CA_4b. How many years would you want this method to last before you need to get it again?
Enter -99 if there is no response. Number of years ____
[Constraint: Must be between 1 and 35 years.
Error message: "Must be between 1 and 35 years. If less than 1 year, go back to previous screen and select
"Every month or every few months". If more than 35 years, go back and select
"Once; it is permanent"."]