How do you know if two rates are statistically different?
If the P-value is less than 0.05 it can be concluded that there is a statistical significant difference between the two rates. If the P-value is less than 0.05 it can be concluded that the ratio R1/R2 is significantly different from 1 (which is the case when the rates are equal).
What is a statistical test of difference?
A t-test is a type of inferential statistic used to determine if there is a significant difference between the means of two groups, which may be related in certain features. The t-test is one of many tests used for the purpose of hypothesis testing in statistics. Calculating a t-test requires three key data values.
How do you compare two groups in statistics?
When comparing two groups, you need to decide whether to use a paired test. When comparing three or more groups, the term paired is not apt and the term repeated measures is used instead. Use an unpaired test to compare groups when the individual values are not paired or matched with one another.
Which test determines if there is a difference between two proportions?
This lesson explains how to conduct a hypothesis test to determine whether the difference between two proportions is significant. The test procedure, called the two-proportion z-test, is appropriate when the following conditions are met: The sampling method for each population is simple random sampling.
How to test for differences between sample data?
Sometimes we will have too few data points in a sample to do a meaningful randomization test, also randomization takes more time than doing a t-test. This is a test that depends on the t distribution. The line of thought follows from the CLT and we can show differences in means are t distributed.
How to compare incidence rates in two groups?
An incidence rate is a ratio between a count and another measurement, for example the ratio of a number of events observed and the total number of person-years of observation. This procedure allows to compare the incidence rates in two groups. This test is not performed on data in the spreadsheet, but on data you enter in a dialog box.
How to standardize and compare two rate ratios?
– where SRR is the standardized rate ratio, var(log SRR) is the approximate variance of the natural logarithm of SRR, DSR and v are the directly standardized rate and its variance as above, z α/2 is the (100 * α/2) the centile of the standard normal distribution, and CI is the approximate confidence interval for SRR.
How is the rate ratio for two study populations calculated?
This function calculates directly standardized rates (DSR) for two study populations, and then compares the DSRs as a rate ratio. Stratum-specific rates are compared also. DSR is simply a weighted mean event rate for a study population, using the group/stratum sizes of a reference population as the weighting scheme.