Pack-Year Smoking History Best Elicited by Shared-Decision Making

A majority of Americans would like to see the legal smoking age increased.
A majority of Americans would like to see the legal smoking age increased.
Electronic medical records inadequate for determining whether patients meet pack-year requirement for lung cancer screening researchers warn.

Researchers from Seattle, Washington’s Swedish Cancer Institute found significant discrepancies between smoking histories derived from electronic medical records (EMRs) and smoking histories as elicited in a shared-decision making (SDM) process. Results from the retrospective study, involving patients referred to a centralized lung cancer screening program in Seattle from October 2014 to January 2016, were reported in the Annals of the American Thoracic Society.1

The Centers for Medicare & Medicaid Services (CMS) states that in order for beneficiaries to be eligible for Medicare-funded lung cancer screening, they must meet a number of criteria, which include a tobacco smoking history of at least 30 pack-years. A pack-year is a standardized quantification of cigarette smoking derived by multiplying the average number of packs smoked per day by the number of years the person was a regular smoker. CMS does not stipulate how pack-year histories should be elicited.

In order to assess the eligibility of patients referred for lung cancer screening, and to compare EMR-derived smoking histories to smoking histories obtained during an SDM conversation, the research team extracted pack-year smoking histories from the EMRs of patients who were referred for lung cancer screening and determined to be eligible following SDM. During the SDM conversations, a licensed nursing professional explained the risks and benefits of screening; discussed the value of smoking cessation; and recorded information for the variables that CMS uses to determine eligibility for lung cancer screening, including age, smoking status, and pack-year smoking history.2 During the designated study period, 423 patients were referred to the lung cancer screening program, 59.6% (252/423) were determined to be eligible, and of those patients, 88.9% (224/252) elected screening. EMR-derived smoking histories were compared with SDM-derived smoking histories.

Results showed that EMR-derived pack-year histories and SDM-derived pack year histories were discordant in 96.2% (230/239) of patients deemed eligible for screening on the basis of SDM. In patients with discordant results, the EMR under-reported pack-years for 85.2% (196/230; median difference 29.2) and over-reported pack years for 14.8% (34/230, median difference 7.5). Had the EMR been used as the sole determinant of pack-year history, 53.6% (128/239) of eligible patients would have been designated as ineligible for screening due to not meeting CMS’s 30 pack-year requirement.

“In this retrospective study performed within one 5-hospital health system, we found the EMR pack-year smoking history was highly vulnerable to inaccuracies and, if used exclusively, may have led to missed opportunities to identify individuals eligible for lung cancer screening,” concluded the investigators. “Inaccuracies and incompleteness in the EMR reinforces the value of standardized shared decision making conversations as a critical component of patient centered care to ensure safe and responsible screening for lung cancer.”