biostatistic

• Epidemiology is the study of the distribution and determinants of health-related states among specified populations and the application of that study to the control of health problems.
• Average and minimum incubation periods should be close and should represent the probable period of exposure.
• The aims of outbreak investigation are to determine the cause of the outbreak, prevent further spread of the outbreak, and educate responsible individuals in the prevention of similar outbreak in the future.
• If an obvious source of the contamination is identified, institute control measures immediately.
• The purposes of epidemiology in public health practice are to discover the agent, host, and environmental factors that affect health, determine the relative importance of causes of illness, disability, and death, identify those segments of population that have the greatest risk from specific causes of ill health, and evaluate the effectiveness of health programs and services in improving population health.
• Solving health problems involves four steps: data collection, assessment, hypothesis testing, and action.
• Disease causation theories include the filth theory, germ or bacteriological theory, and the concept of multiple causation.
• Prevalence study/survey is used to estimate prevalence.
• Cross-sectional studies do not suffer from lost to follow-up and are generizable.
• Case-Control Studies involve defining and selecting cases, establishing objective criteria, selecting cases, defining control group, and ascertaining exposure.
• Case-Control Studies can examine multiple etiologic factors for a single disease.
• Limitations of Case-Control Studies include inability to establish temporal sequence and potential for bias.
• Limitations of cross-sectional studies include difficulty in establishing the temporal relationship between study variables and inability to establish causality.
• Temporality: Cross-Sectional Studies involve measuring Exposure (E) and Outcome/Disease (D) variables at one point in time or over a very short period of time.
• Case-Control Studies are resource-efficient and do not suffer from selection bias, but may miss disease of short duration or with periods of remission.
• Koch’s postulates, stated by Robert Koch in 1877 and 1882, state that four conditions must be met before a causal relationship can be accepted between a particular bacterial parasite and the disease in question.
• The concept of multiple causation states that disease results from the interaction of multiple ecologic factors within a dynamic system made up of an agent of disease, host and the environment.
• The web model states that effects never depend on single isolated causes but rather develop as the result of chains of causation.
• The epidemiologic triangle consists of the host, agent, and environment.
• Environmental factors of disease are external to the host and in which the agent may exist, survive or originate.
• Monitoring and evaluating surveillance systems involves identifying elements of surveillance that should be enhanced to improve its attributes, improving the quality of data and interpretations provided by surveillance, and assessing how surveillance findings affect control efforts.
• Standard categorization of age in biostatistics is used with epidemiology.
• Disease occurrence is often analyzed by time and place simultaneously.
• Rates are usually displayed in a table or a map.
• Timely, regular dissemination of basic data and their interpretation is a critical component of surveillance.
• Disseminating data and interpretations involves providing them to those responsible for controlling health and to persons, agencies or institutions who use surveillance data for planning or managing control programs.
• Interpreting results of analysis involves identifying an increase in the incidence or variation in pattern of disease.
• Common causes of artifactual changes include changes in case definition, laboratory error, duplicate reporting, increase in population size, and inability to test.
• Most common person characteristics for analysis are age, sex, race and ethnicity.
• Surveillance systems in the Philippines include Integrated Disease Surveillance and Response (PIDSR), Notifiable Diseases, National Endemic Sentinel Surveillance System (NESS), Expanded Program on Immunization Surveillance System (EPI Surveillance), and HIV-AIDS Registry.
• Levels of disease include Baseline, Sporadic, Endemic, Hyperendemic, Epidemic, Outbreak, Cluster, and Pandemic.
• Chloropleth maps and other sophisticated applications are used for disease occurrence analysis by time and place.
• Person variables useful for analysis depend on the health problems.
• Analysis can be organized and presented in tables or series of maps highlighting different periods or populations.
• Physical environmental factors include water, humidity, geologic formations, etc.
• Ecologic studies, also known as correlational or aggregate studies, measure the characteristics that represent the entire population and compare groups rather than individuals.
• Descriptive studies are the first step in risk factor determination and lead to the formulation of research hypotheses.
• Types of analytic studies include observational and experimental.
• Case series are collections of individual reports and are used as early means to identify the presence of an epidemic and can lead to hypothesis generation.
• Analytic studies aim to test a hypothesis; a statement about the relationship between 2 variables.