Answer Happy

Hers are asked by the number of years smoked. Typically, patients a or fractions health. Smoking history is recorded in pack-years and determined by multiplying the number of packs smoked per day many cigarettes (on average) they smoke per day. If they state that they have smoked a pack of cigarettes a day for 20 years, then their smoking history is 20 pack-years. If patients describe of a pack, the calculation becomes more difficult. Two examples may be helpful in this situation. There are 20 cigarettes per pack. their smoking in terms of the number of cigarettes, orf If a patient states he or she has smoked a pack and a half cigarettes per day for 20 years, the smoking history is calculated 30 cigarettes/20 cigarettes per pack = 1.5 packs x 20 years = 30 pack years smoking history as follows: