Turn down - turn up: a simple and low-cost protocol for preparing platelet-rich plasma

OBJECTIVE: To describe and analyze a new protocol for the extraction of platelet-rich plasma (PRP) for use in clinical practice and compare this technique with methods that have been previously described in the medical literature. METHODS: We extracted PRP from 20 volunteers using four different protocols (single spin at 1600 ×g, single spin at 600 ×g, double spin at 300 and 700 ×g, and double spin at 600 and 900 ×g). In another group of 12 individuals, we extracted PRP with our new technique (named 'turn down-turn up') consisting of a double spin (200 ×g and 1600 ×g) closed system using standard laboratory equipment (including an ordinary benchtop centrifuge), where the blood remained in the same tube during all processes, reducing the risk of contamination. Platelet counts adjusted to baseline values were compared using analysis of covariance (ANCOVA). RESULTS: Using the four previously described protocols (mentioned above), we obtained concentrations of platelets that were 1.15-, 2.07-, 2.18-, and 3.19-fold greater than the baseline concentration, respectively. With the turn down-turn up technique, we obtained a platelet count that was 4.17-fold (95% confidence interval (CI): 3.09 to 5.25) greater than the baseline platelet count (p=0.063 compared with the double spin at 600 and 900 ×g method). The total cost of the disposable materials used in the extraction process was less than US$10.00 per individual. CONCLUSION: In the present study, we described a simple and safe method for obtaining PRP using low-cost devices.

Costs of examinations performed in a hospital laboratory in Chile / Custos de exames em um laboratório clínico hospitalar no Chile / Costos de exámenes en un laboratorio clínico hospitalario de Chile

ABSTRACT Objective: To determine the total average costs related to laboratory examinations performed in a hospital laboratory in Chile. Method: Retrospective study with data from July 2014 to June 2015. 92 examinations classified in ten groups were selected according to the analysis methodology. The costs were estimated as the sum of direct and indirect laboratory costs and indirect institutional factors. Results: The average values obtained for the costs according to examination group (in USD) were: 1.79 (clinical chemistry), 10.21 (immunoassay techniques), 13.27 (coagulation), 26.06 (high-performance liquid chromatography), 21.2 (immunological), 3.85 (gases and electrolytes), 156.48 (cytogenetic), 1.38 (urine), 4.02 (automated hematological), 4.93 (manual hematological). Conclusion: The value, or service fee, returned to public institutions who perform laboratory services does not adequately reflect the true total average production costs of examinations.

RESUMO Objetivo: Determinar os custos médios totais associados à realização de exames laboratoriais em um laboratório clínico hospitalar no Chile. Método: Estudo retrospectivo com informações de julho de 2014 a junho de 2015. Foram selecionados 92 exames classificados em dez grupos de acordo com a metodologia de análise. Os custos foram estimados como a soma dos custos diretos e indiretos de laboratório e fatores institucionais indiretos. Resultados: Os valores médios dos custos foram obtidos de acordo com o grupo de exames (em dólares): 1,79 (química clínica), 10,21 (técnicas de imunoensaio), 13,27 (coagulação), 26,06 (cromatografia líquida de alta resolução), 21,2 (imunológicos), 3,85 (gases e eletrólitos), 156,48 (citogenéticos), 1,38 (urina), 4,02 (hematológicos automáticos), 4,93 (hematológicos manuais). Conclusão: O valor retornado às instituições públicas, ou taxas de serviço, que prestam serviços laboratoriais não refletem adequadamente os custos totais reais da produção de exames.

RESUMEN Objetivo: determinar los costos medios totales asociados a la realización de exámenes de laboratorio en un laboratorio clínico hospitalario de Chile. Método: estudio retrospectivo con información del período julio 2104 a junio 2015. Se seleccionaron 92 exámenes clasificados en diez grupos según la metodología de análisis. Los costos se estimaron como la suma de costos directos e indirectos de laboratorio y factores indirectos institucionales. Resultados: se obtuvieron los valores promedio para los costos según grupo de exámenes (en dólares): 1,79 (química clínica), 10,21 (técnicas de inmunoensayos), 13,27 (coagulación), 26,06 (cromatografía líquida de alta resolución), 21,2 (inmunológicos), 3,85 (gases y electrolitos), 156,48 (citogenéticos), 1,38 (orina), 4,02 (hematológicos automatizados), 4,93 (hematológicos manuales). Conclusión: el valor que retorna a las instituciones públicas, o arancel por servicio, que prestan servicios de laboratorio no refleja adecuadamente los verdaderos costos medios totales de producción de exámenes.

Budgetary impact of diagnostic tests for visceral leishmaniasis in Brazil / Impacto orçamentário dos testes diagnósticos para leishmaniose visceral no Brasil / Impacto presupuestario de las pruebas diagnósticas para la leishmaniosis visceral en Brasil

Abstract: The aim of the present study was to estimate the financial costs of the incorporation and/or replacement of diagnostic tests for human visceral leishmaniasis (VL) in Brazil. The analysis was conducted from the perspective of the Brazilian Unified National Health System (SUS) over a period of three years. Six diagnostic tests were evaluated: the indirect immunofluorescence antibody test (IFAT), the IT LEISH rapid test, the parasitological examination of bone marrow aspirate, the direct agglutination test (DAT-LPC) standardized in the Clinical Research Laboratory, René Rachou Institute of the Oswaldo Cruz Foundation, the Kalazar Detect rapid test, and polymerase chain reaction (PCR). The assumptions used were the number of suspected cases of VL reported to the Brazilian Ministry of Health in 2014 and the direct cost of diagnostic tests. The costs to diagnose suspected cases of VL over three years using the IFAT and the DAT-LPC were estimated at USD 280,979.91 and USD 121,371.48, respectively. The analysis indicated that compared with the use of the IFAT, the incorporation of the DAT-LPC into the SUS would result in savings of USD 159,608.43. With regard to the budgetary impact of rapid tests, the use of IT LEISH resulted in savings of USD 21.708,72 over three years. Compared with a parasitological examination, diagnosis using PCR resulted in savings of USD 3,125,068.92 over three years. In this study, the replacement of the IFAT with the DAT-LPC proved financially advantageous. In addition, the replacement of the Kalazar Detect rapid test with the IT LEISH in 2015 was economically valuable, and the replacement of parasitological examination with PCR was indicated.

Resumo: O estudo teve como objetivo estimar os custos financeiros da incorporação e/ou substituição dos testes diagnósticos para a leishmaniose visceral (LV) humana no Brasil. A análise foi realizada na perspectiva do Sistema Único de Saúde (SUS) ao longo de três anos. Foram avaliados seis testes diagnósticos: reação de imunofluorescência indireta (RIFI), teste rápido IT LEISH, exame parasitológico de aspirado de medula óssea, teste de aglutinação direta DAT-LPC padronizado pelo Laboratório de Pesquisas Clínicas do Instituto René Rachou, Fundação Oswaldo Cruz, teste rápido Kalazar Detect e reação em cadeia da polimerase (PCR). Os parâmetros utilizados foram o número de casos suspeitos de LV notificados ao Ministério da Saúde em 2014 e o custo direto dos testes diagnósticos. Os custos do diagnóstico de casos suspeitos de LV ao longo de três anos usando o RIFI e DAT-LPC foram estimados em USD 280.979,91 e USD 121.371,48, respectivamente. De acordo com a análise, comparado ao uso do RIFI, a incorporação do DAT-LPC pelo SUS resultaria numa economia de USD 159.608,43. Com relação ao impacto dos testes rápidos, o uso do IT LEISH resultou em economia de USD 21.708,72 ao longo de três anos. Comparado ao exame parasitológico, o diagnóstico com PCR resultou em economia de USD 3.125.068,92 ao longo de três anos. Neste estudo, a substituição do RIFI pelo DAT-LPC mostrou ser financeiramente vantajosa. Além disso, a substituição do teste rápido Kalazar Detect com o IT LEISH em 2015 foi economicamente apropriada, e a substituição do exame parasitológico pela PCR está economicamente indicada.

Resumen: El objetivo del estudio fue estimar los costes financieros de la incorporación y/o sustitución de las pruebas diagnósticas para la leishmaniasis visceral (LV) humana en Brasil. El análisis se realizó desde la perspectiva del Sistema Único de Salud (SUS) a lo largo de tres años. Se evaluaron seis pruebas diagnósticas: reacción de inmunofluorescencia indirecta (RIFI), test rápido IT LEISH, examen parasitológico de aspirado de medula ósea, test de aglutinación directa DAT-LPC, estandarizado por el Laboratorio de Investigación Clínica del Centro de Investigación René Rachou, Fundación Oswaldo Cruz, test rápido Kalazar Detect y la reacción en cadena de la polimerasa (PCR). Los parámetros utilizados fueron el número de casos sospechosos de LV notificados al Ministerio de Salud en 2014 y el coste directo de los test diagnósticos. Los costes del diagnóstico de casos sospechosos de LV a lo largo de tres años, usando el RIFI y DAT-LPC, se estimaron en USD 280.979,91 y USD 121.371,48, respectivamente. De acuerdo con el análisis, comparado con el uso del RIFI, la incorporación del DAT-LPC por el SUS resultaría en un ahorro de USD 159.608,43. En relación con el impacto de los test rápidos, el uso del IT LEISH aportaba un ahorro de USD 21.708,72 a lo largo de tres años. Comparado con el examen parasitológico, el diagnóstico con PCR suponía un ahorro de USD 3.125.068,92 a lo largo de tres años. De acuerdo con el estudio, la sustitución del RIFI con el DAT-LPC mostró ser financieramente ventajosa. Asimismo, la sustitución del test rápido Kalazar Detect con el IT LEISH en 2015 representó un ahorro económico, y los resultados favorecieron la sustitución del examen parasitológico con PCR.

Impacto económico de la resistencia a la meticilina en pacientes con bacteriemia por Staphylococcus aureus en hospitales de Bogotá / Economic burden of methicillin-resistant Staphylococcus aureus bacteremia in critical care patients in hospitals in Bogotá

Introducción. Las infecciones por microorganismos resistentes, especialmente las que involucran el torrente sanguíneo, se asocian a un mayor uso de recursos. Sus estimaciones son variables y dependen de la metodología utilizada. Staphylococcus aureus es el agente de sangre aislado con mayor frecuencia en nuestro medio. No existe información sobre el costo asociado con la atención de bacteriemias por S. aureus resistente a meticilina en nuestro país. Objetivo. Presentar una aproximación del costo de atención de las bacteriemias por S. aureus resistente a la meticilina en nueve hospitales de Bogotá. Materiales y métodos. Se incluyeron 204 pacientes en un estudio de cohortes multicéntrico en una razón de 1:1 según la resistencia. Se aproximaron los costos médicos directos con base en las facturas del período de hospitalización; en cuanto al período de la bacteriemia, los costos detallados se calcularon aplicando las tarifas estandarizadas. Resultados. No se encontraron diferencias significativas en las características clínicas y demográficas de los grupos, salvo en los antecedentes de la bacteriemia. El 53 % de los sujetos falleció durante la hospitalización. La estancia y el valor total facturado por la hospitalización fueron significativamente mayores en el grupo con bacteriemia por S. aureus resistente a la meticilina, así como los costos de la estancia en cuidados intensivos, de los antibióticos, los líquidos parenterales, los exámenes de laboratorio y la terapia respiratoria. El incremento crudo del costo de la atención asociado con la resistencia a meticilina fue de 31 % y, el ajustado, de 70 %. Conclusión. Este estudio constituye un respaldo a los tomadores de decisiones para la búsqueda y la financiación de programas de prevención de infecciones causadas por microorganismos resistentes.

Introduction: Resistant infections, especially those involving the bloodstream, are associated with a greater use of resources. Their estimates are variable and depend on the methodology used. Staphylococcus aureus is the main pathogen isolated in blood in our hospitals. There is no consolidated data about economic implications of methicillin-resistant S. aureus infection. Objective: To describe the cost of care of methicillin-resistant S. aureus bacteremia in a reference population from nine hospitals in Bogotá. Materials y methods: A multicenter cohort study included 204 patients in a 1:1 ratio according to resistance. Direct medical costs were calculated from hospitalization bills, while the bacteremia period was calculated by applying microcosting based on standard fares. Results: We found no significant differences between groups in demographic and clinical characteristics, except for resistance risk factors. Fifty-three percent of patients died during hospitalization. Hospital stay and total invoiced value during hospitalization were significantly higher in the group with methicillin-resistant S. aureus bacteremia. For this group, higher costs in ICU stay, antibiotics use, intravenous fluids, laboratory tests and respiratory support were recorded. A crude increase of 31% and an adjusted increase of 70% in care costs associated with methicillin resistance were registered. Conclusion: Our study supports decision makers in finding and funding infection prevention programs, especially those infections caused by resistant organisms.

Development of a new method for diagnosis of Group B Coxsackie genome by reverse transcription loop-mediated isothermal amplification.

Background: Coxsackie B viruses (genus, Enterovirus; family, Picornaviridae) can cause aseptic meningitis, encephalitis, pleurodynia, and fatal myocarditis, and are implicated in the pathogenesis of dilated cardiomyopathy. The differentiation of the group B Coxsackieviruses into their subtypes has potential clinical and epidemiological implications. Objective: In this study, we developed a one-step, single-tube genogroup-specific reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of group B Coxsackie genomes targeting 5′ UTR region. Materials and Methods: The amplification can be obtained in less than 1 hour by incubating all the reagents in a single tube with reverse transcriptase and Bst DNA polymerase at 63°C. Detection of gene amplification could be accomplished by agarose gel electrophoresis and the monitoring of gene amplification can also be visualised with the naked eye by using SYBR green I fluorescent dye. Results: A total of 40 samples comprising 31 positive samples and 9 negative samples were used in this study for comparative evaluation. The results were compared with those from Real-Time Polymerase Chain Reaction (RT-PCR). None of the RT-PCR-positive samples were missed by RT-LAMP, thereby indicating a higher sensitivity of the RT-LAMP assay. Conclusion: Thus, due to easy operation without a requirement of sophisticated equipment and skilled personnel, the RT-LAMP assay reported here is extremely rapid, cost-effective, highly sensitive, and specific and has potential usefulness for rapid detection of non-polio enterovirus (NPEV) not only by well-equipped laboratories but also by peripheral diagnostic laboratories with limited financial resources in developing countries.

Use of "Parasep filter fecal concentrator tubes" for the detection of intestinal parasites in stool samples under routine conditions.

Parasitic gastrointestinal infections are a major cause of morbidity and mortality in the developing world, with stool microscopy being the mainstay of diagnostic practice. Both direct microscopy and concentration techniques can be utilized; direct microscopy may be time consuming and tedious; however clinical laboratories in developing countries lack trained staff who can effectively use concentration methods. In our practice we used the Parasep O and P filter concentrator tubes (manufactured by DiaSys Ltd, Berkshire, England. Product Code 146000) along with direct microscopic techniques and found that Parasep filters enhanced the ability to detect intestinal parasites that would have been missed on routine microscopy. We found the Parasep filter concentration method to be easy, cost-effective and reliable for routine stool examinations.

Significance and cost effectiveness of pre-operative routine laboratory investigations in young healthy patients undergoing elective ear, nose and throat surgery

Pre-operative preparation is an important component of surgical workup. Adequate clinical assessment to determine fitness for anaesthesia and surgery and to outrule possibilities of existing disease or risk factors against the procedure would suffice in elective surgery on healthy young patients. Still routine investigations are carried out following a protocol, that does not offer added benefit and is not cost effective. We evaluated one hundred and fifty young healthy patients planned for elective surgery, to compare adequate clinical assessment with results of routine investigations in such patients, in terms of significance and cost effectiveness. Significant co-relation was demonstrated between clinical assessment and routine investigations. Only 03 abnormal results were reported following 600 laboratory investigations on 150 patients. Thorough clinical assessment is mandatory for successful outcome of surgery. There is significant co-relation with routine investigations in elective Ear, Nose and Throat [ENT] surgery. Investigations should be restricted to where indicated by clinical assessment. Such policy will significantly reduce the costs and workload, thereby improving quality of health care system

Survey Results of Medical Insurance Reimbursement System for Independent Medical Laboratories in Korea / 대한진단검사의학회지

BACKGROUND: A questionnaire survey was performed to perceive the problem of the current medical insurance reimbursement system for laboratory tests referred to independent medical laboratories; then, we intended to find a way to improve the reimbursement system. METHODS: Questionnaires were distributed to 220 independent medical laboratories and 700 laboratory physicians from July through October 2005. Frequency analysis was used to analyse the replies from 109 respondents to 25 questionnaire items regarding the current medical insurance reimbursement system for referral tests, problems with the system, and suggestions for the improvement of the system. RESULTS: Among the 109 respondents to this survey, 49 (45.8%) considered the current reimbursement system to be unsatisfactory, while only 16 (15.0%) answered satisfactory. The problem was that the referral clinics-not the laboratories that performed the tests--would first receive their reimbursement for the laboratory tests from Health Insurance Review Agency (HIRA) and then give a portion of the laboratory test fees to the independent medical laboratories after the deduction of administrative fees. They (62.5% of the respondents) would prefer a separated reimbursement system by which the referral clinic-as well as the independent medical laboratory-would receive their reimbursement directly from HIRA through an Electronic Data Interchange (EDI) system. In this new system, 34% of the respondents expected the quality of the laboratory tests to be improved; however, 41.6% answered that the income of the referral clinic is expected to decrease. CONCLUSIONS: For the improvement of the medical insurance reimbursement system, the administrative fee for the referral clinic and the test fee for the independent medical laboratory should be reimbursed directly to the respective organizations. These changes could be made possible with the proper analysis of medical costs and the development of an effective EDI reimbursement system.

Seis sigma no laboratório clínico: impacto na gestão de performance analítica dos processos técnicos / Six sigma in clinical laboratory: impact in analytical performance management of technical process

INTRODUÇAO: A visão Seis Sigma da qualidade constitui uma nova ferramenta para o laboratório clínico, objetivando conjugar qualidade de desempenho de processos à gestão de custos. OBJETIVOS: Verificar a viabilidade e o impacto da utilização de conceitos Seis Sigma na gestão de processos técnicos em laboratório clínico. MATERIAIS E MÉTODOS: Foi realizado um estudo comparativo para 14 parâmetros básicos de bioquímica em dois sistemas automatizados, Bayer ADVIA 1650 e Ortho-Clinical Diagnostics VITROS 950, comparando-os em termos de performance analítica com a utilização de métrica sigma, calculada frente a diferentes especificações de desempenho. Resultados: Para ambos os equipamentos avaliados, as maiores métricas foram obtidas para triglicérides (TG) e ácido úrico, nas especificações do Clinical Laboratory Improvement Amendments (CLIA) e baseadas em variação biológica. As menores métricas foram obtidas para as transaminases (AST e ALT) no ADVIA 1650 e para cloretos no VITROS 950. Esses resultados estão em função direta da magnitude das especificações utilizadas no cálculo da métrica sigma. DISCUSSAO: Os resultados mostraram tendência a melhores índices de performance nos testes realizados no equipamento VITROS 950 em relação aos do ADVIA 1650. A definição do limite de especificação a ser utilizado para cálculo da métrica sigma se mostrou essencial para a adequada avaliação de desempenho analítico dos testes laboratoriais. CONCLUSÕES: A utilização da métrica sigma como índice de performance dos processos técnicos no laboratório clínico proporciona a padronização de um sistema de controle de qualidade custo-efetivo, alinhando qualidade e metas de custo, com foco na satisfação dos clientes e na saúde financeira da organização.

Economical choices in setting up a diagnostic myeloma laboratory.

In setting up a diagnostic myeloma laboratory the popular, highly automated and otherwise excellent choices of equipment and laboratory practices, so exorbitantly raise costs that the sustainability, even in large government hospitals in third world countries may become difficult. Based on our experience in a regional cancer center in India, we offer here, guidelines for carrying out high resolution electrophoresis, densitometry, immunofixation and urine concentration. We show that by simply employing well established techniques and doing them properly, one can get results of excellent quality at minimum cost and minimum dependence on costly imports.

Cost analysis of laboratory tests: a study of the Central Laboratory of King Chulalongkorn Memorial Hospital.

OBJECTIVES: To present cost analysis on laboratory management of laboratory tests provided by the Central Laboratory of King Chulalongkorn Memorial Hospital (KCMH). MATERIAL AND METHOD: The expenditure and income of the laboratory were studied using a descriptive design. RESULTS: The Central Laboratory provided routine hematology, urinalysis, and chemistry tests, and performed 2,157,275 tests in year 2002. The expenditure of the Central Laboratory was 32,094,960.24 baht, while the income was 97,393,244.40 baht. The average calculated profitability ratio for all parameters was 3.03. CONCLUSION: The authors concluded that the Central Laboratory is a good Revenue Producing Cost Center (RPCC) for the hospital. To improve the laboratory efficiency, the data needed for laboratory management should be easily available to the laboratory manager. In addition, the authors strongly suggest that the organization structure and the data management system of the hospital and the faculty should be simplified for future management. In addition, all laboratories should perform their own cost analysis.

Value of clinical features in the diagnosis of enteric fever.

There is no objective data on the value of individual clinical symptoms or signs in the diagnosis of enteric fever in a febrile patient. The purpose of the study was to assess the value of some clinical and simple laboratory features in the diagnosis of enteric fever. One hundred & six patients with microbiologically confirmed enteric fever and 170 patients with other established febrile illnesses were included in the evaluation. History of stepladder pattern of rise of temperature, loose motions, relative bradycardia and coated tongue proved to be powerful markers of enteric fever with high specificity (100%, 94.71%, 94.71%, 94.12% respectively), positive and negative predictive values. Headache, hepatomegaly and splenomegaly were moderately powerful. ESR and WBC count appeared to have little value in the diagnosis of enteric fever. Pattern of onset and loose motions did not discriminate between typhoid and paratyphoid fever. Most of these patients had illness persisting beyond one week by which viral infections and infectious enterocolitides were largely excluded. Elucidation of power of these markers in distinguishing enteric fever from other febrile illnesses with the help of better designed prospective studies would lessen our dependence on expensive and time consuming laboratory investigations.

Estudo dos custos unitários de análises bioquímicas realizadas por processo manual / A method to get unitary costs in a manual laboratory analysis

O presente trabalho, tem como objetivo criar uma metodologia para apuração de custos unitários em análises clínicas. Esta metodologia refere-se ao custo de uma análise bioquímica manual, porém, serve de exemplo para as demais áreas. Trata-se portanto, de um trabalho metodológico, isto é, que se propõe a elaborar métodos e não apurar resultados.

Laboratory investigation utilization in pediatric out-patient department Ramathibodi Hospital.

HYPOTHESES: Laboratory investigations are inappropriately utilized in the Pediatric OPD of Ramathibodi Hospital and this is due to lack of knowledge and unawareness of the cost of tests. OBJECTIVES: 1) To obtain information on laboratory utilization. 2) To evaluate the appropriateness of the residents' test ordering behavior. 3) To estimate the cost of unnecessary tests. 4) To reduce the utilization by combined education, feedback, and peer-review strategies. STUDY DESIGN: Randomized controlled trial carried out from January 1987 to May 1988, consisting of pre-intervention period (Jan-May 1987). intervention period (June-November 1987), and post-intervention period (July 1987-May 1988). STUDY POPULATION: There were 3 intervention groups and 3 control control groups which were stratified by level of seniority as 10 first year residents (R1I vs R1C), 8 second year residents (R2I vs R2C), and 18 staff (SI vs SC). INTERVENTION: For the residents, education on diagnostic tests, chart audit and feedback on their test ordering behavior were provided twice a week. The second year residents also played an active role in giving comments on the first year residents' performances. For the staff, the strategy used was peer-review. The simulated cases derived from the actual medical records serviced by the residents were reviewed and rated, according to the appropriateness of the residents' test ordering behavior, from 0 (poor) to 10 (excellent). A score of less than 5 was considered to indicate inappropriate ordering behavior. OUTCOME: 1) Numbers and cost of tests per patient for each group. 2) The achievement of a score indicating appropriate test ordering behavior of the resident groups. STATISTICAL ANALYSIS: Kruskal-Wallis test, Mann Whitney test, Wilcoxon test and Chi-square test. RESULTS: 1. The utilization pattern was not correlated to the level of seniority of the physicians. 2. There was inappropriate laboratory utilization in this group of residents: overutilization defined as should not be ordered (26.9%), and underutilization defined as should have been ordered (17.7%). Most of the inappropriateness occurred in the ordering of microbiology (50%) and special blood chemistry (40%). 3. Only the number of tests per patient ordered by the R2I group was significantly lower than that of the R2C group in the late post-intervention period. The cost of tests per patient ordered by the R2C group was significantly increased as compared to their baseline. This suggested that the combination of education, chart audit and active feedback strategies was more effective than each strategy alone. 4. The appropriateness of the test ordering behavior of the resident intervention groups improved during the post-intervention period, although the change was not statistically significant. The control groups' behavior was statistically worse. This suggested that the strategy prevented the inappropriateness of test ordering behavior. 5. With the intervention, the overutilization significantly decreased while the underutilization increased. The underutilization might be a consequence of cost containment on laboratory utilization. 6. The cost of unnecessary tests accounted for 17.6 per cent of the total cost of tests ordered by the residents.

Valor de los métodos de seguimiento en el postoperatorio del cáncer de mama / The value of routine follow-up studies in breast cancer

A fin de evaluar la utilidad de los estudios complementarios en el seguimiento de cáncer de mama 108 pacientes con estadio I y II fueron seguidos de acuerdo con un esquema fijo durante los primeros 5 años de postoperatorio. En este período, 14 de ellas tuvieron metástasis a distancia (7 sintomáticas y 7 asintomáticas). Los diferentes exámenes de laboratorio mostraron baja sensibilidad y valor predictivo positivo, y alta especificidad y valor predictivo negativo. El costo de la detección de metástasis en pacientes con ganglios negativos fue de 7 veces mayor que en aquellos con ganglios positivos. No hubo diferencia estadísticamente significativa entre los pacientes con metástasis sintomáticas versus asintomáticas en cuanto al intervalo libre de enfermedad o sobrevida después de la detección dela metástasis. Se concluye que la realización de estudios de laboratorio en el seguimiento del paciente con estadio I y II de cáncer de mama es una forma costosa de detectar unas pocas metástasis asintomáticas, para las cuales no se puede esperar una ventaja terapéutica

SIDA: perfil de una epidemia / AIDS: profile of an epidemy

Indica los resultados de un esfuerzo hecho por encontrar una forma más sencilla, barata y rápida de obtener antígenos víricos apropiados para la confirmación serológica de la infección por el VIH