Why Use Statistics? 1 - Handling Variability 1
Introduction. Statistics offers the means of dealing with data and producing more useful results than raw data, so an understanding of statistical methods is absolutely essential for anyone in any scientific discipline. How variations can occur when making measurements and variability of data discussed. Using statistical methods can help describe the reliability of the results and therefore the conclusions we can draw. How variations and uncertainties are demonstrated by the process involved of taking measurement blood pressure is discussed. Shots of Doctor taking a patient's blood pressure. Exercise 1: Interval pause provided for thinking about possible sources of error in a specific measurement calculation experienced.
Why Use Statistics? 1 - Handling Variability 2
Return to Doctor taking blood pressure. Animated sequence of blood oscillating in artery due to beating of heart. Explanation of the blood pressure measurement. Mercury column used as a measure - hence blood pressure measured in mmHg. Systolic and Diastolic points in measuring blood pressure are explained with animated graphics. Examples of different blood pressures being taken in different situations. Exercise 2. Interval pause provided for thinking about possible sources of error in blood pressure measurements, whether the source of error is the situation or the subject.
Why Use Statistics? 1 - Handling Variability 3
Montage of various measurement situations. Discussion of factors causing possible variations or error. Age, pregnancy, warm room, sex and stress level should all be considered - random errors between different subjects. Random errors in same subject also discussed - standing/sitting and different environments. Random errors between subjects or within subjects are explained. Exercise 3. Identifying random errors within the subject or between subjects.
Why Use Statistics? 1 - Handling Variability 4
Error relating to the way we take measurement discussed, with reference to options for taking blood pressure. Demonstration of instruments for measuring blood pressure. Systematic errors explained and how they lead to bias. Observer can also be responsible for the bias. Variation and bias lead to two different type of error (systematic and random error) - dart players are used as an analogy. No systematic error and reduced random error is desirable when taking measurements.
Why Use Statistics? 1 - Handling Variability 5
Practical examples of measuring blood pressure. Column of mercury on screen as pumping blood sounds are heard. Exercise 4 - comparison of blood pressures recorded and sources of possible error.
Why Use Statistics? 1 - Handling Variability 6
Summary of programme content. Statistics do not eliminate the variations in results but help in handling them, and so enable us to come to more meaningful results.