(4) Rates per user per day
§to determine whether the DDD is close to the average daily maintenance dose for the drug’s main indication (as determined by WHO).
§# of DDDs per day per user
= 750,000 DDDs per year / 365 days per year / 10,000 users
= 0.21 DDDs per user per day
§We expect this measure to be close to 1 for drugs used for chronic diseases (i.e., for drugs for which the DDD is likely to be prescribed for every user for every day of the year).