From the Guidelines
A person's smoking history is never too little to record, as any amount of smoking exposure can significantly impact health outcomes and treatment decisions. When considering the recording of smoking history, it's essential to prioritize the potential risks associated with smoking, regardless of the duration or quantity of smoking. According to the NCCN Guidelines 1, individuals who previously smoked have a substantially higher risk of lung cancer compared with those who have never smoked, and there is no substantive drop off in that risk after 15 years since quitting.
Key points to consider when recording smoking history include:
- Frequency of smoking
- Quantity of cigarettes or other tobacco products consumed
- Duration of smoking
- Date of quitting and duration of abstinence, if applicable
- Exposure to secondhand smoke
These details are crucial because any level of tobacco exposure can affect:
- Cardiovascular risk
- Respiratory function
- Wound healing
- Medication metabolism As noted in the NCCN Guidelines 1, the risk of lung cancer remains more than 3-fold higher in individuals who previously smoked after 25 years since quitting than in those who had never smoked. Therefore, it is essential to document all smoking histories, no matter how minimal, to provide appropriate preventive care, risk assessment, and personalized treatment recommendations.
From the Research
Smoking History Recording
- A person's smoking history is considered significant in determining their eligibility for lung cancer screening, with a 30 pack-year smoking history being a common criterion 2.
- The accuracy of smoking history in electronic health records is unclear, and it may often underestimate smoking intensity, which can impact who receives lung cancer screening 3.
- There is no specific guideline on when a person's smoking history is too little to record, but studies suggest that even minimal smoking history can be significant in determining health risks.
Definition of a Never-Smoker
- The U.S. Centers for Disease Control defines a never-smoker as someone who has smoked < 100 cigarettes per lifetime 4.
- However, a study suggests that 19 cigarettes per lifetime may be a more conservative cutpoint for defining the never-smoker phenotype 4.
Health Risks and Smoking Reduction
- Substantial smoking reduction may decrease lung cancer risk, but the relationships between smoking reduction and other endpoints, including all-cause mortality and cardiovascular disease, remain unclear 5.
- Complete cessation remains the most effective approach for cancer and CVD prevention, and smoking reduction may not significantly decrease health risks for those who do not quit entirely 5.