Administration & Statistics Flashcards
What is the incidence?
Number of new cases within a specific time period (usually 1 year)
What is the prevalence?
Proportion of the population with a certain condition at any given time
How can prevalence be calculated?
Prevalence = Number of existing cases / total population
What is the standard deviation?
Measure of dispersion for a subject data set from the mean
What does a high standard deviation mean?
The value is far from the mean of the group
What is the standard error of the mean?
How far a sample mean is likely to be from the population mean
How can standard error of the mean be calculated?
SD of multiple different data set means
SEM = SD / (square root of sample size)
What is the power of a study?
The ability of a study to detect a statistically significant result
How can the power of a study be defined in relation to the hypothesis of the study?
Power is the probability of correctly rejecting the null hypothesis if it is false
What is the null hypothesis?
Theory at start of a study that states there is no difference between current method and new proposed method
What is the alternative hypothesis?
Theory at start of a study that states there is a difference between current method and new proposed method
How can the power be calculated?
Power = 1 - (probability of a type 2 error)
How can the power of a study be increased?
Increasing the sample size or reducing the p value
What is the p value of a study?
The probability of getting the results that have been found if the null hypothesis is true
What value is usually ascribed to p?
<0.05
What does a p value of 0.05 mean?
There is 95% chance that the given results did not occur by chance
What are the names given to the normal distribution curve?
Bell curve or Gaussian curve
Where does the normal distribution curve occur?
In many natural phenomenon e.g. if you plotted the heights of all the people in a room
What is plotted along the x axis of the normal distribution curve?
Z score
What is the z score along x axis of normal distribution curve?
The standard deviations from the average
How can the mean, median, and mode be calculated from a normal distribution curve?
They are all the same and will occur at the zero line in the centre of the curve
In the normal distribution curve, what percentage of the results will lie within 1 standard deviation of the mean?
68%
In the normal distribution curve, what percentage of the results will lie within 2 standard deviations of the mean?
95%
In the normal distribution curve, what percentage of the results will lie within 3 standard deviations of the mean?
> 99%