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Biomedical subjects

J S Weissman

Publications and source records attributed to J S Weissman.

At least 73 records · Page 4Linked to original sources
PubMed1994

Physician discretion and racial variation in the use of surgical procedures.

BACKGROUND: Racial variation in the use of surgical procedures raises concern about equitable access. The goal of our study was to examine racial differences in utilization across a broad range of procedures in Massachusetts and to assess whether racial variation is related to physician discretion. METHODS: We obtained fiscal year 1988 hospital discharge data for all Massachusetts residents, identified 10 clinically important surgical procedures, and calculated age- and sex-adjusted rate ratios for white and black patients. Level of discretion was determined by using a modified Delphi technique. RESULTS: Whites had higher rates for eight procedures (abdominal aortic aneurysm repair, appendectomy, cardiac valve replacement, carotid endarterectomy, cholecystectomy, lumbar disk procedures, open reduction/internal fixation of the femur, and tonsillectomy) and lower rates for two procedures, hysterectomy and prostatectomy. Of the eight procedures for which utilization was higher among whites, four were ranked as moderate- or high-discretion procedures and four were ranked as low-discretion procedures. Hysterectomy, the only procedure for which utilization was substantially higher among blacks (white:black rate ratio < 0.90), was ranked as a high-discretion procedure. CONCLUSIONS: With the exception of hysterectomy and prostatectomy, procedure rates for whites were greater than those for blacks for a wide range of surgical procedures. Racial variation exists for low-discretion procedures as well as for those associated with moderate and high discretion. Variation among low-discretion procedures that is not explained by medical need suggests the possibility of race-related differences in access to care or in the way patients and physicians make clinical decisions.

Adult↗
PubMed1994

Correlates of employment after AIDS diagnosis in the Boston Health Study.

OBJECTIVES: The purpose of this study was to determine the impact of personal and job characteristics on the time to employment loss after diagnosis of the acquired immunodeficiency syndrome (AIDS) and to examine how job loss affects patients' income. METHODS: Data were collected from 305 patients with AIDS at three sites in Boston, Mass, between February 1990 and July 1991. Life-table methods were used to estimate the number of months employed after diagnosis. A Cox proportional hazards model was used to estimate the effect of risk factors on the probability of ceasing employment in a month. RESULTS: Seventy-six percent of respondents were working at the time of diagnosis; 53% still had a job at the time of the baseline interview, which averaged 16 months later, but about one in three was on sick or disability leave. Mental and physical demands of jobs significantly influenced the likelihood of employment loss. The loss of earnings reduced monthly income by 75%. CONCLUSIONS: Job characteristics affect the likelihood of employment loss, which in turn has a deleterious effect on income. Programs supporting persons with AIDS during the transition out of work or enabling them to modify their job demands may also reduce these problems.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Changes in insurance status and access to care for persons with AIDS in the Boston Health Study.

The purpose of this study was to measure unmet needs and changes in insurance status for persons with acquired immunodeficiency syndrome (AIDS). Thirty-six percent of the study's Boston-area respondents (n = 305) had a change in insurance coverage between AIDS diagnosis and interview. Medicaid coverage increased from 14% to 41%. Pneumocystis carinii pneumonia prophylaxis was nearly universal. Only 5% did not receive zidovudine, and intravenous drug users were at higher risk. Approximately 14% to 15% of patients reported problems in obtaining medical and dental services; Blacks, homeless persons, and those who were not high school graduates were at higher risk. Use of selected treatments for which there were clear clinical guidelines was adequate, yet disadvantaged groups were more likely than other persons with AIDS to face obstacles to other services.

Acquired Immunodeficiency Syndrome↗
PubMed1994

The impact of patient socioeconomic status and other social factors on readmission: a prospective study in four Massachusetts hospitals.

Readmissions to hospitals may serve as markers for morbidity, high costs, and potentially poor quality of care, yet little is known about the relation of socioeconomic factors to the likelihood of readmission. In this article, we used logistic regression models to examine the readmission experience of nearly 12,000 patients, adjusting for age, gender, hospital, severity of illness, and the overall probability of readmission within each diagnosis related group (DRG). After adjustment, patients were more likely to be readmitted within 60 days if they were poor (OR = 1.25, p < .05), worked in unskilled or semiskilled occupations (OR = 1.25, p < .05), or rented their homes (OR = 1.23, p < .01). Nonwhites (OR = .76, p < .01) and uninsured patients (OR = .48, p < .01) were less likely to be readmitted. Within a 7-day period, patients who rented their homes were more likely to be readmitted (OR = 1.32), while patients were less likely to be readmitted if they were uninsured (OR = .36) or nonwhite (OR = .72) (all p < .05). Social support factors including marital status, living situation, and availability of help at home were not associated significantly with the risk of readmission. Our results suggest that patients in lower socioeconomic positions have higher readmission rates, at least for readmissions within longer time periods. Providers designing interventions to reduce the risk of readmission may want to target the groups identified by our study.

Demography↗
PubMed1993

Efficient catalysis of disulphide bond rearrangements by protein disulphide isomerase.

Protein disulphide isomerase (PDI) is a highly abundant and ubiquitous eukaryotic protein that is essential for viability in yeast. Although PDI is thought to catalyse disulphide bond formation and isomerization during protein biosynthesis, PDI has been found previously to have only moderate effects (approximately 25-fold) on the rate of oxidative folding of proteins in vitro. In addition, PDI has been implicated in several apparently unrelated cellular functions. For example, PDI is the beta-subunit of prolyl 4-hydroxylase and is part of the triglyceride transfer complex. The oxidative folding of bovine pancreatic trypsin inhibitor (BPTI) is slow and inefficient in vitro. Here we report that PDI increases by a factor of 3,000-6,000 the rates of folding of kinetically trapped BPTI folding intermediates, in which native structure impedes disulphide bond formation. By contrast, PDI has only small effects on the rate of disulphide bond formation in intermediates that are oxidized readily in the absence of PDI. These results suggest that an important function of PDI is to catalyse disulphide bond formation and rearrangements within kinetically trapped, structured folding intermediates.

Animals↗
PubMed1993

Discussion of preferences for life-sustaining care by persons with AIDS. Predictors of failure in patient-physician communication.

OBJECTIVES: To assess the determinants of communication about resuscitation between persons with acquired immunodeficiency syndrome (AIDS) and their physician. DESIGN AND SETTING: Structured patient interview at a staff-model health maintenance organization (HMO), an internal medicine group practice at a private teaching hospital, and an AIDS clinic at a public hospital. PATIENTS: 289 persons with AIDS. MAIN RESULTS: Only 38% of patients had discussed their preferences for resuscitation with their physician. Using logistic regression, we found that patients were less likely to have discussed resuscitation with their physician if they were nonwhite (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.24 to 0.99), had never been hospitalized (OR, 0.52; 95% CI, 0.27 to 0.99), or were cared for in the HMO (OR, 0.44 relative to the private teaching hospital; 95% CI, 0.23 to 0.82). Patients were more likely to have discussed their preferences if they were not currently taking zidovudine (OR, 1.76; 95% CI, 1.02 to 3.03) and if they had decided to defer life-sustaining therapy (OR, 2.30; 95% CI, 1.35 to 3.91). Among nonwhites, those with a nonwhite physician were more likely to have discussed resuscitation (OR, 4.38; 95% CI, 1.13 to 16.93). Of patients who had not discussed their preferences for life-sustaining care, 72% wanted to do so. Patient desire for discussion of this issue did not vary by race, severity of illness, hospitalization status, use of zidovudine, or site of care. CONCLUSIONS: A majority of persons with AIDS in this study had not discussed their preferences for life-sustaining care with their physician, despite the desire to do so. Interventions to improve patient-physician communication about resuscitation for nonwhites and other groups at risk of inadequate discussion might lead to clinical decisions that are more consistent with patient preferences.

Acquired Immunodeficiency Syndrome↗
PubMed1992

The pro region of BPTI facilitates folding.

The in vitro folding pathway of bovine pancreatic trypsin inhibitor (BPTI) has been described previously in terms of the disulfide-bonded intermediates that accumulate during folding of the protein. Folding is slow, occurring in hours at pH 7.3, 25 degrees C. In addition, approximately half of the BPTI molecules become trapped as a dead-end, native-like intermediate. In vivo, BPTI is synthesized as a precursor protein that includes a 13 residue amino-terminal pro region. This pro region contains a cysteine residue. We find that, in vitro, both the rate of formation and the yield of properly folded BPTI are increased substantially in a recombinant model of pro-BPTI. The cysteine residue is necessary for this effect. Moreover, a single cysteine residue, tethered to the carboxy-terminal end of BPTI with a flexible linker of repeating Ser-Gly-Gly residues, is sufficient to assist in disulfide formation. Thus, the pro region appears to facilitate folding by providing a tethered, solvent-accessible, intramolecular thiol-disulfide reagent.

Amino Acid Sequence↗
PubMed1992

Rates of avoidable hospitalization by insurance status in Massachusetts and Maryland.

OBJECTIVE: To determine whether uninsured and Medicaid patients have higher rates of avoidable hospitalizations than do insured patients. DESIGN: We used 1987 computerized hospital discharge data to select a cross-sectional sample of hospitalized patients. Population estimates from the Current Population Survey were used to estimate rates of admission, standardized for age and sex. SETTING: Nonfederal acute care hospitals in Massachusetts and Maryland. PATIENTS: All patients under 65 years of age who were uninsured, privately insured, or insured by Medicaid. Hospitalizations for obstetric and psychiatric conditions were excluded. MAIN OUTCOME MEASURES: Relative risk of admission for 12 avoidable hospital conditions (AHCs) identified by a physician panel. RESULTS: Uninsured and Medicaid patients were more likely than insured patients to be hospitalized for AHCs. Rates for uninsured patients were significantly greater than for privately insured patients in Massachusetts for 10 of 12 individual AHCs, and in Maryland for five of 12 AHCs. After adjustment for baseline utilization, the results were statistically significant for 10 of 12 AHCs in Massachusetts and seven of 12 AHCs in Maryland. For Medicaid patients, rates were significantly greater than for privately insured patients for all AHCs in each state before adjustment, and for nine of 12 and seven of 12 AHCs in each state, respectively, after adjustment for baseline utilization. CONCLUSION: Our findings suggest that patients who are uninsured or who have Medicaid coverage have higher rates of hospitalization for conditions that can often be treated out of hospital or avoided altogether. Our approach is potentially useful for routine monitoring of access and quality of care for selected groups of patients.

Adult↗
PubMed1992

Kinetic role of nonnative species in the folding of bovine pancreatic trypsin inhibitor.

We have shown previously that during the oxidative folding of bovine pancreatic trypsin inhibitor only intermediates with native disulfide bonds are well populated. Nevertheless, these studies also confirmed the earlier conclusion [Creighton, T. E. (1977) J. Mol. Biol. 113, 275-293] that the rate-limiting transition in the kinetically preferred route for folding involves intramolecular disulfide bond rearrangements. Consequently, intermediates with nonnative disulfide bonds must form transiently during folding. Two specific nonnative species, denoted [30-51; 5-14] and [30-51; 5-38], in which numbers indicate residues participating in a disulfide bond, can be detected at low levels in kinetic folding experiments with bovine pancreatic trypsin inhibitor. By working with purified reversibly trapped intermediates, the role of these two nonnative species has been examined directly. These species are found to be in relatively rapid exchange with each other and with an initially formed native two-disulfide intermediate [30-51; 14-38]. Thus, the low abundance of the two nonnative species detected in kinetic folding experiments reflects primarily their low thermodynamic stability as compared to this native intermediate. To a small extent, these nonnative species form the productive native intermediate [30-51; 5-55], which is the immediate precursor to the native protein. However, an equal amount of [5-55; 14-38], a nonproductive dead-end intermediate, is also produced. Thus, the nonnative species detected during the folding of bovine pancreatic trypsin inhibitor are not committed to forming the productive native intermediate, nor do they serve to direct folding specifically toward a productive route.

Animals↗
PubMed1991

Reexamination of the folding of BPTI: predominance of native intermediates.

Bovine pancreatic trypsin inhibitor (BPTI) continues to be the only protein for which a detailed pathway of folding has been described. Previous studies led to the conclusion that nonnative states are well populated in the oxidative folding of BPTI. This conclusion has broadly influenced efforts to understand protein folding. The population of intermediates present during the folding of BPTI has been reexamined by modern separation techniques. It was found that all well-populated folding intermediates contain only native disulfide bonds. These data emphasize the importance of native protein structure for understanding protein folding.

Amino Acid Sequence↗
PubMed1991

Delayed access to health care: risk factors, reasons, and consequences.

OBJECTIVE: To determine characteristics of patients reporting delays in care before hospitalization and the reasons for those delays. DESIGN: Survey; personal interviews. SETTING: Five hospitals in Massachusetts. PATIENTS: Subjects were drawn from a consecutive sample of all adult patients (excluding obstetrics or psychiatry patients) hospitalized during the first 6 months of 1987 as part of a larger study of hospital costs. For the current study, if patients were re-admitted, we included in our analysis only data on the first admission during the study period. We obtained usable survey data from 12,068 of 17,231 eligible patients. RESULTS: Delays in care were reported by 16% of patients. The odds of reporting delays in care among patients who were black, poor, uninsured, or without a regular physician were 40% to 80% greater than those for other patients (P less than 0.01). Most patients who reported delays thought that their problem was not serious (64%). Cost was an important factor in delaying care for patients in lower socioeconomic positions; the odds of delaying care because of cost for patients who were both poor and uninsured were 12 times greater than the odds for other patients (P less than 0.001). After controlling for diagnosis-related groups (DRGs) and severity, patients who reported delays had 9% longer hospital stays compared with others (P less than 0.001). CONCLUSIONS: Patients generally thought to be disadvantaged are at especially high risk for delaying care for conditions that eventually lead to hospitalization. Because these delays are associated with longer hospital stays and potentially poorer health outcomes, interventions that reduce delays seem especially important.

Adolescent↗
PubMed1990

The association of payer with utilization of cardiac procedures in Massachusetts.

To investigate the importance of the payer in the utilization of in-hospital cardiac procedures, we examined the care of 37,994 patients with Medicaid, private insurance, or no insurance who were admitted to Massachusetts hospitals in 1985 with circulatory disorders or chest pain. Using logistic regression to control for demographic, clinical, and hospital factors, we found that the odds that privately insured patients received angiography were 80% higher than uninsured patients; the odds were 40% higher for bypass grafting and 28% higher for angioplasty. Medicaid patients experienced odds similar to those of uninsured patients for receiving angiography and bypass, but had 48% lower odds of receiving angioplasty. In addition, the odds for Medicaid patients were lower than for privately insured patients for all three cardiac procedures. These findings suggest that insurance status is associated with the utilization of cardiac procedures. Future studies should determine the implications these findings have for appropriateness and outcome and whether interventions might improve care.

Adult↗
PubMed1990

Do the poor cost more? A multihospital study of patients' socioeconomic status and use of hospital resources.

There is controversy about whether hospitalized poor patients use more resources and whether hospitals that provide care for the poor therefore merit supplementary payment under per-case prospective payment systems. We previously reported that patients of low socioeconomic status with connective-tissue disease had longer hospital stays and higher costs than patients of higher socioeconomic status at a single hospital. To examine the generalizability of this phenomenon, we interviewed 16,908 (83 percent) of 20,278 consecutive adult patients (excluding obstetrical and psychiatric patients) admitted in 1987 to five Massachusetts hospitals, to obtain information on three direct measures of socioeconomic status (income, occupation, and education). We divided each measure into three strata. Thus, there were 15 comparisons--three measures of socioeconomic status applied to each of five hospitals. After excluding outliers and adjusting for diagnosis-related group (DRG), we found that the patients of the lowest socioeconomic status had hospital stays 3 to 30 percent longer than those of patients of higher status, the differences varying with the hospital and the indicator of socioeconomic status (P less than or equal to 0.05 for 11 of the 15 comparisons). Hospital charges were 1 to 18 percent higher for the patients of lowest socioeconomic status than for those of higher status (P less than or equal to 0.05 for 9 of 15 comparisons). When we adjusted for age, severity of illness, and DRG, the patients of lowest socioeconomic status had longer stays than those of higher status in 14 of 15 comparisons (P less than 0.05 for 7 of the 15) and higher charges in 13 of 15 comparisons (P less than 0.05 for 6 of the 15). The differences between patients of high and low status ranged up to 21 percent for length of stay and 13 percent for charges. Our findings suggest that hospitalized patients of lower socioeconomic status have longer stays and probably require more resources. Supplementary payments to hospitals for the treatment of poor patients merit further consideration.

Diagnosis-Related Groups↗
PubMedDate not supplied

Market forces and unsponsored research in academic health centers.

CONTEXT: Increased competitive pressures on academic health centers may result in reduced discretionary funds from patient care revenues to support the performance of unsponsored research, including institutionally funded and faculty-supported activities. OBJECTIVE: To measure the amount and distribution of unsponsored research activities and their outcomes. DESIGN AND SETTING: Survey conducted in academic year 1996-1997 of 2336 research faculty in 117 medical schools. Responses were weighted to provide national estimates. MAIN OUTCOME MEASURES: Institutionally funded research as a proportion of total direct costs of research was compared across stages of market competition. Logistic regression was used to assess the relationship of performing unsponsored research to faculty characteristics and market stage. RESULTS: Overall, 43% of faculty received institutional funding for research. Young faculty were more likely than others to receive institutional support (adjusted odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.9; P = .004). The amount of institutional support as a proportion of total funding was more than twice as high in less competitive markets (6.1%) compared with the most competitive markets (2.5%; P = .05). Most faculty (55%) performed faculty-supported research. Clinical researchers (OR, 1.6; 95% CI, 1.1-2.3), principal investigators (OR, 4.3; 95% CI, 2.8-7.0), faculty with high levels of research effort (OR, 6.2; 95% CI, 4.0-9.5) or institutional funding (OR, 1.9; 95% CI, 1.4-2.6), and faculty in the most competitive markets (OR, 1.9; 95% CI, 1.4-2.5) were more likely than others to conduct faculty-supported research. When undertaken by clinical researchers, these activities were supported by clinical income, extra hours worked, and discretionary funds, and often led to publications (76%) or grant awards (51%). CONCLUSIONS: Many academic health center faculty receive institutional support to conduct their research or fund the research themselves. Market pressures may be affecting the level of institutional funding available to faculty.

Academic Medical Centers↗
PubMedDate not supplied

The stability of preferences for life-sustaining care among persons with AIDS in the Boston Health Study.

BACKGROUND: Clinicians recognize the importance of eliciting patient preferences for life-sustaining care, yet little is known about the stability of those preferences for patients with serious disease. OBJECTIVES: To examine the stability of preferences for life-sustaining care among persons with AIDS and to assess factors associated with changes in preferences. DESIGN: Two patient surveys and medical record reviews, administered four months apart in 1990-1991. SETTING: Three health care settings in Boston. PATIENTS: 252 of 505 eligible persons with AIDS who participated in both baseline and follow-up surveys. MAIN OUTCOME MEASURES: A single question assessing desire for cardiac resuscitation and a scale of preferences for life-extending treatment conditional on hypothetical health states. RESULTS: Approximately one-fourth of the respondents changed their minds about life-sustaining care during a four-month period. Of patients who initially desired cardiac resuscitation, 23% decided to forego it four months later, and of those who initially said they would decline care, 34% later said they would accept it. Of those who initially desired any of the life-extending treatments, 25% decided to forego them four months later, and of those who initially said they would decline life-extending care, 24% later said they would accept some treatment. Patients reporting changes in physical function, pain, or suicide ideation were more likely to modify their desires to be resuscitated (all p< or =0.05). Patients lacking an advance directive, not completing high school, or becoming more severely ill were more likely to change their preferences on the Life Extension scale (p< or =0.05). Patients who discussed their preferences with at least one physician were just as likely as others to change desires for cardiac resuscitation. Age, gender, race, emotional health, clinical severity, social support, and site of care were not significant correlates of change for either measure. CONCLUSIONS: Health care providers should periodically reassess preferences for life-sustaining care, particularly for patients with progressive disease, given the instability in patient preferences. However, predictors of instability may vary with how preferences are measured. In particular, changes in health status may be related to instability of preferences for certain types of treatments.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Quality of care for two common illnesses in teaching and nonteaching hospitals.

Teaching hospitals are recognized for treating rare diseases, but their value in caring for common illnesses is less clear. To assess quality of care for congestive heart failure and pneumonia, we reviewed the medical records of Medicare beneficiaries in major teaching, other teaching, and nonteaching hospitals in four states. Overall quality was rated better in major and other teaching hospitals than in nonteaching hospitals by physician reviewers and explicit process criteria, but the results varied for different subsets of explicit measures. Future studies should assess whether outcomes differ between teaching and nonteaching hospitals.

Aged↗