Smoking pack History
Below is a list of answers to the most frequently asked questions about the smoking pack years calculator. This version was prepared by Dr Nigel Masters and Catherine Tutt RN, RM and updated on 21st May 2007.
Smoking is a leading cause of preventable morbidity and premature mortality in developed and developing countries.
As such, clinicians need to work out total cigarette load at the consultation to attempt individualised disease prediction. To be effective this information needs to be highly visible on the patient's summary screen.
At present computerised systems only record basic smoking data, i.e. ex-smoker, 20 cigarettes a day, non-smoker etc.
With the introduction of computers there are many calculators available to the clinician such as the Framingham Cardiovascular Score and eGFR kidney disease measure, but it could be argued that the smoking pack year calculator is more helpful and predictive of disease. For example eye maculopathy is strongly associated with a 40 pack year history.
Some smoking histories can be complicated and a calculator simplifies the task and provides a universal standard for smoking load/pack year recording, across all Healthcare settings.
One practice is effectively using smoking load to screen its population of active or ex smokers.
By using case finding and carefully recording smoking load, patients were selected for spirometry screening as an aid to detecting chronic obstructive pulmonary disease (COPD).
Ex-smokers or active smokers with a smoking load greater than 15 pack years were invited for spirometry screening entitled 'a free lung check'! Up to 56% of those offered this free check attended screening.
Please note that this referral process simply involved using smoking load rather than symptoms as the key to screening.
Often patients with COPD do not have symptoms and/or are in denial of their symptoms. The spirometry screen in this group of patients had a 28% diagnosis rate.
As a result of this approach the practice increased the number of patients on its COPD register.
In addition targeted smoking advice could be given to this needy selection of patients if they wished.
(Nigel Masters, Catherine Tutt, Jenny Eades. Early diagnosis of COPD. British Journal of General Practice December 2006 page 969.)
Smoking load should be recorded on clinical summaries so that information can be transferred between clinicians and healthcare systems. For example radiologists having smoking load recording on chest X-ray forms will be more sensitised to look for smoking related disease. This will benefit smokers and clinicians alike!
Pack years is a vital smoking load tool used by epidemiologists but can be difficult to use in a non-computerised environment as the calculation can be difficult. Changing smoking patterns over an individual's lifetime and the use of loose tobacco can complicate what seems a simple calculation. One pack year is equivalent to 7300 cigarettes smoked (i.e. 20 cigarettes smoked per day for 1 year divided by 20).
At present because of inadequate read codes it is difficult to record simply whether a patient is a current smoker of X amount of pack years or an ex-smoker with X amount of pack years, so it is necessary to free text the number of pack years on the summary. A small change in the systems will lead to easy dissemination of this vital piece of clinical information.
The smoking load information on individual patient records should be useful in research. Certainly the General Practice database should incorporate this feature in future and it could explore the value of this item for research developments.