COUNTERPOINT: Should Only Primary Care Physicians Provide Shared Decision-making Services to Discuss the Risks/Benefits of a Low-Dose Chest CT Scan for Lung Cancer Screening? No

The National Lung Screening Trial, the largest randomized controlled lung cancer screening study ever performed, showed a 20% relative decrease in lung cancer mortality and a 7% decrease in overall mortality in high-risk individuals who were screened with LDCT scanning of the chest vs those screened with chest radiographs.1, 2 LDCT screening may cause harm, an important concern given that most individuals undergoing screening do not have cancer and therefore cannot benefit from screening. Moreover, LDCT screening is a complex process requiring careful coordination. The process begins with selecting appropriate candidates for screening and discussing screening tradeoffs with patients, includes annual screening LDCT scans, and extends through evaluation of suspicious findings and treatment of screen-detected cancers.

To provide these beneficial services in a structure that maximizes the benefits and minimizes the harms, the final coverage decision issued by the Centers for Medicare & Medicaid Services recommended coverage for lung cancer screening services for high-risk individuals within screening programs that meet strict eligibility criteria and that are committed to reporting data in a national registry.³ Key components of the coverage decision include the following: (1) eligible high-risk individuals are defined as current or former smokers aged 55 to 77 years with at least 30 pack-years of exposure and with smoke exposure within 15 years; (2) for the initial LDCT scan, there must by a written order from a licensed provider after completion of a shared decision-making visit that uses decision aids⁴; (3) scanning center eligibility is restricted to centers with radiologists experienced in reading chest CT studies with capability to provide LDCT scans; and (4) centers are required to collect and submit demographic and imaging data to a registry approved by the Centers for Medicare & Medicaid Services. As issued, the coverage decision is intended to provide a comprehensive standardized screening program that addresses key components of screening⁵ while balancing the benefits and harms of this process.

An important question is whether the initial steps of the screening process should now be restricted to primary care physicians (PCPs). These initial steps include the following: (1) assessment of eligibility; (2) performance of a shared medical decision-making visit; and (3) referral of patients for screening services. An advantage of this approach is that patients may have a prior relationship with PCPs who could facilitate execution of the screening process. To address this question, we will determine if restriction to primary care providers is feasible and if it can be as effective as a nonexclusive structure.

A policy to restrict shared decision-making to primary care providers is feasible if the supply of PCPs is sufficient and if the providers’ knowledge about screening is adequate. The demand for PCPs is projected to grow more rapidly than supply through 2020. The gap in PCP supply will be alleviated in part by increased use of nurse practitioners and physician assistants, but the supply will still be insufficient to meet the projected demand. Thus, it is not clear that the current supply of primary care providers can meet the anticipated demand from the 12.5% of Medicare beneficiaries who are projected to be eligible for LDCT screening.⁶

Some LDCT programs have assigned shared decision-making to PCPs at the time of referral for screening.⁷ However, recent reports indicate that PCPs may be less familiar with the nuances of LDCT screening and have competing demands during visits. Ersek et al⁸ reported on the results of a survey distributed to members of the South Carolina Academy of Family Physicians in 2015. Less than one-half of the respondents (41%) believed that screening reduces lung cancer mortality, but 98% responded that screening increases the chance of detecting early-stage disease. Responses about practice patterns showed that 73% of the physicians discussed the risks and benefits of LDCT screening with high-risk patients; the majority did so sometimes (35%) or infrequently (51%). Raz et al⁹ reported similar results from a survey of Los Angeles primary care providers. Lewis et al¹⁰ surveyed PCPs from the departments of internal medicine, family medicine, and obstetrics and gynecology at an academic medical center after dissemination of guideline statements endorsing LDCT screening. Only 47% of providers knew three or more of the six guideline components, and 24% did not know any of the components. Importantly, more providers reported using chest radiographs (21%) than LDCT scans (12%) for lung cancer screening despite the absence of evidence demonstrating the efficacy of chest radiographs as a screening modality for lung cancer.

The knowledge and practice deficiencies noted in the studies of PCPs have been detected, albeit at less extreme levels, in surveys of pulmonary specialists. Iaccarino et al¹¹ surveyed a national registry of staff pulmonologists active in Veterans Health Administration pulmonary clinics. The majority of respondents indicated familiarity with the results of the National Lung Screening Trial and comfort with managing pulmonary nodules. However, when presented with clinical vignettes, 74% stated that they would offer screening to a guideline-eligible patient and 24% stated that they would offer screening to a guideline-ineligible patient.

Taken together, the recent LDCT scan experience and evidence base do not support a programmatic effort to restrict the initial steps of lung cancer screening to primary care providers. Rather, efforts should be directed toward disseminating tools and educational programs that can enhance identification of patients who are eligible for screening and can equip providers with the necessary resources to deliver an informed shared decision-making visit. In a joint statement from the American Thoracic Society and the American College of Chest Physicians, Wiener et al¹² emphasized that clinicians should be well versed in the benefits and harms of LDCT screening and how tradeoffs vary depending on the patient’s personal risk profile and comorbidities. The responsibility for education and for dissemination of knowledge and tools appropriately lies within the LDCT screening programs. A model of centralizing the counseling and shared decision-making visit within the LDCT program has been shown to deliver services that positively affect patients’ knowledge and understanding of lung cancer screening.¹³ It is likely that similar results can be achieved through a decentralized process that maintains strict supervision over provider education and shared decision-making visit efficacy.

In summary, the composition of the providers who will administer the shared decision-making visit should be determined locally based on the referral patterns and availability of educated primary care and specialty providers who are comfortable with discussing the nuances of LDCT scanning with eligible patients. If we are successful, as we move toward wider implementation of population health management, the lessons learned from delivery of LDCT services by PCPs and subspecialists¹⁴ will then help to guide delivery of respiratory disease pathways going forward.