Increase successful quit attempts in pregnant women who smoke — TU‑15 Data Methodology and Measurement

All entries are converted to the number of cigarettes (1 pack = 20 cigarettes). An entry of "0" indicates no cigarette use at that time period. If a mother reports smoking at any time during the three trimesters of pregnancy she is classified as a smoker (smoked anytime during pregnancy). Women with unknown smoking status for any trimester who report not smoking in the remaining trimesters are classified as "unknown smoking status". Women who report smoking in the three months prior to pregnancy but report not smoking during all three trimesters are considered to have quit before pregnancy. Women who report smoking only in the first trimester and/or second trimesters, but not the third trimester, are considered to have quit smoking during pregnancy and women who smoked in the first trimester, but not the second trimester (among births with gestational age less than 27 weeks) are also considered to have quit smoking during pregnancy. If smoking status during the third trimester of pregnancy is unknown, quitting status is classified as "unknown". Also, among women who give birth at gestational age less than 27 weeks, if smoking status for the second trimester is "unknown", quitting status is classified as "unknown".