Viviana Pineda

What Is the Methodologic Quality of Human Therapy Studies in ISI Surgical Publications

Objective:To determine the methodologic quality of therapy articles about humans published in ISI surgical journals, and to explore the association between methodologic quality, origin, and subject matter. Summary Background Data:It is supposed that ISI journals contain the best methodologic articles. Methods:This is a bibliometric study. All journals listed in the 2002 ISI under the subject heading of “Surgery” were included. A simple randomized sampling was conducted for selected journals (Annals of Surgery, The American Surgeon, Archives of Surgery, British Journal of Surgery, European Journal of Surgery, Journal of the American College of Surgeons, Surgery, and World Journal of Surgery). Published articles related to therapy on humans of the selected journals were reviewed and analyzed. All kinds of clinical designs were considered, excluding editorials, review articles, letters to the editor, and experimental studies. The variables considered were: place of origin, design, and the methodologic quality of articles, which was determined by applying a valid and reliable scale. The review was performed interchangeably and independently by 2 research teams. Descriptive and analytical statistics were used. Statistical significance was defined as P values less than 1%. Results:A total of 653 articles were studied. Studies came predominantly from the United States and Europe (43.6% and 36.8%, respectively). The subject areas most frequently found were digestive and hepatobiliopancreatic surgery (29.1% and 24.5%, respectively). Average and median methodologic quality scores of the entire series were 11.6 ± 4.9 points and 11 points, respectively. The association between methodologic quality and journals was determined. Also, the association between methodologic quality and origin was observed, but no association with subject area was verified. Conclusions:The methodologic quality of therapy articles published in the journals analyzed is low; however, statistical significance was determined between them. Association was observed between methodologic quality and origin, but not with subject matter.

Surgery for Morbid Obesity: Selection of Operation Based on Evidence from Literature Review

Background: Bariatric surgery is the therapy for morbid obesity. There are a number of surgical procedures, which are performed by open surgery (OS) and more recently also by laparoscopy (LS). The objective of this study was to consider the evidence for the best bariatric surgical options. Methods: Systematic review of the literature was conducted. Morbid obesity studies published between 1990 and 2002 were analyzed. MEDLINE, LiLACS and COCHRANE databases were used, utilizing MeSH terms and free words. Selected studies were analyzed using a specially designed score of methodological quality, to analyze and compare studies. This validated scale is composed by 3 items, and the final score may range between 6 and 36 points. Means, medians and weighted means were calculated, and a comparative analysis by therapy was performed using median 95% confidence intervals (CI). Number of treated patients, reduction in body mass index (BMI), reduction in co-morbidity, %EWL, morbidity and mortality, hospital stay, follow-up, success and failure of operations, and methodological quality were analyzed. Results: 283 related articles were considered. Only 31 of them had selection criteria (these include 5,216 patients operated by OS and 3,230 by LS). Operative mortality was 0.0% for OS and 0.4% for LS. At 36 months, OS techniques show reduction in BMI, %EWL and reductions in co-morbidity of 30.9%, 61.9% and 74.1% respectively. At 36 months, LS techniques show reduction in BMI, %EWL and reduction in comorbidity of 23.7%, 55.9% and 70.9%. Hospital stay was 3.8 days for LS and 7 for OS. At 2-year follow-up, morbidity was 14.8% for LS and 16.7% for OS, and reoperations were 17.7% for LS and 11.3% for OS.Median score for methodological quality was 13 for OS and 11 for LS. Conclusions: Methodological quality of primary studies to 2002 has been poor.

Factors associated with morbitity in liver hydatid surgery

Background:  The purpose of the present paper was to determine the association between clinical evolutionary and laboratory variables with postoperative morbidity in patients surgically treated for liver hydatidosis (LH).

Systematic Review of Literature with Different Types of Designs

En ciertas situaciones, en especial frecuentes en el ambito de la cirugia y sus disciplinas afines (donde lo que predomina son estudios de tipo observacional), la conduccion de ensayos clinicos con asignacion aleatoria (EC) es muy dificil; por ende, realizar revisiones sistematicas (RS) con base en EC y posteriormente meta-analizar la informacion lo es aun mas. Por esta razon hemos generado una metodologia para realizar RS con diferentes tipos de disenos (incluyendo estudios observacionales), como una alternativa para aclarar la incertidumbre en el ambito de la terapia cuando existen pocos EC y la evidencia se apoya fundamentalmente en estudios descriptivos y observacionales. El objetivo de este estudio fue exponer una metodologia para conducir RS con diversos tipos de disenos. La metodologia, se basa en la ponderacion de los diferentes estudios primarios a traves de la aplicacion de un escore de calidad metodologica compuesto por 3 items (tipo de diseno del estudio, tamano de la poblacion estudiada y metodologia empleada en el estudio). Una vez asignado un puntaje se aplica un calculo de promedios ponderados con sus respectivos intervalos de confianza del 95% a cada variable que se desee estudiar, lo que permite finalmente realizar un meta-analisis y comparar grupos. Se presenta una propuesta metodologica para conducir RS con diversos tipos de disenos.

Clinical relevance of ErbB-2/HER2 nuclear expression in breast cancer

BackgroundThe biological relevance of nuclear ErbB-2/HER2 (NuclErbB-2) presence in breast tumors remains unexplored. In this study we assessed the clinical significance of ErbB-2 nuclear localization in primary invasive breast cancer. The reporting recommendations for tumor marker prognostic studies (REMARK) guidelines were used as reference.MethodsTissue microarrays from a cohort of 273 primary invasive breast carcinomas from women living in Chile, a Latin American country, were examined for membrane (MembErbB-2) and NuclErbB-2 expression by an immunofluorescence (IF) protocol we developed. ErbB-2 expression was also evaluated by immunohistochemistry (IHC) with a series of antibodies. Correlation between NuclErbB-2 and MembErbB-2, and between NuclErbB-2 and clinicopathological characteristics of tumors was studied. The prognostic value of NuclErbB-2 in overall survival (OS) was evaluated using Kaplan-Meier method, and Cox model was used to explore NuclErbB-2 as independent prognostic factor for OS.ResultsThe IF protocol we developed showed significantly higher sensitivity for detection of NuclErbB-2 than IHC procedures, while its specificity and sensitivity to detect MembErbB-2 were comparable to those of IHC procedures. We found 33.6% NuclErbB-2 positivity, 14.2% MembErbB-2 overexpression by IF, and 13.0% MembErbB-2 prevalence by IHC in our cohort. We identified NuclErbB-2 positivity as a significant independent predictor of worse OS in patients with MembErbB-2 overexpression. NuclErbB-2 was also a biomarker of lower OS in tumors that overexpress MembErbB-2 and lack steroid hormone receptors.ConclusionsWe revealed a novel role for NuclErbB-2 as an independent prognostic factor of poor clinical outcome in MembErbB-2-positive breast tumors. Our work indicates that patients presenting NuclErbB-2 may need new therapeutic strategies involving specific blockage of ErbB-2 nuclear migration.

Progesterone receptor assembly of a transcriptional complex along with activator protein 1, signal transducer and activator of transcription 3 and ErbB-2 governs breast cancer growth and predicts response to endocrine therapy

IntroductionThe role of the progesterone receptor (PR) in breast cancer remains a major clinical challenge. Although PR induces mammary tumor growth, its presence in breast tumors is a marker of good prognosis. We investigated coordinated PR rapid and nonclassical transcriptional effects governing breast cancer growth and endocrine therapy resistance.MethodsWe used breast cancer cell lines expressing wild-type and mutant PRs, cells sensitive and resistant to endocrine therapy, a variety of molecular and cellular biology approaches, in vitro proliferation studies and preclinical models to explore PR regulation of cyclin D1 expression, tumor growth, and response to endocrine therapy. We investigated the clinical significance of activator protein 1 (AP-1) and PR interaction in a cohort of 99 PR-positive breast tumors by an immunofluorescence protocol we developed. The prognostic value of AP-1/PR nuclear colocalization in overall survival (OS) was evaluated using Kaplan-Meier method, and Cox model was used to explore said colocalization as an independent prognostic factor for OS.ResultsWe demonstrated that at the cyclin D1 promoter and through coordinated rapid and transcriptional effects, progestin induces the assembly of a transcriptional complex among AP-1, Stat3, PR, and ErbB-2 which functions as an enhanceosome to drive breast cancer growth. Our studies in a cohort of human breast tumors identified PR and AP-1 nuclear interaction as a marker of good prognosis and better OS in patients treated with tamoxifen (Tam), an anti-estrogen receptor therapy. Rationale for this finding was provided by our demonstration that Tam inhibits rapid and genomic PR effects, rendering breast cancer cells sensitive to its antiproliferative effects.ConclusionsWe here provided novel insight into the paradox of PR action as well as new tools to identify the subgroup of ER+/PR + patients unlikely to respond to ER-targeted therapies.

Resección abierta frente a laparoscópica en el cáncer de colon no complicado. Revisión sistemática

Resumen Introduccion El objetivo de este trabajo es determinar la mejor alternativa terapeutica con criterio curativo para pacientes con cancer de colon no complicado mediante la comparacion de las resecciones abiertas y laparoscopicas. Pacientes y metodo Se realizo una revision sistematica de la bibliografia. Se analizaron los estudios realizados en adultos con cancer de colon no complicado tratados con reseccion abierta y reseccion laparoscopica, publicados entre 1990 y 2002. Se utilizaron las bases de datos MEDLINE, LILACS y COCHRANE, y se utilizaron los terminos MeSH y palabras libres. Los estudios seleccionados fueron analizados mediante un score de calidad metodologica. Se consideraron las siguientes variables: numero de pacientes tratados, supervivencia actuarial y libre de enfermedad a los 3 anos, recurrencia, morbilidad, mortalidad y calidad metodologica de los estudios primarios. Se calcularon los promedios, las medianas, los valores extremos y los promedios ponderados, y posteriormente se comparo la calidad metodologica de los estudios primarios agrupados, para lo que se utilizaron los intervalos de confianza del 95% de las medianas. Resultados Se encontraron 680 articulos relacionados, de los cuales se analizaron 11. La estancia hospitalaria fue de 10,1 dias para la reseccion abierta y de 6,5 dias para la reseccion laparoscopica. La morbilidad fue del 19,5% para la reseccion abierta y del 26,9% para la reseccion laparoscopica, y la mortalidad fue del 1,6 y del 1,7%, respectivamente. Con un promedio de seguimiento de 58 meses para la reseccion abierta y 30 meses para la reseccion laparoscopica, la supervivencia actuarial y libre de enfermedad fue del 74,3 y 75,6% para la reseccion abierta y del 87,0 y 89,5% para la reseccion laparoscopica. La mediana del score de calidad metodologica fue 16 y 18,5 puntos, respectivamente. Conclusiones Los resultados a corto y mediano plazo de la reseccion laparoscopica son similares a los de la reseccion abierta en pacientes con cancer de colon no complicado.

Calidad metodológica de un artículo de tratamiento de cáncer gástrico adoptado como protocolo por algunos hospitales chilenos

BACKGROUND Surgery is a curative treatment for gastric cancer (GC). As relapse is frequent, adjuvant therapies such as postoperative chemo radiotherapy have been tried. In Chile, some hospitals adopted Macdonalds study as a protocol for the treatment of GC. AIM To determine methodological quality and internal and external validity of the Macdonald study. MATERIAL AND METHOD Three instruments were applied that assess methodological quality. A critical appraisal was done and the internal and external validity of the methodological quality was analyzed with two scales: MINCIR (Methodology and Research in Surgery), valid for therapy studies and CONSORT (Consolidated Standards of Reporting Trials), valid for randomized controlled trials (RCT). Guides and scales were applied by 5 researchers with training in clinical epidemiology. RESULTS The readers guide verified that the Macdonald study was not directed to answer a clearly defined question. There was random assignment, but the method used is not described and the patients were not considered until the end of the study (36% of the group with surgery plus chemo radiotherapy did not complete treatment). MINCIR scale confirmed a multicentric RCT, not blinded, with an unclear randomized sequence, erroneous sample size estimation, vague objectives and no exclusion criteria. CONSORT system proved the lack of working hypothesis and specific objectives as well as an absence of exclusion criteria and identification of the primary variable, an imprecise estimation of sample size, ambiguities in the randomization process, no blinding, an absence of statistical adjustment and the omission of a subgroup analysis. CONCLUSION The instruments applied demonstrated methodological shortcomings that compromise the internal and external validity of the.

Es el factor de impacto un índice apropiado para determinar el grado de evidencia de estudios sobre procedimientos terapéuticos en revistas quirúrgicas

Resumen Introduccion El objetivo de este estudio es determinar la asociacion entre el factor de impacto (FI) de las revistas quirurgicas y el grado de evidencia de los articulos publicados en ellas sobre procedimientos terapeuticos. Material y metodo Estudio bibliometrico. Se incluyeron revistas quirurgicas registradas en ISI ® 2002, que fueron agrupadas segun el percentil 33 de su FI en: grupo 1 (0,128 a 1,690), grupo 2 (1,691 a 2,886) y grupo 3 (2,887 a 6,674). Se aplico un muestreo aleatorio simple de las revistas de cada grupo, con lo que los grupos quedaron conformados por: grupo 1: European Journal of Surgery, American Surgeon y World Journal of Surgery ; grupo 2: Journal of the American College of Surgeons, Surgery y Archives of Surgery ; y grupo 3: The British Journal of Surgery y Annals of Surgery . Los articulos fueron analizados de forma cruzada e independiente por 2 equipos de revisores. Resultados Un total de 751 articulos estaba relacionado con la terapeutica (41,2%). El FI promedio de los grupos en estudio fue 1,66 ± 0,48 para el grupo 1; 2,61 ± 0,15 para el grupo 2 y 4,69 ± 1,57 para el grupo 3 (p Conclusiones Se verifico la asociacion entre el FI de las revistas quirurgicas y el grado de evidencia en publicaciones relacionadas con la terapeutica.

Diagnostic properties of a symptoms scale for diagnosing reflux esophagitis

OBJECTIVE To the objective of the study was to determine accuracy and predictive values of a symptoms scale for diagnosing reflux esophagitis (RE). STUDY DESIGN AND SETTING Standard criterion study. All recruited patients from two centers in Chile underwent both digestive endoscopy (reference standard) and a symptoms scale known to be valid and reliable for diagnosing gastroesophageal reflux disease. The RE variable was dealt with dichotomously. A receiver operating characteristic curve was constructed. Sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of the scale were calculated. RESULTS Two hundred and thirty eight (238) subjects (57.6% female), with an average age of 44.2+/-13.0 years were included. Of these, 57.1% presented with RE. With a cut-off score of six, association was confirmed between the symptoms scale and RE with an odds ratio of 7.26 and a correct classification i.e. diagnostic accuracy of 73.1%. Sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, of 74.3%, 71.6%, 77.7%, 67.6%, 2.61, and 0.36 respectively, were obtained. CONCLUSION A seven-item symptoms scale when compared to endoscopy as gold standard was useful for diagnosing RE. Using a cutoff of six points, the diagnostic accuracy of the scale was 73.1%.