[Predictive value of breast imaging report and database system (BIRADS) to detect cancer in a reference regional hospital]. / Valor predictivo del sistema BIRADS para detección de cáncer de mama con mamografía en biopsias por punción con aguja gruesa: Revisión de 5 años en un hospital de referencia.

BACKGROUND: To validate the BIRADS in mammography, the calculation of its predictive value in each center is required, as recommended by the American College of Radiology. AIM: To determine the predictive value of the BIRADS system in our center. MATERIAL AND METHODS: All ultrasound guided needle percutaneous biopsies, performed at our center between 2006 and 2010 were reviewed. Predictive value, sensitivity, specificity and diagnostic accuracy of BIRADS were calculated, with a confidence interval of 95%. RESULTS: Of 1,313 biopsies available, 1,058 met the inclusion criteria. Fifty eight percent of biopsies were performed to women with mammographies classified as BIRADS 4 or 5. The presence of cancer in mammographies classified as BIRADS 0 was 4%. The prevalence of cancer for mammographies BIRADS 1, 2, 3, 4 and 5 were 0, 3, 2.7, 17.7 and 72.4% respectively. The positive and negative predictive values of BIRADS classification were 55 and 92 % respectively. CONCLUSIONS: In our institution BIRADS classification 4 and 5 has a high positive predictive value for detecting cancer as in developed countries.

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.

INTRODUCTION: The 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. METHODS: We 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. RESULTS: We 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. CONCLUSIONS: We 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.

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

BACKGROUND: The 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. METHODS: Tissue 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. RESULTS: The 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. CONCLUSIONS: We 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.

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 morbidity 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). METHODS: A case-control nested cohort study was undertaken. Patients were studied and surgically treated in Hospital Regional of Temuco between 1994 and 2001. The morbidity variable registered with a minimum 12-month follow-up period was considered in a dichotomous way. The association with clinical, laboratory, evolutionary, and surgical variables was studied. Descriptive statistics, bivariate analysis using chi(2) and Fisher's exact test for categorical variables; t-test, anova, and Kruskal-Wallis for continuous variables; odds ratio calculations, and ordinal and multivariate logistic regression models were applied. RESULTS: The cohort was composed of 202 patients surgically treated for LH, 112 women (55.5%) and 90 men (44.5%), with an average age of 45.2 years. Average morbidity of the series, with a median follow-up period of 53 months, was 16.4%. Six variables were significantly associated in the bivariate analysis (age, haematocrit, total leucocyte count, alkaline phosphatase, history of previous surgery for LH and existence of biliary communications), but only two achieved statistical significance in the multivariate model (age and history of previous surgery for LH; P = 0.017 and 0.018; and odds ratio of 1.0 and 4.1, respectively). CONCLUSIONS: In surgical decision making for patients with LH, the history of previous surgery for LH must be considered as a risk factor for postoperative morbidity.

Heregulin Co-opts PR Transcriptional Action Via Stat3 Role As a Coregulator to Drive Cancer Growth.

Accumulated findings have demonstrated the presence of bidirectional interactions between progesterone receptor (PR) and the ErbB family of receptor tyrosine kinases signaling pathways in breast cancer. We previously revealed signal transducer and activator of transcription 3 (Stat3) as a nodal convergence point between said signaling pathways proving that Stat3 is activated by one of the ErbBs' ligands, heregulin (HRG)ß1 via ErbB2 and through the co-option of PR as a signaling molecule. Here, we found that HRGß1 induced Stat3 recruitment to the promoters of the progestin-regulated cell cycle modulators Bcl-XL and p21(CIP1) and also stimulated Stat3 binding to the mouse mammary tumor virus promoter, which carries consensus progesterone response elements. Interestingly, HRGß1-activated Stat3 displayed differential functions on PR activity depending on the promoter bound. Indeed, Stat3 was required for PR binding in bcl-X, p21(CIP1), and c-myc promoters while exerting a PR coactivator function on the mouse mammary tumor virus promoter. Stat3 also proved to be necessary for HRGß1-induced in vivo tumor growth. Our results endow Stat3 a novel function as a coregulator of HRGß1-activated PR to promote breast cancer growth. These findings underscore the importance of understanding the complex interactions between PR and other regulatory factors, such as Stat3, that contribute to determine the context-dependent transcriptional actions of PR.

Valor predictivo del sistema BIRADS para detección de cáncer de mama con mamografía en biopsias por punción con aguja gruesa: Revisión de 5 años en un hospital de referencia / Predictive value of breast imaging report and database system (BIRADS) to detect cancer in a reference regional hospital

Background: To validate the BIRADS in mammography, the calculation of its predictive value in each center is required, as recommended by the American College of Radiology. Aim: To determine the predictive value of the BIRADS system in our center. Material and Methods: All ultrasound guided needle percutaneous biopsies, performed at our center between 2006 and 2010 were reviewed. Predictive value, sensitivity, specificity and diagnostic accuracy of BIRADS were calculated, with a confidence interval of 95%. Results: Of 1,313 biopsies available, 1,058 met the inclusion criteria. Fifty eight percent of biopsies were performed to women with mammographies classified as BIRADS 4 or 5. The presence of cancer in mammographies classified as BIRADS 0 was 4%. The prevalence of cancer for mammographies BIRADS 1, 2, 3, 4 and 5 were 0, 3, 2.7, 17.7 and 72.4% respectively. The positive and negative predictive values of BIRADS classification were 55 and 92 % respectively. Conclusions: In our institution BIRADS classification 4 and 5 has a high positive predictive value for detecting cancer as in developed countries.

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%.

Grosor de la íntima-media carotídea como predictor de evento cardiovascular: revisión sistemática de la literatura / Thickness of carotid intima-media as a predictor of cardiovascular event: systematic review of the literature

La ateroesclerosis es una enfermedad y evolutiva crónica que afecta a todas las arterias del organismo. Existen numerosos factores de riesgo (FR) relacionados, sin embargo un tercio de los eventos cardiovasculares (ECV) no son atribuibles a los FR conocidos. Existe evidencia que la medición del grosor de íntima-media (GIM) permite evaluar estados precoces de la enfermedad y la carótida es una localización adecuada para ello. El objetivo de este estudio es determinar si la evidencia disponible avala al GIM carotídea (GIMC), como factor asociado al desarrollo de ECV o muerte, en adultos asintomáticos de la población general. Revisión sistemática de la literatura. Se analizaron estudios primarios publicados de 2006 a la fecha, sin restricción de diseño ni de idioma; que incluyeran población adulta, sin antecedentes de ECV; y en los que se considerara la medición del GIMC mediante ultrasonografía. Se consultó las bases de datos MEDLINE, SciELO y LILACS. Se utilizaron términos MeSH y palabras libres. La calidad metodológica (CM) de los estudios seleccionados fue determinada mediante un escore validado para tal efecto. Se valoraron las siguientes variables: edad, género, raza; antecedentes de diabetes mellitus (DM), hipertensión arterial (HTA), dislipidemia, tabaquismo, obesidad y CM de los estudios primarios. Las estrategias de búsqueda permitieron recuperar 9 estudios primarios, que incluyen 24016 pacientes; 54,3% de los cuales son de género femenino. El FR asociado más frecuentemente fue el hábito de fumar (54%), seguido por HTA y DM. Las mediciones ultrasonográficas permitieron verificar una amplia variedad de técnicas utilizadas tanto en carótida común como en carótida interna y externa. Se verificó gran heterogeneidad en las técnicas de medición, lo que impide comparar en sentido estricto los resultados obtenidos; por ende, la evidencia disponible no permite determinar asociación entre GIMC y ECV en adultos asintomáticos de la población general. Se requieren estudios de mejor nivel de evidencia y CM para aclarar esta incertidumbre.

Atherosclerosis is a chronic and evolutionary disease that affects all the arteries of the body. There are many risk factors (RF) related, but a third of cardiovascular events (CVE) are not attributable to traditional RF. There is evidence that the measurement of intima-media diameter allows evaluation at early stages of the disease and carotid artery is a suitable location for it (CIMD). The aim of this study is to determine whether the available evidence supports the CIMD as a factor associated with the development of CVE or death in asymptomatic adults in the general population. Systematic review. We analyzed studies primary studies published from 2006 to date, without restriction of language or design, to include adult population with no history of CVE and in those that CIMD was measurement by ultrasound. MEDLINE, SciELO and LILACS databases were consulted. MeSH terms and free words were used. Selected studies were analyzed using MINCIR methodological quality (MQ) scores of therapy and prognosis. The following variables were considered: age, gender, race, history of diabetes, hypertension, dyslipidemia, smoking, obesity and MQ of primary studies. Results: 9 primary studies were analyzed, including 24,016 patients, 54.3% of whom are female. The RF more frequently reported and associated with CVE were smoking (54%) followed by hypertension and diabetes. Ultrasonographic measurements allowed us to verify a wide variety of techniques used, indicating a large heterogeneity and therefore not possible to compare the results. The available evidence to determine the association between CIMD and CVE is insufficient. Studies with better level evidence and MQ are needed to clarify the uncertain.

[How should the results of a research study be presented? II. The manuscript and the publication process]. / ?Cómo presentar los resultados de una investigación científica? II. El manuscrito y el proceso de publicación.

Publishing a manuscript is the logical result of any research study, allowing information to be shared with the scientific community, and providing personal satisfaction and career enhancement. The present article reviews some of the rules and recommendations for drafting the main sections of an original study (introduction, methodology, results, discussion). We discuss several aspects of the editorial process and the main reasons why manuscripts are returned. However well a manuscript is written, it cannot hide the methodological defects of a poorly designed study. The best way to avoid difficulties when writing is to have a good working hypothesis, clear objectives, and impeccable methodology.

[Use of opioid analgesics in diagnosis and decision-making in patients with acute nontraumatic abdominal pain. A systematic review of the literature]. / Utilización de analgésicos opiáceos en el proceso diagnóstico y de toma de decisiones sobre pacientes con dolor abdominal agudo no traumático. Revisión sistemática de la literatura.

INTRODUCTION: The use of analgesics during the diagnosis and decision-making process in patients with acute nontraumatic abdominal pain is controversial. The aim of the present study was to determine whether the use of opioid analgesics in patients with acute nontraumatic abdominal pain increases the risk of diagnostic error. METHOD: We performed a systematic review of the literature. Randomized clinical trials (RTCs) comparing the use of opioid analgesics with placebo administered before any procedure in patients with acute nontraumatic abdominal pain were included. There was no restriction on language. RTCs unrelated to this subject were excluded. The variables analyzed were age, gender, and the percentage of adverse effects, appendicitis, changes on physical examination and diagnostic error, modification of pain severity measured by a visual analog scale, and methodological quality of the studies. A search was performed in the MEDLINE and Cochrane databases, using MeSH terms. Each article was analyzed by applying a methodological quality score through which weighted means were applied for each variable. The Chi-square and Student's t-test were applied to compare the groups. RESULTS: Six articles meeting the selection criteria were found. The mean methodological quality score was 21.6 points. The studies represented a population of 363 patients treated with opioids and 336 patients treated with placebo. There were no differences in the mean age of the patients (39.4 vs 39.6 years), distribution by gender, prevalence of acute appendicitis (23.3% vs 24%) or diagnostic error (15.6% vs 21.1%; p = 0.0637). Differences were found in the variable of pain reduction (27.2 vs 7.2 mm, respectively; p = 0.0167). CONCLUSIONS: The use of opioid analgesics in patients with acute nontraumatic abdominal pain does not increase the risk of diagnostic error and reduces pain during the decision-making process.

[How should the results of a scientific study be presented? I. The oral presentation]. / Cómo presentar los resultados de una investigación científica? I. La comunicación oral.

The results of a research study can be presented through oral communications, posters, conferences and publications, etc. The present article suggests ways in which oral communications and posters can be presented. The sequence of steps leading up to an oral presentation can be divided into writing a summary, designing the graphic material, giving the presentation and defending the results. Posters have a similar structure but this format allows complex experiments to be clearly presented and a variety of illustrations to be introduced, without the strict time constraints that apply to oral presentations. Whichever format is followed, we recommend that authors answer the following questions: what was the question studied and why?, how was it studied?, what were the results?, and what do they mean? These questions help to structure the presentation effectively.

[Methodological quality of an article on the treatment of gastric cancer adopted as protocol by some Chilean hospitals]. / 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 Macdonald's 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 reader's 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.

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.

[Open versus laparoscopic resection in non-complicated colon cancer. A systematic review]. / Resección abierta frente a laparoscópica en el cáncer de colon no complicado. Revisión sistemática.

INTRODUCTION: The objective of this study was to determine the best surgical option for elective surgery in non-complicated colon cancer by comparing open (OR) and laparoscopic resection (LR). PATIENTS AND METHOD: A systematic review of the literature was performed. Studies of non-complicated colon cancer in adults treated by OS and LS published between 1990 and 2002 were analyzed. The MEDLINE, LILACS and COCHRANE databases were used, employing MeSH terms and free words. Selected studies were analyzed using a specially designed score of methodological quality to examine and compare studies with different types of design. The number of treated patients, 3-year actuarial survival rate, 3-year disease-free survival, recurrence, morbidity, mortality and the methodological quality of primary studies were analyzed. Means, medians, extreme values and weighted means were calculated, and the methodological quality of primary studies was compared using median 95% confidence intervals. RESULTS: Six hundred eighty related articles were found; of these, 11 were analyzed. Hospital stay was 10.1 days for OR and 6.5 days for LR. Morbidity was 19.5% for OR and 26.9% for LR and mortality was 1.6% and 1.7% respectively. With mean follow-up periods of 58 months for OR and 30 months for LR, actuarial and free-disease survival rates were 74.3% and 75.6% for OR and 87.0% and 89.5% for LR. The median score for methodological quality was 16 for OR and 18.5 for LR. CONCLUSIONS: The early and medium-term results of LR are similar to those observed in OR in patients with non-complicated colon cancer.

[Is impact factor an appropriate index to determine the level of evidence of studies on therapeutic procedures in surgery journals?]. / Es el factor de impacto un índice apropiado para determinar el grado de evidencia de estudios sobre procedimientos terapéuticos en revistas quirúrgicas?

INTRODUCTION: The aim of this study was to determine the association between the IF of surgery journals and the level of evidence of articles on therapeutic procedures published in these journals. MATERIAL AND METHOD: A bibliometric study was performed. Journals listed in the 2002 ISI under the subject heading of Surgery were included. Journals were classified by applying the 33rd percentile of their IF (group 1 from 0.128 to 1.690, group 2 from 1.691 to 2.886, and group 3 from 2.887 to 6.674). Simple randomized sampling was conducted of journals in each group (group 1: Eur J Surg, Am Surg and World J Surg; group 2: J Am Coll Surg, Surgery and Arch Surg; and group 3: Br J Surg and Ann Surg). A crossover analysis was performed by 2 independent teams of reviewers. RESULTS: There were 751 article on therapy (41.2%). The mean IF was 1.66 +/- 0.48 for group 1, 2.61 +/- 0.15 for group 2, and 4.69 +/- 1.57 for group 3 (P<.001). There were 16 systematic reviews, 82 randomized clinical trials, 96 cohort studies, 474 case series and 79 review articles. Level 1 evidence was found in only 4.8% of the articles. Statistical differences were verified in 15.1% of the study sample, which was represented by systematic reviews and randomized clinical trials (most frequent in group 3 (P<.001). CONCLUSIONS: An association between the IF of scientific surgical journals and the level of evidence in articles published on therapy was verified.

Effectiveness of laparoscopic surgery for gallstones and common bile duct lithiasis: a systematic overview / Efectividad de la cirugía laparoscópica para colecistolitiasis y coledocolitiasis: revisión global de la evidencia

The aim of the present study was to evaluate the available evidence on the effectiveness of laparoscopic surgery for treating gallstones and common bile duct lithiasis (CBDL). A systematic overview was performed. Medline, EMBASE and The Cochrane Library were searched (1998-2008). Systematic reviews (SR), clinical practice guidelines (CPG), randomised clinical trials (RCT) and observational studies were included. Internal validity and overall quality of the evidence were assessed. The available evidence was classified according to the Oxford Centre for Evidence Based Medicine proposal. 87 studies were included in this review (12 SR, 23 RCT, 3 CPG, 13 cohort studies, 3 cross-sectional studies, 2 case and control studies and 31 case series). Compared with open cholecystectomy, laparoscopic cholecystectomy (LC) is associated with shorter operating time, shorter hospital stay and better quality of life (high quality evidence). The use of antibiotic prophylaxis does not appear to reduce the infection rate in low-risk patients (high quality evidence). Although many techniques have been advocated to perform LC their effectiveness is as yet inconclusive (low-quality evidence). Two-stage surgery is the most appropriate strategy for high-risk patients with CBDL (high-quality evidence). Mortality is similar to open surgery, as the effectiveness is similar to that of endoscopic treatment (high-quality evidence). As a conclusion we can state that the evidence concerning the effectiveness of laparoscopic surgery for gallstones and CBDL is scarce and of low methodological quality and that better quality studies are warranted to assess these techniques more adequately.

El objetivo del presente estudio fue evaluar la evidencia disponible respecto de la efectividad de la cirugía laparoscópica en el tratamiento de la colelitiasis y la litiasis de la vía biliar (LVBP). Para ello, se realizó una revisión global de la evidencia disponible. Se realizaron búsquedas en las bases de datos MEDLINE, EMBASE y The Cochrane Library (1998-2008). Se incluyeron guías de práctica clínica (GPC), revisiones sistemáticas (RS), ensayos clínicos con asignación aleatoria (EC) y estudios observacionales. Se valoró la validez interna y la calidad global de los estudios. Los datos disponibles y la evidencia generada se clasificaron en base a la propuesta del Centro de Oxford de Medicina Basada en la Evidencia. 87 estudios fueron incluidos en esta revisión (3 GPC, 12 RS, 23 EC, 13 estudios de cohortes, 3 estudios transversales, 2 estudios de casos y de controles y 31 series de casos). En comparación con la colecistectomía abierta, la colecistectomía laparoscópica (CL) se asocia con menor tiempo operatorio y estancia hospitalaria y mejor calidad de vida (evidencia de alta calidad). El uso de profilaxis antibiótica no parece reducir la tasa de infección en pacientes de bajo riesgo (evidencia de alta calidad). Aunque se han descrito numerosas técnicas para realizar una CL, su eficacia no es aún concluyente (evidencia de baja calidad). La cirugía en dos etapas es la estrategia más adecuada para los pacientes de alto riesgo con LVBP (evidencia de alta calidad). La mortalidad del tratamiento laparoscópico de la LVBP es similar a la de la cirugía abierta; y como su eficacia es similar a la del tratamiento endoscópico (evidencia de alta calidad). Se puede concluir señalando que la evidencia disponible respecto de la efectividad de la cirugía laparoscópica para el tratamiento de la colelitiasis y la LVBP es escasa y de baja calidad metodológica; y que se requieren estudios de mejor calidad para valorar de forma más apropiada estas técnicas.

Systematic review of literature with different types of designs / Revisión sistemática de la literatura con diferentes tipos de diseños

In certain situations, which occur with particular frequency in the field of surgery and its related disciplines (where what predominates are observational-type studies), the management of randomized controlled clinical trials (RCT) is very difficult and as such, conducting a systematic review (SR) based on RCT and realice a meta-analysis is even more difficult. Therefore, we have generated a methodology for implementing a SR with different types of designs (including observational studies) as an alternative in order to clarify the uncertainty in the field of therapy when there are few RCT and the evidence relies so heavily on descriptive and observational studies. The aim of this study, was to set out a methodology that leads to a SR with various types of designs. Methodologycally, this is based on consideration of the different primary studies through the application of a methodological quality score made up of 3 items (type of study design, size of the population studied and methodology used in the study). Once assigned a point score, a calculation of weighted averages with their respective confidence intervals of 95 percent is applied to each variable to be studied, which finally enables to apply a meta-analysis and compare groups. A methodological proposal leading to a SR with various types of designs.

En ciertas situaciones, en especial frecuentes en el ámbito de la cirugía y sus disciplinas afines (donde lo que predomina son estudios de tipo observacional), la conducción de ensayos clínicos con asignación aleatoria (EC) es muy difícil; por ende, realizar revisiones sistemáticas (RS) con base en EC y posteriormente meta-analizar la información lo es aún más. Por esta razón hemos generado una metodología para realizar RS con diferentes tipos de diseños (incluyendo estudios observacionales), como una alternativa para aclarar la incertidumbre en el ámbito 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 metodología para conducir RS con diversos tipos de diseños. La metodología, se basa en la ponderación de los diferentes estudios primarios a través de la aplicación de un escore de calidad metodológica compuesto por 3 ítems (tipo de diseño del estudio, tamaño de la población estudiada y metodología empleada en el estudio). Una vez asignado un puntaje se aplica un cálculo de promedios ponderados con sus respectivos intervalos de confianza del 95 por ciento a cada variable que se desee estudiar, lo que permite finalmente realizar un meta-análisis y comparar grupos. Se presenta una propuesta metodológica para conducir RS con diversos tipos de diseños.

Efectividad del tratamiento laparoscópico de la colelitiasis y la coledocolitiasis: revisión global de la evidencia / Efficacy of Laparoscopy for treatment of cholecystolithiasis and common bile duct lithiasis

Introducción: La laparoscopia es el estándar de referencia en el tratamiento de la colecistolitiasis. No obstante su efectividad es todavía poco conocida. El objetivo de este estudio es evaluar la evidencia disponible sobre la efectividad de la cirugía laparoscópica en el tratamiento de la colecistolitiasis y de la litiasis de la vía principal (LVBP). Material y Métodos: Se realizó una búsqueda en las bases de datos MEDLINE, EMBASE y la biblioteca Cochrane. Se consideraron todo tipo de estudios publicados entre 1988 y 2006. Se llevó a cabo la evaluación de la validez interna de la evidencia así como su calidad global. Resultados: Se seleccionaron 80 estudios (9 revisiones sistemáticas, 19 ensayos clínicos, 4 guías de práctica clínica, 15 estudios de cohortes, 1 de casos y controles y 32 series de casos). La colecistectomía laparoscópica (CL), respecto de la colecistectomía, se asocia a mayor tiempo operatorio, menor estancia hospitalaria y mejor calidad de vida, siendo un procedimiento relativamente seguro (calidad alta). El uso de profilaxis antibiótica no ofrece ningún beneficio en términos de disminución de la tasa de infecciones en pacientes de bajo riesgo [calidad alta]. Se han descrito multiplicidad de variantes tecnológicas para la realización de una CL, no obstante, la efectividad de las mismas es escasa y no concluyente. En el tratamiento de la LVBP, la cirugía en dos etapas es la estrategia más apropiada en pacientes de alto riesgo (calidad alta). La mortalidad es similar a la de la cirugía abierta y la efectividad es similar al tratamiento endoscópico (calidad alta). Conclusiones: La evidencia disponible es escasa y de baja calidad metodológica, situación que dificulta la formulación de recomendaciones. Son necesarios estudios de mejor calidad que evalúen de manera adecuada éstas técnicas.