Scielo RSS <![CDATA[Revista médica de Chile]]> http://www.scielo.cl/rss.php?pid=0034-988720090005&lang=es vol. 137 num. 5 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[<b>El Comité Asesor Internacional, desde el año 2009</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500001&lng=es&nrm=iso&tlng=es Starting in 2001, Revista Médica de Chile has received advice and contributions from eight distinguished physicians from Belgium, Italy, Spain and the U.S.A., nominated Members of its International Advisory Board. A list of their contributions appears in the References section of this Editorial. The Editors have considered opportune to renew this Committee. Two of the previous members will remain in office because of their frequent and outstanding contributions. Seven new members have been selected among prominent physicians and scientists working out of Chile, with brilliant academic and professional careers, who have established regular contacts with different Chilean Societies in the fields of Internal Medicine and its subspecialties. The Editors expect to receive their advice and contributions to stimulate progress in a journal that currently has expanded its presence in the international literature in Internal and General Medicine, and in related specialties and biomedical science. <![CDATA[<b>Violencia sexual en hombres y mujeres jóvenes en Chile</b>: <b>Resultados de una encuesta (año 2005) a estudiantes universitarios</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500002&lng=es&nrm=iso&tlng=es Background: Experiences of sexual violence in adolescence and young adulthood have received little attention in Chilean public health research and practice. Aim: To describe the prevalence and contexts of sexual violence victimization in a sample of university students in Chile. Material and Methods: A self-administered, quantitative survey including items on sexual violence was completed by 484 female and 466 male students at a public university in Chile in 2005. Results: Thirty-one percent of women and 21 % of men reported having experienced at least one incident of sexual violence since age 14; the corresponding percentages for the past 12 months were 17% and 12%, respectively. The perpetrators were identified predominantly as an acquaintance; another important fraction corresponded to a partner or a date. Alcohol or other substances were involved in most cases. Among students who indicated having been assaulted, the incident was reported to the police by none of the men and 2% of women. Twenty one percent of women and 9% of men reported having experienced sexual violence before age 14. Conclusions: The high prevalence of sexual violence found in this study indicates that this issue merits further public health attention in Chile. <![CDATA[<b>Asociación de la variante GHRd3 del receptor de la hormona de crecimiento con autoinmunidad en la diabetes tipo 1</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500003&lng=es&nrm=iso&tlng=es Background: Growth Hormone Receptor (GRH) is expressed in the liver, pancreas, stomach and small intestine. A high expression of GHR mRNA in the mucosal gut suggests a possible role of this receptor on digestive and immune functions. Aim: To investigate the putative effects of the GHRd3 variants on the cytokine profile and distribution of auto-antibodies in children with type 1 diabetes (T1D). Material and Methods: Unrelated unaffected controls (n =192) and incident cases of children with T1D (n =127) were analyzed for GHRd3 polymorphism, cytokine profile and a panel of auto-antibodies. Results: The allele frequency for d3 was 24.8% in type 1 diabetics and 34.1% in controls (p =NS). Among type 1 diabetic children, the carriers of the GHRd3 polymorphism had significantly higher levels of interleukin-lB than homozygous for the wild type genotype (5.7 and 17.7, pg/ml respectively p <0.015). Carriers of d3 variant had a higher frequency of positive anti-insulin antibodies (anti-IAA) than children without this variant (39.6 and 17.7% respectively, p <0.01). Conclusions: The observed frequency of the GHR d3/d3 genotype was comparable to other reports. A relationship between d3 variant and anti-IAA antibodies and interleukin-lß was observed. <![CDATA[<b>Mejoría en las habilidades de comunicación escrita de estudiantes de medicina: Impacto de un taller de escritura</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500004&lng=es&nrm=iso&tlng=es Background: Despite being among the best academically prepared of the country, many medical students have difficulties to communicate in writing. In 2005, the School of Medicine at the Pontificia Universidad Católica de Chile introduced a writing workshop in the undergraduate curriculum, to enhance the students' writing skills. Aim: To describe the workshop and its impact on the writing skills of 3 cohorts of students. Material and methods: This 30-h workshop used a participative methodology with emphasis on deliberate practice and feedback. Students worked in small groups with a faculty member specially trained in writing. The qualities of the essays written before and after the workshop were compared. Essays were rated by a professional team that used an analytic rubric to measure formal aspects of text writing as well as more complex thinking processes. Results: There was a significant improvement in the quality of the texts written after the workshop; the main changes occurred in argumentation, and in paragraph and text structure. This improvement was inversely proportional to the initial level of performance, and independent of gender Conclusions: A writing workshop based on deliberate practice and personalized feedback is effective to enhance the writing proficiency of medical students. Due to its design, this workshop could be useful for students of other careers and universities. <![CDATA[<b>Calidad de vida en pacientes operadas de <i>bypass </i>gástrico hace más de un año</b>: <b>Influencia del nivel socioeconómico</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500005&lng=es&nrm=iso&tlng=es Background: The study of the effects of bariatric surgery on quality of life in patients of different socioeconomic levels (SEL) is worthwhile. Aim: To study quality of life (QoL), eating behavior, depressive symptoms and sexuality in patients subjected to a gastric bypass (GBP) more than 1 year before. Material and methods: The sample was composed of 33 GPB patients (19 high SEL and 14 low SEL), and 27 non-operated women (18 high SEL and 9 low SEL) of similar weight and age, as controls. Assessment included medical history anthropometry radiological densitometry. Eating behavior was assessed using the three factor eating questionnaire, quality of life using SF-36 and the Bariatric Analysis of Reporting Outcome System (BAROS) depressive symptoms were assessed using the Beck scale version II and sexual behavior using the female sexual function index (FSFI). Results: QoL was lower in operated patients from low SEL, especially when compared to high SEL control women. Operated patients had a predominantly restrictive pattern of eating behavior Eating behavior disorders were detected in 5 of 33 operated patients versus 4 of 27 controls (p =ns). Sexual function was absent or dysfunctional in 22 operated versus 8 controls (p =0,02). No significant differences were observed for depressive symptoms, between operated patients and controls. Conclusions: In the long term, QoL of bariatric patients, especially those from low SEL, is inferior to control women and Chilean general population. Operated patients have restrictive eating patterns and lower sexual satisfaction indexes. Frequency of depressive symptoms was high both in bariatric and control women. <![CDATA[<b>Cálculo del impacto económico para Chile del uso de losartán en diabéticos tipo 2 con nefropatía diabética, basado en resultados del estudio RENAAL</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500006&lng=es&nrm=iso&tlng=es Background: The study RENAAL (Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan) demonstrated that Losartan was more effective lo reduce the progression of kidney disease in diabetic patients with proteinuria and a reduction in glomerular filtration rate. Aim: To perform a cost benefit analysis of Losartan use from provider and payer points of view. Material and methods: Published data of the RENAAL study was analyzed. The costs of the use or not use of Losartan in patients with diabetic nephropathy were compared in terms of total costs of the disease including medications, hospital admissions for myocardial infarction, cerebrovascular accidents and congestive cardiac failure and the costs of chronic hemodialysis. Results: The reduction in antihypertensive medication use, hospital admissions, and the delay in dialysis requirement from a mean of 65 to 79 months induced by Losartan use, results in net savings of $7,576,135 per patient, at 3.5 years of intervention. The figure does not change using different sensitivity scenarios. Conclusions: The eventual use of Losartan in type 2 diabetic patients results in important savings. <![CDATA[<b>Coinfecciones por virus hepatitis B, virus hepatitis C, <i>Treponema pallidum </i>y <i>Toxoplasma gondii </i>en la cohorte de pacientes VIH positivos en control en la Pontificia Universidad Católica de Chile</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500007&lng=es&nrm=iso&tlng=es Background: Some infections share common modes of transmission with HIV and have the potential to change the course of the latter. Aim: To assess the prevalence of hepatitis B virus (HBV) hepatitis C virus (HCV), Treponema palladium and Toxoplasmosis gondii co-infections in HIV-1 infected patients followed at a university hospital. Material and methods: Clinical records of HIV-positive individuals were reviewed. The analysis included: demographical data, hepatitis B surface antigen (HBsAg), IgM and IgG anti-HBc, antibodies, anti-HCV antibodies, RPR or VDRL test and IgG anti Tgondii antibodies. Results: Three hundred ninety five patients (aged 16 to 89years, 359 males) were included in the review. Seventy nine percent had been tested for HBV status with HBsAg, and the global HIV-HBV co-infection prevalence was 6.1%. A subgroup of190 individuals were tested for HBV infection with HBsAg and IgM/IgG anti-HBc markers. Of these, 46% fulfilled co-infection criteria: eight with acute hepatitis B, 11 with chronic hepatitis B and 69 with inactive HBV infection. The frequency of HIV-HBV co-infection was 48% and 22% among men and women respectively (NS). HCV-HN co-infection was detected in 3%, syphilis-HIV co-infection in 21% and T gondii-HIV co-infection in 26%. Conclusions: In this cohort, HIV infection is accompanied by a high prevalence of other co-infections, particularly HBV among men. <![CDATA[<b>Quimiorradioterapia adyuvante en el cáncer gástrico resecado con intención curativa</b>: <b>Análisis de supervivencia y toxicidad de pacientes tratados entre 1995 y 2003 en el Instituto Nacional del Cáncer, Chile</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500008&lng=es&nrm=iso&tlng=es Background: Survival rates after curative surgery for gastric cancer are disappointing. Therefore adjuvant therapeutic strategies are required. Aim: To analyze survival and side effects of treatment among gastric cancer patients treated with adjuvant chemo radiotherapy after curative resection of gastric adenocarcinoma. Material and methods: Retrospective review of medical records of 74 patients aged 20 to 74 years, treated with complete resection of gastric adenocarcinoma followed by adjuvant chemo radiation. Survival analysis was based on the records and information from the National Mortality Registry. Results: Five years survival fluctuated from 50% among patients in stage IB to 25% among those is stage IV. Significant acute toxicity was observed in 23 patients (31%). No patients died due to acute toxicity. Eleven patients (16.4%) developed significant late toxicity, with two possible deaths related to treatment. Conclusions: Postoperative chemo radiotherapy is feasible in our experience. Continues infusion of 5-fluoruracil is recommended to reduce toxicity. <![CDATA[<b>Validación en Chile de la Escala de Sobrecarga del Cuidador de Zarit en sus versiones original y abreviada</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500009&lng=es&nrm=iso&tlng=es Background: Six percent of the Chilean population has a disability requiring assistance with daily-living-activities and 69% of these individuals are cared by direct family members. The latter are at risk of developing caregiver burden. Zarit scales are used to assess the severity of caregiver burden. Aim: To validate the original and abbreviated Zarit scales for caregiver burden. Material and methods: Two groups of interviewers applied the original and abbreviated Zarit scales, along with a single subjective indicator for burden and surveys for depression, to 32 caregivers from an outpatient clinic in Melipilla, Chile. In 22 subjects, the instruments were applied again, four months later Results: Both Zarit scales showed high correlation with the subjective indicator for burden and with depression (r =0.51 and 0.67, respectively), supporting its construct validity. The abbreviated scale had a high correlation with the original scale (r =0.92), supporting its criterion validity. It had a 100 % sensitivity 77.7%, specificity 86.6% positive predictive value and 100% negative predictive value to discriminate severe caregiver burden, using the original scale as standard. Both instruments showed high internal consistency (Cronbach alpha =0.84 and 0.87, respectively), inter-observer reliability (intraclass correlation coefficient =0.81 and 0.86, respectively) and stability reliability (Kappa test-retest =0.91 and 0.93, respectively). Conclusions: Both original and abbreviated Zarit burden scales are valid to assess caregiver's burden in a Chilean context. The abreviate scale Szeged particularly useful for primary care. <![CDATA[<b>Esofagitis eosinofílica en niños</b>: <b>Características clínicas y endoscópicas</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500010&lng=es&nrm=iso&tlng=es Eosinophilic esophagitis in adults (EE) is a disease of unknown cause, characterized by symptoms such as reflux and dysphagia that traditionally do not respond to antacid treatment. It affects mostly young men with a strong personal or familial history of a topy asthma and allergies. We repot three male patients aged 10, 14 and 15years, all with symptoms of dysphagia, two of them with chest pain caused by spasm of the esophagus, with heterogeneous endoscopic findings which included from leucoplakia to stenosis that needed endoscopic dilatation. All of them had abnormal findings in immunity studies (prick test or IgE levels). They received treatment based on diet measures, acid suppression and leukotriene inhibitors, with satisfactory clinical, endoscopic and histological response. EE should be suspected in children and adults with esophageal symptoms and personal or family history of allergy and asthma. <![CDATA[<b>Esófago negro secundario a esofagitis necrotizante aguda</b>: <b>Reporte de un caso clínico</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500011&lng=es&nrm=iso&tlng=es Acute esophageal necrosis, which presents as a black esophagus on endoscope, is an uncommon occurrence. It is defined as a dark pigmentation of the esophagus associated with histological mucosal necrosis. We report a 75-year-old man who developed black esophagus due to acute esophageal necrosis caused by septicemia. The patient had a favorable evolution. <![CDATA[<b>Encefalitis límbica por anticuerpos anticanales de potasio dependientes de voltaje</b>: <b>Caso clínico</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500012&lng=es&nrm=iso&tlng=es Limbic encephalitis (LE) can be associated to cancer, viral infection or be idiopathic. One form is associated to voltage dependent potassium channel (VKC) antibodies. The clinical presentation includes impairment of consciousness, amnesia and temporal lobe seizures; typical abnormalities are also found in brain magnetic resonance. We report a 68 year-old male who had LE associated to VKC antibodies. The patient was treated with steroids with a partial response. At the moment of the report he is asymptomatic and continues with prednisone treatment . <![CDATA[<b>Síndrome de POEMS con lesión lítica aislada y hemangiomas glomeruloides</b>: <b>Caso clínico</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500013&lng=es&nrm=iso&tlng=es POEMS syndrome (polyneuropathy, organomegaly, endocrine abnormality, M-protein, plasma cell dyscrasia, and skin lesions) is a rare atypical plasma cell dyscrasia with characteristic para neoplastic manifestations. Glomeruloid hemangioma is a typical skin change pathogenetically related with elevated levels of Vascular Endothelial Growth Factor (VEGF). We report a 69 year-old woman that presented cachexia associated with diabetes, hypothyroidism and severe sensitive motor polyneuropathy. Her skin changes included hyper pigmentation, acrocyanosis and glomeruloid hemangioma. The subsequent study revealed a monoclonal gammopathy lambda type; a unique lytic vertebral lesion and a clonal plasma cell proliferation. Treatment with prednisone 0.5 mg/kg and melphalan 0,25 mg/kg in cycles of 4 days every 4 weeks was started, but the patient was lost from follow up. <![CDATA[<b>Síndrome metabólico</b>: <b>Bases clínicas y fisiopatológicas para un enfoque terapéutico racional</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500014&lng=es&nrm=iso&tlng=es Regardless of the diagnostic criteria, the metabolic syndrome is found at least in 20% of the population. The adipose tissue plays an important role in the insulin resistance found in this syndrome. Free fatty acids released by intra-abdominal adipocytes produce an inflammatory and pro-thrombotic response and the persistence of the insulin resistance state, phenomenon termed lipotoxicity. This altered phenotype explains the development of the different components of the metabolic syndrome, such as hypertension, dyslipidemia and altered glucose metabolism. The treatment is based on weight loss and healthy lifestyle. A balanced diet, physical activity and avoidance of smoking are key management features. The use of drugs with pleiotropic effects, which inhibit the renin angiotensin aldosterone axis or acts on the peroxisome proliferators-activated receptors (PPAR) seems promising. <![CDATA[<b>Telangiectasia hemorrágica hereditaria: Tratamiento farmacológico</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500015&lng=es&nrm=iso&tlng=es Hereditary hemorrhagic telangiectasia (HHT) of Rendu-Osler-Weber disease is a multi system vascular dysplasia characterized by the presence of multiple telangiectasias, mainly affecting mucosal tissue and arterial-venous connections. It commonly affects lungs, liver and central nervous system. Bleeding is the most common symptom and its treatment can be surgical or pharmacological. We herein review the systemic therapy that attempts to minimize bleeding as well as blood transfusion therapy. Blood therapy and fibrinolytic treatment especially aminocaproic acid and tranexamic acid are discussed. Danazol, hormone therapy and other less common drugs used in the treatment of HHT are also reviewed. <![CDATA[<b>¿Podemos mantenernos actualizados en medicina en el siglo XXI?</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500016&lng=es&nrm=iso&tlng=es The amount of information in health care has steadily grown in the past years and this trend will probably continue in the near future. Traditional ways to keep updated are no longer sufficient, particularly in broad areas of knowledge as Internal Medicine or Family Medicine. Therefore, it is necessary to use new approaches. The present article describes five proposals for the clinician that tries to maintain updated but feels overwhelmed by the amount of available information. <![CDATA[<b>Situación actual de la Educación Médica en Chile</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500017&lng=es&nrm=iso&tlng=es The Chilean Academy of Medicine published a "Report on the Current Status of Medical Education in Chile". This report reviews the history of medical education in this country and its close relationship with the Health Care System, public and private; highlights the main changes that took place during the last 25 years in superior and medical education; provides information on the 26 currently existing Medical Schools; refers to the availability of medical doctors and specialists; discusses the mechanisms that control the quality of institutions involved and their programs; and summarizes the results of the Annual National Medical Examination. The members of the Committee on Superior Education of the Academy provided a critical analysis of medical education in Chile and recommendations on how to improve it. Revista Médica de Chile reproduces the Summary, Conclusions and Recommendations. The complete document (in Spanish) can be accessed freely at www.institutodechile.cl . <![CDATA[<b>¿Cuándo puedo comparar un mismo test realizado en diferentes laboratorios? Conceptos de trazabilidad y armonización en el laboratorio clínico</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500018&lng=es&nrm=iso&tlng=es The results of a determination performed in two different laboratories can only be compared if the techniques used are comparable, independently of the methodology or manufacturer. For this purpose, methods must be traceable to common materials and methods. Despite the common sense of this statement, only few laboratory determinations fulfill this requisite. In general, during the follow up of a patient, the physician must try to use the same laboratory or at least laboratories that use the same method. Moreover, laboratories should define the method used for determinations in their reports as indispensable information for attending physicians.<hr/>Los resultados de un mismo examen realizado en dos laboratorios diferentes, sólo se pueden comparar si las técnicas utilizadas son comparables, independientemente del fabricante o metodología. Para que ello ocurra, ios métodos deben ser trazabies a un material y a un método de referencia común. A pesar de que esto parece obvio, sólo unos pocos exámenes de laboratorio logran esta condición. En general, y especialmente en el seguimiento o control de los pacientes, el médico debe optar por usar siempre el mismo laboratorio o laboratorios que utilicen el mismo método. Además, los laboratorios clínicos deben expiicitar el método utilizado en su informe de Resultados, como información indispensable para la correcta interpretación por parte del médico tratante. <![CDATA[<b>Profesor Dr. Roque Kraljevic Orlandini (1911-2009)</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500019&lng=es&nrm=iso&tlng=es The results of a determination performed in two different laboratories can only be compared if the techniques used are comparable, independently of the methodology or manufacturer. For this purpose, methods must be traceable to common materials and methods. Despite the common sense of this statement, only few laboratory determinations fulfill this requisite. In general, during the follow up of a patient, the physician must try to use the same laboratory or at least laboratories that use the same method. Moreover, laboratories should define the method used for determinations in their reports as indispensable information for attending physicians.<hr/>Los resultados de un mismo examen realizado en dos laboratorios diferentes, sólo se pueden comparar si las técnicas utilizadas son comparables, independientemente del fabricante o metodología. Para que ello ocurra, ios métodos deben ser trazabies a un material y a un método de referencia común. A pesar de que esto parece obvio, sólo unos pocos exámenes de laboratorio logran esta condición. En general, y especialmente en el seguimiento o control de los pacientes, el médico debe optar por usar siempre el mismo laboratorio o laboratorios que utilicen el mismo método. Además, los laboratorios clínicos deben expiicitar el método utilizado en su informe de Resultados, como información indispensable para la correcta interpretación por parte del médico tratante. <![CDATA[<b>Certificación de Especialistas</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500020&lng=es&nrm=iso&tlng=es The results of a determination performed in two different laboratories can only be compared if the techniques used are comparable, independently of the methodology or manufacturer. For this purpose, methods must be traceable to common materials and methods. Despite the common sense of this statement, only few laboratory determinations fulfill this requisite. In general, during the follow up of a patient, the physician must try to use the same laboratory or at least laboratories that use the same method. Moreover, laboratories should define the method used for determinations in their reports as indispensable information for attending physicians.<hr/>Los resultados de un mismo examen realizado en dos laboratorios diferentes, sólo se pueden comparar si las técnicas utilizadas son comparables, independientemente del fabricante o metodología. Para que ello ocurra, ios métodos deben ser trazabies a un material y a un método de referencia común. A pesar de que esto parece obvio, sólo unos pocos exámenes de laboratorio logran esta condición. En general, y especialmente en el seguimiento o control de los pacientes, el médico debe optar por usar siempre el mismo laboratorio o laboratorios que utilicen el mismo método. Además, los laboratorios clínicos deben expiicitar el método utilizado en su informe de Resultados, como información indispensable para la correcta interpretación por parte del médico tratante. <![CDATA[<b>Unraveling the causes of negative studies</b>: <b>a case of <i>S boulardii </i>for the prevention of antibiotic-associated diarrhea</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500021&lng=es&nrm=iso&tlng=es The results of a determination performed in two different laboratories can only be compared if the techniques used are comparable, independently of the methodology or manufacturer. For this purpose, methods must be traceable to common materials and methods. Despite the common sense of this statement, only few laboratory determinations fulfill this requisite. In general, during the follow up of a patient, the physician must try to use the same laboratory or at least laboratories that use the same method. Moreover, laboratories should define the method used for determinations in their reports as indispensable information for attending physicians.<hr/>Los resultados de un mismo examen realizado en dos laboratorios diferentes, sólo se pueden comparar si las técnicas utilizadas son comparables, independientemente del fabricante o metodología. Para que ello ocurra, ios métodos deben ser trazabies a un material y a un método de referencia común. A pesar de que esto parece obvio, sólo unos pocos exámenes de laboratorio logran esta condición. En general, y especialmente en el seguimiento o control de los pacientes, el médico debe optar por usar siempre el mismo laboratorio o laboratorios que utilicen el mismo método. Además, los laboratorios clínicos deben expiicitar el método utilizado en su informe de Resultados, como información indispensable para la correcta interpretación por parte del médico tratante. <![CDATA[<b>Centenario de la enfermedad de Chagas (1909-2009)</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872009000500022&lng=es&nrm=iso&tlng=es The results of a determination performed in two different laboratories can only be compared if the techniques used are comparable, independently of the methodology or manufacturer. For this purpose, methods must be traceable to common materials and methods. Despite the common sense of this statement, only few laboratory determinations fulfill this requisite. In general, during the follow up of a patient, the physician must try to use the same laboratory or at least laboratories that use the same method. Moreover, laboratories should define the method used for determinations in their reports as indispensable information for attending physicians.<hr/>Los resultados de un mismo examen realizado en dos laboratorios diferentes, sólo se pueden comparar si las técnicas utilizadas son comparables, independientemente del fabricante o metodología. Para que ello ocurra, ios métodos deben ser trazabies a un material y a un método de referencia común. A pesar de que esto parece obvio, sólo unos pocos exámenes de laboratorio logran esta condición. En general, y especialmente en el seguimiento o control de los pacientes, el médico debe optar por usar siempre el mismo laboratorio o laboratorios que utilicen el mismo método. Además, los laboratorios clínicos deben expiicitar el método utilizado en su informe de Resultados, como información indispensable para la correcta interpretación por parte del médico tratante.