Biomedical subjects

J Erdos

Publications and source records attributed to J Erdos.

8 recordsLinked to original sources

PubMed2000

Using a computer database to monitor compliance with pharmacotherapeutic guidelines for schizophrenia.

OBJECTIVE: The study examined whether prescription data from a computerized database could be used to measure conformance with treatment recommendations of the Schizophrenia Patient Outcomes Research Team (PORT). METHODS: Records of an academically affiliated Veterans Affairs medical center were reviewed to identify patients who were hospitalized for schizophrenia and later seen for at least two outpatient visits in the six months after discharge (N=353). RESULTS: Conformance with only three of the 18 PORT pharmacotherapeutic recommendations could be measured with the available data. In regard to the recommendation to use antipsychotics other than clozapine as first-line treatments in acute episodes, 77 percent of the sample filled a prescription for an antipsychotic during the acute episode. Of these, only 6 percent received an antipsychotic regimen that included clozapine. In regard to the PORT recommendation on dosage during acute symptom episodes, 42 percent of the patients on conventional antipsychotics received dosages below the recommended range, 5 percent were above the range, and 53 percent were within it. In contrast, of the 53 patients who received clozapine or risperidone, 87 percent received prescriptions within the recommended dosage range. As for the recommendation to offer a trial of clozapine to patients who do not respond to adequate trials of two different classes of conventional drugs, 10 percent of patients who were switched from conventional regimens to clozapine were receiving dosages of conventional medications below the recommended range. CONCLUSIONS: Patient prescription data can provide preliminary measures to cost-effectively assess conformance with treatment. However, the approach has several limitations, and complementary analyses would enhance its usefulness.

Aged↗

PubMed1999

Cost-effectiveness of clozapine in patients with high and low levels of hospital use. Department of Veterans Affairs Cooperative Study Group on Clozapine in Refractory Schizophrenia.

BACKGROUND: This study examined the relationship between pretreatment hospital use and the cost-effectiveness of clozapine in the treatment of refractory schizophrenia. METHODS: Data from a 15-site randomized clinical trial were used to compare clozapine with haloperidol in hospitalized Veterans Affairs patients with refractory schizophrenia (n = 423). Outcomes were compared among those with many days in the hospital use (hereafter, high hospital users) (n = 141; mean = 215 psychiatric hospital days in the year prior to study entry) and those with few days in the hospital use (hereafter, low hospital users) (n = 282; mean = 58 hospital days). Analyses were conducted with the full intention-to-treat sample (n = 423) and with crossovers excluded (n = 291). RESULTS: Clozapine treatment resulted in greater reduction in hospital use among high hospital users (35 days less than controls, P = .02) than among low users (21 days less than controls, P = .05). Patients taking clozapine also had lower health care costs; after including the costs of both medications and other health services, costs were $7134 less than for controls among high hospital users (P = .14) but only $759 less than for controls among low hospital users (P = .82). Clinical improvement in the domains of symptoms, quality of life, extrapyramidal symptoms, and a synthetic measure of multiple outcomes favored clozapine in both high and low hospital user groups. CONCLUSIONS: Substantial 1-year cost savings with clozapine are observed only among patients with very high hospital use prior to initiation of treatment while clinical benefits are more similar across groups. Cost-effectiveness evaluations, and particularly studies of expensive treatments, cannot be generalized across type of use groups.

Adult↗

PubMed1997

Possible association of a polymorphism of the tryptophan hydroxylase gene with suicidal behavior in depressed patients.

OBJECTIVE: This study was designed to test the hypothesis that serotonin-system-related genes may be correlated with suicide risk. METHOD: Fifty-one unrelated Caucasian inpatients with major depression, with or without a history of suicidal acts, were genotyped for a biallelic polymorphism at the tryptophan hydroxylase locus. RESULTS: The less common tryptophan hydroxylase U allele occurred with greater frequency in the patients who had attempted suicide. A logistic regression analysis confirmed an association between tryptophan hydroxylase genotype and lifetime history of suicide attempts. CONCLUSIONS: Serotonergic-system-related genes may influence the risk of suicide in persons with major depression.

Adult↗

PubMed1996

Single photon emission computerized tomography imaging of amphetamine-induced dopamine release in drug-free schizophrenic subjects.

The dopamine hypothesis of schizophrenia proposes that hyperactivity of dopaminergic transmission is associated with this illness, but direct observation of abnormalities of dopamine function in schizophrenia has remained elusive. We used a newly developed single photon emission computerized tomography method to measure amphetamine-induced dopamine release in the striatum of fifteen patients with schizophrenia and fifteen healthy controls. Amphetamine-induced dopamine release was estimated by the amphetamine-induced reduction in dopamine D2 receptor availability, measured as the binding potential of the specific D2 receptor radiotracer [123I] (S)-(-)-3-iodo-2-hydroxy-6-methoxy-N-[(1-ethyl-2-pyrrolidinyl) methyl]benzamide ([123I]IBZM). The amphetamine-induced decrease in [123I]IBZM binding potential was significantly greater in the schizophrenic group (-19.5 +/- 4.1%) compared with the control group (-7.6 +/- 2.1%). In the schizophrenic group, elevated amphetamine effect on [123I]IBZM binding potential was associated with emergence or worsening of positive psychotic symptoms. This result suggests that psychotic symptoms elicited in this experimental setting in schizophrenic patients are associated with exaggerated stimulation of dopaminergic transmission. Such an observation would be compatible with an abnormal responsiveness of dopaminergic neurons in schizophrenia.

Adult↗

PubMed1988

International social security agreements: the U.S. experience.

International social security agreements are advantageous both for persons who are working now and for those whose working careers are over. For current workers, the agreements eliminate the dual contributions they might otherwise be paying to the social security systems of both the United States and another country. They also favorably affect the profitability and competitive position of American companies with foreign operations by reducing their cost of doing business. For persons who have worked both in the United States and abroad, and who are now retired, disabled, or deceased, the agreements often result in the payment of benefits to which the worker or the worker's family members would not otherwise have become entitled. Credit for social security coverage the worker earned in the United States and the other country can be combined, if necessary, to meet eligibility requirements, and partial benefits can be paid by one or both countries. Because international social security agreements benefit both workers and employers, the agreements program is supported by organized labor and the international business community. Since the first agreement was signed 15 years ago, every Presidential administration has endorsed the program. In view of this support, and the fact that the agreements enhance the image of the United States as a socially progressive member of the international community, it is expected that totalization agreements will be concluded with additional countries in the future.

Emigration and Immigration↗

PubMedDate not supplied

Software balancing of multiple detectors during CT scanning.

The general requirements for balancing of detectors in a multiple detector CT scanner are discussed, and the specific requirements for software balancing using data acquired within the body section during the scan are outlined. A particular technique which can be implemented in a scanner employing a simultaneous translation and rotation of the source/detector package is presented. The technique produces an exact balancing offset and gain factors, to within accuracy limits imposed by the statistical uncertainty due to noise in the measurements. However, the technique admits a redundancy of solutions with allows the statistical sample to be expanded to include virtually all data acquired during the scan, thereby suppressing detector imbalance artifacts to the same level as overall quantum noise in the image.

Technology, Radiologic↗

PubMedDate not supplied

Exploring the degree of concordance of coded and textual data in answering clinical queries from a clinical data repository.

OBJECTIVE: To query a clinical data repository (CDR) for answers to clinical questions to determine whether different types of fields (coded and free text) would yield confirmatory, complementary, or conflicting information and to discuss the issues involved in producing the discrepancies between the fields. METHODS: The appropriate data fields in a subset of a CDR (5,135 patient records) were searched for the answers to three questions related to surgical procedures. Each search included at least one coded data field and at least one free-text field. The identified free-text records were then searched manually to ensure correct interpretation. The fields were then compared to determine whether they agreed with each other, were supportive of each other, contained no entry (absence of data), or were contradictory. RESULTS: The degree of concordance varied greatly according to the field and the question asked. Some fields were not granular enough to answer the question. The free-text fields often gave an answer that was not definitive. Absence of data was most logically interpreted in some cases as lack of completion of data and in others as a negative answer. Even with a question as specific as which side a hernia was on, contradictory data were found in 5 to 8 percent of the records. CONCLUSIONS: Using the data in the CDR to answer clinical questions can yield significantly disparate results depending on the question and which data fields are searched. A database cannot just be queried in automated fashion and the results reported. Both coded and textual fields must be searched to obtain the fullest assessment. This can be expected to result in information that may be confirmatory, complementary, or conflicting. To yield the most accurate information possible, final answers to questions require human judgment and may require the gathering of additional information.

Hernia, Ventral↗

PubMedDate not supplied

Exploring performance issues for a clinical database organized using an entity-attribute-value representation.

BACKGROUND: The entity-attribute-value representation with classes and relationships (EAV/CR) provides a flexible and simple database schema to store heterogeneous biomedical data. In certain circumstances, however, the EAV/CR model is known to retrieve data less efficiently than conventionally based database schemas. OBJECTIVE: To perform a pilot study that systematically quantifies performance differences for database queries directed at real-world microbiology data modeled with EAV/CR and conventional representations, and to explore the relative merits of different EAV/CR query implementation strategies. METHODS: Clinical microbiology data obtained over a ten-year period were stored using both database models. Query execution times were compared for four clinically oriented attribute-centered and entity-centered queries operating under varying conditions of database size and system memory. The performance characteristics of three different EAV/CR query strategies were also examined. RESULTS: Performance was similar for entity-centered queries in the two database models. Performance in the EAV/CR model was approximately three to five times less efficient than its conventional counterpart for attribute-centered queries. The differences in query efficiency became slightly greater as database size increased, although they were reduced with the addition of system memory. The authors found that EAV/CR queries formulated using multiple, simple SQL statements executed in batch were more efficient than single, large SQL statements. CONCLUSION: This paper describes a pilot project to explore issues in and compare query performance for EAV/CR and conventional database representations. Although attribute-centered queries were less efficient in the EAV/CR model, these inefficiencies may be addressable, at least in part, by the use of more powerful hardware or more memory, or both.

Database Management Systems↗