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Biomedical subjects

B Shea

Publications and source records attributed to B Shea.

88 records · Page 5Linked to original sources

Osteoporosis clinical trials endpoints: candidate variables and clinimetric properties.

We reviewed evidence on endpoints used in osteoporosis clinical trials to assist in the development of a set of endpoints to be included in all trials. A MEDLINE search was conducted using the Cochrane Collaboration strategy for each endpoint. Additional published literature was obtained from content experts. A proposed list of endpoints was developed after consultation with experts in the field. Each endpoint was evaluated with respect to validity, reproducibility, redundancy, and feasibility. We classified the endpoints into 2 major categories: clinical health status outcomes and intermediate endpoints, and for each endpoint we present current evidence from the literature as pertains to defined methodologic criteria. Multiple endpoints have been used in osteoporosis clinical trials, and an agreement on a core set of measures needs to be evidence based with an emphasis on validity, reproducibility, and feasibility and to satisfy clinical credibility.

Biomarkers↗

Responsiveness of endpoints in osteoporosis clinical trials.

The usefulness of an endpoint depends in part on its responsiveness to clinically important change. From existing randomized controlled trials, the responsiveness of endpoints currently employed in osteoporosis clinical trials were examined. The responsiveness is presented as the sample size per group needed to show a statistically significant difference. The large variation found means that careful attention needs to be given to the responsiveness of the population studied when estimating the sample size.

Bone Density↗

Ribotyping of nosocomial methicillin-resistant Staphylococcus aureus isolates from a Canadian hospital.

OBJECTIVE: To evaluate the clonality of methicillin-resistant Staphylococcus aureus (MRSA) strains among hospitalized patients. SETTING: University-affiliated, 465-bed tertiary-care teaching hospital with adjacent cancer clinic in Hamilton, Ontario, Canada. DESIGN: Thirty-five colonized and 30 infected patients from January 2, 1992, through August 31, 1993, were investigated retrospectively. Analysis by restriction fragment-length polymorphisms of ribosomal RNA genes (ie, ribotyping) of 103 nosocomial isolates of MRSA from these 65 patients and of 25 selected unrelated strains was completed. Ribotyping results were compared with the phage typing data obtained prospectively during the course of prospective MRSA surveillance. RESULTS: HindIII ribotyping was more discriminating than phage typing when epidemiologically unrelated strains were differentiated by these methods (19 different ribotypes versus 14 page types; P < .005). Two early index cases were identified. Isolates from the index cases were two different strains, identified by ribotyping analysis as ribotype A (clonal group 1) and ribotype B (clonal group 2), respectively. These two ribotypes were not found when typing the unrelated control strains. Thirty-six colonized and infected patients (55%) had clonal group 1 isolates, and 20 (31%) had clonal group 2 isolates. These two clones emerged in the hospital in January and February 1992 and dominated the entire investigated period. There also were six patients with an additional clonal group (group 4) that emerged and disappeared in the second quarter of 1993. CONCLUSIONS: This study highlights the utility of ribotyping in investigating nosocomial MRSA. Three MRSA clones caused nosocomial colonization or infection in patients at this hospital. Two of these MRSA clones, once introduced, were maintained among our patients throughout the study period.

Bacteriophage Typing↗

Ancrod as prophylaxis or treatment for thromboembolism in patients with multiple trauma.

OBJECTIVE: To report the initial clinical experience with fibrinogen depletion using ancrod as prophylaxis and treatment for deep vein thrombosis and pulmonary embolism (DVT/PE) in patients with multiple trauma. DESIGN: A series of cases, selected because of their extreme risk of DVT/PE or because of the appearance of thromboembolic complications despite prophylaxis using conventional methods. SETTING: University teaching hospital. PATIENTS: A referred sample comprising 30 patients with multiple blunt trauma. The mean injury severity score was 30. Most cases involved a combination of lower extremity, pelvic and chest injuries. INTERVENTIONS: Fibrinogen was slowly depleted over 24 to 36 hours and the concentration maintained at 0.2 to 0.5 g/L thereafter. Ancrod was continued prophylactically (22 patients) or for established DVT/PE (8 patients) until the patients were mobilized or until there was no longer a contraindication to heparin, or until treatment with warfarin became practical. MAIN OUTCOME MEASURE: Monitoring for DVT by duplex ultrasonography or iodine-125-labelled-fibrinogen scanning, whichever could be applied. RESULTS: Twenty patients were treated with ancrod for prophylaxis from the outset because it offered theoretic and practical benefits over other methods. No patient treated with ancrod for prophylaxis suffered a clinically significant DVT/PE. Patients in whom heparin prophylaxis failed and who experienced thromboembolic complications were effectively managed with ancrod. There were no deaths and no bleeding complications specifically due to the therapy. CONCLUSIONS: Slow depletion of fibrinogen with ancrod may provide a safe and effective means to prevent DVT/PE in multiple trauma patients or to treat DVT/PE when the risk of bleeding from heparin is great. This initial experience should be evaluated by a randomized controlled trial.

Adolescent↗

Survival with AIDS in Massachusetts, 1979 to 1989.

OBJECTIVES: The goal of the study was to determine survival time after diagnosis of acquired immunodeficiency syndrome (AIDS) and to identify predictors of survival. METHODS: We conducted a population-based prospective survival analysis of all Massachusetts-resident adult AIDS patients diagnosed from January 1, 1979, through December 31, 1988. RESULTS: Median survival was 406 days, with a 5-year survival rate of 3%. Age older than 40 years (P = .001), a diagnosis other than Kaposi's sarcoma (P = .001), and a history of intravenous drug use (P < or = .01) were associated with shorter survival after confounding was controlled. Survival increased as year of diagnosis became more recent (P < .0001). This temporal effect was strongest for patients with Pneumocystis carinii pneumonia. Individuals with Kaposi's sarcoma, Hispanics, homosexual men who were concurrent intravenous drug users, and residents of the greater Boston standard metropolitan statistical area, excluding the city of Boston, did not experience increases in survival over time. CONCLUSIONS: With the exception of cases initially defined by Kaposi's sarcoma, recently diagnosed AIDS case subjects survive longer than those diagnosed earlier in the epidemic. Further work is needed to determine whether this effect is due to lead-time bias or better treatment after diagnosis.

Acquired Immunodeficiency Syndrome↗

Cigarette smoking and peripheral arterial occlusive disease.

BACKGROUND: The importance of cigarette smoking in the etiology of peripheral arterial occlusive disease is well known, but there have been few studies that have quantified this relationship. METHODS: A case-control study design was used in which the case subjects were men with a history of claudication for at least 1 year and abnormal findings on noninvasive blood flow studies or on arteriography; control subjects were men attending the same hospital for conditions other than cancer, with no history of cancer or vascular disease and with a normal ankle-brachial index. Case and control subjects were interviewed by a trained nurse interviewer using a pilot-tested questionnaire. Current smoking status was confirmed by serum cotinine level estimation. Univariate odds ratios for smoking and other potential risk factors were calculated, and their significance was tested by comparison with the chi-squared distribution. Logistic regression analysis was used to adjust the effect of smoking for confounding variables, and the regression equation was used to estimate the proportion of disease attributable to smoking. RESULTS: Of the patients approached, 94% of the eligible case subjects and 93% of the eligible control subjects agreed to participate. Recruitment ended with 102 cases of peripheral arterial occlusive disease and 99 controls. Most of the control subjects were attending clinics for other surgical specialties. Compared with men who had never smoked the relative risk was 7 for exsmokers and 16 for current smokers (p < 0.001). The relative risk increased directly with the lifetime number of cigarettes smoked, the chi-squared test for trend being highly significant (p < 0.001). Age, lipoprotein concentration, body mass index, and history of hypertension or heart disease were also significant risk factors. CONCLUSIONS: After adjustment for confounding variables the estimate of the fraction of disease attributable to smoking was 76%.

Arterial Occlusive Diseases↗

Perinatally acquired human immunodeficiency virus infection: extent of clinical recognition in a population-based cohort. Massachusetts Pediatric HIV Surveillance Working Group.

To evaluate factors that may affect the timely diagnosis of children with human immunodeficiency virus (HIV) infection, we compared data derived from two population-based pediatric HIV studies. Data from anonymous newborn HIV serosurveys were used to estimate the number of children born to HIV-seropositive mothers. A statewide active surveillance project determined the number of HIV-exposed children who had been clinically recognized. Of 88,732 Massachusetts newborn specimens tested anonymously for HIV antibodies during a 12-month period (November, 1987, to October, 1988), 223 were positive. As of October, 1991, 78 of these children (35%) had been identified by a statewide network of infectious disease physicians. HIV-exposed children born in inner city hospitals were more likely to have come to medical attention than those born in suburban hospitals (47% vs. 17%). Among the 29 children with confirmed HIV infection (13% of 223), the initial evaluation for HIV occurred at an earlier age among children born in inner city hospitals than among children born in other areas. HIV testing practices that rely heavily on risk assessment may result in delayed diagnosis of HIV infection in children whose mothers are not perceived to be at risk.

AIDS Serodiagnosis↗

Breast cancer rehabilitation.

The Breast Surgery Rehabilitation Group (BSRG), established initially in 1970, assists patients at Memorial Sloan-Kettering Cancer Center (MSKCC) with psychical and emotional recovery from breast cancer surgery and promotes return to preoperative activities. The team includes a physical therapist, social worker, and nurse. Attendance at sessions is prescribed by all physicians on the Breast Service. Problems such as threat to life by cancer and emotional impact of breast loss are addressed, in addition to aid in actual physical recovery from surgery with exercise instruction and interaction with other women in the group who have a similar diagnosis. The information and support provided in this way help the patient to achieve a sense of control in a situation that threatens their emotional and physical world.

Breast Neoplasms↗

Identifying adverse drug events: development of a computer-based monitor and comparison with chart review and stimulated voluntary report.

BACKGROUND: Adverse drug events (ADEs) are both common and costly. Most hospitals identify ADEs using spontaneous reporting, but this approach lacks sensitivity; chart review identifies more events but is expensive. Computer-based approaches to ADE identification appear promising, but they have not been directly compared with chart review and they are not widely used. OBJECTIVES: To develop a computer-based ADE monitor, and to compare the rate and type of ADEs found with the monitor with those discovered by chart review and by stimulated voluntary report. DESIGN: Prospective cohort study in one tertiary-care hospital. PARTICIPANTS: All patients admitted to nine medical and surgical units in a tertiary-care hospital over an eight-month period. MAIN OUTCOME MEASURE: Adverse drug events identified by the computer-based monitor, by chart review, and by stimulated voluntary report. METHODS: A computer-based monitoring program identified alerts, which were situations suggesting that an ADE might be present (e.g., an order for an antidote such as naloxone). A trained reviewer then examined patients' hospital records to determine whether an ADE had occurred. The results of the computer-based monitoring strategy were compared with two other ADE detection strategies: intensive chart review and stimulated voluntary report by nurses and pharmacists. The monitor and the chart review strategies were independent, and the reviewers were blinded. RESULTS: The computer monitoring strategy identified 2,620 alerts, of which 275 were determined to be ADEs. The chart review found 398 ADEs, whereas voluntary report detected 23. Of the 617 ADEs detected by at least one method, 76 ADEs were detected by both computer monitor and chart review. The computer monitor identified 45 percent; chart review, 65 percent; and voluntary report, 4 percent. The ADEs identified by computer monitor were more likely to be classified as "severe" than were those identified by chart review (51 versus 42 percent, p = .04). The positive predictive value of computer-generated alerts was 16 percent during the first eight weeks of the study; rule modifications increased this to 23 percent in the final eight weeks. The computer strategy required 11 person-hours per week to execute, whereas chart review required 55 person-hours per week and voluntary report strategy required 5. CONCLUSIONS: The computer-based monitor identified fewer ADEs than did chart review but many more ADEs than did stimulated voluntary report. The overlap among the ADEs identified using different methods was small, suggesting that the incidence of ADEs may be higher than previously reported and that different detection methods capture different events. The computer-based monitoring system represents an efficient approach for measuring ADE frequency and gauging the effectiveness of ADE prevention programs.

Adverse Drug Reaction Reporting Systems↗