GI Epidemiology -- Contents -- Contributors -- Foreword -- Preface -- About the companion website -- PART ONE Gastrointestinal Diseases and Disorders: The Public Health Perspective -- 1 The burden of gastrointestinal and liver disease around the world -- Introduction -- Diarrheal disease -- Global burden -- Gastrointestinal malignancies -- Global burden -- Colorectal cancer -- Gastric cancer -- Selected diseases of the liver -- Hepatitis B -- Hepatitis C -- Viral hepatitis in the United States -- Liver cancer -- Selected gastrointestinal diseases -- Clostridium difficile infections -- Gastroesophageal reflux disease -- Inflammatory bowel disease -- Gastrointestinal diseases responsible for hospitalization -- Limitations of the data -- Implications -- Multiple choice questions -- Appendix 1.A -- Sources -- References -- Answers to multiple choice questions -- PART TWO How to Critically Read the Gastrointestinal Epidemiology Literature -- Introduction and overview -- 2 How to read a cohort study -- Brief introduction to cohort studies -- Biases commonly seen in cohort studies -- 10-Point checklist of important issues when reading a report of a cohort study -- Case study: Critical evaluation of cohort study "Long-term use of aspirin and nonsteroidal anti-inflammatory drugs and risk of colorectal cancer" [8] -- Multiple choice questions -- References -- Answers to multiple choice questions -- 3 How to read a case-control study -- Brief introduction to case-control studies -- Biases commonly seen in case-control studies -- 10-Point checklist of important issues when reading a report of a case-control study -- Case study: Critical evaluation of a case-control study "Effect of aspirin and NSAIDs on risk and survival from colorectal cancer" -- Multiple choice questions -- References -- Answers to multiple choice questions.

4 How to read a randomized controlled clinical trial -- Brief introduction to randomized controlled trials -- Biases commonly seen in randomized controlled trials -- 10-Point checklist for evaluating a clinical trial -- Case study: Critical evaluation example -- Multiple choice questions -- References -- Answers to multiple choice questions -- 5 How to read a systematic review and meta-analysis -- Introduction -- Biases commonly seen in meta-analyses -- Other important strengths and limitations of meta-analyses -- Important issues to consider when reading a meta-analysis -- Case study: Critical evaluation -- Multiple choice questions -- References -- Answers to multiple choice questions -- 6 How to decide if any of this matters -- Introduction -- Is the relationship described in the paper causal? -- The evidence hierarchy -- Austin Bradford Hill -- Strength -- Consistency -- Specificity -- Temporality (timing) -- Biological gradient (dose response) -- Plausibility -- Coherence -- Is the relationship important? -- Relative versus absolute risk -- Severity of disease -- Is the relationship something we can affect or influence? -- Number needed to treat (NNT) and numbers needed to harm (NNH) -- Population attributable fraction -- Cost implications -- Conclusion -- References -- PART THREE How to Do Clinical Research in GI -- 7 How to develop and validate a GI questionnaire -- Why do we need questionnaires? -- Do we need to develop a questionnaire? -- Development of a questionnaire -- Determining the scope -- Survey method -- Writing the questions -- Adapting a questionnaire -- Validation of a questionnaire -- Feasibility -- Reliability -- Validity -- Using questionnaires in research -- Conclusions -- Multiple choice questions -- General reference -- References -- Answers to multiple choice questions.

8 How to do population-based studies and survey research -- Introduction -- Population-based surveys -- Research question and aim of the study -- Location of survey and engaging the population of study -- Sampling -- Data collection in a survey -- Methods of data collection -- Design of population-based studies -- Descriptive design -- Analytical designs -- Conclusion -- Multiple choice questions -- References -- Answers to multiple choice questions -- 9 How to find and apply large databases for epidemiologic research -- Introduction -- Commonly used databases -- Global death and cancer registries -- United States of America databases -- SEER program -- Medicare claims files -- Department of Veterans Affairs (VA) administrative databases -- SEER-Medicare linked database -- Healthcare Cost and Utilization Project (HCUP) -- National Hospital Discharge Survey (NHDS) -- Medical Expenditure Panel Survey (MEPS) -- Swedish national registers -- The Total Population Register -- Swedish Conscription Register -- Cause of Death Register -- Cancer Register -- Hospital Discharge Register (HDR) and Outpatient Register -- Medical Birth Register -- Multigeneration Register -- Other registers -- UK databases -- UK primary care databases -- Hospital Episode Statistics (HES) -- Office for National Statistics for England and Wales (ONS) -- Socioeconomic status information -- Linked UK electronic data -- Other UK data -- Personal identity numbers -- Other databases -- Recommendations for the use of large databases for research studies -- Completeness of the database -- Representativeness of the database -- Accuracy of information -- Use of publicly available statistical calculators -- Determining patient comorbidity -- Robustness of findings -- Power and sample size considerations -- References -- 10 How to do genetic and molecular epidemiologic research.

Genetic epidemiology (GE) -- Molecular epidemiology (ME) -- Epidemiology principles -- Error in GE and ME studies -- Study designs and approaches -- Molecular epidemiology study designs -- Genetic epidemiology study designs -- Clinical and historical studies -- Family studies -- Segregation analyses -- Linkage analysis -- Genome-wide association studies -- Candidate gene-disease association studies -- Conclusion -- Multiple choice questions -- References -- Answers to multiple choice questions -- 11 Diagnostic studies -- Introduction -- Measures of test accuracy -- Sensitivity and specificity -- Positive and negative predictive values -- Likelihood ratios -- Single measures of test performance -- The influence of choice of population on diagnostic test performance -- The choice of a reference standard -- Latent class analysis -- Bayesian analysis -- The effect of study design on diagnostic test performance -- Conclusions -- References -- 12 Randomized controlled trials -- Introduction -- The key building blocks of randomized controlled design -- Stages of drug trial development -- Key issues relating to phase II and phase III trials -- Objective -- Number of subjects -- Inclusion/exclusion criteria -- Types of randomized controlled trial -- Conclusions -- References -- PART FOUR Epidemiology of Major GI Diseases -- 13 Epidemiology of GERD, Barrett's esophagus and esophageal cancer -- Introduction -- Gastroesophageal reflux disease -- Prevalence of GERD -- Secular trends in GERD -- Overlap between GERD and other diseases -- Risk factors for GERD -- Barrett's esophagus -- Prevalence of BE -- Risk factors for BE -- Esophageal cancer -- Prevalence of esophageal cancer -- Risk factors -- Multiple choice questions -- References -- Answers to multiple choice questions.

14 Epidemiology of Helicobacter pylori infection, peptic ulcer disease and gastric cancer -- Helicobacter pylori infection -- Clinical microbiology and expression -- Distribution of H. pylori infection in the general population -- Transmission of H. pylori -- Risk factors for H. pylori infection in the adult population -- Peptic ulcer -- Clinical outline -- Occurrence of peptic ulcer in the general population -- Secular trends in peptic ulcer occurrence -- Incidence and prevalence of peptic ulcer from the healthcare perspective -- Healthcare utilization -- Peptic ulcer in Asian populations -- Risk factors for peptic ulcer: environmental exposures -- Diet -- Psychological factors -- Genetic predisposition -- Gastric cancer -- Clinical outline -- A disappearing disease? -- Geographic distribution -- Demographic distribution -- Opposing secular trend for cardia cancer? -- Risk factors for stomach cancer -- Multiple choice questions -- References -- Answers to multiple choice questions -- 15 Epidemiology of dyspepsia -- Disease definitions -- Incidence and prevalence -- Risk factors -- Differential diagnosis -- Clinical diagnosis -- Alarm features -- Natural history and mortality -- Disability, quality of life, and healthcare seeking -- Prevention -- Areas for further study -- Conclusions -- Multiple choice questions -- References -- Answers to multiple choice questions -- 16 Epidemiology of upper gastrointestinal bleeding -- Clinical summary -- Incidence of acute upper gastrointestinal bleeding -- Causes and their trends -- Nonvariceal upper gastrointestinal hemorrhage -- Helicobacter pylori -- Medications -- Comorbidities -- Other -- Variceal hemorrhage -- Natural history and risk stratification -- Nonvariceal hemorrhage -- Variceal hemorrhage -- Healthcare costs -- Multiple choice questions -- References -- Answers to multiple choice questions.

17 Epidemiology of celiac disease.