MindMap Gallery Epidemiology—descriptive research
Descriptive research in epidemiology is the most basic type of epidemiological research methods. It is mainly used to describe the distribution of diseases or health conditions and exposure factors in the population. The purpose is to propose causal hypotheses and provide clues for further investigation and research. It is the basis of analytical research.
Edited at 2023-12-21 15:05:47This article discusses the Easter eggs and homages in Zootopia 2 that you may have discovered. The main content includes: character and archetype Easter eggs, cinematic universe crossover Easter eggs, animal ecology and behavior references, symbol and metaphor Easter eggs, social satire and brand allusions, and emotional storylines and sequel foreshadowing.
[Zootopia Character Relationship Chart] The idealistic rabbit police officer Judy and the cynical fox conman Nick form a charmingly contrasting duo, rising from street hustlers to become Zootopia police officers!
This is a mind map about Deep Analysis of Character Relationships in Zootopia 2, Main content: 1、 Multi-layer network of relationships: interweaving of main lines, branch lines, and hidden interactions, 2、 Motivation for Character Behavior: Active Promoter and Hidden Intendant, 3、 Key points of interaction: logic of conflict, collaboration, and covert support, 4、 Fun Easter eggs: metaphorical details hidden in interactions.
This article discusses the Easter eggs and homages in Zootopia 2 that you may have discovered. The main content includes: character and archetype Easter eggs, cinematic universe crossover Easter eggs, animal ecology and behavior references, symbol and metaphor Easter eggs, social satire and brand allusions, and emotional storylines and sequel foreshadowing.
[Zootopia Character Relationship Chart] The idealistic rabbit police officer Judy and the cynical fox conman Nick form a charmingly contrasting duo, rising from street hustlers to become Zootopia police officers!
This is a mind map about Deep Analysis of Character Relationships in Zootopia 2, Main content: 1、 Multi-layer network of relationships: interweaving of main lines, branch lines, and hidden interactions, 2、 Motivation for Character Behavior: Active Promoter and Hidden Intendant, 3、 Key points of interaction: logic of conflict, collaboration, and covert support, 4、 Fun Easter eggs: metaphorical details hidden in interactions.
descriptive research
descriptive research
Features
Observation is the main research method, and no intervention measures are taken on the research subjects.
Exposures are not randomly assigned, and there is no control group at the beginning of the study
No causal inference can be made
type
Current situation study (cross-sectional study)
Purpose
Three-dimensional distribution describing a disease or health condition
Discover clues to the cause
Suitable for secondary prevention of diseases (early detection, early diagnosis, early treatment)
Identify high-risk groups
Evaluate the effectiveness of monitoring, prevention, and control measures
Features
Observational study, no intervention measures are taken on the research subjects
The allocation of exposure factors is not random and no control group is established
No causal inference can be made
Specific time (short time)
Causal inferences can be made about exposure factors (gender, race, age) inherent to the research subjects.
Replace or estimate past exposure with current exposure
condition
Exposure now correlates well with past conditions or has been shown to change little
Known trends in current exposure compared with the original exposure
Exposure to recalled past is highly unreliable
Repeat regularly to obtain incidence data
Generally not used for diseases of short duration
Type of Study
census
Purpose (census and census)
Need early detection, early diagnosis, early treatment
Understand the prevalence of chronic diseases and the distribution of acute infectious diseases
Understand the health level of residents
Understand the normal value ranges of various physiological and biochemical indicators
Applicable conditions
Diseases with higher prevalence
The disease detection method is simple and easy to implement, with high sensitivity and specificity
Have human, material and financial resources
When the survey scope is small and the number of people is small, census can be used directly
A certain census rate should be ensured (generally no less than 80%)
Census rate = number of people actually enumerated/number of people to be enumerated
advantage
Overall, no sampling error
Simultaneously investigate the distribution of multiple diseases and health conditions
Achieve "three morning" prevention
shortcoming
Not suitable for diseases with low prevalence and no easy diagnostic methods
The workload is heavy and it is inevitable that the inspection will be missed
Spending manpower and material resources
sample survey
in principle
randomization
Sample size is appropriate
advantage
Save human, financial and material resources
Small investigation workload
shortcoming
The design and implementation of sample surveys are complex
Duplication or omission of information is difficult to detect
The research object has too much variation and is not suitable for use.
Prevalence is too low to be applicable
Sample size is difficult to randomize and sufficient
Sampling method
simple random sampling
advantage
Simple and basic
Each object has an equal probability of being drawn
shortcoming
Difficult to implement when the overall volume is large
systematic sampling
advantage
Can sample without knowing the population
Easier to perform among live crowds
The sample distribution is relatively even and representative.
shortcoming
If the distribution of each unit in the population has a periodic trend, and the extraction interval happens to coincide with this period, deviation may occur.
cluster sampling
advantage
Save manpower and material resources
shortcoming
Sampling error is large
stratified sampling
Classification
be divided in portion
optimal allocation
advantage
accurate
shortcoming
Improper selection of stratification factors will lose the meaning of stratification
multi-stage sampling
advantage
Make full use of the advantages of each sampling method
shortcoming
Before sampling, it is necessary to understand the demographic information and characteristics of survey units at all levels.
Error size order
Cluster sampling > Simple random sampling > Systematic sampling > Stratified sampling
investigation method
Face-to-face interviews are the most reliable
Petitions, online surveys, telephone interviews, self-administered questionnaires, physical examinations and laboratory tests
Design and implementation
Clarify the purpose of the investigation
Determine the objects of investigation
Determine investigation type and method
Estimate sample size
Factors that determine sample size
Overall disease prevalence (π)
The smaller π, the larger the sample size required
Allowable error (d)
The smaller the allowed error, the larger the sample size
Significance level (a)
The smaller a is, the larger the sample size is
Calculation method
Metrological data (measurement)
n=4S*2/d*2
S: estimate of population standard deviation
d: Allowable error
Count data (rate)
n=Za*2PQ/d*2
P: estimated prevalence
Q:1-P
dallowable error
Determine study variables and design questionnaire
data collection
General registration and reporting
Letter survey
Clinical examination data
Data compilation and analysis
bias
Control Method
Improve research subject compliance and testing rates
Strictly follow sampling methods
Correct selection of measurement tools and methods
Statistical analysis to identify confounding factors
Possible biases in current situation surveys
selection bias
Bias caused by improper selection methods of research subjects
No response bias (response rate higher than 90%)
survivorship bias
information bias
Respondent bias
Investigator bias
measurement bias
Advantages and Disadvantages
advantage
Commonly used sample surveys
There is a naturally occurring contemporaneous control group from the same population so that the results are comparable
Multiple exposure factors can be observed simultaneously
shortcoming
It is difficult to determine the temporal relationship between cause and effect
Incidence data not available
Research subjects may be in the preclinical stage and mistakenly classified as normal.
case reportcase report
case series analysis case series analysis
case investigation case investigation
investigation method
Visits and on-site investigations
ecological studyecological study
Features
Instead of using individuals as the unit of observation and analysis, we use groups as the unit
Unable to know individual exposure-disease relationship
Descriptive research in broad strokes
use
Provide clues to the cause and generate hypotheses about the cause
Evaluate the effectiveness of population-based interventions
type
ecological comparative study
Ecological Trend Research
advantage
Save manpower and material resources
Research into unknown causes may provide clues to causes
The only research method available when individual exposure doses cannot be measured
Evaluation of population-based interventions
Ecological trend research can estimate the development trend of a certain disease
shortcoming
Ecological fallacy—exposure levels are not true for the individual
Confounding factors are difficult to control
Difficult to determine cause and effect