Lec Module 1-4 Flashcards
branch of applied statistics directed toward applications in the health sciences and biology.
Biostatistics
Design experiments and observational studies
Making hypotheses
Summary of data
Gathering data
Testing of hypotheses
Drawing Interferences
Application of Biostatistics
In community medicine and public health
In cancer research
In advanced biomedical technologies
In pharmacology
In ecology
In demography
In population genetics and statistical genetics
In bioinformatics
In systems biology
In agriculture
In genetics
In physiology and anatomy
2 Types of Non-Experimental Studies
- Population based studies
- Individual based studies
Population Based Studies
A. Descriptive study
B. Analytic study
This study aims to generate a hypothesis by answering the following questions,
1. What?
2. Who?
3. Where?
4. When?
Descriptive Study
characteristics (age, sex, occupation) of the individuals affected by the outcome
Person
geography (residence, work, hospital) of the affected individuals
Place
when events (diagnosis, reporting; testing) occurred
Time
Newly reported or registered disease cases compared over time, place, or person
Population estimates or other population group totals used as denominators
Incidence Study
This study aims to generate a hypothesis by answering the the “why?” and “how?” questions.
The goal of this study is to measure the association between exposure and outcome.
This type of study uses a comparison group.
Analytic Study
Example,
Ecological Study
Rates are linked to the level of exposure to some agent for the group as a whole
prepared for illustrating novel, unusual, or atypical features identified in patients in medical practice, and they potentially generate new research questions.
Case Reports
means new and not resembling something formerly known or used.
novel
Example - Case reports
Descriptive Study
Examples - Cross-sectional study, Case-control study, and Cohort study
Analytic Study
To learn about the characteristics of a population at one point in time
Does not use a comparison group
Cross-Sectional Study
To study rare diseases
To study multiple exposures that may be related to a single outcome
Case-Control Study
Can be used to find multiple outcomes from a single exposure
A cohort is a well-defined group of individuals who share a common characteristic or experience
Cohort Study/ Longitudinal Study/ Follow-up Study
study in which people are allocated at random (by chance alone) to receive one of several clinical interventions.
Randomized Controlled Trial (RCT)
The control may be a standard practice, a placebo (“sugar pill”), or no intervention at all. Someone who takes part in a randomized controlled trial (RCT) is called a participant or subject.
standard of comparison or control.
Under this branch is Clinical trial and Control trial
Randomized Study
Under this branch are Quasi-experimental study, Field trial, and Community trial
Non-randomized Study
Shares similarities with the traditional experimental design or randomized controlled trial, but it specifically lacks the element of random assignment to treatment or control.
Quasi-Experimental Research
Applies preventive interventions to healthy individuals
Field Trial
Applies intervention to aggregative units
Community Trial
Aims of Experimental Study
-To provide scientific proof of etiological factors which may permit modification or control of disease
-To provide a method of measuring the effectiveness and efficiency of health services for the prevention, control and treatment of disease and improve the health of the community.
observations of random variables made on the elements of a population or sample.
Data
researchers simply collect data based on what is seen and heard and infer based on the data collected. Researchers should not interfere with the subjects or variables in any way.
Observational Data
researchers produced this by measurement, test method, experimental design. The researcher has control over some variables.
Experimental Data
The data gathered are presented in paragraph form. Data are written and read. It is a combination of texts and figures.
Textual
Method of presenting data using the statistical table.
Tabular
The most effective manner of presenting data since it can be easily understood. Examples are Pie, Barr, Venn, Histogram, Line Diagram and Epidemic curve
Graphical
consists of table number and title
Table heading
categories which are found at the left side of the body of the table
Stubs
the top of the column
Box head
main part of the table
Body
any statement or note inserted
Footnotes
source of the statistics
Source Note
To examine a relationship between two (non-sequential) variables.
Scatterplot
where the x- axis represents some sequential variable like time, or distance along a transect (right, and below). In both cases there is an explicit (spatial or temporal) relationship between adjacent points along the x-axis, and the inclusion of the line makes the pattern of this sequence much clearer.
Line Plot
have two different y-axes, allowing variables with different scales to be plotted on the same graph. Primarily used in the same sorts of situations as line plots, where you want to compare the pattern of change in two different types of variable.
Double Y Plot
Probably the most widely used type of graph in science. This chart can be presented horizontally or vertically. straightforward to produce, and generally are either used to represent means
Bar Charts
combine features of line plots and stacked bar charts. They have similar disadvantages to the latter, though since such plots are generally used to show trends in time or space it is often easier to interpret, as the patterns of expansion or contraction of areas on the graph have a logical meaning.
Area Plot
familiar to everyone, much beloved of business graphics packages and the media, but of relatively limited use for scientific figures.
Pie Chart
plot that lets you discover, and show, the underlying frequency distribution (shape) of a set of continuous data.
Histogram
method of organizing raw data in a compact form by displaying a series of scores in ascending or descending order, together with their frequencies
Frequency table
diagram representing mathematical or logical sets pictorially as circles or closed curves within an enclosing rectangle (the universal set), common elements of the sets being represented by the areas of overlap among the circles.
Venn Diagram
A visual display of the onset of illness among cases associated with an outbreak.
Epidemic curve
is used to estimate the extent of the disease in the population.
Survey Study
is designed to monitor or detect specific diseases.
Surveillance Study
investigate association between an exposure and a disease outcome. They rely on “natural”allocation of individuals to exposed or non-exposed groups.
Observational Study
also investigate the association between an exposure, often therapeutic treatment, and disease outcome individuals are “intentionally” placed into the treatment groups by the investigators.
Experimental Study
subset of the population
sample
Summary measures computed on the sample are used to make statistical inference on the population.
Measures of Central Tendency and Measures of Variability
all items or individuals of interest.
Population
A finite subset of statistical individuals obtained from the population.
Sample