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S F Lanes

Publications and source records attributed to S F Lanes.

30 records · Page 2Linked to original sources

Misclassification of covariates.

In the context of reported data on asthma mortality, we examine two types of covariate misclassification. The first type is non-differential misclassification, in which the proportion of subjects misclassified is invariant over exposure and disease status. Building on work by Cox and Elwood and by Blettner and Wahrendorf, we find that the range of admissible values for misclassification proportions is bounded by the observed data, and may not include any values that account for observed heterogeneity of effect estimates. The second type is differential misclassification, in which the classification error differs according to the disease or exposure classes to which study subjects belong. If the relation between exposure and the confounding variable or between the confounding variable and disease is strong, differential misclassification can produce large variations in the stratum-specific odds ratio estimates.

Asthma↗

Tampon absorbency, composition and oxygen content and risk of toxic shock syndrome.

Tampon use has been identified as a major risk factor for toxic shock syndrome, although the etiologic role of tampons is not clearly understood. Two epidemiologic studies conducted to date have reported an association between tampon absorbency and risk of toxic shock syndrome. This finding is not corroborated by laboratory studies, however, which have suggested that absorbency may be a marker for other characteristics that create an environment conductive to the elaboration of toxic shock syndrome toxin 1. We used data from the previously reported Tri-state study to estimate simultaneously the effects of tampon oxygen content, absorbency and chemical composition. Although the data are sparse, oxygen content was more strongly associated with risk of toxic shock syndrome than either absorbency or chemical composition. The results suggest that it may be possible to develop a highly absorbent tampon that is not associated with a high risk of toxic shock syndrome.

Acrylates↗

Mortality of cellulose fiber production workers.

Mortality was studied among 1271 employees of a cellulose fiber production plant in Rock Hill, South Carolina, in the United States. Each subject was employed for at least three months between 1 January 1954 and 1 January 1977 in jobs that entailed exposure to the highest concentrations of methylene chloride. In the cohort 122 deaths were identified through 1 September 1986, and mortality rates for the cohort were compared with mortality rates for York County, South Carolina. Deficit mortality was observed for cancers of the respiratory system, breast, and pancreas and from ischemic heart disease. Excess mortality was observed for cancers of the buccal cavity and pharynx and the liver and biliary tract, and for melanoma as well. The largest relative excess was for liver and biliary tract cancers. There were only four deaths in this category; however, three of the four deaths were cancer of the biliary tract (3 observed, 0.15 expected, standardized mortality ratio 20).

Biliary Tract Neoplasms↗

Toxic shock syndrome, contraceptive methods, and vaginitis.

To elucidate further the etiology of toxic shock syndrome, we assessed the effects of certain contraceptive methods and recent history of vaginal infection on the incidence of toxic shock syndrome, with confounding effects of other risk factors controlled. We found a strong but imprecise positive association between toxic shock syndrome and tubal ligation (rate ratio = 7.9, 90% confidence interval 1.4 to 42.7). We also observed a negative association with oral contraceptives (rate ratio = 0.49, 90% confidence interval 0.22 to 1.1) and a positive association with a recent history of vaginitis (rate ratio = 2.1, 90% confidence interval 1.2 to 3.9).

Contraceptive Devices, Female↗

A cost density analysis of benign prostatic hyperplasia.

We assessed the frequency and cost of care for benign prostatic hyperplasia (BPH) among approximately 165,000 subscribers to Fallon Community Health Plan (FCHP), a group model health maintenance organization located in central Massachusetts. We computed rates of episodes of medical services for BPH using automated utilization files, and we estimated costs using Medicare reimbursement schedules and medication average wholesale prices. We identified 3919 men who visited a physician for BPH from January 1, 1991, until December 31, 1994, during which time they contributed 8336 person-years to the analysis. This population comprises approximately 12% of men at least 40 years old at FCHP. From 1991 to 1994, 696 (18%) men received terazosin, 219 (6%) men underwent a prostatectomy, and 41 (1%) men received finasteride. Men averaged 1.66 office visits per year to a physician for BPH. Most office visits (61%) were to a primary care physician, with 39% of the visits to a urologist. Among patients who received terazosin, the frequency of office visits increased slightly after receiving terazosin, from 2.14 to 2.62 visits per year. Among surgery patients, the frequency of visits declined after prostatectomy, from 6.31 visits per year to 1.67 visits. The individual annual cost rate for BPH care ranged from $25.00 to $25,352.00, with an average of $364.00 per person and a median cost of $126.00. The major components of the overall costs were hospital admissions (35%), terazosin dispensings (29%), and physician office visits (19%), with outpatient hospital care and ambulatory procedures accounting for the remaining 17%. Among men receiving terazosin, the average cost was $1190.00 per person-year, and among patients undergoing prostatectomy, the cost was $2630.00 per person-year. The prostatectomy rate declined by nearly 80% during the study period, while the dispensing rate for terazosin doubled, resulting in an overall decline in the total cost of care for BPH from 1991 to 1994.

Adult↗