Semantic memory impairment in schizophrenia--deficit in storage or access of knowledge?

This study evaluates whether patients with schizophrenia have a degraded memory store for semantic knowledge. 20 patients with a chronic history of schizophrenia and evidence of cognitive impairment were selected, since the literature indicates that this subgroup is most likely to manifest a degraded semantic knowledge store. Their profile of semantic memory impairments was compared to that of a group of Alzheimer's Dementia (AD) patients (n=22), who met neuropsychological criteria for degraded semantic store. Both groups were matched for Performance IQ. 15 elderly healthy controls were also included in the study. The AD and schizophrenia groups produced substantially different profiles of semantic memory impairment. This is interpreted as indicating that the semantic impairments in this subgroup of patients with schizophrenia do not result from a degraded store. This is corroborated by an analysis of the data using other neuropsychological criteria for determining degraded store. We conclude that there is little evidence for a classic degradation of semantic knowledge in schizophrenia, and it appears that impairments result from an inability to use semantic knowledge appropriately, particularly when selection of salient semantic relations is required.

Do overinclusion and distorted semantic category boundaries in schizophrenia arise from executive dysfunction?

Semantic memory impairments have been reported extensively in people with schizophrenia. Inefficient search and retrieval strategies, due to an executive dysfunction, rather than a primary loss of semantic knowledge are a primary candidate for such impairments. In order to test this hypothesis we compared the performance of 20 patients meeting DSM-IV-TR criteria for schizophrenia with that of 20 healthy controls and 10 patients with acquired brain injury (ABI) with a dysexecutive syndrome. Seventy percent of the people with schizophrenia and 100% of the ABI patients in this study met criteria for executive impairment. However, the two groups performed significantly differently on a range of semantic memory tests. Whereas 45% of the patients with schizophrenia met criteria for distorted semantic category boundaries (n.b. overinclusion), this was true for only 10% of the ABI patients. In addition, no correlation was found between severity of executive dysfunction and tendency to overinclude in the schizophrenia group. This pattern of neuropsychological findings suggests that overinclusion, or disorganized semantic categorization procedures, in schizophrenia does not result from a classical executive dysfunction. Alternative explanations are discussed.

Garlic shows promise for improving some cardiovascular risk factors.

OBJECTIVES: To summarize the effects of garlic on several cardiovascular-related factors and to note its adverse effects. METHODS: English and non-English citations were identified from 11 electronic databases, references, manufacturers, and experts from January 1966 through February 2000 (depending on the database searched). Reports of cardiovascular-related effects were limited to randomized controlled trials lasting at least 4 weeks. Reports of adverse effects were not limited by study design. From 1798 pertinent records, 45 randomized trials and 73 additional studies reporting adverse events were identified. Two physicians abstracted outcomes and assessed adequacy of randomization, blinding, and handling of dropouts. Standardized mean differences of lipid outcomes from placebo-controlled trials were adjusted for baseline differences and pooled using random effects methods. RESULTS: Compared with placebo, garlic preparations may lead to small reductions in the total cholesterol level at 1 month (range of average pooled reductions, 0.03-0.45 mmol/L [1.2-17.3 mg/dL]) and at 3 months (range of average pooled reductions 0.32-0.66 mmol/L [12.4-25.4 mg/dL]), but not at 6 months. Changes in low-density lipoprotein levels and triglyceride levels paralleled total cholesterol level results; no statistically significant changes in high-density lipoprotein levels were observed. Trials also reported significant reductions in platelet aggregation and mixed effects on blood pressure outcomes. No effects on glycemic-related outcomes were found. Proven adverse effects included malodorous breath and body odor. Other unproven effects included flatulence, esophageal and abdominal pain, allergic reactions, and bleeding. CONCLUSIONS: Trials suggest possible small short-term benefits of garlic on some lipid and antiplatelet factors, insignificant effects on blood pressure, and no effect on glucose levels. Conclusions regarding clinical significance are limited by the marginal quality and short duration of many trials and by the unpredictable release and inadequate definition of active constituents in study preparations.

The effect of anesthetic technique on postoperative outcomes in hip fracture repair.

BACKGROUND: The impact of anesthetic choice on postoperative mortality and morbidity has not been determined with certainty. METHODS: The authors evaluated the effect of type of anesthesia on postoperative mortality and morbidity in a retrospective cohort study of consecutive hip fracture patients, aged 60 yr or older, who underwent surgical repair at 20 US hospitals between 1983 and 1993. The primary outcome was defined as death within 30 days of the operative procedure. The secondary outcomes were postoperative 7-day mortality, postoperative myocardial infarction, postoperative pneumonia, postoperative congestive heart failure, and postoperative change in mental status. Numerous comorbid conditions were controlled for individually and by several comorbidity indices using logistic regression. RESULTS: General anesthesia was used in 6,206 patients (65.8%) and regional anesthesia in 3,219 patients (3,078 spinal anesthesia and 141 epidural anesthesia). The 30-day mortality rate in the general anesthesia group was 4.4%, compared with 5.4% in the regional anesthesia group (unadjusted odds ratio = 0.80; 95% confidence interval = 0.66-0.97). However, the adjusted odds ratio for general anesthesia increased to 1.08 (0.84-1.38). The adjusted odds ratios for general anesthesia versus regional anesthesia for the 7-day mortality was 0.90 (0.59-1.39) and for postoperative morbidity outcomes were as follows: myocardial infarction: adjusted odds ratio = 1.17 (0.80-1.70); congestive heart failure: adjusted odds ratio = 1.04 (0.80-1.36); pneumonia: adjusted odds ratio = 1.21 (0.87-1.68); postoperative change in mental status: adjusted odds ratio = 1.08 (0.95-1.22). CONCLUSIONS: The authors were unable to demonstrate that regional anesthesia was associated with better outcome than was general anesthesia in this large observational study of elderly patients with hip fracture. These results suggest that the type of anesthesia used should depend on factors other than any associated risks of mortality or morbidity.

A cross-cultural consumer-based decision aid for screening mammography.

BACKGROUND: "Women should have mammograms" is the usual perspective of educational interventions about screening. The perspective that "women should be informed" about potential risks and benefits so they can make value- and evidence-integrated personal decisions has recently been advocated. However, this perspective has not previously been operationalized. We developed an evidence-based cross-cultural mammography decision aid (MDA), for European American and Mexican American women who are 50-70 years old, at average risk of breast cancer, of varying educational levels, and English- or Spanish-speaking. METHODS: MDA development included: (1) content development by a multidisciplinary team and lay women and (2) testing for validity and reliability. Four parts include: (1) introduction; (2) information about logistics (cost, time, discomfort) and risks (sequelae of false-positive or negative results; (3) probability of developing breast cancer; and (4) benefit of mammography regarding breast cancer outcomes (e.g., death and recurrence). We assessed reliability (stability of decisions with the same information) after 1-2 weeks. We assessed validity (comprehension of information) quantitatively (probabilities were changed to see whether preferences changed predictably) and qualitatively (focus groups, standardized probes for comprehension). Subjects were a convenience sample of 49 European American (50-81 years old) and 54 Mexican American (49-89 years old) women from administrative staff at a medical school, the waiting room of an indigent primary care clinic, and a community center. RESULTS: Reliability was 100%. In quantitative validity testing, 22 of 28 women (89%) changed preference as predicted with changed probabilities. Comprehension was confirmed qualitatively in all phases of testing with both Spanish and English versions. CONCLUSION: The decision aid is valid and reliable in English and Spanish for southwestern Mexican American and European American women at average risk of breast cancer, including those of low educational levels.

Systematic differences in validity of self-reported mammography behavior: A problem for intergroup comparisons?

BACKGROUND: Prior studies of recall accuracy for screening mammogram behavior have examined relatively homogeneous groups. Data are limited on possible systematic group differences, so we evaluated women's recall accuracy in two separate care systems in one city. Methods. Women 50 to 70 years old with and without screening mammograms 10 to 14 months prior were identified from fiscal, clinic, and radiology records at a military care system (MCS) and a county-funded system (CFS) for indigents. Mammogram status was verified through radiology records. Women were excluded if mammograms were diagnostic, done for other than annual screening, or had abnormal results. Interviewers blinded to mammogram status surveyed randomly selected eligible women. RESULTS: For 62 screened/31 unscreened MCS women and 78 screened/61 unscreened CFS women, specificity was similar, at 65 and 62%, respectively. In contrast, sensitivity varied significantly: 95% versus 79% (P = 0. 011). Primary ethonocultural groups were Euro-American (MCS-60%) and Mexican American (CFS-85%). Although not different in specificity of recall (67% versus 61%), these major subgroups significantly differed in sensitivity (97% versus 80%, P = 0.017), proportion of true negatives due to never having a mammogram (35% versus 57%, P = 0.003), and proportion with >/=high school education (78% versus 19%, P < 0.00001). CONCLUSION: Systematic differences in recall validity may exist and compromise the accuracy of intergroup comparisons.

How you look determines what you find: severity of illness and variation in blood transfusion for hip fracture.

PURPOSE: Utilization report cards are commonly used to assess hospitals. However, in practice, they rarely account for differences in patient populations among hospitals. Our study questions were: (1) How does transfusion utilization for hip fracture patients vary among hospitals? (2) What patient characteristics are associated with transfusion and how do those characteristics vary among hospitals? (3) Is the apparent pattern of variation of utilization among hospitals altered by controlling for these patient characteristics? SUBJECTS AND METHODS: We included consecutive hip fracture patients aged 60 years or older who underwent surgical repair between 1982 and 1993 in 19 hospitals from four states, excluding those who refused blood transfusion, had multiple trauma, metastatic cancer, multiple myeloma, an above the knee amputation, or were paraplegic or quadriplegic. The outcome of interest was postoperative blood transfusion. "Trigger hemoglobin" was the lowest hemoglobin recorded before transfusion or recorded at any time during the week before or after surgery for patients who were not transfused. RESULTS: There was considerable variation in transfusion among hospitals postoperatively (range 31.2% to 54.0%, P = 0.001). Trigger hemoglobin also varied considerably among hospitals. In unadjusted analyses, four of nine teaching and two of nine nonteaching hospitals had postoperative transfusion rates significantly higher than the reference (teaching) hospital, while one nonteaching hospital had a lower rate. In an analysis controlling for trigger hemoglobin and multiple clinical variables, one of nine teaching and four of nine nonteaching hospitals had rates higher than the reference hospital, while four teaching hospitals and one nonteaching hospital had lower rates. CONCLUSIONS: The apparent pattern of variation of transfusion among hospitals varies according to how one adjusts for relevant patient characteristics. Utilization report cards that fail to adjust for these characteristics may be misleading.

Perioperative blood transfusion and postoperative mortality.

CONTEXT: The risks of blood transfusion have been studied extensively but the benefits and the hemoglobin concentration at which patients should receive a transfusion have not. OBJECTIVE: To determine the effect of perioperative transfusion on 30- and 90-day postoperative mortality. DESIGN: Retrospective cohort study. SETTING: A total of 20 US hospitals between 1983 and 1993. PARTICIPANTS: A total of 8787 consecutive hip fracture patients, aged 60 years or older, who underwent surgical repair. MAIN OUTCOME MEASURES: Primary outcome was 30-day postoperative mortality; secondary outcome was 90-day postoperative mortality. The "trigger" hemoglobin level was defined as the lowest hemoglobin level prior to the first transfusion during the time period or, for patients in the nontranfused group, as the lowest hemoglobin level during the time period. RESULTS: Overall 30-day mortality was 4.6% (n=402; 95% confidence interval [CI], 4.1%-5.0%); overall 90-day mortality was 9.0% (n=788; 95% CI, 8.4%-9.6%). A total of 42% of patients (n=3699) received a postoperative transfusion. Among patients with trigger hemoglobin levels between 80 and 100 g/L (8.0 and 10.0 g/dL), 55.6% received a transfusion, while 90.5% of patients with hemoglobin levels less than 80 g/L (8.0 g/dL) received postoperative transfusions. Postoperative transfusion did not influence 30- or 90-day mortality after adjusting for trigger hemoglobin level, cardiovascular disease, and other risk factors for death: for 30-day mortality, the adjusted odds ratio (OR) was 0.96 (95% CI, 0.74-1.26); for 90-day mortality, the adjusted hazard ratio was 1.08 (95% CI, 0.90-1.29). Similarly, 30-day mortality after surgery did not differ between those who received a preoperative transfusion and those who did not (adjusted OR, 1.23; 95% CI, 0.81-1.89). CONCLUSIONS: Perioperative transfusion in patients with hemoglobin levels 80 g/L (8.0 g/dL) or higher did not appear to influence the risk of 30- or 90-day mortality in this elderly population. At hemoglobin concentrations of less than 80 g/L (8.0 g/dL), 90.5% of patients received a transfusion, precluding further analysis of the association of transfusion and mortality.

Preoperative spirometry and laparotomy: blowing away dollars.

STUDY OBJECTIVE: Increasing evidence indicates that routine preoperative diagnostic spirometry (pulmonary function tests [PFTs]) before elective abdominal surgery does not predict individual risk of postoperative pulmonary complications and is overutilized. This economic evaluation estimates potential savings from reduced use of preoperative PFTs. DESIGN: Analyses of (1) real costs (resource consumption to perform tests) and (2) reimbursements (expenditures for charges) by third-party payers. SETTING: University-affiliated public and Veterans Affairs hospitals. PATIENTS: Adults undergoing elective abdominal operations. MEASUREMENTS AND RESULTS: Average real cost of PFTs was $19.07 (95% confidence interval [CI], $18.53 to $19.61), based on a time and motion study. Average reimbursement expenditure by third-party payers for PFTs was $85 (range, $33 to $150; 95% CI, $68 to $103), based on Medicare payment of $52 and a survey of nine urban US hospitals with a spectrum of bed sizes and teaching status. Estimates from published literature included the following: (1) annual number of major abdominal operations, 3.5 million; and (2) proportion of PFTs not meeting current guidelines, 39% (95% CI, 0.31 to 0.47). Local data were used when estimates were not available in the literature: (1) proportion of laparotomies that are elective, 76% (95% CI, 0.73 to 0.79); and (2) frequency of PFTs before laparotomy, 69% (95% CI, 0.54 to 0.84). Estimated annual national real costs for preoperative PFTs are $25 million to $45 million. If use of PFTs were reduced by our estimate for the proportion of PFTs not meeting current guidelines, potential annual national cost savings would be $7,925,411 to $21,406,707. National reimbursement expenditures by third-party payers range from more than $90 million to more than $235 million. If use were reduced, potential annual savings in reimbursements would be $29,084,076 to $111,345,440. Potential savings to Medicare approach $8 million to $20 million annually. CONCLUSION: Reduced use of PFTs before elective abdominal surgery could generate substantial savings. Current evidence indicates reduced use would not compromise patients' outcomes.

Where does it hurt? Stability of recordings of pain location using the McGill Pain Map.

OBJECTIVE: To evaluate the validity and reliability of recordings of pain location among patients with pain from 2 different sources, using the McGill Pain Map (MPM). METHODS: Consecutive outpatients from a rheumatology clinic and inpatients recovering from surgical interventions participated in a structured interview during which the McGill Pain Questionnaire and the MPM were administered. After an interval of 3 to 6 weeks for the rheumatology patients and 1 to 2 days for the postoperative patients, a 2nd identical interview was administered. Criterion related validity was examined by testing whether the extent [total number of painful areas (NPA)] and distribution (individual body areas affected) of pain differed significantly between the 2 patient groups and whether, among postoperative patients, the distribution of pain was consistent with the site of surgical incision. Test-retest reliability of the recordings on the MPM was measured by calculating a kappa coefficient for each individual body area on the MPM, and an intraclass correlation coefficient for the NPA. RESULTS: 51 rheumatology and 47 postoperative patients were interviewed. Significant differences in the total NPA (4.1 +/- 3.0 vs 11.5 +/- 6.2; p < 0.001) and in the distribution of the painful areas were observed between the 2 groups. Among postoperative patients, there was no significant difference in the NPA between the 2 interviews (4.1 +/- 3.0 vs 4.3 +/- 3.5; p = 0.53), while among rheumatology patients, there was a reduction in the NPA at the second interview (11.5 +/- 6.2 vs 9.8 +/- 5.3; p = 0.007). Reliability of the recordings of pain location by individual areas averaged 0.50 (range 0.04 to 0.76). The reliability of the NPA was 0.82 for the combined group of patients (0.71 and 0.84, respectively). CONCLUSION: Recordings of pain location using the MPM are valid and reliable. The MPM is a valuable instrument for studies of the distribution of pain in populations.

Risk of pulmonary complications after elective abdominal surgery.

STUDY OBJECTIVE: Intra-abdominal operations are relatively high risk for pulmonary complications. Previous research has more intensely investigated cardiac operative risk, but recent work suggests that significant pulmonary complications may be more common than cardiac complications and associated with longer length of stay. This study identified risk indicators for pulmonary complications after elective abdominal operations. DESIGN: Nested case-control. SETTING: University affiliated Veterans Affairs hospital. PATIENTS: We used a computerized registry of all 2,291 patients undergoing elective abdominal operations from 1982 to 1991. Ascertainment and verification of pulmonary and cardiac complications were systematic and explicit. Charts of all 116 patients identified by the registry as having complications and 412 (19%) randomly selected from 2,175 remaining patients were reviewed to verify complications, using explicit criteria and independent abstraction of preoperative and postoperative components of charts. From 528 validated subjects (23% of the cohort), 82 cases and 82 control subjects were closely matched by operation type and age, +/- 10 years. MEASUREMENTS AND RESULTS: The primary outcome measure was postoperative pulmonary complications. Among 82 cases with pulmonary complications, 27 (33%) also had cardiac complications. Preoperative variables independently associated with pulmonary complications by multivariable analysis (p < or = 0.05) included the following: Charlson comorbidity index (per point odds ratio [OR], 1.6; 95% confidence interval [CI], 1.004 to 2.6), Goldman cardiac risk index (per point OR, 2.04; 95% CI, 1.17 to 3.6), abnormal chest radiograph (OR, 3.2; 95% CI, 1.07 to 9.4), and abnormal findings on lung examination (OR, 5.8; 95% CI, 1.04 to 32). Equal proportions of cases and control subjects had preoperative diagnostic spirometry. No component of spirometry predicted complications, including severity of obstructive lung disease. CONCLUSIONS: For pulmonary operative risk, abnormal results of lung examination and chest radiography plus cardiac and overall comorbidity were important. Spirometry was not helpful. Because 33% of cases had both cardiac and pulmonary complications, future studies should prospectively examine comparative incidence, outcomes, and predictors of both type of complications.

Appendicitis: higher risk in Mexican Americans?

OBJECTIVES: Mexican Americans (MAs), compared to white non-Hispanics (WNHs), have higher rates of biliary disease, noninsulin dependent diabetes, and endstage renal disease but lower rates of lung cancer, hip fractures, and mortality from coronary heart disease. Relatively little research has been done to identify other ethnic differences in disease incidence. We used surgical procedure rates to confirm known ethnic differences and to explore our clinical suspicion that MAs have higher rates of appendectomy than WNHs. METHODS: We used a registry of surgical procedures at two teaching hospitals in South Texas to calculate proportional operation ratios (PORs) for MAs versus WNHs. These two hospitals are the primary source of acute hospital care for the indigent in the area. The POR is arithmetically identical to proportional incidence and mortality ratios. RESULTS: MAs underwent appendectomy proportionally more often than WNHs at both hospitals (POR = 1.41 and 1.75, p < 0.0001). Other significant PORs were consistent with known ethnic disease differences in biliary tract operations, vascular access for chronic hemodialysis, lung cancer, and coronary artery bypass. CONCLUSIONS: These findings support the hypothesis that MAs may undergo appendectomy more often than WNHs and so may be at higher risk of appendicitis.

Incidence and hospital stay for cardiac and pulmonary complications after abdominal surgery.

OBJECTIVE: Internists frequently evaluate preoperative cardiopulmonary risk and co-manage cardiac and pulmonary complications, but the comparative incidence and clinical importance of these complications are not clearly delineated. This study evaluated incidence and length of stay for both cardiac and pulmonary complications after elective laparotomy. DESIGN: Nested case-control. SETTING: University-affiliated Department of Veterans Affairs Hospital. PATIENTS: Computerized registry of all 2,291 patients undergoing elective abdominal operations from 1982 to 1991. MEASUREMENT AND MAIN RESULTS: Strategy for ascertainment and verification of complications was systematic and explicit. The charts of all 116 patients identified by the registry as having complications and 412 (19%) randomly selected from 2,175 remaining patients were reviewed to verify presence or absence of cardiac or pulmonary complications, using explicit criteria and independent abstraction of pre- and postoperative components of charts. From these 528 validated cases and controls (23% of the cohort), 96 cases and 96 controls were matched by operation type and age within ten years. Hospital and intensive care unit stays were significantly longer (p < 0.0001) for the cases than for the controls (24.1 vs 10.3 and 5.6 vs 1.5 days, respectively). All 19 deaths occurred among the cases. Among the cases, pulmonary complications occurred significantly more often than cardiac complications (p < 0.00001) and were associated with significantly longer hospital stays (22.7 vs 10.4 days, p = 0.001). Combined cardiopulmonary complications occurred among 28% of the cases. Misclassification-corrected incidence rates for the entire cohort were 9.6% (95% CI 7.2-12.0) for pulmonary and 5.7% (95% CI 3.6-7.7) for cardiac complications. CONCLUSIONS: For noncardiac surgery, previous research has focused on cardiac risk. In this study, pulmonary complications were more frequent, were associated with longer hospital stay, and occurred in combination with cardiac complications in a substantial proportion of cases. These results suggest that further research is needed to fully characterize the clinical epidemiology of postoperative cardiac and pulmonary complications and better guide preoperative risk assessment.

The relationship between disease and function and perceived health in very frail elders.

OBJECTIVE: To study associations between disease and observed function and self-perceived health in very frail elders. DESIGN AND SETTING: Cross-sectional survey of nine nursing homes in San Antonio, TX. PARTICIPANTS: 194 elderly long-stay nursing home residents dependent in at least two ADLs and without severe cognitive impairment. MEASURES: Burden of disease (BOD) was chart abstracted using a standardized protocol that assessed types and severities of 59 categorizations of chronic and acute medical conditions. Observed function and self-perceived health status were assessed independently by the Katz Activities of Daily Living scale (ADL) and the Sickness Impact Profile (SIP), respectively. RESULTS: Summary BOD scores had a low, but statistically significant, univariate correlation with ADL scores (r = 0.21, P = 0.003) and no significant correlation with SIP scores (R = -0.008). Multiple linear regression analyses, including the 24 most frequent disease categories, showed that disease explained significant amounts of ADL (r2 = 0.25, P = 0.001) and borderline significant amounts of SIP (r2 = 0.16, P = 0.11). Models including both disease and sociodemographic, cognitive, and affective variables showed disease added significant incremental explantation beyond the other factors to ADL (incremental r2 = 0.14, P = 0.04), but not to SIP (incremental r2 = 0.08, P > 0.10). CONCLUSIONS: Disease, observed function, and self-perceived health status are separate, but interrelated entities, with disease having a stronger relationship to observed function than self-perceived health. Comprehensive assessment of frail elders may need to include all three areas, and studies that focus on one area should take into account the other two as potential important covariates.

Preoperative HIV testing: is it less expensive than universal precautions?

Universal precautions are officially recommended to prevent HIV transmission in health care settings but for elective surgery some advocate routine preoperative HIV testing. These strategies have not been tested in clinical trials but universal precautions are very expensive and not cost-effective. Thus, for elective surgery, routine testing might save resources by permitting selective use of additional barrier precautions. We performed an economic evaluation to compare both strategies, using a simple approach to determine if routine testing (RT) is less expensive than universal precautions (UP). Conservatively assuming equal effectiveness in preventing HIV transmission, we compared a minimized estimate for the average cost of RT with a maximized estimate for the average cost of UP per elective operation. The minimized estimate for RT (US$57) was greater than the maximized estimate for UP (US$36) per procedure. Results were stable or strengthened by sensitivity analysis. Routine HIV testing is not a valid economic alternative to UP for elective surgery. The simple methodology used in this study can be a preliminary strategy to review other strategies for preventing HIV transmission. This method is particularly useful when data are inadequate for a formal economic evaluation to determine the utility of collecting the detailed information necessary for a full comparison.