Survey Study Objectives and Epidemiological Surveys

Introduction to Research Methodology & Research Ethics

• The word "research" comes from the old French word "recerchier," meaning to search and search again.
• Research is a systematic and orderly approach to answer a question, solve a problem, or generate new knowledge, to make research useful in decision-making.

Steps of Research

• Asking a research question
• Understanding the problem to be studied and identifying the related area of knowledge.
• Reviewing literature to understand how others have approached or dealt with the problem
• Data Collection: Observing, measuring, or recording information
• Data analysis: Arranging and organizing collected data to find its significance and generalize about it.
• Report writing: A final outcome of a research study (drawing conclusions and making generalizations) for conveying information.

Difference between Research Problem and Research Question

• A research problem is an issue, difficulty, or gap in knowledge that is being addressed.
• A research question is a statement in the form of a question to examine and explore a research topic.

According to Type of Data:

• Qualitative Research: Data takes the form of words
• Quantitative Research: Data takes the form of numbers.
• Action Research: Data takes the form of words or numbers.

Epidemiological Quantitative Research

• Measures disease frequency
• Determines disease factors
• Evaluates Screening tests
• Measures mortality and morbidity
• Determines prognostic factors
• Tests new vaccines or treatments

Qualitative Behavioral / socioeconomic and cultural research

• Aims to understand underlying behavior for a phenomena.

Action research/ Health system research

• Aims to identify priority problems, design and evaluate policies and programs for optimal resource use.

According to Source of Data:

• Primary data collection involves collecting original data.
• Secondary data collection involves using data already collected by someone else.

According to Objective:

• Observational Study: takes measurements of something as it is
• Experimental Study: Will you perform an experiment

According to Application:

• Basic Research: is related to new discoveries and basic molecular science.
• Applied research can potentially improve health and quality of life further.

Research Ethics

• Research Ethics: Moral principles that a person follows; research ethics should include protections of human and animal subjects.

What Makes Research Ethical

• Social value to lead to improvements in health
• Scientific validity with a complete description of the purpose of the study
• Fair subject selection for healthy etc.
• Favorable risk benefit ratio: Balance in the risks and benefits of the research.

Informed consent

• Patient agrees with medical Activities
• Consent is given by guardian/parent in children/incapacitated persons

Content of Informed Consent:

• 1 Name of Institution
• 2. Title of Project
• 3. Principal Investigator
• 4. Other Investigators
• 5. Participant's Names
• 6. Purpose of Research
• 7. Procedures (main & alternatives)
• 8. Time and Duration of Procedures and Study
• 9. Discomforts and Risks
• 10. Potential Benefits
• 11. Statement of Confidentiality
• 12. Costs for Participation
• 13. Compensation for Participation
• 14. Research Funding
• 15. Voluntary Participation
• 16. Contact Information for Questions or Concerns

Principles of Biomedical Ethics:

• Respect for autonomy: Respect for the individual and their ability to make decisions regarding health and future
• Beneficence: Actions intended to benefit the patient / others
• Non-maleficence: Actions intended not to harm a patient
• Justice: Being fair to the wide community in terms of the consequences of an action
• Fidelity: A duty is to observe the action made by the profession

No-maleficence (Calculate risk)

• When harm may occur, offer compensation and compelling possibility of benefits to justify the action.

Forms of Justice:

• Procedural Justice: Distribution according to precedence.
• Distributive Justice: Distribution is particularly important for resources that are limited.
• Compensatory Justice: A punishment to combat discrimination

Fidelity:

• Truthfulness: Telling the patient the whole truth without direct paternalism.
• Confidentiality: Access to a patient's record is legally restricted to health professionals; fake names should be used in conferences and teaching situations.

Sampling

• Sampling definition: A procedure/technique to obtain information only for limited number of subjects.
• Sample definition: A number of individuals that are from total population.

Advantages of sampling:

• Lower cost
• Saves time
• Provides more intensive and accurate investigations and information
• Eliminates bias

Difference Between Target Population and Sample:

• Target population: The total group of individuals from which the sample might be drawn.
• Sample: A subset of the population that is used to gain information about the entire population.

Precautions to Take in Sampling

• It must be well chosen (Representative to the parent population)
• The Sample must be sufficiently large to minimize sampling variation
• Adequate coverage of the sample to avoid sample bias.

Methods of Sampling:

• I. Non probability sample
• II. Probability Sample (Random sample)

Non-Probability Sample:

• convenience sampling
• purposive samples
• quota samples
• snow ball sampling

Convenience Sampling

• Collecting samples by taking samples located around a location or Internet service
• Used to explore to get the feel of the situation

Purposive samples

• Serves a very specific purpose

Quota samples

• Used in sampling public opinions
• Population is divided into sub-groups, as in stratified sampling.
• Judgment is used to select subjects/ from each sub-group based on a specified proportion.

Snow ball sampling

• Known as chain/ sequential sampling.
• Used where one respondent identifies other respondents (from his/her relations/friends)
• Adopted in situations where identifying members in a sample is hard

Probability Sample (Random Sample):

• Unit in a sample population has =probability/ is a chance of getting selected.

Types of random samples

• Simple Random Sample
• Systematic Random Sample
• Stratified Random Sample
• Cluster Sample
• Multistage Random Sample

Simple Random Sample:

• Population is uniform or homogenous
• Each unit in the population has equal & the independent chance of getting selected.
• Listing of Units in the population randomly (sampling frame).
• Select required number by using random computer programs/lottery/ number table entirely based on chance.
• Easy to conduct.
• Requires sampling frame.
• Unsuitable for heterogeneous population (gender, age, etc.)

Systematic Sampling:

• The Frame is selected systematically for sampling
• To secure the desired number selection process picks some random point
• To select 100 subjects, from a sampling frame of 1000 we must select 1 subject from each 10.
• After randomly selecting the 1st subject, subsequent subjects are selected at regular intervals.
• Advantage: Easy to conduct.
• Disadvantage: Requires sampling frame

Stratified random sampling:

• Used when population is considered heterogeneous i.e. people in population differ based on relevant characteristics e.g. gender, age range, income, job.
• heterogeneous population divided into homogenous strata
• Select simple random sample from each stratum after this.
• Should have proper allocation to ensure its representativeness More expensive and Time consuming

Cluster Sample

• Sample = a group, not an individual (family, school class, ...).
• Selected randomly, all groups being of the same type.
• Selected group's ALL member will be included in the study
• concentrated field is simple & inexpensive
• Causes errors if cause / variable is clustered in the population

Multistage Sample:

• Sampling is carried out in 2+ stages. The example includes school children:

1. a random sample of schools is taken
2. from each selected school select a random sample for further study.

• Advantages may more resources can be concentrated
• No whole population's sampling system

Descriptive Studies

• Health: A state of complete wellbeing and not merely absence of any disease or infirmity and the ability to have a productive life

What is Epidemiology?

• Epidemiology: the study of the distribution and determinants of health related events or states, controling the health problems.

Uses of Epidemiology:

• Identify disease pattern among a population
• Identify the causative factor
• Determine cause importance of illness, disability or death.
• Identify segments of the population suffering ill health.
• Evaluate the effectiveness of health programs.

Epidemiological Research Methodology

• Epidemiological studies are categorized as observational or experimental.

Observational studies

• Observational studies study nature, with no outside interference
• Include descriptive and analytical studies

Descriptive study:

• A description limited to an occurrence of disease.

Analytical study:

• Analysing relationships from other variables relating to health.

Experimental research

• Attempts through behavior, exposure, or treatment to change.

Quality of Research Studies

• Quality of research studies from weak to strong.
• Descriptive studies
• Analytical studies
• Clinical trials
• Systematic Reviews
• Met analysis studies.

Descriptive studies

• Studies done in the first phase of an epidemiological investigation.
• Describe disease distribution in population, give data :

1. When disease occur- the time
2. Where disease occur- the place
3. Who isGetting disease-persons

Types of Descriptive Studies:

• Case Reports: Presentation of a single case e.g., Report new therapeutic effect, describes disease
• Case Series: Describes multiple patients with a given disease, aims well to describe variations of a disease/unusual variations to create generating a hypothesis
• Ecological (or correlational) studies: These studies are useful for generating hypotheses.

Aspects of Community Based Studies

• Comparing population with different places over time
• They extracted from vital statistics, censuses, and national health surveys

Cross-Sectional Studies (Prevalence Studies):

• "observational" surveys status and exposure to illness in a moment.
• Measures well-being that are results to health over a period of time.

Examples of cross-sectional studies

• Investigate diabetes when related to obesity.
• Investigate on musculoskeletal problems of radiologists.

Advantages of Cross-Sectional Studies

• Study common condition with a high degree of chronic conditions.
• Generates good hypothesis
• Estimates specific disease prevalence rates
• Easy, quick and inexpensive.
• It starts with causal association.

Disadvantages of Cross-Sectional Studies

• Not helpful in studying acute or seasonal diseases.
• Impractical in studying rare diseases.
• Ineffective in knowing the rate of new cases.
• Does not determine which came first.

Prevalence Rate definition

• existing diseases are frequently in number at specific time.
• Prevalence P; no.of people with condition within a stated time or area over tot. people examined during examination in a specified area x 100

Definition of Survey Study

• descriptive field study to study specific diseases and community problems.

Classification of target population on survey:

• Local survey: limited to places like school, camp and or factory.
• National Survey: over the whole country.

Objectives of survey:

1. Case finding:
   • Pre-clinical phase: screening procedures reveal changes.
   • Clinical phase phase:symptoms & signs.

• Complicated cases: more complex pathological damage occurs.

2. To know the size of problem within that community
3. Determine the disease features according to ecological factors.
4. Data usage for planning that helps with awareness.

Steps for Conducting a Survey Study

• Preliminary stage: clarifying purpose, reviewing literature, considering ethics and formulating the topic
• Objectives: determining the the study objective
• Defining, study type as Descriptive, analytical, etc.
• Identifying the Target population: use population-sampling size for consideration.
• Establishing a timeline before prep: man power, money, and surveying material needed.
• Data collection: to collect data using questionnaires, investigations or interviews.
• Data analysis: tabulation and analysis of data
• Writing Reports: use conclusion disc and recommendations for results.

Analytical Studies

• In Analytical Epidemiology we investigate the relation between disease and exposure

Types of Analytical Studies:

• Case-control (Retrospective) studies is like ""observational"" and to assess exposure or specific risk, compares them with individuals w/ no disease.
• Cohort (follow-up or incidence) studies

Case-Control studies

• Case-control studies provide an easy simple way that is relatively way to investigates rare diseases of an individual.
• Steps to conduct: Identify the study group or cases.
• Define criteria for diagnosis with inclusion and exclusion of individuals.

Identifying Need for Contrasting Controls

• To identify controls, it helps contrast from studied disease from that of other controls.
• Control Matching happens if it influence the data.

Sources of Controls

• hospitals
• the people next door
• friends /co-workers/or family

Measurement Calculations on Data Data:

• Pl for the exposed with 1 case. to define formula P1= Ala + c Pl proportion of the exposed among 1 case.
• P2 for the exposed with control formula for that= b/b =d for P 2 exposed with controls *

Retributive contribution can be defined by P1 P2

• to represent relative contribution of suspected.
• the odds of exposure, for those that cases Rl-Alb exposure to risk among others as controls R 2.

It Is the Indirect Estimation of the Risk.

• Interpretation If > 1 i.e. cases had more frequencies than control.
• Odds ratio, Diabetic all which equals, cases that have two to four times that of others, control to over consuming carbohydrates

Advantages of Case Control studies:

1. Quick and easy, can be done for multiple risk factors, with long latency, even with rare cases.
2. No large samples as to prove it: can be related for exposure, which then estimates the case via ratio.

Disadvantages of Case Control Study:

1. Difficult to do for a rare exposure rate because prone to: Liable to bias & cannot calculate prevalence.
2. recall or selection bias.
3. Not east to estimate timespan exposure.

Cohort (follow-up or incidence) Studies

• It designs and begins with a group to see who is free but is divided into groups. Variables are measured to see that development, but others do have the exposure
• Best Observational Studies

How to Conduct Studies:

1. Free cohort, divided into 2 groups, exclusion for any study.
2. Exposed group will be exposed to risk, the individuals.

• Both groups follow up the stable groups If the disease in the group is high then expose group will cause this for its potential.

Analyzed Measures

• To find total of individuals in a cohort study, one must perform with both cohort and disease state.
• A RR is for ""how many times to exposed develop in disease?""
• AR is for "How much to study disease as to the exposure?"

Advantages of Cohort Studies:

1. Can be study in multiple outcomes from a single exposure.
2. It will calculate rate, relative risk and attributable risk
3. This can be suitable due to is less bias

Disadvantages of Cohort Studies:

• Rare disease inefficient for their eval
• Followup can lead to drop in cases/can be expensive also involve subjects that take a while to adjust habits during changes.
• Can be diagnosed over an extended period.

Advantage & Disadvantage of Studies:

• case: good for risk quick
• Cohort good in incidence, time

Experimental (Interventional) Studies

• Definition: Clinical trials= researches involving therapeutic for patients with safety or efficacy.
• To see better solutions to improving care for people who are suffering from a long term disease.

Ways an Individual Assessed

• Effectiveness and any given safe measures
• assessment of efface & compare towards standard therapy

Types (Therapeutic for test or Prevention to cure disease)

• new drugs to treat
• ways to prevent reccurance

Diagnostic Trials:

• trials of validity of diag measures can include radiologic.
• to search better test
• better procedures for a good diagnosis.

Screening Trials:

• best way to detect the diseases/early in the disease.

Life Style Trials:

• in patient chronically ill patients to see comfort and to improve quality of life.

Stages of Trials on How It Should Be Done:

1. IN-Vitro: animal studies 1st
2. Human testing=4 phases
3. Phase 1 - PreClinical- use small groups among healthy group for month-basic safety info, safe dosage& see side effects.
4. Phase 2-100 or 300 patients with ailment over long term, preliminary over safety and toxicity
5. Phase 3- Applied and tested for with a large group around a thousand or more, or is to see monitoring for the tests.
6. Phase 4 - POST marketing - use over the field or wide use to know effectiveness.

Steps on Clinical Trials:

• Group selection
• Getting consent to participate in study
• To classify between and control groups to receive it.
• Experiment group is all or procedure with either placebo/passive etc.
• Followup with period or specific timeframe. compare the groups from each other.

Avoid the Study

• Ensure Masking

Blind trial:

• Subject or treatment which appear alike

Double Blind

• Neither subject nor observers know

Triple blind:

• Subject/observers and analyst unaware

Advantages of Randomized Clinical trials:

• minimize bias, population is selected more accurate
• Blinding reduces bias.

Disadvantages of Randomized Clinical trials:

• takes time, difficult ethics and cases with loss.

Role of Screening Tests In Disease Diagnosis:

• Definition: investigation used on healthy to find diseases or recognize individuals that have high risk of illness. Prevent disease and to fix is prognosis when illness exists.
• Objective not to diagnosis but with who is suffering

Intervention with some natural disease with chronic ones.

• if any pathology has development with the test.
• early intervention will do work, that helps will test treatment.

Screen Tests:

• Apply to great numbers to pick which can be suffering from a disease.

The Difference Between Screen Tests and Diagnostic Tests Is:

• Screen Test is is done amongst is those that have already have have illness.

Tests has some requirements. simple.

1. Simple / inexpensive
2. Limited time
3. Acceptable Has Special Requirements:

• the tests are precise, valid of each test

Types of Screening:

1. Mass Screening (irrespective of any disease).
2. Risked Screening with offered that comes with special Risk, those can identify the close relatives.
3. Multiphase screening has diseases occurring in both time, that of antenatal within school exams,
4. Can be applied
5. Requirements regarding The disease can be from a program it should be, which has help to see why it’s rare.

How to Identify

• The test shows in the rate measured by predictive values
• If positive can = anxiety, if false or is suffering when is reassured can be really wrong.

Sensivity

• Ability to tell the correctly individual disease,

Specificity

• ability when individual no disease, with little false/positive results.

predictive value:

• individuals and correctly labeled and non-labeled of all, use the test and if needs to reliability
• Agreement that measurements are the same, then technique will give same on same persons data. test Is repeatable for the certain conditions. it measure the variability.

Medical Statistics I

• Medical Statistics encompass data and methods summarizing such, by with analytical conclusions within Medicine field.
• Presenting facts by taking simplifying many figures, test, and assumptions and policies to check overall standard of health to look at test terms.

Basic Terms:

• Population: of individuals analyzed
• Sample: Set of population

This quiz assesses understanding of survey study objectives, including determining disease prevalence and investigating outbreaks. Questions cover prevalence rate calculations and distinctions between survey types. It tests knowledge of epidemiological survey methodology.