numeric:

• -1 = Frequency not known. MED_DO contains dosage per day
• 0.33 = 1 dose every third day
• 0.5 = 1 dose every second day
• 1 = 1 daily dose/qd
• 2 = 2 daily doses/bid
• 3 = 3 daily doses/tid
• 4... = code gives number of daily doses