Teaching meta-analysis using Stata

Systematic reviews and meta-analyses contribute to the objectivity and transparency of literature reviews and play an increasingly important role in evidence-based medicine and public health. In addition to the expertise needed for critical reading of papers using these methodologies, researchers and professionals in areas related to clinical medicine and public health also need to have the appropriate skills to conduct systematic assessments of the published literature and quantitative synthesis of the results through meta-analysis. I describe the use of Stata in a short course aiming to introduce the essential aspects of the computation of summary estimates and the exploration of heterogeneity and publication bias in meta-analyses of observational studies. The course includes three practical exercises built over real data. It starts with a "pen and paper" exercise used to address the basic statistical methods of meta-analysis, and it ends with an introduction to meta-analysis in Stata, including the calculation of summary estimates (fixed- and random-effects models), the appraisal (visual inspection of funnel plots, I2 statistics, and hypothesis testing) and explanation of heterogeneity (subgroup analysis), and the assessment of bias (analysis of funnel plots). I will emphasize the strategies adopted to enable the achievement of the course objectives by participants unfamiliar with Stata.

Global trends in Kaposi sarcoma incidence and mortality: the need for action to reduce inequalities

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Associação entre cuidados infantis e diarréia aguda em crianças portuguesas

OBJECTIVE: To quantify the influence of the type of child-care on the occurrence of acute diarrhea with special emphasis on the effect of children grouping during care. METHODS: From October 1998 to January 1999 292 children, aged 24 to 36 months, recruited using a previously assembled cohort of newborns, were evaluated. Information on the type of care and occurrence of diarrhea in the previous year was obtained from parents by telephone interview. The X² and Kruskal-Wallis tests were used to compare proportions and quantitative variables, respectively. The risk of diarrhea was estimated through the calculation of incident odds ratios (OR) and their respective 95% confidence intervals (95% CI), crude and adjusted by unconditional logistic regression. RESULTS: Using as reference category children cared individually at home, the adjusted ORs for diarrhea occurrence were 3.18, 95% CI [1.49, 6.77] for children cared in group at home, 2.28, 95% CI [0.92, 5.67] for children cared in group in day-care homes and 2.54, 95% CI [1.21, 5.33] for children cared in day-care centers. Children that changed from any other type of child-care setting to child-care centers in the year preceding the study showed a risk even higher (OR 7.65, 95% CI [3.25, 18.02]). CONCLUSIONS: Group care increases the risk of acute diarrhea whatsoever the specific setting.OBJETIVO: Quantificar a associação entre o tipo de cuidados infantis e a ocorrência de diarréia aguda, sendo dada especial atenção aos diferentes tipos de cuidados infantis prestados a grupos de crianças. MÉTODOS: De outubro de 1998 a janeiro de 1999, foram avaliadas 292 crianças, com idades entre 24 e 36 meses, recrutadas com base numa coorte de recém-nascidos previamente constituída. Foi obtida informação acerca do tipo de cuidados infantis e da ocorrência de diarréia no ano anterior ao estudo por meio de entrevista telefônica aos pais das crianças participantes. Foram utilizadas as provas do X² e de Kruskal-Wallis para comparar proporções e variáveis quantitativas, respectivamente. O risco de diarréia foi estimado pelo cálculo de odds ratios (OR) incidentes e respectivos intervalos de confiança a 95% (IC 95%), brutos e ajustados por regressão logística não condicional. RESULTADOS: Utilizando como classe de referência as crianças cuidadas sozinhas na própria casa, o OR para a ocorrência de diarréia foi 3,18, IC 95% [1,49-6,77] para as crianças cuidadas na própria casa mas em grupo, 2,28, IC 95% [0,92-5,67] para as cuidadas em casas de amas, em grupo, e 2,54, IC 95% [1,21-5,33] para as cuidadas em creches (instituições de prestação de cuidados infantis, em grupo). Nas crianças que mudaram de qualquer outro tipo de cuidados infantis para creches no ano que antecedeu a entrevista o risco de diarréia foi 7,65, IC 95% [3,25-18.02]. CONCLUSÕES: Os cuidados infantis em grupo associaram-se a um maior risco de diarréia aguda, quer fossem prestados na própria casa, em casas de amas ou em creches

Monuments du Champa et du Cambodge

includes tables and 5 double maps; 67 x 38 cm; additional digital copy accessed 10/2011 http://gallica.bnf.fr/ark:/12148/bpt6k56065372.r=+Atlas+arch%C3%A9ologique+de+l%27Indo-Chine.langEN</a

Modifiable factors and esophageal cancer: a systematic review of published meta-analyses.

There are marked differences in the etiology of the major histological types of esophageal cancer (EC)—squamous cell carcinomas (ESCC) and adenocarcinomas (EAC). This study aimed to summarize the current scientific knowledge on modifiable risk factors for EC, by histological type, through a systematic review of meta-analyses referenced in PubMed and ISI Web of Knowledge. We identified 100 meta-analyses on risk factors for ESCC (n = 54), EAC (n = 43), or EC (n = 51). ESCC risk significantly increased with alcohol and maté drinking, smoking, red and processed meat consumption and human papillomavirus infection, while it was negatively associated with body mass index and consumption of fruit, vegetables, white meat, folate, and some carotenoids. Cessation of drinking and smoking significantly reduced ESCC risk. For EAC, an increased risk was reported for smoking, body mass index, and red and processed meat consumption, while risk decreased with Helicobacter pylori infection, low/moderate alcohol drinking, physical activity, and consumption of fruit, vegetables, folate, fiber, beta-carotene, and vitamin C. Differences in results between meta-analyses and mechanisms underlying some of the associations found are discussed. This work reinforces the importance of a separate assessment of EC subtypes to allow for a proper evaluation of incidence trends and planning of prevention/control interventions.This work was supported by FEDER funds through the Operational Competitiveness Programme and by national funding from the Foundation for Science and Technology–FCT (Portuguese Ministry of Science, Technology and Higher Education) (FCOMP-01-0124-FEDER-021181), under the project “Determinants of gastric and esophageal cancers incidence in the north of Portugal” (PTDC/SAU-EPI/122460/2010), and the Unidade de Investigação em Epidemiologia - Instituto de Saúde Pública da Universidade do Porto (EPIUnit) (POCI-01-0145-FEDER-006862; UID/DTP/04750/2013). An individual Postdoc grant attributed to BP (SFRH/BPD/75918/2011) was co-funded by the FCT and the "Programa Operacional Capital Humano" (POCH/FSE)

Cumulative incidence estimates in the presence of competing risks

This study was funded by FEDER through the Operational Program Competitiveness and Internationalization and national funding from the Foundation for Science and Technology—FCT (Portuguese Ministry of Science, Technology and Higher Education) under the Unidade de Investigação em Epidemiologia—Instituto de Saúde Pública da Universidade do Porto (EPIUnit) (POCI-01-0145-FEDER-006862; Ref. UID/DTP/04750/2013). An individual PhD grant attributed to S.M. (SFRH/BD/102585/2014) was funded by FCT and the “Programa Operacional Capital Humano” (POCH/FSE). The funding sources had no involvement in the conduct of the research and/or preparation of the commentary