous women and for nursing. Perimenopausally diagnosed patients (menopause to 10 years after) were similar to premenopausally diagnosed women on most risk factors. Risk variables determined by this and other case-control studies cannot account for the magnitude of differences in the international incidence of breast cancer.

Adult↗
PubMed1977

Comparative epidemiology of tobacco-related cancers.

In a retrospective study, interviews were obtained with 3,716 patients with histologically proven cancer of the lung (Kreyberg types I and II), mouth, larynx, esophagus, or bladder and with over 18,000 controls. For each of these cancers, the relative risk of both male and female present smokers increased with the quantity smoked and the duration of the habit. The strongest increase occurred for cancer of the lung and larynx, and the least increase occurred for cancer of the esophagus and bladder. For exsmokers the risk decreased with years of cessation. The risk for mouth cancer of pipe and cigar smokers who inhaled much less than cigarette smokers was less than that of the latter and increased with the quantity smoked. The risk of mouth, larynx, and esophagus cancer among smokers increased with the quantity of alcohol consumed. Greater smoking habits and lesser cessation rates were noted among lower socioeconomic groups, suggesting that these groups will bear an ever increasing proportion of the burden of tobacco-related cancer.

Adult↗