Surveillance and Epi Investigation Flashcards
Basic stat measures for descriptive stats
Measures of frequency
Measures of central tendency
Measures central dispersion
Percentiles
What are the measures of frequency
Ratio
Rates
Proportions
Relationship between two groups, offers insights into proportion and connections inherent within the data
Ratio
Occurrence of particular event within specified population during defined period, facilitate comparisons and trend assessments across different populations and time intervals
Rate
Relative magnitude of a specific category or event within a larger context. Show distribution and relevance if events within a dataset
Proportion
Percentage of people in population who have a specific condition at a particular moment
Prevalence
How many new cases of a particular condition occur within a population during a set period of time
Incidence
Number of deaths that happen within a population during a specific period of time
Mortality rate
Percentage of people who were exposed to a risk factor and ended up developing the condition
Attack rate
Average of the values in a data srt
Mean
Middle value in a ranked data set
Median
Mode
Value that appears most freq in a dataset
Which measure of central tendency is impacted by outliers?
Mean
Span between the smallest and largest value within a data set
Range
Average square difference between each data point and the mean. It provides a comprehensive understanding of how individual values vary from the data set Central value
Variance
Difference between an individual data point and the mean of the data set. It gives us a sense of how much each value deviates from the average
Deviation
Distribution and values around the mean. It quantifies the extent to which data points deviate from the central value helping us gauge overall variability.
Standard deviation
Set of methods that can be used for improving systems, processes, and outcomes
Statistical process control
Variation that is inherent to the system
Common cause variation
Variation that is indicative of exceptional events or changes
Special cause variation
Best process control chart for less than 25 points
Run chart
Best chart for 25-50 points
Control chart
Evaluates whether differences observed in data are significant and not due to chance
Hypothesis testing
Provide range within which population parameters are likely to exist
Confidence intervals
Unveiled relationships between variables and forecast outcomes
Regression analysis
Compares means across multiple groups helping us discern more meaningful distinctions
Anova
What are the two types of hypotheses used in statistical testing?
H0- null hypothesis- there is no association or difference between groups or relationship between variables
Ha- alternative hypothesis- there is a difference between groups or relationship between two variables
Describe the one sample test
Compare a sample mean to a known population parameter
Determines if the sample mean is significantly different from the population mean
Used when analyzing a single groups data
Describe the two sample t-tests
Compares means between two independent groups
Independent samples t-test is an example
Determines if it means of the two groups are significantly different
What are the two types of t-test
Dependent samples t-test
Independent samples t test
Describe the dependent samples t test
It compares means of related pairs of data
Describe independent samples t-test
Compares means between two independent groups
Describe chi-square test
-Used for categorical data
- Test for association or Independence between categorical variables
- Compare observed and expected frequencies
When should you reject the null hypothesis
When the p-value is less than alpha. The alpha is reset by the researcher and is typically 0.05 or 0.01. the p-value is calculated from the data
Type 1 error
False positive
-Occurs when the null hypothesis is wrongly rejected
- Concluding an effect exist when it doesn’t
- controlled by setting the significance level alpha before the test
- results in a p-value below alpha leading to the rejection of a true null hypothesis
Type 2 error or beta
False negative
- occurs when the null hypothesis is wrongly accepted
- failing to detect a true effect that exists
- controlled by sample size, affect size, and variability
- and results in a p-value above alpha leading to the acceptance of a false null hypothesis
Confidence interval
Range of values within which the true population parameter is likely it’s a lie
Offer insight into the precision and reliability of an estimate
Confidence intervals
If the confidence interval includes the null value the result is..
Not statistically significant
If the confidence interval excludes the null value the result is..
Statistically significant
What does a wider confidence interval suggest
Higher uncertainty and less precise estimates
What does a narrower confidence interval suggest
Greater precision and higher confidence in the estimate
Describe regression analysis
Statistical technique used to model the relationship between one or more independent variables and a dependent variable
Linear regression
Models linear relationship between independent and dependent variables
Used when the relationship appears to be a straight line
Multiple regression analysis
Incorporates more than one independent variable
Accounts for multiple factors influencing the dependent variable
Logistic regression
Used when the dependent variable is binary with two possible outcomes
Models the probability of an event occurring
Analysis of variance (ANOVA)
Statistical technique used to compare means across multiple groups
Assesses whether there are statistically significant differences in means among different categories
What are the types of anova tests?
One Way anova and two-way anova
One Way anova
Compares means among three or more independent groups
Determines if there is a significant difference between at least one pair of groups
Two-way anova
Analyzes the effect of two independent variables on a dependent variable
Unveils interactions between the variables and their combined effects
Systemic and ongoing collection, analysis, interpretation, and dissemination of data on the occurrence and distribution of health related events in a population
Surveillance
Diseases, injuries, behaviors, or health-related indicators to identify patterns, trends, or changes within a population
Health related events (outcomes
Healthcare workers, patients, visitors, or specific at risk groups
Population
Surveillance can be used to improve..
Performance, patient safety, and infection prevention
Types of surveillance methodologies
Total house surveillance and targeted surveillance
Comprehensive monitoring of all health Care associated infections across the entire population of a healthcare facility. Provides broad and inclusive perspective enabling the identification and potential risk and patterns on a facility-wide scale.
Total house surveillance
Surveillance that narrows its focus to a specific care unit and heis. By concentrating on specific areas where risk may be higher or wear specific interventions are needed, this methodology allows for more precise assessments. This approach is especially valuable when allocating resources efficiently and addressing particular concerns.
Targeted surveillance
Measure that accurately captures and represents the specific concept of construct it is intended to measure
Valid
Measurement produced same results when used repeatedly under consistent conditions
Reliable
Unusual aggregation, real or perceived, if health events that are grouped together in time and space
Cluster
Increase in disease among specific population in geographic area during a specific period of time
Outbreak
Cluster of positive microbiological results without actual clinical illness
Pseudo-outbreak
Study of distribution and determinants of health related states among specified populations
Epidemiology
Difference between surveillance and epidemiology
Surveillance - continuous monitoring of specific health events and conditions
Epidemiology- studies the causes, distribution, and determinants of health and disease in populations
Goals of infectious disease epi
- Prevention, control, and intervention strategies
- Hypotheses
- Associations between risk factors and disease
Parts of the epi triangle
Host, agent, env
Epi models
Triangle model
Wheel model
Web of causation
Chain of infection
Statistical relationship between a risk factor and a disease, two variables tend to occur together more often than would be expected by chance
Associaition
Cause and effect relationship between risk factor and diisease
Causation