Scielo RSS <![CDATA[Revista médica de Chile]]> http://www.scielo.cl/rss.php?pid=0034-988720100006&lang=es vol. 138 num. 6 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[<b>Revista Médica de Chile</b>: <b>Nuevo miembro del "International Committee of Medical Journal Editors"</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600001&lng=es&nrm=iso&tlng=es After a worldwide call for applications that took place in 2009, two medical journals were selected to become new members of the “International Committee of Medical Journal Editors (ICMJE)”: Chinese Medical Journal and Revista Médica de Chile. Both Editors: Getu Zhaori, MD, and Humberto Reyes, MD, respectively, attended the ICMJE Meeting, 12-14 April 2010, in Queenstown, New Zealand. The meeting agenda included several topics that had been studied in advance by the at-tendants: editors or deputy editors of the 14 journals integrating this Committee plus a representative for the U.S. National Library of Medicine and another one for the World Association of Medical Journal Editors (WAME). The Committee agreed in new recommendations tending to safeguard the integrity and transparency of every manuscript published in all journals that adhere to the “Uniform Requirements for Manuscripts Submitted to Biomedical Journals (URM)”. These recommendations will be published shortly in ICMJE member journals. An important issue discussed refers to improvements in the “ICMJE Uniform Disclosure Form for Potential Conflicts of Interest”, that had some changes, a glossary of terms will be attached to it and the Instructions will be accompanied by translations into the offcial WHO languages as well as other languages used by ICMJE member journals. For our journal it is an honor and a great responsibility to become a member of this highly qualifed Committee, the only journal published in Spanish and the frst one from Latin America. <![CDATA[<b>Prevalencia de resistencia primaria en pacientes con infección reciente por VIH-1 en Chile</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600002&lng=es&nrm=iso&tlng=es Background: The main cause of virological failure during AIDS treatment is the resistance to antiretroviral medications (ARV). Aim: To search for mutations associated with ARV resistance in recently HIV-1 infected patients naïve to treatment, in Chile. Material and Methods: Patients over 18 years old with HIV-1 infection, naïve to antiretroviral drugs before the study were included. Patients with CD4 cell counts less than 200 cells/mm³, viral load below 2.000 copies/mL or any condition indicative of advanced AIDS were excluded. Criteria for diagnosis of recent infection (< 18 months) were a previous negative test for HIV antibodies or a history of an acute retroviral syndrome in the past 18 months. Resistance to drugs was analyzed using the TRUGENEtm HIV-1 assay from Bayer and the OpenGene DNA sequencing system. Results: Ninety nine percent of patients had at least one mutation, 27% had 4 or more mutations, but high level resistance to ARV was found only in 2.7% of cases. Point mutations for non nucleoside reverse transcriptase inhibitors (NNRTI) were detected in 4.1% of cases (K103N in 1 patient, V179D in 2 patients), for nucleoside reverse transcriptase inhibitors (NRTI) in 8.1% of cases (T215S in 1 patient, V118I in 4 patients, M41L in 1 patient) and for protease inhibitors (PI) in 1.3% of cases. All mutations detected in the protease gene were secondary. Of these, the most common were L63P/T (38 patients), L10I/V (27 patients) and V77I (26 patients). Resistance to two or more antiretroviral classes was not detected. Conclusions: This study supports that, by now, primary resistance has a low prevalence in Chile. Therefore, a genotyping test before starting antiretroviral therapy is not necessary. <![CDATA[<b>Evaluación del ambiente educacional pre-clínico en seis Escuelas de Medicina en Chile</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600003&lng=es&nrm=iso&tlng=es Background: The Dundee Ready Education Environment Measure (DREEM) is the most valid and reliable instrument to measure the educational environment (EE) in undergraduate medical education. Aim: To evaluate the EE perceived by undergraduate medical students in Chile, using a Spanish version of the DREEM questionnaire. Material and Methods: The DREEM was applied during 2008 in third, fourth and ffith undergraduate years of six medical schools. The individual results were calculated and means of both global and individual domain scores of the DREEM were compared, by year, gender and between different Schools. Results: One thousand ninety two students (77% of the total universe of students), answered the questionnaire. The mean score of the six Schools was 113.9. The domains of Perception of Learning and Social Self-Perception obtained the lower scores, with a global outcome indicating a more positive than negative EE. Two schools obtained mean scores of 128.32 and 126.87, that were significantly higher than the global scores obtained by other schools. No relevant differences by years or gender were observed. Conclusions: There is a signifiicant variability between the six schools evaluated and two of these obtained signifiicantly better scores than the rest. The identified positive and negative areas will orient the actions to improve the EE for undergraduate medical students. <![CDATA[<b>Desarrollo y validación de un instrumento en Español para evaluar el desempeño de docentes clínicos a través de las percepciones de sus estudiantes</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600004&lng=es&nrm=iso&tlng=es Background: The modernization of clinical teaching has called for the creation of faculty development programs, and the design of suitable instruments to evaluate clinical teachers’ performance. Aim: To report the development and validation of an instrument in Spanish designed to measure the students’ perceptions of their clinical teachers’ performance and to provide them with feedback to improve their teaching practices. Material and Methods: In a process that included the active participation of authorities, professors in charge of courses and internships, clinical teachers, students and medical education experts, we developed a 30-item questionnaire called MEDUC30 to evaluate the performance of clinical teachers by their students. The internal validity was assessed by factor analysis of 5,214 evaluations of 265 teachers, gathered from 2004 to 2007. The reliability was measured with the Cronbach’s alpha coefficient and the generalizability coefficient (g). Results: MEDUC30 had good content and construct validity. Its internal structure was compatible with four factors: patient-centered teaching, teaching skills, assessment skills and learning climate, and it proved to be consistent with the structure anticipated by the theory. The scores were highly reliable (Cronbach’s alpha: 0.97); five evaluations per teacher were sufficient to reach a reliability coefficient (g) of 0.8. Conclusions: MEDUC30 is a valid, reliable and useful instrument to evaluate the performance of clinical teachers. To our knowledge, this is the first instrument in Spanish for which solid validity and reliability evidences have been reported. We hope that MEDUC30 will be used to improve medical education in Spanish-speaking medical schools, providing teachers a specific feedback upon which to improve their pedagogical practice, and authorities with valuable information for the assessment of their faculty. <![CDATA[<b>Enfermedades afectivas y actividad solar</b>: <b>Seguimiento a 16 años</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600005&lng=es&nrm=iso&tlng=es Background: Exposure to solar activity may be associated with incidence of depressive and manic disorders. Aim: To assess the link between solar activity and appearance of affective disorders. Material and Methods: We examined 1862 clinical records of a psychiatric clinic located in Santiago, Chile. Patients with major depression and manic disorders were included in the study, only when they were admitted at the clinic for the first time. Solar activity was calculated using the Wolf number, which is given by the formula R= K(10g+f), where “g” stands for the groups of sunspots and “f ” is the total number of sunspots. We examined the correlation between annual incidence of hospital admissions and average Wolf numbers for the period 1990-2005, which corresponds to approximately one and half solar cycles of 16 years. Results: A total of 450 medical records corresponding to 299 patients (199 women) with depressive symptoms and 151 patients (73 women) with mania, were analyzed. There was a higher number of admissions for depression during the years with lower solar activity. Admissions due to mania tended to increase in the years with high solar activity. There was a negative correlation between the number of hospital admissions due to depression and solar activity (Spearman r =-0.812, p < 0.01). The association between the latter parameter and admissions due to mania did not reach statistical significance. Conclusions: There is a significant negative association between the rate of hospital admissions due to depressive disorders and solar activity. <![CDATA[<b>Prevalencia y evolución de síntomas depresivos en pacientes hospitalizados por infarto agudo al miocardio y su relación con procedimientos de revascularización</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600006&lng=es&nrm=iso&tlng=es Background: Persistence of depressive symptoms after myocardial infarction (MI) is associated with an adverse outcome. The relationship between depression and Invasive Revascularization Therapy (IRT) is not yet fully understood. Aim: To compare the frequency of depressive symptoms and other psychosocial variables among patients with MI, undergoing or not undergoing IRT. Material and Methods: Prospective evaluation of 45 patients aged 58 ± 11 years (87% males) with a diagnosis of MI (Killip I and II). On admission to hospital and at follow up 3 months after discharge, all patients completed the Beck Depression Inventory (BDI), the Zung Anxiety Inventory (ASI), and the Medical Outcomes Study (MOS) social support survey. Depressive symptoms were considered to be present if the BDI score was over 10. Results: Thirty seven percent were hypertensive, 15% diabetic and 44% smokers. Sixty four percent of patients underwent IRT (11.1% revascularization surgery and 53.3% coronary angioplasty). Forty four percent of patients scored over 10 in the BDI at baseline assessment and 26.5% at 3 months follow-up (p < 0.01). At baseline BDI score was 10.2 ± 5.1 and 9.1 ± 4.4 among patients subjected or not subjected to IRT, respectively (NS). The fgures at 3 months of follow up were 9.9 ± 5.6 and 4.1 ± 2.5, respectively (p < 0,01). At baseline and three months BDI, anxiety and perceived social support were significantly correlated. Conclusions: Depressive symptoms were frequent after MI in this group of patients, and decreased at follow up only among patients not subjected to IRT. <![CDATA[<b>Prevalencia de síndrome metabólico en población adulta Chilena</b>: <b>Datos de la Encuesta Nacional de Salud 2003</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600007&lng=es&nrm=iso&tlng=es Background: There are several diagnostic criteria for Metabolic Syndrome (MS) defnition. Aim: To study their application in the Chilean general adult population. Material and Methods: We analyzed data from a random sub sample of 1.833 adults aged 17 years and older surveyed during the First Chilean National Health Survey conducted in 2003. The prevalence of MS was estimated using the update Adult Treatment Panel III (ATP III) of the National Cholesterol Education Program (NCEP) and the International Diabetes Federation (IDF 2005) criteria. The distribution of MS was analyzed according to age, gender, educational level, geographic area, obesity and sedentary lifestyle. Results: The overall prevalence of MS was 31.6% (95% CI 28.5-34.9) and 36.8% (95% CI 33.5-40.3), according to update ATPIII-NCEP and IDF criteria respectively. Both criteria had a 90% concordance. Demographic and socioeconomic distribution was similar for both criteria. The prevalence of high blood pressure, high fasting glucose, and low HDL cholesterol (MS components) were: 46, 22 and 53% respectively. The prevalence of abnormal waist circumference was 30 and 59% according to update ATPIII-NCEP and IDF criteria, respectively. Using update ATPIII-NCEP criteria, the gender, age and educational level adjusted odds ratio (OR) for having MS was 9.59 (95% IC 6.8- 13.6) for obese subjects compared with normal weight subjects and 2.14 (95% IC 1.3-3.7) for sedentary subjects compared with non sedentary. Conclusions: There was a 90% agreement between update ATPIII-NCEP and IDF criteria for the diagnosis of MS. The overall prevalence of MS in this population was 32% usuing update ATPIII-NCEP criteria, with higher prevalence among obese and sedentary subjects. <![CDATA[<b>Ejercicio físico en mujeres con cáncer de mama</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600008&lng=es&nrm=iso&tlng=es Background: Exercise may reduce anxiety and depression associated to the diagnosis and treatment of cancer. Aim: To assess the effects of a physical training program during chemotherapy among women with breast cancer. Patients and Methods: Twenty two women aged 49 ± 7 years with breast cancer voluntarily agreed to take part in the study, after surgical treatment. Functional capacity (Karnofsky Performance Status), psychological status (General Health Questionnaire, GHQ) and quality of life (EORTC QLQ-C30) were evaluated at baseline and at the end of the study. Before beginning with adjuvant chemotherapy, ten women were randomly assigned to a program of physical exercise and seven to a control group. The program lasted 18 to 22 weeks, depending on the duration of chemotherapy. Results: Five women were lost from follow up. Before starting chemotherapy, 41% of women were working and all had to kit. At baseline all had a normal Karnofski score and quality of life was compromised. At the end of the study, the intervention group had an improvement of their quality of life, compared to the control group that did not experience significant changes. Conclusions: An exercise training program improves quality of life of women with breast cancer on chemotherapy. <![CDATA[<b>Survival of patients with vulvar cancer</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600009&lng=es&nrm=iso&tlng=es Background: Vulvar cancer corresponds to 3 to 5% of all female reproductive tract malignancies. Therefore it is classifed as a low frequency disease. Aim: To estimate overall and conditional survival one and two years after diagnosing women with vulvar cancer. Material and Methods: Retrospective cohort study. The patient database of an oncological hospital was revised and patients with vulvar cancer diagnosed between 1997 and 2006 were selected. The clinical records of these women were reviewed. Results: Eighty six women aged 32 to 92 years, were identified. Eighty percent had a squamous carcinoma, 46% were in stage III, 48% received incomplete treatment, 40% consulted due to the presence of a vulvar mass and 18% had lesions in labia majora or minora. Overall five years survival at 5 years was 41.8%. There were statistically significant differences in survival depending on the initial stage of cancer (p = 0.02). Five year conditional survival, one and two years after the diagnosis, was 59 and 79%, respectively. Conclusions: Five years overall survival of these group of women with vulvar cancer was 41.8%. The figures increased to 59 and 79% in patients who had survived one and two years after the diagnosis. The stage of the lesion and the initial survival are survival prognostic factors for vulvar cancer. <![CDATA[<b>Efecto de un modelo de apoyo telefónico en el auto-manejo y control metabólico de la Diabetes tipo 2, en un Centro de Atención Primaria, Santiago, Chile</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600010&lng=es&nrm=iso&tlng=es Background: Telephone based self-management support may improve the metabolic control of patients with type 2 (DM2) diabetes if it is coordinated with primary care centers, if telephone protocols and clinical guidelines are used and if it is provided by nurses trained in motivational interviewing. Aim: To assess the efficacy ofi a tele-care self-management support model (ATAS) on metabolic control of patients with DM2 attending primary care centers in a low income area in Santiago, Chile. Material and Methods: Two primary care centers were randomly assigned to continue with usual care (control group, CG) or to receive additionally 6 telecare self-management support interventions (IG) during a 15 month period. Glycosylated hemoglobin (HbA1c) was used to measure metabolic control of DM2; the “Summary of Diabetes Self-care Activities Measure” and the “Spanish Diabetes Self-efficacy” scale were used to measure self-management and self efficacy, respectively. Changes in the use of health services were also evaluated. Results: The IG maintained its HbA1c level (baseline and final levels of 8.3 ± 2.3 % and 8.5 ± 2.2% respectively) whereas it deteriorated in the CG (baseline and final levels of 7.4 ± 2.3 and 8.8 ± 2.3 % respectively, p < 0.001). The perception of self-efficacy in the IG improved while remaining unchanged in the CG (p < 0.001). Adherence to medication, physical activity and foot care did not change in either group. In the IG, compliance to clinic visits increased while emergency care visits decreased. Conclusions: The ATAS intervention, in low income primary care centers, significantly increased the probability of stabilizing the metabolic control of patients with DM2 and improved their use of health services. <![CDATA[<b>Metástasis pancreáticas tardías secundarias a cáncer de células renales</b>: <b>Caso clínico</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600011&lng=es&nrm=iso&tlng=es We report the case of a 60 year old woman with multiple pancreatic nodules found on abdominal computed tomography. Thirteen years earlier she had undergone a left nephrectomy for renal cell carcinoma. The patient underwent surgery with a preoperative diagnosis of multifocal metastatic or neuroendocrine tumor. At surgery, two metastatic nodules of renal cell carcinoma were found and excised. After four years of follow up there is no evidence of recurrence. <![CDATA[<b>Pólipo fibrovascular esofágico</b>: <b>Estudio por imágenes multimodalidad</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600012&lng=es&nrm=iso&tlng=es We report a 47 years old woman presenting with dysphagia. A chest CAT scan and barium swallow showed an endoluminal mass that extended to four vertebrae. An endoluminal sonography localized the pediculum of the mass, that was excised endoscopically. The pathological study disclosed a fibrovascular polyp. After 18 months of follow up, the patient is asymptomatic. <![CDATA[<b>Trombosis de senos venosos encefálicos como posible primera manifestación de enfermedad de Behçet</b>: <b>Caso clínico</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600013&lng=es&nrm=iso&tlng=es Behçet’s disease (BD) is a systemic inflammatory vascular disease with several clinical manifestations and geographical differences in disease expression. In Middle Eastern countries it is one of the most common causes of cerebral venous thrombosis. We report a 29-year-old female admitted for acute headache and vomiting. A magnetic resonance image showed a large thrombosis of sagital and transverse sinuses. She developed oral and genital ulcers a week later. Ophthalmologic examination revealed left anterior uveitis and ipsilateral papilledema. Multiple studies ruled out a hypercoagulability syndrome. The patient used oral contraceptives. Anticoagulant therapy was prescribed. A biopsy of a genital ulcer demonstrated diffuse lymphocytic infiltration with vasculitis. After treatment with topical and systemic corticoids, her condition improved. Venous sinus thrombosis followed by oral and genital ulcers is an unusual presentation of Behçet’s disease. <![CDATA[<b>Puente al trasplante de 4 semanas utilizando el sistema de asistencia ventricular Levitronix Centrimag® en el shock cardiogénico post-infarto al miocardio</b>: <b>Caso clínico</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600014&lng=es&nrm=iso&tlng=es Cardiogenic shock after myocardial infarction has a high mortality even if early revascularization is achieved. Biventricular assist devices have not been used in Chile in this critical setting. We report a case of a 55 year-old diabetic man who suffered an acute chest pain and ventricular fibrillation. Prompt outside hospital defibrillation/ reanimation restored pulse and allowed emergency room transfer on mechanical ventilation. Electrocardiogram showed an anterior myocardial infarction and early revascularization was achieved by anterior descending artery angioplasty. However, severe cardiogenic shock continued in spite of inotropic and intra aortic balloon pump support. Levitronix Centrimag® biventricular mechanical circulatory support was inserted during reanimation for recurrent ventricular fibrillation and the patient listed for urgent cardiac transplantation upon stabilization. Heart transplantation was performed successfully 28 days later and the patient was discharged after a 21-day recovery period. Twelve months after transplant the patient is in NYHA functional class I with normal biventricular function. Levitronix Centrimag® biventricular mechanical circulatory support could be used successfully as a bridge-to-transplant for myocardial infarction cardiogenic shock. <![CDATA[<b>Las expectativas futuras de la interleukina (IL)-35</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600015&lng=es&nrm=iso&tlng=es Purpose: To elucidate and discuss the role of IL-35 in immunity to parasitic and bacterial infections as well as in autoimmunity in terms of its anti-infammatory properties, we highlight significant findings on this novel member of the IL-12 family. Methods: Studies using genetically defcient mice have greatly enhanced our understanding of the biology of IL-35. On the basis of data derived from the analysis of these genetically deficient mice published by NIH, we focus on the key features of this heterodimeric cytokine, especially its relation to the other IL-12 family members, and discuss its potential relevance to the clinical usage. Principal fndings: IL-35 is required for the CD4+CD25+ Treg cells-mediated immune regulation, the alleviation of some inflammatory responses, as well as the expansion of CD4+CD25- Teff cells simultaneously. Moreover, administration or augmentation of IL-35 suppresses some diseases of autoimmune or allergic origin like collagen-induced arthritis or Helicobacter- induced colitis in animal models, demonstrating its potential in therapy of diseases mediated by inflammatory cytokines. However, some questions involving it are still unclear, including the composition of IL-35 receptor, IL-35-related cell signaling pathway, the different expression patterns of IL-35 between human and murine T cells, etc. Conclusion: As our understanding of the IL-35 is rapidly growing and changing, it will bring us more therapeutic strategies towards some intractable immune diseases such as Lupus Erythematosus.<hr/>Esta es una revisión acerca del rol de IL-35, un nuevo miembro de la familia IL-12, en la respuesta inmunitaria contra infecciones parasitarias y bacterianas y de su rol benefcioso en reacciones auto inmunes, debido sus propiedades antiinfamatorias. Basándose en estudios de ratones genéticamente defcientes se ha determinado que se requiere IL-35 para la acción inmunoreguladora de las células T reguladoras CD4+CD25+, para mitigar algunos procesos inflamatorios y para expandir simultáneamente los clones de células T efectoras CD4+CD25-. Mas aún, la administración o estimulación de la acción de IL-35 en modelos animales, suprime algunas enfermedades de origen alérgico o autoinmune tales como la colitis colágena y la colitis inducida por Helicobacter. Estos experimentos demuestran el potencial terapéutico de IL-35 en enfermedades mediadas por citokinas inflamatorias. Sin embargo, algunos aspectos de la citokina aún no han sido dilucidados, tales como la composición del receptor de IL-35, la vía de señalización celular asociada a IL-35 y los diversos patrones de expresión de la citokina en células humanas y de ratones. En la medida que aumente el conocimiento acerca de las acciones de IL-35, nos podrá proveer tratamientos para algunas enfermedades auto inmunes actualmente limitadas en su tratamiento, como el lupus eritematoso. <![CDATA[<b>Marcadores genéticos en hipertensión esencial</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600016&lng=es&nrm=iso&tlng=es Essential hypertension (HTA) is a multifactorial disease and in Chile, its prevalence is 33.7%. There is a genetic predisposition to develop hypertension, whose magnitude is approximately 30 to 50%. At present, some factors are known to increase the risk for cardiovascular disease, but widely accepted biomarkers for screening are missing. The frst studies that looked for candidate genes have focused on the reninangiotensin - aldosterone, aducina, adrenoreceptors ß, G protein subunits, G protein signaling regulators, kinases associated with G proteins and Rho kinases. Studies of DNA sequencing, search for polymorphisms and variants through single nucleotide polymorphisms, have been used to seek partnerships with complex or multifactorial diseases, like HTA. Examples of these are: components of collagen proteins, genes related to cell myocardial proteins belonging to cytochrome P450 and growth factors, among others. It is still unlikely to count in a near future with a universal marker. Most probably, a series of markers that confer susceptibility to a specifc individual will have to be used in prevention programs or personalized therapy. <![CDATA[<b>El diagnóstico diferencial entre la Depresión Bipolar y la Depresión Monopolar en la práctica clínica</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600017&lng=es&nrm=iso&tlng=es When assessing a patient with depression it is crucial not to miss a diagnosis of bipolar depression. In this review we suggest that it can be achieved, first, by consistently using standardised diagnostic criteria (e.g. DSM-IV-TR or ICD 10) and, second, by ascertaining the presence of some clinical features. The latter include previous episodes of mood elevation, current or past episodes of psychotic depression, onset of recurrent depressive disorder before the age of 25, a strong family history of mood disorder and suicide, lack of response or “wearing off” of response to well conducted antidepressant treatment, and an unusually fast response to antidepressants with features of elation. Although more and better research is required to establish the validity, sensitivity, specificity, and predictive value of each one of these features we suggest that from a practical point of view they would increase clinicians’ awareness of bipolar depression. <![CDATA[<b>¿Cuándo dos exámenes seriados de laboratorio representan un cambio en el estado de salud de un paciente?</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600018&lng=es&nrm=iso&tlng=es Sources of variation between two serial tests must be considered in interpreting if there was a clinically significant change. The main causes of variation are the biological variation coefficient (CVB) of the test in question, which must be obtained from the literature, and the analytical coefficient of variation (CVA) of the same test, which must be obtained from the internal quality control laboratory data. With both data we can calculate the critical difference or “reference change value” which helps us to decide whether there was a real change in the patient’s health. <![CDATA[<b>Dr. Rodolfo Armas Merino, MACP</b>: <b>Premio Nacional de Medicina 2010</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600019&lng=es&nrm=iso&tlng=es Sources of variation between two serial tests must be considered in interpreting if there was a clinically significant change. The main causes of variation are the biological variation coefficient (CVB) of the test in question, which must be obtained from the literature, and the analytical coefficient of variation (CVA) of the same test, which must be obtained from the internal quality control laboratory data. With both data we can calculate the critical difference or “reference change value” which helps us to decide whether there was a real change in the patient’s health. <![CDATA[<b>La ausencia de la proteína choreína se expresa como un trastorno obsesivo-compulsivo, descontrol de impulsos, movimientos anormales y acantocitosis</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600020&lng=es&nrm=iso&tlng=es Sources of variation between two serial tests must be considered in interpreting if there was a clinically significant change. The main causes of variation are the biological variation coefficient (CVB) of the test in question, which must be obtained from the literature, and the analytical coefficient of variation (CVA) of the same test, which must be obtained from the internal quality control laboratory data. With both data we can calculate the critical difference or “reference change value” which helps us to decide whether there was a real change in the patient’s health. <![CDATA[<b>Casuística de gammapatía monoclonal de significado incierto y mieloma múltiple en el Hospital Naval Almirante Nef, Viña del Mar, Chile</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600021&lng=es&nrm=iso&tlng=es Sources of variation between two serial tests must be considered in interpreting if there was a clinically significant change. The main causes of variation are the biological variation coefficient (CVB) of the test in question, which must be obtained from the literature, and the analytical coefficient of variation (CVA) of the same test, which must be obtained from the internal quality control laboratory data. With both data we can calculate the critical difference or “reference change value” which helps us to decide whether there was a real change in the patient’s health. <![CDATA[<b>Hacia la evaluación de "Chile Crece Contigo"</b>: <b>Resultados psicosociales del estudio piloto</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0034-98872010000600022&lng=es&nrm=iso&tlng=es Sources of variation between two serial tests must be considered in interpreting if there was a clinically significant change. The main causes of variation are the biological variation coefficient (CVB) of the test in question, which must be obtained from the literature, and the analytical coefficient of variation (CVA) of the same test, which must be obtained from the internal quality control laboratory data. With both data we can calculate the critical difference or “reference change value” which helps us to decide whether there was a real change in the patient’s health.