I am trying to test whether the difference between the two proportion I have found is significant or not. I am just unsure as to whether my samples are independent or dependent and as a result what test to use.
I have a sample of patients from one GP practice. Some have been sent recalls by text message and some have been sent recalls by letter. I have found the % of people who followed through with their recall for each group (those who were sent a text message and those who were sent a letter). It is possible that the same person has been sent a letter and a text message as the data is over a 2.5 year time period.
What test should I use to see if the % increase or decrease is significantly different? z-test (independent sample)? chi-squared test?