Introduction Flashcards
What is statistics and biostatistics
Statistics is the study and use of the theory and methods of analysis and data arising from the random processes or phenomena. It is the branch of maths that deals with the collection,organization,analysis and interpretation of numerical data
Biostatistics: Branch of applied statistics directed toward the Application of statistics in the health sciences and biology
What are the Scientific methods
Forming hypothesis Designing experimental and observational studies Gathering data Summarizing data Drawing differences from data
What is the different between the field of statistics and statistics
Field of statistics is the process used to obtain statistics while statistics refers to the numerical quantity computed from a sample data example, mean and median
Field of statistics can be divided into two. Name and explain them
Mathematical stat: study and development of stat theory and method in the abstract
Applied stat: application of stat methods to solve real problems involving random data and the development of new stat methodology motivated by real stat data
Examples of branches of applied stat: psychometrics, econometrics, chemometrics.
Difference between biostat and biometry
Biostat is the application of stat in the health sciences while biometry is the app of stat in the broader biology
What are variables:
Element or factor that’s liable to change
Find the mean , median and standard deviation of the following numbers
12.0,9.5,13.5,7.2,10.5,6.3,12.5
Mean-all the numbers divided by the total number of numbers
10.21
Median( arrange all the values in ascending order and choose the middle number for even number of values) 10.5
Standard deviation- find the mean, subtract each of the given values from the mean , divide the sum by the number of values given
Find the square route of the answer
Square root of 7.3
Answer is 2.509
Importance of biostatistics
Helps to find factors that contribute to diseases or risk factors concerning diseases: since biostatistics is the application of statistics to the health sciences then as a PA if I want to know the risk factors concerning a disease, using statistics I will carry out an investigation to determine which people usually get the disease and what they do that causes them to get the disease. After getting the statistics then I will draw inferences from the data I collected and will be successful in finding the risk factors concerning that disease
Biostatistics helps researchers to go through scientific methods to find answers to problems that worry the health field
Biostatistics through statistical research helps one to find out the effectiveness of a drug. By using statistics I will be able to identify when a drug is effective, what conditions will not make the drug effective and if a drug is effect in that using clinical trials , if different people take the drug the statistics will show if the people reacted to the drug properly if yes, Yh drug is effective if no it’s not
Name four methods of collecting data
Surveys
Experiments
Routine data forms
Registers
Name two
Methods of summarizing data
Graph
Table
numerical
Name two
Methods of making inferences from
Data
Test of association
Test of significant difference
- A variable is a name, a symbol or a letter that is used to represent a data set. True or false
- A variable can take on several values; as against a constant which stays the same. True or false
- All characteristics that are measured or counted are called variables true or false
True
True
True
Name the two types of data and variables
Numeric or quantitative
non numeric or qualitative
Define data
Data are a set of numeric or non-numeric observations on characteristics of a target population.
Types of numeric data and explain
Continuous data-
•are measurable;
•can assume an uninterrupted range of values.
•For example:
–age of patients in years
–weight of a new-born in grams and
–volume of urine in (mls) produced by a patient.
Discrete data-
are countable,
•possible values are distinct or separated.
•For example:
–the size of a family measured as number of children in a family
–the frequency of use of a health facility by a patient measured by number of times
–the number of days since onset of illness.
What’s re non numeric data
Qualitative description of categories within a characteristic.
•For example:
–the blood group type of a patient
–temperature reading recorded as high or low or normal
–list of diagnosis made at a clinic will
–sex of a patient is recorded as “male” or “female.
The manner in which the data are analysed and the amount of information obtained depend in part on the
Scale or level(nominal, ordinal,interval or ratio) on which data is measured
Name four scales of measurement of variables
NOMINAL ; categorical, dichotomous, qualitative
•ORDERED (ORDINAL); similar to the nominal scale but has inherent or predetermined order in the categories.
•INTERVAL scale: Similar to the ordinal scale, however, distances between two points on the scale are of known sizes, and the ZERO point is ARBITRARY;
•RATIO scale: Also similar to the interval scale, but the ZERO point is DEFINITE
Define nominal scale and give one example
The data may simply represent categories. In which case they are referred to as being nominal either, dichotomous, or also as qualitative.
For example:
the sex of patient: males and females
blood group: A, B, AB, and O.
Define ordinal scale
the recorded data represent an ordering, then the data are said to be ordinal. It is similar to the nominal scale but has inherent or predetermined order in the categories.
Eg: results of hospital management of a case could be;
considerable improvement
moderate improvement
no change
Define interval scale
On this scale, distances between any two points on the scale are of known sizes, and the zero point is arbitrary. Example:
the temperature scale, the actual numerical value of the temperature scale is a comparison with an arbitrary point called ‘zero degree’
the apgar score for grading the health status of new-born.
Define ratio scale
For quantitative data, on this scale, the zero point is definite i.e. the zero on the scale of measurement indicates absence of the attribute:
the age of patients
the blood pressure reading
the volume of urine produced by the p
The units of measurement of data are important in determining whether the measurement is qualitative or quantitative.
True or false
What kind of scales are for these examples
temperature of children examined at a health facility level
diseases diagnosed
•age of women who use contraceptives
•educational level of patients
Interval
Nominal
Ratio
Ordinal
Name two main sources of data to the health personnel
The routinely generated data from the practice of the health personnel, which can be found in registers or patient’s notes and
•the data obtained from periodic or special research studies.
Amen four examples of routine data collection forms
OPD forms Death Register Cancer register Admission forms Diagnosis index card
Name two sources of data collection methods
Primary sources-they are gotten directly from the source. Information from a patient Questionnaire
Extraction from registers
Telephone
Sampling
Randomization
• Secondary source: Info from nurses notes, lab forms, births no death records
Annual reports
publicationsImportance of statistics
To guide the design of an experiment or survey prior to data collection
To analyze data using proper statistical procedures
To present and interpret the results
Shows the kind of statistical method to use and how to do it
Data collection techniques name em
Using available information Observing Interviewing Administering Written questionnaires
Name one data collection tool each for the techniques
Using available info- checklist, data compilation form
Observing- senses, microscope, watch
Interviewing- interview guides
Types of biostatistics
Descriptive : Methods of data collection
Methods of summarizing or describing data
Inferential: Test of significance and test of association
The units of measurement of data are important in determining whether the measurement is qualitative or quantitative. When age is recorded as adult or child, we have qualitative data and measured as ordinal.
The type of measurement will determine whether in summarizing the data one would use a proportion or calculate a numerical summary index such as a mean.
True or false
True
In sample surveys Data are collected from a fraction of the population in order to make inferences about the total population from which the sample was taken.
True or false
True
sample which is badly selected or inadequately covered remain a biased one; however big it may be.
True or false
True
Advantages of systematic sampling
The method is useful when there is a list of items in the population or if
•elements or items are arranged in rows like houses along a street. or
•patients arriving at a health service.
There is no bias cuz it’s a probability sample
What is standard error
The standard error is a statistical term that measures the accuracy with which a sample distribution represents a population by using standard deviation. In statistics, a sample mean deviates from the actual mean of a population; this deviation is the standard error of the mean.
The standard error tells you how accurate the mean of any given sample from that population is likely to be compared to the true population mean. When the standard error increases, i.e. the means are more spread out, it becomes more likely that any given mean is an inaccurate representation of the true population mean.26 Sep 2018
What is gravidity and pavidity
Gravidity is defined as the number of times that a woman has been pregnant. Parity is defined as the number of times that she has given birth to a fetus with a gestational age of 24 weeks or more, regardless of whether the child was born alive or was stillborn.21
Name theee methods used to make inferences from data
Regression analysis
Hypothesis testing
Confidence intervals
Example of type 1 and type 2 error
Type I error /false positive: is same as rejecting the null when it is true. Few Examples: (With the null hypothesis that the person is innocent), convicting an innocent person.
while a type II error is the non-rejection of a false null hypothesis (also known as a “false negative” finding or conclusion; example: “a guilty person is not convicted”).
Why is geometric mean used than arithmetic mean
The geometric mean differs from the arithmetic average, or arithmetic mean, in how it is calculated because it takes into account the compounding that occurs from period to period. Because of this, investors usually consider the geometric mean a more accurate measure of returns than the arithmetic mean.
The arithmetic mean is more useful and accurate when it is used to calculate the average of a data set where numbers are not skewed and not dependent on each other. However, in the scenario where there is a lot of volatility in a data set, a geometric mean is more effective and more accurate.
www.educba.com › geometric-mean…
Difference between median and mode
The median is described as the numeric value separating the higher half of a sample, a population, or a probability distribution, from the lower half. The mean is used for normal distributions. The median is generally used for skewed distributions.
