Non-Hodgkin Lymphoma Epidemiology in Children From 2 Socioeconomic Regions in Mexico: 20-Year Registry (1996-2015).

PURPOSE: We analyzed the epidemiologic characteristics of different types of non-Hodgkin Lymphoma (NHL), excluding Burkitt Lymphoma, in 2 Mexican regions with different socioeconomic status. MATERIALS AND METHODS: In this surveillance study, we analyzed the incidence rates (cases per million children/year) of different types of NHL according to the ICCC3, registered in 1996-2015, from 2 different socioeconomic regions in Mexico: central and southern, with higher and lower status, respectively. RESULTS: The principal NHL subgroups were precursor (IIb1), mature B cell (IIb2), mature T/NK cell, and no other specification (NOS; 42.3%, 15.8%, 14.1%, and 27.8%, respectively). In both regions, the overall incidence rates were similar (central=5.3, 95% confidence interval [CI], 4.6-6.1 vs. southern=6.3, 95% CI, 4.6-8.4); also, there were no differences by types (precursor cell LNH, 2.3 vs. 2.5; mature B cell, 0.9 vs. 0.8; mature T/NK cells, 0.8 vs. 0.8; and NOS, 1.4 vs. 2.3). In both regions, a decreasing trend was found (central= -0.17%, 95% CI, -0.03 to -0.3, P=0.04; southern= -0.32%, 95% CI, -0.07 to -0.57, P=0.02), with major reduction of NHL NOS from 1996 to 2000. In both regions, men predominated (2.1:1). CONCLUSIONS: Socioeconomic status did not influence the incidence rates of NHL. In this study, we found a reduction of NHL NOS, possibly due to better typing.

Information and Communication Technology, Mobile Devices, and Medical Education.

Information and communication technologies (ICT) are practical and highly available tools. In medical education, ICTs allow physicians to update their knowledge and remember the necessary information within reach of current mobile devices. ICTs as preparation tools for medical education have not been reported for medical students in Mexico. To assess the use of mobile devices as ICTs with medical education purposes, we distributed a questionnaire through an online survey management system to all the medical students (n = 180) from a private university in Mexico City, 100% agreed to participate. We developed a questionnaire based on previous surveys and adapted it to our university. All participants reported possession of an electronic mobile device, and 95% used it regularly for learning purposes. Regardless of the school year, the most frequent usage given to these devices was the search and reading of medical articles, the use of medical calculators, and taking notes. As the levels in career advances, there was a reduction in the use of electronic devices. According to the students, the main barriers towards using mobile devices for learning purposes were both the lack of access to the Internet and permission from the professor to use them. Most medical students use mobile devices for learning purposes, but usage changes during their education. It is convenient to encourage the use of mobile devices and the development of ICT skills as tools for educational purposes rather than banning their use in schools and hospitals.

Neurological repercussions of changes in cerebral blood flow in neonates undergoing cardiovascular surgery.

INTRODUCTION: Surgery for congenital heart disease can generate cerebral perfusion-associated alterations with neurological repercussions. OBJECTIVE: To analyze the relationship of peri-surgical cerebrovascular resistance index (RI) with mediate neurological functions after congenital heart disease surgery. METHOD: Prospective cohort study of 34 neonates in whom basilar artery RI, serum oxygen, carbon dioxide and lactate levels were determined before and after palliative or corrective procedures. We related pre-surgical RI with post-surgical ability to initiate the enteral route or to restore unassisted spontaneous breathing. RESULTS: Three groups were formed: 79 neonates with high RI (> 0.73), 73 with normal RI (0.63 to 0.73) and eight with low RI (< 0.63). In the former group, high RI persisted in the postoperative period, with persistent hyperlactatemia and hypoxia; in 86 %, the enteral route could not be initiated, and neither could assisted ventilation be withdrawn. In the second group, RI remained within normal values. In the third group, although RI, serum lactate and arterial oxygen pressure tended to normalize, 71 % had severe neurological damage. CONCLUSIONS: RI changes were common, although neurological damage appears to occur more commonly when RI remains high, possibly associated with low cerebral blood flow.

INTRODUCCIÓN: La cirugía de cardiopatías congénitas puede generar alteraciones perfusorias cerebrales con repercusión neurológica. OBJETIVO: Analizar la relación del índice de resistencia (IR) vascular cerebral periquirúrgico con funciones neurológicas mediatas posteriores a cirugía de cardiopatía congénita. MÉTODO: Estudio de cohorte prospectivo de 34 neonatos en quienes se determinó IR de la arteria basilar, niveles séricos de oxígeno, dióxido de carbono y lactato, antes y después de procedimientos paliativos o correctivos. Relacionamos el IR prequirúrgico con la capacidad posquirúrgica para iniciar la vía enteral o restablecer la respiración espontánea no asistida. RESULTADOS: Se integraron tres grupos: 79 neonatos con IR alto > 0.73, 73 con IR normal de 0.63 a 0.73 y ocho con IR bajo < 0.63. En los primeros persistió IR elevado en el posquirúrgico, con hiperlactatemia e hipoxia persistentes; en 86 % no se logró iniciar la vía enteral ni retirar la ventilación asistida. En los segundos, el IR se mantuvo en valores normales. En los terceros, si bien el IR, el lactato sérico y la presión arterial de oxígeno tendieron a normalizarse, 71 % presentó daño neurológico grave. CONCLUSIONES: Los cambios en el IR fueron frecuentes, aunque el daño neurológico parece presentarse más cuando el IR se mantiene alto, posiblemente asociado con flujos cerebrales bajos.

Importancia del "diagnóstico temprano" en los niños con cáncer para mejorar el pronóstico: concepto con poco sustento científico.

La mortalidad por cáncer en niños mexicanos no ha disminuido a los niveles informados en países desarrollados. Una explicación frecuentemente declarada es el alto porcentaje (57.3 %) de pacientes diagnosticados en estadios avanzados (III/IV), atribuible a errores en la sospecha o en la metodología empleada, consideración dudosa si se toma en cuenta que el tiempo de diagnóstico y la proporción de estadios avanzados en México son semejantes a los de países desarrollados. En la mayoría de los niños con cáncer, los días transcurridos desde el primer síntoma a momento del diagnóstico oncológico no correlacionan con el estadio clínico y tampoco con la probabilidad de supervivencia. El éxito en la supervivencia depende en gran medida del tratamiento integral (específico y de la atención a las complicaciones). Esta visión obliga a estrategias dirigidas principalmente a invertir más recursos en opciones terapéuticas eficaces y eficientes, capacitación oncológica integral del equipo de salud (médicos, enfermeras, técnicos), tecnologías diagnósticas, fomento a la colaboración interinstitucional e internacional y apoyo socioeconómico a las familias durante el proceso terapéutico.Cancer mortality in Mexican children has not decreased to the levels reported in developed countries. A commonly proposed explanation is the high percentage (53.7%) of patients diagnosed at advanced stages (III/IV), which is attributed to erroneous assumptions or mistakes in the diagnostic approach ­a questionable consideration taking into account that both time to diagnosis and the proportion of advanced stage cases in Mexico are similar to those in developed countries. In most cancer cases in children, the number of days elapsed from the moment of the first symptom to the cancer diagnosis is not correlated with clinical stage, and neither with the probability of survival. Survival success largely depends on comprehensive treatment (specific and for the care of complications). This view calls for strategies mainly aimed at spending more resources on efficacious and efficient therapeutic strategies, comprehensive oncology training of healthcare personnel (physicians, nurses and technicians), diagnostic technologies, promotion of interinstitutional and international collaboration and socioeconomic support to families during the therapeutic process.

Cancer incidence and mortality in children in the Mexican Social Security Institute (1996-2013).

OBJECTIVE: To identify the cancer incidence and mortality in Mexican Social Security Institute beneficiary (MSSI-B) children during 1996-2013. MATERIALS AND METHODS: Both cancer cases (n=4 728) and deaths (n=2 378) were analyzed in MSSI-B children who were registered in five states of the Mexican Republic. The incidence and mortality trends and the incidences (rate x 1 000 000 children / year) of the type of cancer, age, sex, and place of residence were obtained. RESULTS: For both indicators (incidence and mortality), there was a downward trend for the period of 1996-2001 and a stable trend for 2002-2013. This occurred in the overall mortality and incidence trends of the Estado de México and Chiapas and in the leukemia and the acute lymphoid subgroups. The annual overall incidence was 128 cases per 1 000 000 children. Leukemia, lymphomas, and central nervous system tumors were the principal cancer groups. CONCLUSIONS: Cancer mortality for the period of 2002-2013 did not diminish. Interinstitutional and/or international research should be designed to improve the care of these children.

Childhood lymphoma incidence patterns by ICCC-3 subtype in Mexico City metropolitan area population insured by Instituto Mexicano del Seguro Social, 1996-2010.

PURPOSE: We reviewed the childhood lymphomas epidemiological data for the Mexico City metropolitan area (MCMA). METHODS: Data analysis from children (0-14 years old) diagnosed with lymphoma during the period 1996-2010 was performed at the Mexican Childhood Cancer Registry. Histological subtype was determined according to the International Classification of Childhood Cancer 3 (ICCC-3). Age-adjusted incidence rates were calculated per 1,000,000 children/year by age, gender, and ICCC-3 subtype; trends, by average annual percent change (AAPC). RESULTS: A total of 328 lymphoma cases included in the study had an incidence rate of 11.8, showing a decreasing trend [AAPC: -3.5; CI 95% (-5.9, -1.0)], primarily due to non-Hodgkin lymphomas (NHL) and Hodgkin lymphoma (HL) mixed cellularity subtype. NHL had the major incidence (5.8), with the precursor cell subtype being the most frequent (38.3%). Nodular sclerosis was the most frequent HL subtype. The incidence of Burkitt lymphoma was low (1.3). During the study period, there was an important reduction in the not-otherwise-specified subtype of NHL, which translated into a relative increase in the IIb3 subtype [AAPC: 7.3 (1.2, 13.8)]. Low incidences of NHL and of HL and NHL were found for < 1-year-olds and for 10- to 14-year-olds, respectively. Incidence rates for children in the MCMA, particularly the < 1 and 10-14 age groups, were lower than those for developed countries. The overall male/female ratio was 2.3. CONCLUSIONS: There was a trend toward a reduced incidence, for some lymphoma subtypes, in particular for NOS lymphomas, which may be the result of improvement in diagnostic techniques.

[Medical treatment of the uterine miomas in perimenopausal patients]. / Tratamiento de los miomas uterinos con medroxiprogesterona en pacientes perimenopáusicas.

BACKGROUND: Leiomyomas are the most common benign tumors of the uterus, frequently associated with abnormal uterine bleeding. Medroxyprogesterone (MP) acetate it is a therapeutic alternative. OBJECTIVE: To determine the efficacy of the medroxyprogesterone for abnormal uterine bleeding associated with leiomyomatosis in perimenopause women. METHODS: An observational, prospective, longitudinal study. We selected 31 patients with uterine myomas and abnormal uterine bleeding. Two years monthly doses of 150 mg of MP were given. If the bleeding did not stop at six months of treatment or increased a hysterectomy was performed. RESULTS: Two (6.4%) patients abandoned the treatment after a first doses; 21 (67.7%) completed the treatment without uterine bleeding (efficacy observed of 72.4%; CI 95% 54.4 to 90.4%, intention to treat efficacy 67.7%, CI 95% 49.6 to 86.8%). Eight (25.8%) patients persisted with uterine bleeding before 6 months of treatment and a hysterectomy was performed. There was no severity secondary effect informed. CONCLUSIONS: Management with medroxyprogesterone may be an effective treatment to control the uterine bleeding associated with myomatosis. Their use could reduce the necessity of some hysterectomies.

Children's perception on obesity and quality of life: a Mexican survey.

BACKGROUND: Child obesity has become a major health problem worldwide. In order to design successful intervention strategies, it is necessary to understand how children perceive obesity and its consequences. METHODS: With the aim to evaluate scholar children perception of obesity as a significant factor on the quality of life, we developed and validated the "Obesity impact on the quality of life perception-questionnaire" (ObI-Q). We surveyed 1335 healthy children aged 6-12 years, randomly selected from elementary schools in Mexico City. The ObI-Q comprises eight multiple-choice items that explore aspects related to the quality of life during adult life; such as health, life span, emotional status, lifestyle, social recognition and economic status. In order to identify perceptional modifier factors, results were analyzed through multivariable logistic regression. Variables included gender, age, and child nutritional status, as well as the child's perception of parental nutritional status. RESULTS: ObI-Q results showed that most children (64.71%) considered obesity as a negative condition that influences health and social performance. This perception was inversely related to age (OR = 0.64, p = 0.003), as well as to the perception of their mother nutritional status (OR = 0.47, p = 0.01). CONCLUSIONS: This study provides an overview of children's perception on obesity and its consequences. Because the high proportion of schoolchildren who do not view obesity as an adverse consequence to the quality of life, then the results of this study could be used as part of strategies for the prevention of overweight and obesity.

Efficiency and Safety of CyberKnife Robotic Radiosurgery in the Multimodal Management of Patients with Acromegaly.

OBJECTIVE: To analyze, in a cohort of acromegalic patients, the results of the efficiency and safety of radiosurgery (CyberKnife), as well as the prognostic factors associated with disease remission. MATERIAL AND METHODS: Observational, retrospective, longitudinal, and analytical study that included acromegalic patients with persistent biochemical activity after initial medical-surgical treatment, who received treatment with CyberKnife radiosurgery. GH and IGF-1 levels at baseline after one year and at the end of follow-up were evaluated. RESULTS: 57 patients were included, with a median follow-up of four years (IQR, 2-7.2 years). The biochemical remission rate was 45.6%, 33.33% achieved biochemical control, and 12.28% attained biochemical cure at the end of follow-up. A progressive and statistically significant decrease was observed in the comparison of the concentrations of IGF-1, IFG-1 x ULN, and baseline GH at one year and at the end of follow-up. Both cavernous sinus invasion and elevated baseline IGF-1 x ULN concentrations were associated with an increased risk of biochemical non-remission. CONCLUSION: Radiosurgery (CyberKnife) is a safe and effective technique in the adjuvant treatment of GH-producing tumors. Elevated levels of IGF x ULN before radiosurgery and invasion of the cavernous sinus by the tumor could be predictors of biochemical non-remission of acromegaly.

[Methodology for the elaboration of prognosis studies]. / Metodología para la elaboración de los estudios sobre pronóstico.

Prognostic studies are investigations to estimate the risk or probability of future outcomes in people with established disease. Ideally based on cohort studies where it is established: the time of onset or analysis of the evolution of a disease, the follow-up period for the outcome of interest, the type of outcome and the prognostic factors or markers to investigate. Ultimately, the decision on how to run and analyze forecast studies will depend on their purpose: exploratory, explanatory, or predictive.

Los estudios pronósticos son investigaciones para estimar el riesgo o probabilidad de desenlaces futuros en las personas con una enfermedad establecida. Idealmente deben sustentarse en estudios de cohortes en los que se establece el momento de inicio o de análisis sobre la evolución de una enfermedad, el periodo de seguimiento al desenlace de interés, el tipo de desenlace y los factores o marcadores pronósticos por investigar. Finalmente, la decisión de la forma de ejecutar y analizar los estudios de pronóstico dependerá de su propósito: exploratorio, explicativo o predictivo.

Differential fetal growth rates mediated by sociodemographic factors in Yucatan, Mexico: an epidemiological study.

BACKGROUND: Fetal growth restriction (FGR) may be related to ethnicity. Additionally, ethnic groups experience adverse socioeconomic circumstances that increase FGR risk. However, the dearth of evidence of the interaction between socioeconomic factors and FGR highlights the need for additional research. OBJECTIVE: To analyze the association between socioeconomic factors and FGR in Maya and non-Maya populations in Yucatan, Mexico. METHODS: A total of 21,320 singleton births in 2017 in Yucatan were analyzed. The student's t-test and the chi-square test were used to compare the means and proportions of maternal and perinatal variables between the FGR group and the birthweight appropriate for gestational age (AGA) group. Path analysis was performed to identify the direct and indirect effects of socioeconomic factors on FGR and mediators between predictors and FGR. RESULTS: The prevalence of FGR at birth was 9.06%; this rate was higher in the Maya population (12.4, 95% CI 11.3-13.5), without differences between socioeconomic levels. Path analysis revealed sociostructural variables (ethnicity and poverty) are reliable predictors of FGR at birth mediated by maternal education (ß = -.152, p < .001) and teenage pregnancy (ß = .065, p = .037). The proposal path model had a good fit index CFI = .968, TLI = .920, RMSEA = .046. CONCLUSION: The prevalence of FGR was higher among Maya women than non-Maya women The socioeconomic conditions associated with FGR at birth were ethnicity, poverty, maternal education, and teenage pregnancy. Maternal education and teenage pregnancy act as mediators between sociostructural variables and FGR at birth.

Risk Factors Associated with Mortality among Patients with COVID-19: Analysis of a Cohort of 1213 Patients in a Tertiary Healthcare Center.

The presence of cardio-metabolic and respiratory comorbidities, immunosuppression, and chronic kidney disease have been associated with an increase in mortality from COVID-19. The objective of this study is to establish the risk factors associated with 30-day mortality in a cohort of hospitalized patients with COVID-19. This paper conducts a retrospective and analytical study of patients hospitalized for COVID-19 in a tertiary care center. A Cox proportional hazard analysis was performed to estimate the association of comorbidities with 30-day mortality. A total of 1215 patients with a median age of 59 years were included. In the adjusted Cox proportional hazards regression model, hypothyroidism, D-dimer ≥ 0.8 µg/mL, LHD ≥ 430 IU/L, CRP ≥ 4.83 ng/mL, and triglycerides ≥ 214 mg/dL were associated with an increased risk of death. The presence of a history of hypothyroidism and biomarkers (D-dimer, lactic dehydrogenase, CRP, and triglycerides) were associated with an increase in mortality in the studied cohort.

[The pediatric patient at the end-of-life. A challenge for its identification and treatment. A survey in pediatricians and medical residents]. / El paciente pediátrico en etapa terminal: un reto para su identificación y tratamiento. Encuesta a médicos pediatras y residentes.

BACKGROUND: Identification of pediatric patients at the end-of-life is not easy because criteria used are based on adults' criteria. OBJECTIVES: In this survey we explore the children end-of-life definition pediatricians have, as well as to determine which interventions they use when caring a patient at end-of-life. SETTING: Tertiary referral pediatric hospital. PARTICIPANTS: Staff pediatricians (SP) and medical residents (MR). METHODS: A self-administrated questionnaire was built and validated. It contains five vignettes of pediatric patients: Two with WHO criteria for an end-of-life condition (EC) and three without an end-of-life condition (NEC). PARTICIPANTS identified each patient with or without an end-of-life condition, and which palliative actions they would perform accordingly Their responses were recorded in a 4-option Likert scale. Ordinal regression was used to assess if some of the participants' characteristics were related to the identification of an end-of-life condition. RESULTS: Response rate was 84.2% (128/152); of whom 63 were SP and 65 MR. EC cases were well identified in 90 and 93%, while NEC in 30 and 40%, respectively Palliative actions were more according in EC patients, but around 20% would not provide them. Among NEC patients, there were more disparities of palliative actions to be delivered, and it was statistically significantly. Ordinal regression showed that some participants' characteristics are associated to the appropriate identification of end-of-life patients; however, these factors were not consistent across the five scenarios. CONCLUSIONS: Among pediatricians, criteria of end-of-life conditions are not well established, neither the palliative actions. Educational interventions are needed to improve the quality of life of these children.

[Cancer in children from Morelos state]. / Cáncer en niños residentes del estado de Morelos.

A total of 183 new cases of childhood cancer were registered in the state of Morelos during the period understudy (1996-2007). Taken together, leukemias (45.4%), tumors of the central nervous system (CNST, 13.1%), and lymphomas (10.4%) represented 68.9 % of the total cases. The overall incidence was 141.9 (all rates per 1000 000 children/year), with leukemias having the highest incidence (60.9 per 1,000,000 children/year). By age, children under one year of age had the highest incidence (201.2 per 1 000 000 children/year). The male/female ratio was 1.1. Leukemias and bone tumors showed a tendency to decrease (average annual percent change, AAPC -5.3; CI 95% -8.7, -1.9; and AAP -9.5, CI 95% -17.7, -0.6, respectively. Of the cases of children with solid tumors, 59.4 % was diagnosed in either stage III or IV.

[Cancer epidemiology in Mexican children. Overall results]. / Epidemiología del cáncer en niños mexicanos. Resultados globales.

A total of 3238 new cases of childhood cancer were registered during the period under study (1996-2007). These cases showed predominately the Northamerican/European pattern of neoplasias: leukemias were the most frequent (46.1%), followed by tumors of the central nervous system (CNST, 12.0%), and lymphomas (10.8%); the overall incidence was 125.6 (all rates per 1000 000 children/year), with incidences of 136.3, 164.1, 95.2, 114.7, for < 1, 1-4, 5-9, 10-14 age group, respectively. Compared to children in the United States, Mexican children had a greater incidence of leukemias, retinoblastomas, and germ cell tumors; a lower incidence of CNST, neuroblastomas, kidney tumors, soft-tissue sarcomas, and carcinomas; and similar incidences of lymphomas, liver tumors, and bone tumors. The male/female ratio was 1.1 and the highest incidence was found for those less than five years of age. Overall, the incidence showed a trends to decrease (average annual percent change (AAPC), -3.3; CI 95%, -6.3, -0.1), with the greatest decrease during the period 1996-2000 (AAPC, -7.9; CI 95%, -15.5, 0.3) and remaining stable thereafter (2000-2007) (AAPC, -0.5; CI 95%, -4.0, 3.2). Stages III and IV were found in 57.4 % of the cases of solid tumors.

[Risk, association, and impact measures in clinical research studies. How to interpret them for their application in medical care]. / Medidas de riesgo, asociación e impacto en los estudios de investigación clínica. Cómo interpretarlas para su aplicación en la atención médica.

The practice of evidence-based medicine includes the critical analysis of clinical research studies, and, within it, the interpretation of the results reported. In addition, to statistical data, there are estimators that can help clinicians transfer research findings to routine clinical practice. These estimators are measures of risk, association, and impact. Risk measures report current uncertainty or probability (prevalence of a disease, sensitivity, specificity) or for future events (cumulative incidence, incidence density). Measures of association are related to the identification of the risk in order to determine whether certain factors increase or decrease the probability of development of a disease (relative risk, odds ratio, hazard ratio). While measures of impact allow, among other things, to estimate the effect of a treatment (relative risk reduction, absolute risk reduction, number needed to treat). In this review, each of these estimators is described, defined, and presented with examples.

Parte del ejercicio de la medicina basada en evidencia incluye el análisis crítico de los estudios de investigación clínica y dentro de este, la interpretación de los resultados presentados. Además de los datos estadísticos, existen estimadores que pueden ayudar a los clínicos a trasladar los hallazgos de las investigaciones a la práctica clínica habitual. Estos estimadores son las medidas de riesgo, asociación e impacto. Las medidas de riesgo informan sobre la incertidumbre o probabilidad en el presente (prevalencia de una enfermedad, sensibilidad, especificidad) o para eventos futuros (incidencia acumulada, densidad de incidencia). Las medidas de asociación se relacionan con la identificación del riesgo para determinar si ciertos factores aumentan o disminuyen la probabilidad del desarrollo de una enfermedad (riesgo relativo, razón de momios, cociente de riesgo). Mientras que las medidas de impacto permiten, entre otros, estimar el efecto de un tratamiento (reducción del riesgo relativo, reducción del riesgo absoluto, número necesario por tratar). En esta revisión se describen, definen y presentan ejemplos de cada uno de estos estimadores.

[Statistical methods for effect size analysis]. / Métodos estadísticos para el análisis del tamaño del efecto.

Informing in the studies about the effect size of an intervention or the impact of the factor(s) about an outcome, allows better decision-making for the application of the results in clinical practice. This article presents different methods to analyze the effect size, which can be through direct or indirect statistical methods. Within the direct methods, there's the difference in means between groups and the difference of absolute or relative frequencies. Among the indirect methods, Cohen's "d" family (which are based on standard deviation values), the "r and R2" family, measures of association (e.g. OR, RR, HR), and impact measures (e.g. NNT) are shown. The decision to use any of these methods depends on the objectives of the study and the measuring scale that is used to assess the results, as well as the data distribution. In order to enhance the understanding of the methods described in this article, examples are included, and the need to include level of precision (e.g. confidence intervals) is highlighted, along with the clinical decision thresholds for a better interpretation.

Informar en los estudios sobre el tamaño del efecto de una intervención o del impacto de factor(es) sobre un desenlace, permite tomar mejores decisiones para la aplicación de los resultados a la práctica clínica. En este artículo se presenta la manera de analizar el tamaño del efecto, lo cual puede ser mediante métodos estadísticos directos o indirectos. Dentro de los métodos directos, se encuentra la diferencia de promedios entre grupos y la diferencia de frecuencias absolutas o relativas. Dentro de los métodos indirectos se muestran los índices de la familia de "d" de Cohen (que se basan en valores de desviación estándar), la familia de "r y R2", medidas de asociación (RM, RR, HR) e impacto (NNT). La decisión del uso de cualquiera de los métodos descritos, depende de los objetivos del estudio, la escala de medición usada para evaluar los resultados y la distribución de los datos. Para facilitar la comprensión, se incluyen ejemplos y se resalta la necesidad de incluir los diferentes estadísticos con su nivel de precisión (ej. intervalos de confianza), junto con los umbrales clínicos de decisión, a fin de mejorar su interpretación.

Risk factors associated with thyroid nodular disease in acromegalic patients: A case-cohort study in a tertiary center.

INTRODUCTION: Goiter is very common in patients with acromegaly; its development is correlated to the duration of the disease. Thyroid cells express the IGF-1 receptor and the TSH/IGF-1 interaction has been demonstrated to have a synergistic effect in thyroid cell growth. There is a correlation between IGF-1 levels and the thyroid volume of patients with acromegaly. The aim of this study was to evaluate, in a retrospective case-cohort study of patients with acromegaly, the associated risk factors for thyroid nodules disease in this population. METHODS: This was a case-cohort study matched by age, gender, and growth hormone at diagnosis. Cases consisted of acromegalic patients that developed thyroid nodules during the follow up, and controls consisted in acromegalic patients without thyroid nodules. A Cox proportional hazard estimation was carried out for measure the associated risk factors for thyroid nodules disease in acromegalic patients. A nodular thyroid disease-free survival analysis was estimated using the Kaplan-Meier analysis. RESULTS: We recruited 49 cases and 56 controls. In a multivariate Cox proportional hazard analysis age and IGF-1 ≥ 2.2 x ULN were significantly related with the presence of thyroid nodules [HR of 2.21 (95% CI; 1.15-4.25, p = 0.01)]. Nodularity-free survival rates in patients who had an IGF-1 X ULN ≥ 2.2 was found to be lower in comparison to those who had IGF-1 X ULN < 2.2, according to a Kaplan-Meier survival analysis. CONCLUSIONS: Our findings support that exist more probability to develop thyroid nodular disease in patients with acromegaly that present IGF-1 X ULN ≥ 2.2, suggesting a possible direct effect between the time of exposure to the IGF-1 axis hyperactivity and the genesis of thyroid nodules.

[The third dimension tomography versus cranial X-ray cephalometry to predict maxilla advance by distraction in hypoplastic maxilla]. / Cefalometría tomográfica en 3D y radiografía craneal para predecir avance maxilar en hipoplasia maxilar.

BACKGROUND: the osteogenic distraction is the treatment for the correction of the hypoplastic maxilla secondary to the repair of a cleft lip-palate. Its planning is based on articulated models. Our objective was to describe the accuracy of three-dimensional Cephalometry (CT3D) for projecting jaw displacement. METHODS: three patients with hypoplastic maxilla. Interventions estimation of the advance required of lateral maxilla through Cephalometry of skull (CLC), CT3D and an articulated model (gold standard). Two months after distraction finalized the advance predicted was compared. RESULTS: the error of the advance projection in each patient was smaller with the CT3D versus CLC (+1, +1 and +1 mm versus -10, -14 and -9mm). Corrections post-distraction were of +25 %, +26 % and +38.4 % on the programmed one. CT3D predicted better the correction (+19 %, +10.8 %, +33.4 % versus CLC: -50 %; -60.8 % and -34.6 %). Chewing alterations were not seen in any patient. CONCLUSIONS: the planning of the necessary advance for distraction in patients with hypoplastic maxilla by CT3D can shorten the time of studies and should be consider as next to the projection of articulated model.

[Therapeutic conduct in children attended in emergency room during the epidemic of influenza A H1N1]. / Conducta terapéutica en niños atendidos en urgencias durante la epidemia de influenza A H1N1.

OBJECTIVE: To analyze the prescription of antiviral and antibiotic agents in children with upper airway infection (UAI) during Influenza H1N1 epidemic. METHODS: A cross-section study (01/04/2009 to 31/03/2010) was performed. We analyzed the antiviral and antibiotic agents' prescription and its relation with the presence of the triad of symptom of suspicion (migraine, fever and cough) and the cost for attention (medicines and screening test). RESULTS: 838 children were attendance for UAI, 40.3% with the suspicion triad. In 733 patients, the screening test were done with 155 positive results (120 had the triad). All patient with a positive result received oseltamivir. During the first five months of the epidemic, the medical prescriptions were: antibiotics 60-85%, 0-7% anti-viral and 20-30% symptomatic drugs. At the 6th at 8th months (peak of outbreak) antibiotics 35-70%, antivirals 20-25% and 10-30% symptomatic drugs. At final months (9th to 11th) antimicrobials 65-80%, antivirals 20-30% and symptomatic 0-10%. The cost for URI attention increased a 27%. CONCLUSIONS: Medical prescription changed during the epidemic, with an increased in the antivirals, especially for patients with high suspicion for influenza and positive screening test.