| Smoking status | ||
| Read Code | Description | Coding |
| 137. | Tobacco consumption | 2 |
| 1371. | Never smoked tobacco | 0 |
| 1372. | Trivial smoker <1 cigarette/day | 2 |
| 1373. | Light smoker 1–9 cigarettes/day | 2 |
| 1374. | Moderate smoker 10–19 cigarettes/day | 2 |
| 1375. | Heavy smoker 20–39 cigarettes/day | 2 |
| 1376. | Very heavy smoker 40+ cigarettes/day | 2 |
| 1377. | Ex-trivial smoker (<1/day) | 1 |
| 1378. | Ex-light smoker (1–9/day) | 1 |
| 1379. | Ex-moderate smoker (10–19/day) | 1 |
| 137A. | Ex-heavy smoker (20–39/day) | 1 |
| 137B. | Ex-very heavy smoker (40+/day) | 1 |
| 137C. | Keeps trying to stop smoking | 2 |
| 137D. | Admitted tobacco consumption untrue | SYSMIS |
| 137E. | Tobacco consumption unknown | SYSMIS |
| 137F. | Ex-smoker — amount unknown | 1 |
| 137G. | Trying to give up smoking | 2 |
| 137H. | Pipe smoker | 2 |
| 137I. | Passive smoker | SYSMIS |
| 137J. | Cigar smoker | 2 |
| 137K. | Stopped smoking | 1 |
| 137L. | Current non-smoker | 1 |
| 137M. | Rolls own cigarettes | 2 |
| 137N. | Ex-pipe smoker | 1 |
| 137O. | Ex-cigar smoker | 1 |
| 137P. | Cigarette smoker | 2 |
| 137Q. | Smoking started | 2 |
| 137R. | Current smoker | 2 |
| 137S. | Ex-smoker | 1 |
| 137Z. | Tobacco consumption NOS | 2 |
| Smoking cessation advice | ||
| Read Code | Description | Coding |
| 9OOZ. | Stop-smoking monitor administration NOS | 1 |
| 9OOA. | Stop-smoking monitor check done | 1 |
| 9OO9. | Stop-smoking monitoring deletion | 1 |
| 9OO7. | Stop-smoking monitor verbal interview | 1 |
| 9OO2. | Refuses stop-smoking monitor | 0 |
| 9OO1. | Attends stop-smoking monitor | 1 |
| 9OO. | Anti-smoking monitoring administration | 1 |
| 9N4M. | Did not attend smoking cessation advice | 0 |
| 8HTK. | Referral to stop-smoking clinic | 1 |
| 8H7i. | Referral to smoking cessation adviser | 1 |
| 8CAL. | Smoking cessation advice | 1 |
| 8B3Y.1 | Over-the-counter nicotine replacement therapy provided free | |
| 8B2B. | Nicotine replacement therapy | 1 |
| 67H1. | Lifestyle advice re: smoking | 1 |
| 6791. | Health education — smoking | 1 |
| 13p5. | Smoking cessation programme start date | 1 |
| 13p1. | Smoking status at 4 weeks | 1 |
| 13p. | Smoking cessation milestones | 1 |
a
Smoking cessation medication: with regard to the recording of NRT prescriptions, there were 123 different ways of recording these prescriptions, including brand names and different forms of delivery (for example, lozenges, patches, gum). For the purposes of re-coding, all of the 123 different names began with just seven different combinations of first letters — Niq, NiQ, NIQ, niq, Nic, NIC, and nic. Again, a binary variable was formed with ‘NRT not prescribed’ (0) versus ‘NRT prescribed’ (1). NRT = nicotine replacement therapy. SYSMIS = missing.