Sample size issue
Dear Stata forum members,
I sincerely need your help! I am doing my PhD research on malaria incidence and its predictors. To execute the study, I want to recruit all age groups by assessing their baseline characteristics, and follow them for a year. My population are dynamic population where immigration and emigration is high due to the closeness of the study area to border where people influx in and move out. Therefore, what I am intending to measure is incidence density rather than a cumulative incidence. I could not get a study which followed similar design. Other studies done in my country and elsewhere recruited only febrile patients as the study population where the incidence is more likely. Therefore, my question is what is the minimum sample size (person-year) that I should follow for the study to have sufficient power and yield valid result? What is the sample size calculation formula? Can I calculate the sample size using Stata? To be frank, I tried to calculate the sample size by considering the incidence rate as proportion, which is actually not, and the sample size I got became by far less than what I expected. Help!
I sincerely need your help! I am doing my PhD research on malaria incidence and its predictors. To execute the study, I want to recruit all age groups by assessing their baseline characteristics, and follow them for a year. My population are dynamic population where immigration and emigration is high due to the closeness of the study area to border where people influx in and move out. Therefore, what I am intending to measure is incidence density rather than a cumulative incidence. I could not get a study which followed similar design. Other studies done in my country and elsewhere recruited only febrile patients as the study population where the incidence is more likely. Therefore, my question is what is the minimum sample size (person-year) that I should follow for the study to have sufficient power and yield valid result? What is the sample size calculation formula? Can I calculate the sample size using Stata? To be frank, I tried to calculate the sample size by considering the incidence rate as proportion, which is actually not, and the sample size I got became by far less than what I expected. Help!
Comment