Biomedical subjects
Publications and source records attributed to S Polk.
This nested case-control study assessed the putative protective effect of human herpesvirus-8 (HHV-8) against HIV-1-related dementia (dementia). The HHV-8 seropositivity of 210 male age- and HIV disease stage-matched cases and controls was compared. The overall HHV-8 seropositivity of 66% was similar among demented HIV-infected cases and nondemented HIV-infected controls.
OBJECTIVE: To measure how often a breast-related concern was documented in medical records after screening mammography according to the mammogram result (normal, or true-negative vs false-positive) and to measure changes in health care utilization in the year after the mammogram. DESIGN: Cohort study. SETTING: Large health maintenance organization in New England. PATIENTS: Group of 496 women with false-positive screening mammograms and a comparison group of 496 women with normal screening mammograms, matched for location and year of mammogram. MEASUREMENTS AND MAIN RESULTS: 1) Documentation in clinicians' notes of patient concern about the breast and 2) ambulatory health care utilization, both breast-related and non-breast-related, in the year after the mammogram. Fifty (10%) of 496 women with false-positive mammograms had documentation of breast-related concern during the 12 months after the mammogram, compared to 1 (0.2%) woman with a normal mammogram (P =.001). Documented concern increased with the intensity of recommended follow-up (P =.009). Subsequent ambulatory visits, not related to the screening mammogram, increased in the year after the mammogram among women with false-positive mammograms, both in terms of breast-related visits (incidence ratio, 3.07; 95% confidence interval [CI], 1.69 to 5.93) and non-breast-related visits (incidence ratio, 1.14; 95% CI, 1.03 to 1.25). CONCLUSIONS: Clinicians document concern about breast cancer in 10% of women who have false-positive mammograms, and subsequent use of health care services are increased among women with false-positive mammogram results.
BACKGROUND: The cumulative risk of a false positive result from a breast-cancer screening test is unknown. METHODS: We performed a 10-year retrospective cohort study of breast-cancer screening and diagnostic evaluations among 2400 women who were 40 to 69 years old at study entry. Mammograms or clinical breast examinations that were interpreted as indeterminate, aroused a suspicion of cancer, or prompted recommendations for additional workup in women in whom breast cancer was not diagnosed within the next year were considered to be false positive tests. RESULTS: A total of 9762 screening mammograms and 10,905 screening clinical breast examinations were performed, for a median of 4 mammograms and 5 clinical breast examinations per woman over the 10-year period. Of the women who were screened, 23.8 percent had at least one false positive mammogram, 13.4 percent had at least one false positive breast examination, and 31.7 percent had at least one false positive result for either test. The estimated cumulative risk of a false positive result was 49.1 percent (95 percent confidence interval, 40.3 to 64.1 percent) after 10 mammograms and 22.3 percent (95 percent confidence interval, 19.2 to 27.5 percent) after 10 clinical breast examinations. The false positive tests led to 870 outpatient appointments, 539 diagnostic mammograms, 186 ultrasound examinations, 188 biopsies, and 1 hospitalization. We estimate that among women who do not have breast cancer, 18.6 percent (95 percent confidence interval, 9.8 to 41.2 percent) will undergo a biopsy after 10 mammograms, and 6.2 percent (95 percent confidence interval, 3.7 to 11.2 percent) after 10 clinical breast examinations. For every 100 dollars spent for screening, an additional 33 dollars was spent to evaluate the false positive results. CONCLUSIONS: Over 10 years, one third of women screened had an abnormal test result that required additional evaluation, even though no breast cancer was present. Techniques are needed to decrease false positive results while maintaining high sensitivity. Physicians should educate women about the risk of a false positive result from a screening test for breast cancer.
In a prospective cohort of 2,647 human immunodeficiency virus type 1 (HIV-1) seropositive homosexual men enrolled in Baltimore, Chicago, Los Angeles, and Pittsburgh, 891 developed clinical acquired immunodeficiency syndrome (AIDS) between June 1984 and January 1992. Cox proportional hazards models were used to examine temporal trends in survival after AIDS for specific diagnoses, controlling for level of immunosuppression at diagnosis, age, race, and geographic location. Median survival time following AIDS onset increased from 11.6 months in 1984-1985 to 19.5 months in 1988-1989; for those diagnosed in 1990-1991, the median survival time dropped to 17.2 months. Trends in improved survival were diagnosis-specific. Survival after Pneumocystis carinii pneumonia consistently improved from 1984 to 1991 (p < 0.001). Compared with men diagnosed in 1984-1985, those diagnosed with P. carinii pneumonia in 1990-1991 had one-tenth the hazard of dying. For men with > or = 100 helper T-lymphocytes (CD4+ cells) when diagnosed with Kaposi's sarcoma, the relative hazards (95% confidence intervals) of dying after Kaposi's sarcoma were 0.8 (0.42-1.60) in 1986-1987, 0.7 (0.34-1.58) in 1988-1989, and 0.6 (0.19-1.61) in 1990-1991 compared with those diagnosed before 1986. Men with < 100 CD4+ cells when diagnosed with Kaposi's sarcoma did not demonstrate a consistent change in their subsequent survival. After a nonsignificant (p > 0.05) initial improvement in prognosis, there has not been a significant improvement in survival for men who presented with other opportunistic infections. Observed increases in overall survival probably relate to improved treatment of patients who develop P. carinii pneumonia. Limited improvement in survival following other AIDS diagnoses indicates the need for developing effective treatment against these diseases.
Pulse oximetry appears to improve quality of care by the early detection of hypoxia noninvasively. We tested the hypothesis that the widespread use of pulse oximetry over a 5-year period in the operating rooms at our institution had resulted in a reduction in blood gas measurements and in departmental operating costs. The total number of blood gas determinations per hour of anesthetic time at our institution decreased by 44%, from 7.64 to 4.26 measurements per 100 operating room hours. The number of capnography units in the operating rooms increased from 8 to 14, the number of pulse oximeters increased from 0 to 22, and oximeter use increased from 0 to 100% for all anesthetics. The total cost to provide oximetry, capnography, and blood gas measurements in 1989-1990 was less than the cost to provide blood gas measurements alone in 1985-1986. The introduction of these technologies was accomplished without an increase in cost: $76,880 in 1985-1986 versus $71,025 in 1989-1990.
In this study we investigated three possible mechanisms for the decreased airway responsiveness (AR) found in young lambs. To evaluate aerosol delivery, 6 adult sheep (9 mo-3 yr old) and 12 lambs (4-8 wk old) were challenged with aerosol (aH) and intravenous histamine (ivH). Awake animals were intubated and studied in a plethysmograph, which measured dynamic compliance (Cdyn), resistance of the lung, and functional residual capacity. AR to histamine was measured by administration of increasing concentrations of histamine until a significant change in lung mechanics occurred or until the maximum dose of histamine was given. In all six adult sheep, the response to both aH and iVH was a decrease in Cdyn. In two lambs Cdyn was decreased with both aH and ivH, in five lambs with neither, in three lambs with aH only, and in two lambs with ivH only. To examine the role of beta-adrenergic activity in determining AR, six adult sheep and six lambs received ivH and on a separate day ivH with propranolol pretreatment (p + ivH). The median effective dose of histamine that caused a reduction in Cdyn to 65% of normal saline control (ED65Cdyn) for the adult sheep given ivH was 3.60 (range 0.23-4.85) and 0.70 (range 0.49-8.0) micrograms.kg-1.min-1 for p + ivH (P = NS). The median ED65Cdyn for the six lambs was 8.0 micrograms.kg-1.min-1 for both ivH alone and p + ivH. To evaluate the role of airway smooth muscle (SM), AR to aH was quantitated in six adult sheep and six lambs, and then an open-lung biopsy was performed.(ABSTRACT TRUNCATED AT 250 WORDS)