Because the code is sometimes entered for people who have stopped smoking, not only for those who never started. In a 2017 study of Welsh GP records, 26% of people who told a health survey they were ex-smokers had “never smoker” as their nearest GP smoking code. Dr Nigel Masters raised the problem in a 2023 BMJ letter.
What did Dr Masters write in the BMJ?
In a letter published in the BMJ in 2023, written as lung cancer screening was being rolled out in England, Dr Masters said that smoking records in general practice computer systems “have been inadequate for years”. He gave an example: “rather than use the code ceased smoking most practices seem to use the code never smoked when a patient has stopped smoking. This causes confusion in the electronic summary visible to clinicians.”
The study he cited for this point was Atkinson et al, published in BMC Medical Informatics and Decision Making in 2017.
What did the Welsh study find?
The researchers, based at Swansea University Medical School, used the SAIL databank, which at the time held GP data from approximately half of the practices in Wales, covering over two million people. They developed a method for working out a patient’s smoking status from their whole GP record, then compared it with what 6,836 of the same people had said about their smoking in the Welsh Health Survey of 2013 and 2014.
Several of the published findings are relevant to practices:
- When only the nearest smoking code in the GP record was used, 26% of people who told the survey they were ex-smokers were classed as never smokers.
- When the whole record was taken into account, including earlier smoker and ex-smoker codes, that figure fell to 8.6%.
- 34% of people who told the survey they had never smoked had past indications of smoking in their GP record, and so were classed as ex-smokers.
- Smoking status was missing more often in the GP records (6%) than in the survey (1.1%).
The authors name the problem directly: “Another problem is allocating never-smoker status to someone after previous codes denoting smoker or ex-smoker.” The 34% figure shows that the conflict runs both ways: what a patient says now can disagree with what was recorded years earlier. The authors stress that neither the GP records nor the survey can be treated as a gold standard, as both rest on what patients reported.
Their method also counted prescriptions for nicotine replacement therapy, varenicline and bupropion as evidence of smoking, while noting that some people may use nicotine replacement long term without smoking.
Why does a wrong “never smoked” code matter?
A “never smoked” code can stay in place for a long time. The paper describes recording guidance under which patients aged 26 and coded as never having smoked after 25 need no further recording, so an incorrect code may not be revisited.
Dr Masters wrote that general practice smoking records “will be used to target lung cancer screening in people over 55”. Our page on lung screening in England sets out who is invited. He also argued that the screening codes are “not numerate but descriptive and are difficult to search”, and that “years smoked and when the patient has ceased smoking” may be the most useful terms. The case for recording numbers is made in FAQs 1 and 2 and in pack years and years smoked: why record both?
What simple check can a practice run?
A search of the practice’s own records can show how often “never smoked” sits alongside other evidence of smoking. This is a records audit, not a clinical review, and the exact searches will depend on the practice’s clinical system and the codes it uses. One approach:
- List patients whose most recent smoking status is “never smoked”.
- From that list, find those who also have a smoker or ex-smoker code at any earlier date.
- Add those with a smoking cessation prescription on record, such as nicotine replacement therapy, varenicline or bupropion.
- Add those with a COPD diagnosis. The NHS says smoking is thought to be responsible for around 9 in every 10 cases of COPD, but it also lists other causes, such as dust and fumes at work and alpha-1-antitrypsin deficiency, so a diagnosis is a reason to look, not proof of smoking.
- Review the flagged records, and confirm the history with the patient at their next contact before changing any code.
Counting how many records are flagged, and repeating the search later, gives the practice a simple measure of whether its recording is improving. When a history is confirmed, asking the patient to recall what they smoked decade by decade can help, and recording pack years, years smoked and the date stopped gives the record numbers that can be searched, not just a description.
For clinicians updating a record, the calculator for clinicians produces one line to paste into the record, with pack years, years smoked and the date stopped.