To the Editor: With the World Health Organization’s annual World No Tobacco Day to be held on 31 May, it is timely to encourage all patients who smoke to reconsider their actions.

During my registrar training in the 1970s, I developed a simple and effective method of helping smokers consider some consequences of their tobacco habit. I offer this in the hope that others may find it useful too, as a more meaningful exercise than the concept of “pack-years”.1-3

First, enquire when the patient began to smoke regularly. I call this the “tobacco-arche” (analogous to menarche and coitarche).

Next, determine how many years the patient has smoked regularly, remembering to subtract any years he or she may have suspended the habit.

Then, have the patient estimate overall daily usage, relying, if possible, on prompting from an accompanying person to determine a realistic rather than idealised figure.

Finally, multiply the number of years by the daily usage and by the number of days in a year. A reasonable approximation is to multiply by 400 rather than the more cumbersome 365.25.

For example: a 65-year-old person who has smoked 20 cigarettes per day since his or her mid teens (ie, for 50 years) yields 20 × 50 × 400 = 400 000 — approaching half a million cigarettes lifelong.

In my three decades of experience as a general physician, I have noted that an accumulated intake of a quarter of a million cigarettes usually results in at least some cough, breathlessness and end-expiratory wheeze on forced expiration, and decreased exercise tolerance; half a million cigarettes generally causes chronic smoker’s bronchitis, with or without some degree of emphysema, and other harmful effects on the body; while three-quarters of a million cigarettes makes cancer a distinct possibility.4

A further inducement for patients to confront the effects of their harmful habit is to calculate the amount of their lifetime tobacco intake in terms of the dollar cost. In the case of cigarettes, 500 000 at 60 cents each yields the impressive figure of $300 000. This usually comes as a sobering revelation to the smoker and their “significant others”.

The above method can thus contribute to the desirable effect of reducing or eliminating tobacco consumption, with flow-on benefits to patients’ health, finances, and personal and occupational relationships.