basic biostatic Flashcards
what is basic biostatic
The application of statistical principles to questions and
problems in medicine, public health or biology
Include collection of data, presenting and summarising of data
and drawing of inferences from sample data to a population.
Collection of vital statistics such e.g., mortality rates, monitoring
of health status of a population and clinical trials
what’s basic biostats data
the facts that are collected or put together for analysis in
order to draw a conclusion of a process/procedure.
Basic Biostatic sample
small part of the population that is taken for analysis to
gain better insights/understanding of the population (or
phenomenon) from where the sample comes from.
what is basic biostats statistics
the discipline that is concerned with collection and
analysis of numerical data to draw inferences about a population.
research in epidemiology
Inferences about populations by using samples.
Methods of interpreting this data and communicating it to others
Understand epidemiology requires a basic knowledge of
biostatistics (managing data, including the collection,
summarising, analysis and interpretation of data).
It is important for doctors to understand basic concepts in
biostatistics in order to read, understand and judge the medical
literature appropriately.
Summarizing data
Using and interpreting data correctly requires knowledge of the
different data types Analysed and Summarized to provide
useful information
Data exists as two basic types of variables:
1. Numerical variables
2. Categorical variables
A variable is a characteristic that varies between members of a
population. For example: height/weight
types of data
categorical:
binary- variable two possible categories, yes/no dead / alive
ordinal- same can be in categories severity of disease
nominal- no order to categories gender, marital status
Numerical:
discrete- numbers of apples
continous-height
summarising data
Data can be summarised and displayed using tables and
graphs allows it to be quickly and easily understood.
Tables and graphs must contain enough information so that
they can be interpreted without needing to read the text.
The title of the table or graph specifically describes what is
contained in the graph or table.
Advantage: graphs
-Simple and clear to understand.
-The visual images presented are easily remembered.
-Complex relationships can be demonstrated on graphs.
Advantages of tables
-Allow more complex data to be precisely and flexibly
displayed.
-Preparation of tables need less technical skills.
-Information can be presented using less space.
Types of graphs
line graph
histogram
bar graph
component band chart
pie chart
2 types of sampling
Probability (random) sampling
>Includes simple random sampling, systematic sampling,
stratified sampling and clustered sampling.
All eligible individuals have a chance of being included in the
sample, therefore, results can be more generalized.
More expensive and more time-consuming
> Non-probability (non-random) sampling methods
Includes convenience sampling, quota sampling, judgement
sampling and snowballing sampling.
Some individuals have no chance of being selected, therefore
there is a significant risk of results not being generalisable (as
the sample is not representative).
Cheaper and more convenient.
Useful in early stages of research and for generating hypotheses.
methods of summarising data
descriptive statistics:
measure cental tendency- mean
mode
median
measure variability: range
mode
standard deviation
Summary numbers
mean-The mean is the average of a data set. It is calculated by
adding all the numbers in the data set and then dividing the
sum by the number of values in the set.
Median: The median is the middle value, which is found when
the data set is ordered from smallest to largest.
Mode: The mode is the number that occurs most often in the
data set
META-ANALYSIS
Data from separate but similar studies can be statistically
combined and the pooled results are summarized to identify
overall trends.
Does not involve the collection of new data.
Once relevant studies are identified, the remaining results aare
measured, combined and interpreted.
