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Biomedical subjects

B A Barnes

Publications and source records attributed to B A Barnes.

At least 19 recordsLinked to original sources
PubMed1991

The nature of adverse events in hospitalized patients. Results of the Harvard Medical Practice Study II.

BACKGROUND: In a sample of 30,195 randomly selected hospital records, we identified 1133 patients (3.7 percent) with disabling injuries caused by medical treatment. We report here an analysis of these adverse events and their relation to error, negligence, and disability. METHODS: Two physician-reviewers independently identified the adverse events and evaluated them with respect to negligence, errors in management, and extent of disability. One of the authors classified each event according to type of injury. We tested the significance of differences in rates of negligence and disability among categories with at least 30 adverse events. RESULTS: Drug complications were the most common type of adverse event (19 percent), followed by wound infections (14 percent) and technical complications (13 percent). Nearly half the adverse events (48 percent) were associated with an operation. Adverse events during surgery were less likely to be caused by negligence (17 percent) than nonsurgical ones (37 percent). The proportion of adverse events due to negligence was highest for diagnostic mishaps (75 percent), noninvasive therapeutic mishaps ("errors of omission") (77 percent), and events occurring in the emergency room (70 percent). Errors in management were identified for 58 percent of the adverse events, among which nearly half were attributed to negligence. CONCLUSIONS: Although the prevention of many adverse events must await improvements in medical knowledge, the high proportion that are due to management errors suggests that many others are potentially preventable now. Reducing the incidence of these events will require identifying their causes and developing methods to prevent error or reduce its effects.

Adolescent↗
PubMed1990

Identification of adverse events occurring during hospitalization. A cross-sectional study of litigation, quality assurance, and medical records at two teaching hospitals.

STUDY OBJECTIVES: To estimate the efficacy of a medical record review for identifying adverse events and negligent case suffered by hospitalized patients. DESIGN: Cross-sectional study comparing an objective medical record review with information available from hospital quality assurance records as well as risk management and litigation records. SETTING: Two metropolitan teaching hospitals in the northeastern United States. MEASUREMENTS AND MAIN RESULTS: Using the litigation and risk management records as a criterion standard, we found that the medical record review had a sensitivity of 80% (93 of 116; 95% CI, 73% to 88%) for discovering adverse events and a sensitivity of 76% (51 of 67; 95% CI, 66% to 86%) for discovering negligent care. We estimated that record review of a random sample of hospitalizations across a geographic region would have even higher sensitivity (adverse-event sensitivity, 84%; negligence sensitivity, 80%). Moreover, we found that the adverse events we failed to discover led to less costly malpractice claims. A significant number of adverse events (20 of 172) among hospitalizations never gave rise to litigation or risk management investigation. Six of the twenty were due to negligent care. Quality assurance efforts at the level of the clinical departments in one hospital led to review of only 12 out of 82 risk management records. CONCLUSIONS: The overwhelming majority of adverse events and episodes of negligent care are discoverable with the methods we used to evaluate medical records. Quality assurance efforts using similar record review methods should be further evaluated.

Cross-Sectional Studies↗
PubMed1985

Report on variation in rates of utilization of surgical services in the Commonwealth of Massachusetts.

This article presents an analysis of over 140,000 selected surgical procedures performed in Massachusetts in 1980, giving the per capita rates of 14 common procedures and of four less frequently performed procedures. The analysis defines 172 geographic areas for the commonly performed procedures and 45 for the less frequently performed procedures. Per capita surgical rates among the defined areas are significantly different from both a statistical and a clinical point of view. Twofold and threefold variations occur frequently across geographic areas. In certain areas, some surgical services appear to be provided at rates substantially different from the statewide rate. We discuss the importance of these data for physicians as well as the implications for the distribution and quality of clinical care and for containment of medical care costs.

Costs and Cost Analysis↗
PubMed1985

Elective hysterectomy. Benefits, risks, and costs.

This study evaluated the effect of hysterectomy or hysterectomy and bilateral salpingo-oophorectomy (hysterectomy and oophorectomy) versus alternative medical management on life expectancy, quality of life, and direct medical costs. Using techniques of decision analysis and available data on sequelae, it was found that gains in life expectancy and quality of life can be expected when women ages 30-60 undergo hysterectomy for benign neoplasm, disorders of menstruation, acquired abnormal anatomy, cervical disease, or endometriosis, owing primarily to prevention of reproductive tract cancers, which outweighs the impact of operative mortality. However, women who have relatively high operative risk or low expected cancer risks, beyond thresholds estimated in sensitivity analyses, suffer losses in life expectancy. Women younger than 35 not treated with replacement estrogens following hysterectomy and oophorectomy can expect net losses in life expectancy with surgical intervention due to increased risks of heart disease and osteoporosis. For women in the reproductive years who wish to preserve their potential to bear children, sterilization may be an unacceptable consequence of elective hysterectomy in the quality of life.

Adult↗
PubMed1983

Ectopic pregnancy: incidence and review of determinant factors.

The incidence of ectopic pregnancies has been expressed in various ways that are not comparable and provide widely differing estimates due to individual definitions of the denominator. Population-based data are presented based on a count of all ectopic pregnancies reported in short stay hospitals in Maine, Rhode Island, and Vermont in 1974-1976. The incidence is 40 per 10(5) female population age 14-44 and is more consistent across 80 hospital service areas than other gynecological diagnoses. The data do not reveal an increasing incidence over these 3 years in contrast to national surveys based on a longer period of observation. A review of determinant factors for ectopic pregnancy is presented, and current theories concerning the etiology, changes in contraceptive practices, innovations in sterilization procedures, or advances in diagnosis do not appear individually or collectively to explain the increasing incidences reported by others. Further basic biologic and epidemiologic research is needed to determine causes and trends in this principal cause of first trimester mortality among pregnant women.

Abortion, Induced↗
PubMed1982

Professional uncertainty and the problem of supplier-induced demand.

This paper discusses the puzzling problem of large differences in per capita use of certain common surgical procedures among neighboring populations, which by all available measures are quite similar in need for and access to services. The evidence reviewed here supports the hypothesis that variations occur to a large extent because of differences among physicians in their evaluation of patients (diagnosis) or in their belief in the value of the procedures for meeting patient needs (therapy). This hypothesis, which we call the professional uncertainty hypothesis, is germane to current controversies concerning the nature and extent of supplier influence on the demand for medical services. It is also important because of its implications for health regulatory policy. Our plan is to (1) review the relevance of the hypotheses for the supplier-induced demand controversy; (2) review the epidemiologic evidence on the nature and causes of variation; (3) examine patterns of use of common surgical procedures to illustrate the importance of supplier influence on utilization; and (4) consider some of the implications of the professional uncertainty hypotheses for public policy.

Behavior↗
PubMed1982

Cost-benefit and cost-effective analysis in surgery.

Cost-benefit analysis and cost-effective analysis are formal analytical methods to provide a rational, objective means of comparing total costs with total benefits or of comparing effects in the selection of competing programs for financial support. The use of these techniques in the medical field is a relatively recent development and can aid in future cost containment.

Cost-Benefit Analysis↗
PubMed1981

Papanicolaou cervical smears for screening in asymptomatic women.

The annual Papanicolaou smear as a screening test for cervical cancer is evaluated on the basis of cost-effectiveness, predictive value, and other factors of patient selection and comparative trends in mortality rate before and after the introduction of screening programs. For the asymptomatic woman at normal risk for cancer, Papanicolaou smears are recommended only once every five years, although symptomatic or high-risk women should still maintain an annual screening schedule.

Costs and Cost Analysis↗
PubMed1981

An overview of hospital gynecologic practice.

Table 1 presents an overview of current gynecologic practice in hospitals as illustrated by three New England states. We believe the balance of diagnoses and operations displayed are reasonably typical of practice elsewhere in the United States. However, since operative rates are lower in New England than in other parts of the country, the proportions of women undergoing hysterectomy or a sterilization procedure will be somewhat higher elsewhere. The general issue of variation in rates of diagnoses and operations is presented; professional uncertainty is a fact which may account for the variation. Further controlled studies are urgently needed to decrease this element of uncertainty and to distinguish too much diagnosis and treatment from too little. Ultimately, nothing less will meet the standards of the best care for patients or satisfy health insurance or government programs that premiums or taxes are supporting an appropriate level of health care.

Female↗
PubMed1980

The microvasculature is the critical target of the immune response in vascularized skin allograft rejection.

Vascularized first set human skin allografts were rejected largely by a process of extensive and progressive microvascular damage leading to ischemia and infarction. Microvascular injury was associated with a cellular immune response. However, vessel damage was at least in part immunologically nonspecific because vessels of the graft bed (host tissue) were damaged as well as those of the graft itself. We conclude that the microvascular endothelium is the critical target of the immune response in vacularized skin allografts in man, and that this sequence of events--primary vascular damage followed by ischemic infarction--may have significance in a variety of experimental and clinical settings.

Adult↗
PubMed1979

Rejection of first-set skin allografts in man. the microvasculature is the critical target of the immune response.

Recent reports of microvascular injury in delayed hypersensitivity skin reactions prompted us to reexamine the pathogenesis of first-set skin allograft rejection in man using morphologic techniques that allowed both extensive vessel sampling and unequivocal evaluation of microvascular endothelium. We here report that widespread microvascular damage is a characteristic, early consequence of the cellular immune response to first-set human skin allografts and is qualitatively similar to, but substantially more extensive than, that occurring in delayed hypersensitivity reactions. Microvascular damage in invariably preceded significant epithelial necrosis and affected initially and primarily those venules, arterioles, and small veins enveloped by lymphocytes. Vessels of both the allograft itself and the underlying graft bed (recipient tissue) were equally affected. These data suggest that endothelial cells of the microvasculature are the critical target of the immune response in first-set vascularized skin allograft rejection in man and that rejection can be attributed largely to ischemic infarction resulting from extensive microvascular damage. Other mechanisms, such as direct cellular contacts between infiltrating lymphocytes and epithelium, apparently played only a minor role. The findings presented here indicate that the rejection of first-set vascularized skin allografts, though induced by immunologically specific mechanisms, is primarily effected by final pathways that are relatively nonspecific and that may cause damage to both foreign and host vessels and cells. Rather than contradicting studies demonstrating the exquisite specificity of allograft rejection in other systems, these findings provide a further example of the heterogeneity of the cellular immune response. Recognition of the critical role of immunologically mediated microvascular injury may prove important both for an understanding of the biology of allograft rejection and for strategies aimed at prolonging allograft survival.

Antibody Formation↗
PubMed1977

Cost-benefit analysis of surgery. Current accomplishments and limitations.

The general principles of cost-benefit analysis are applicable to health care issues, which are in particular need of carefully detailed study at a time when health care expenditures are increasing and when there is competition for scarce resources. There are limitations to such analyses, particularly in the evaluation of the many intangible values so important in the costs and benefits of health care. As examples of the methodology, a simplified cost-benefit analysis is presented for cholecystectomy for silent gallstones in terms of an individual patient, and a more complex analysis is presented for a national program for renal transplantation or chronic hemodialysis for end-stage renal disease. Finally, costs of intensive care support are presented. These examples illustrate advantages and disavantages of a revealing type of analysis that will be applied with increasing frequency to future health care issues.

Cholecystectomy↗