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Biomedical subjects

C Zhan

Publications and source records attributed to C Zhan.

At least 19 recordsLinked to original sources
PubMed2003

Administrative data based patient safety research: a critical review.

Administrative data are readily available, inexpensive, computer readable, and cover large populations. Despite coding irregularities and limited clinical details, administrative data supplemented by tools such as the Agency for Healthcare Research and Quality (AHRQ) patient safety indicators (PSIs) could serve as a screen for potential patient safety problems that merit further investigation, offer valuable insights into adverse impacts and risks of medical errors and, to some extent, provide benchmarks for tracking progress in patient safety efforts at local, state, or national levels.

Data Collection↗
PubMed2001

Potentially inappropriate medication use in the community-dwelling elderly: findings from the 1996 Medical Expenditure Panel Survey.

CONTEXT: Inappropriate medication use is a major patient safety concern, especially for the elderly population. Using explicit criteria, prior studies have found that 23.5% and 17.5% of the US community-dwelling elderly population used at least 1 of 20 potentially inappropriate medications in 1987 and 1992, respectively. OBJECTIVES: To determine the prevalence of potentially inappropriate medication use in community-dwelling elderly persons in 1996, to assess trends over 10 years, categorize inappropriate medication use according to explicit criteria, and to examine risk factors for inappropriate medication use. DESIGN, SETTING, AND PARTICIPANTS: Respondents aged 65 years or older (n = 2455) to the 1996 Medical Expenditure Panel Survey, a nationally representative survey of the US noninstitutionalized population were included. A 7-member expert panel was convened to categorize inappropriate medications. MAIN OUTCOME MEASURE: Prevalence of use of 33 potentially inappropriate medications. RESULTS: In 1996, 21.3% (95% confidence interval [CI], 19.5%-23.1%) of community-dwelling elderly patients in the United States received at least 1 of 33 potentially inappropriate medications. Using the expert panel's classifications, about 2.6% of elderly patients (95% CI, 2.0%-3.2%) used at least 1 of the 11 medications that should always be avoided by elderly patients; 9.1% (95% CI, 7.9%-10.3%) used at least 1 of the 8 that would rarely be appropriate; and 13.3% (95% CI, 11.7%-14.9%) used at least 1 of the 14 medications that have some indications but are often misused. Use of some inappropriate medications declined between 1987 and 1996. Persons with poor health and more prescriptions had a significantly higher risk of inappropriate medication use. CONCLUSIONS: Overall inappropriate medication use in elderly patients remains a serious problem. Despite challenges in using explicit criteria for assessing inappropriate medications for elderly patients, such criteria can be applied to population-based surveys to identify opportunities to improve quality of care and patient safety. Enhancements of existing data sources to include dosage, duration, and indication may augment national improvement and monitoring efforts.

Aged↗
PubMed2001

Patient Safety Indicators: using administrative data to identify potential patient safety concerns.

OBJECTIVE: To develop Patient Safety Indicators (PSI) to identify potential in-hospital patient safety problems for the purpose of quality improvement. DATA SOURCE/STUDY DESIGN: The data source was 2,400,000 discharge records in the 1997 New York State Inpatient Database. PSI algorithms were developed using systematic literature reviews of indicators and hand searches of the ICD-9-CM code book. The prevalence of PSI events and associations between PSI events and patient-level and hospital-level characteristics, length of stay, in-hospital mortality, and hospital charges were examined. PRINCIPAL FINDINGS: PSIs were developed for 12 distinct clinical situations and an overall summary measure. The 1997 event rates per 10,000 discharges varied from 1.1 for foreign bodies left during procedure to 84.7 for birth traumas. Discharge records with PSI events had twofold to threefold longer hospital stays, twofold to 20-fold higher rates of in-hospital mortality, and twofold to eightfold higher total charges than records without PSI events. Multivariate logistic regression revealed that PSI events were primarily associated with increasing age (p < .001), hospitals performing more inpatient surgery (p < .001), and hospitals with higher percentage of beds in intensive care units (p < .001). CONCLUSIONS: The PSIs provide an efficient and user-friendly tool to identify potential inhospital patient safety problems for targeted institution-level quality improvement efforts. Until better error-reporting systems are developed the PSIs can serve to shed light on the problem of medical errors not limited solely to mortality because of errors.

Adolescent↗
PubMed2000

Economic assessment of the community-acquired pneumonia intervention trial employing levofloxacin.

OBJECTIVE: The purpose of this study was to assess use of a critical pathway designed to manage community-acquired pneumonia more efficiently than its management with conventional therapy. METHODS: Economic outcomes were assessed in conjunction with a cluster-design, randomized, controlled trial. Nineteen participating Canadian hospitals were randomized to implement the critical pathway (n = 9) or conventional therapy (n = 10). The critical pathway included a clinical prediction rule to guide the admission decision, treatment with levofloxacin, and practice guidelines. Patient data on medical resource use, lost productivity, and quality of life were collected prospectively for > or =6 weeks after treatment. Costs were calculated from the government, health care system, and societal perspectives, with imputation of missing outpatient costs and the costs of lost productivity when necessary. Bootstrapping was used to identify 95% CIs for the total cost per patient. RESULTS: The analysis included all eligible patients in the critical pathway (n = 716) and conventional therapy (n = 1027) arms. There were fewer hospital admissions in the critical pathway arm than in the conventional therapy arm, both overall (46.5% vs 62.2%; P = 0.01) and in low-risk patients (33.2% vs 46.8%; P < 0.001). Compared with conventional therapy, hospitals in the critical pathway arm had 1.6 fewer bed days per patient managed (P = 0.05) and used fewer inpatient medical resources. The 2 study arms had similar outpatient, readmission, and lost-productivity costs, and similar quality-of-life outcomes. The critical pathway produced cost savings from all 3 perspectives that ranged from $457 to $994 per patient. CONCLUSIONS: The critical pathway employing levofloxacin resulted in cost savings compared with conventional therapy and did not compromise health outcomes.

Aged↗
PubMed2000

Induction of antibodies against GM2 ganglioside by immunizing melanoma patients using GM2-keyhole limpet hemocyanin + QS21 vaccine: a dose-response study.

In a previous randomized Phase III trial (P. O. Livingston et al, J. Clin. Oncol., 12: 1036-1044, 1994), we demonstrated that immunization with GM2 and bacille Calmette-Guerin reduced the risk of relapse in stage III melanoma patients who were free of disease after surgical resection and who had no preexisting anti-GM2 antibodies. That vaccine formulation induced IgM anti-GM2 antibodies in 74% but induced IgG anti-GM2 antibodies in only 10% of the patients. To optimize the immune response against GM2, a reformulated vaccine was produced conjugating GM2 to keyhole limpet hemocyanin (KLH) and using the adjuvant QS21 (GM2-KLH/QS21). In pilot studies, 70 microg of vaccine induced IgG anti-GM2 antibodies in 76% of the patients. We wished to define the lowest vaccine dose that induced consistent, high-titer IgM and IgG antibodies against GM2. Fifty-two melanoma patients who were free of disease after resection but at high risk for relapse were immunized with GM2-KLH/QS21 vaccine at GM2 doses of 1, 3, 10, 30, or 70 ILg on weeks 1, 2, 3, 4, 12, 24, and 36. Serum collected at frequent and defined intervals was tested for anti-GM2 antibodies. Overall, 88% of the patients developed IgM anti-GM2 antibodies; 71% also developed IgG anti-GM2 antibodies. GM2-KLH doses of 3-70 microg seemed to be equivalent in terms of peak titers and induction of anti-GM2 antibodies. At the 30-microg dose level, 50% of the patients developed complement fixing anti-GM2 antibodies detectable at a serum dilution of 1:10. We conclude that the GM2-KLH/QS21 formulation is more immunogenic than our previous formulation and that 3 microg is the lowest dose that induces consistent, high-titer IgM and IgG antibodies against GM2.

Adult↗
PubMed1998

[Study on the psychological status of video display terminal operator].

Occupational psychological test designed by the Labour Hygiene Department of West China University of Medical Sciences was applied to survey the mental health of 516 video display terminal (VDT) workers and 396 control workers in Chengdu. The results showed that mental health level of VDT workers was higher than that of controls. In the somatic disorder, anxious and hostile are increased obviously. With the prolonging of operating hours per week, somatic disorders, depression and obsession are increased, especially when VDT operating time is more than 30 hours per week and operating on VDT is more than ten years. This indicates that the operating hours should not be more than 30 hours per week. It is found by multiple factors analysis of data that the main adverse effects on mental health are age and VDT operating time.

Adolescent↗
PubMed1998

[Study on the relationship between occupational factors and work ability of middle aged workers].

Based on the assessment of work ability index (WAI) of middle aged workers, associations between occupational factors and work ability decline of middle aged workers were examined in a case-control study. 1037 workers (age ranged from 40 to 60) were included in the study. The study group comprised 180 workers of mean age 47.71 years representing those who's work ability decreased. The control group comprised 857 workers of mean age 47.22 years representing those who's work ability was on a normal level. Results showed that some common occupation hazards such as dusts, noise, vibration, humidity, and high temperature were more frequently occurred in work environment of the study group than that of the control group. High risks were found in workers with these hazards. Another significant risk factor of work ability decline was heavy physical load. Significantly elevated risks were observed for physical load perception(OR = 2.52), repetitive work (OR = 1.36), poor work postures(OR = 1.48), and carrying heavy loads(OR = 1.59). As compared to physical loads, mental loads were not in relation to work ability decline. The information about occupational factors affecting work ability will be helpful for redesiging the work for the middle aged workers.

Adult↗
PubMed1998

[Experimental study on the effect of abstinence with herbal preparation qingjunyin].

The effect of herbal preparation Qingjunyin (QJY) on the animal model of drug dependence was studied. After the morphinistic models of white rats and mice were made by ever increasing doses of morphine each time, the animals were divided into large dosage QJY group, small dosage QJY group, sustained morphine group and control group. The withdrawal symptoms were observed after naloxone was given to the animals intraperitoneally. The results showed that QJY groups withdrawal symptoms of the addicted white rats were alleviated, the number of jumps of the addicted mice was reduced, the scores of the principal symptoms of the animals were decreased, while the body weights of the animals were gained, comparing with the control group, the difference was significant (P < 0.01). The effects of QJY enhanced in the large dosage group, which suggests QJY has abstinence effects.

Animals↗
PubMed1997

[Effect of different Anti-G suits on lower limb blood flow].

To study effects of different Anti-G suits (AGS) and different inflation pressure on human cardiac system, changes in lower limb arterial blood flow (BF), heart rate and blood pressure in 5 male subjects with three bladder coverage AGS and a capstain AGS were observed and recorded until inflation pressure reached to its maximum. The percent of bladder coverage was about 30%, 65% and 90% of lower body for three bladder AGS. All AGS were inflated to maximum pressure in +1Gz seating position. The results showed that calf BF, could be blocked by bladder AGS, and the relationship between the mean pressure for BF block and the percentage of bladder coverage was y = 29.66 - 16.35x. (P < 0.0001, r = -0.9229). While the thigh and calf BF was not blocked in subjects with the capsule AGS. The results indicate that the effect of "the higher bladder coverage AGS + lower IP" is probably equal to that of "the lower bladder coverage AGS + higher IP" in holding calf BF.

Aerospace Medicine↗
PubMed1997

[Clinial study of "qingjunyin" detoxification for the treatment of heroin addicts].

To evaluate the efficacy of treatment of heroin addicts (n = 100) by "Qingjunyin" (QJY) detoxification (10 days program). Methadone detoxification (10 days program) group (n = 50) and colonidine treated group (n = 50) serve as controls. QJY group is given 180 ml P. O daily. The dosage of the two comparatine groups is given according to Documentation, the method of abserving the treatment protocols and detoxification standard is according to current regulation. The scores of abstinence syndrome in QJY detoxification group are lower than those in colonidine treated group in the first three days of potocol, but this difference disappear in the late stage of treatment. While QJY detoxification is effective as methadone detoxification in the control of abstinece syndrome during the first five days of treatment but the difference in the scores of abstinence syndrome between QJY and methadone group is observed during the late five days of protocol. QJY does not result in potential dependence and has definite curative effect in the treatment of heroin addiction.

Adolescent↗
PubMed1996

Crystallization and preliminary X-ray diffraction studies of recombinant staphylokinase.

Staphylokinase, a fibrin-specific plasminogen activator, was highly expressed in Escherichia coli and purified by ion-exchange and gel-filtration chromatography. The purified recombinant staphylokinase was fully active and readily crystallized against 1.2 M sodium citrate in 100 mM Tris-HCl buffer at pH 8.0 using the hanging-drop method. Crystals of staphylokinase diffract to better than 2.2 A resolution. The crystal belongs to the tetragonal space group P4(1)2(1)2 or its enantiomorph with unit-cell parameters a = b = 67.5, c = 150.1 A. There are two molecules in the asymmetric unit. In this paper, we described the first crystallization of a kind of plasminogen activator and present the results of preliminary X-ray diffraction data from the native protein.

Journal Article↗
PubMed1996

[Changes of superoxide dismutase and lipid peroxide in lung tissue of rats after intratracheal injection of crocidolite and benzo(a) pyrene].

Wistar rats were divided into 4 groups: control group, Cro group, B(a) p group and Cro plus B(a) p group. Samples of lung tissue were collected 90, 180, 270, 360 and 540 days after the third time of intratracheal. The superoxide dismutase (SOD) activity, the level of lipid peroxide (LPO) and the ratio of SOD/LPO were observed. The results indicated that there was a synergistic action of Cro. and B(a) p.

Animals↗
PubMed1995

[Some biochemical indexes in white rabbit's blood affected by acute high intensity microwave].

Irradiation of white rabbits by 10, 50, 100 and 200 mW/cm2 microwave respectively can cause the disorder of protein metabolism, the abnormality of blood sugar, and the change of the activity of serum alpha-hydroxybutyrate dehydrogenase, lactate dehydrogenase, glutamic oxalacetic transaminase, glutamic pyruvic transaminase, acid phosphatase ect. These changes can be used as indexes in the evaluation of the effect of acute high intensity microwave exposure. The effect on the organism mainly depends on the intensity of exposure provided the dose of microwave remains the same.

Acid Phosphatase↗
PubMed1995

The effects of hospital-physician integration strategies on hospital financial performance.

STUDY QUESTION: This study investigated the longitudinal relations between hospital financial performance outcomes and three hospital-physician integration strategies: physician involvement in hospital governance, hospital ownership by physicians, and the integration of hospital-physician financial relationships. DATA SOURCES AND STUDY SETTING: Using secondary data from the State of California, integration strategies in approximately 300 California short-term acute care hospitals were tracked over a ten-year period (1981-1990). STUDY DESIGN: The study used an archival design. Hospital performance was measured on three dimensions: operational profitability, occupancy, and costs. Thirteen control variables were used in the analyses: market competition, affluence, and rurality; hospital ownership; teaching costs and intensity; multihospital system membership; hospital size; outpatient service mix; patient volume case mix; Medicare and Medicaid intensity; and managed care intensity. DATA COLLECTION/EXTRACTION: Financial and utilization data were obtained from the State of California, which requires annual hospital reports. A series of longitudinal regressions tested the hypotheses. PRINCIPAL FINDINGS: Considerable variation was found in the popularity of the three strategies and their ability to predict hospital performance outcomes. Physician involvement in hospital governance increased modestly from 1981-1990, while ownership and financial integration declined significantly. Physician governance was associated with greater occupancy and higher operating margins, while financial integration was related to lower hospital operating costs. Direct physician ownership, particularly in small hospitals, was associated with lower operating margins and higher costs. Subsample analyses indicate that implementation of the Medicare prospective payment system in 1983 had a major impact on these relationships, especially on the benefits of financial integration. CONCLUSIONS: The findings support the validity of hospital-physician financial integration efforts, and to a lesser extent the involvement of physicians in hospital governance. The results lend considerably less support for strategies built around direct physician ownership in hospitals, particularly since PPS implementation. RELEVANCE/IMPACT: These findings challenge prior studies that found few financial benefits to hospital-physician integration prior to PPS implementation in 1983. The results imply that financial benefits of integration may take several years after implementation to emerge, are most salient in a managed care or managed competition environment, and vary by hospital size and multihospital system membership.

Analysis of Variance↗
PubMed1995

[A study on human dental embryology in an endemic high fluorosis region].

In a high endemic fluorosis area in Guizhou, China, 40 human fetuses delivered by induced abortion during the 5th-8th month of gestation were utilized to study dental embryonic samples under transmission electron microscope (TEM). Compared with normal controls, ultrastructure findings in the ameloblast cell organs include swelling of mitochondria, enlargement of SER, increase in RNA granules and RER. This study suggests that the irregularities of the collagenous fibers and crystallites are due to the maldevelopment of the ameloblast Tome's processes, which explains the mechanism of motteled enamel.

Ameloblasts↗
PubMed1994

[Comparative study on hemolytic toxicity of trifluoroacetoprimaquine and primaquine in rabbits].

5-trifluoroacetoprimaquine (M8506) exhibited high effect on tissue schizont of P. cynomolgi and low toxicity in mice, rats and dogs as compared with primaquine (PQ) according to our previous studies. In order to determine their hemolytic toxicity, we dosed rabbits with M8506 and PQ at a dose of 40 mg/kg per day for 4 days, respectively. Blood samples were drawn from the ear vein of the rabbits for determining of the following parameters, ie. methemoglobin (metHb), reticulocyte (ret) and Heinzbody (Hbd) on d0 before treatment and on d3, d5, d7, d10, d14 and d21 after treatment. The results showed that after drug administration the levels of metHb, ret and Hbd in PQ group increased on d3-d5, and reached their peak levels on d7-d10, and then declined gradually from d10-d14. The mean percentage concentration of metHb, mean count of ret and Hbd in PQ group on d7 after medication were 22.1 +/- 21.8%, 92.0 +/- 88.0/1,000 RBC and 203.8 +/- 126.7/1,000 RBC, which were significantly higher than those of the control (8.2 +/- 5.3%, 37.5 +/- 16.2/1,000 RBC and 57.4 +/- 45.1/1,000 RBC). In M8506 group, the mean Hbd count (196.3 +/- 123.1/1,000 RBC, on d7 after treatment was also higher than that of the controls, but its mean metHb percentage concentration (10.8 +/- 8.9%) and mean ret count (42.2 +/- 20.3/1,000 RBC) were similar to those of the controls (P > 0.05). The results suggested that the hemolytic toxicity induced by M8506 in rabbits might be similar to or even lower than that induced by PQ.

Anemia, Hemolytic↗