Abstract
Introduction:
Lung cancer screening with low-dose computed tomography (LDCT) is recommended by the U.S. Preventive Services Task Force (USPSTF) in high-risk patients, but a minority of eligible people is screened. It is not clear whether knowledge of USPSTF recommendations among primary care physicians (PCP) impacts utilization of LDCT.
Methods:
A randomly selected sample of 1384 primary care physicians in Los Angeles County was surveyed between January and October 2015, using surveys sent by mail, fax, and email. The response rate was 18% (n=250). Training background, years in practice, practice type, and respondent demographics were collected. We analyzed results based on the response to a question on whether the USPSTF recommends the use of LDCT to screen high-risk individuals for lung cancer.
Results:
117 (47%) PCPs responded that the USPSTF recommends LDCT for LCS. Of PCPs who were aware of USPSTF recommendations, 97% responded that CT was effective at reducing lung cancer mortality among individuals meeting eligibility criteria, compared with 90% who were unaware of guidelines (p=0.02). A larger proportion of PCPs aware of guidelines ordered LDCT (71% vs. 38%, p <0.001) and initiated a discussion on screening (86% vs. 62%, p<0.001). Both groups of PCPs reported similar perceptions of barriers to screening such as insurance coverage, risks of LCS, and cost to society. Practice size, training background, and years in practice did not affect knowledge of guidelines.
Discussion:
Awareness of USPSTF recommendations for LDCT is associated with increased utilization of LDCT for screening. Educational interventions for PCPs may improve adherence with LCS recommendations
Keywords: Lung cancer screening, LDCT, preventative health, USPSTF, health care barriers
MicroAbstract
Lung cancer screening with low-dose computed tomography (LDCT) is recommended in high-risk patients, but a minority of eligible people is screened. Here we analyzed the results of a survey of 250 PCPs to determine whether knowledge guidelines was associated with utilization of LDCT, and to understand what physician features were associated with guidelines knowledge. We found that awareness of guidelines was associated with increased LDCT utilization.
Introduction
Lung cancer screening (LCS) with low-dose computed tomography (LDCT) scanning is effective in reducing lung cancer mortality in high-risk current and former smokers.3,4 Screening with LDCT is recommended by the United States Preventive Services Task Force (USPSTF), the National Comprehensive Cancer Network (NCCN), the American Cancer Society (ACS), and other professional organizations.5–7 Despite these recommendations, only a minority of eligible patients is screened.1 A number of potential physician, patient, and health system barriers exist to explain the lackluster adoption of LCS. We previously reported that primary care physician (PCP) barriers include concerns regarding the benefits of screening, cost of screening to society, and insurance coverage of screening in high-risk patients.1 Moreover, only about half of PCPs are aware of LCS guidelines. Other groups have similarly reported low utilization of LDCT, poor knowledge of guidelines, and identified concerns regarding costs, insurance coverage, and potential harms of LDCT.8–13
Although at least one study describing an educational intervention for PCPs on LDCT has been reported,14 the extent to which knowledge of guidelines for LDCT affects utilization of LCS is unclear. For example, it is possible that PCPs who understand guidelines may still not feel that the data on the benefits of LCS is convincing enough to recommend LDCT to high-risk patients. Here, we sought to determine whether utilization of LDCT and perceived barriers to LDCT varied based on understanding the USPSTF guidelines for LCS. To accomplish this, we analyzed the results of a survey of PCPs on their perceptions and utilization of LDCT, based on knowledge of the USPSTF recommendations for LCS and identification of the appropriate screening study when presented with several hypothetical patient scenarios. We also sought to understand which physician characteristics, board certification, years in practice, and group size, are associated with knowledge of guidelines. Our hypothesis was that knowledge of LCS criteria was closely correlated with utilization of LDCT. Understanding the effect of knowledge of LCS guidelines on utilization and perceptions of LCS can help guide future educational interventions aimed at PCPs.
Methods
Survey Study
We randomly selected 1,840 from a list of 7,890 PCPs, obtained from the American Medical Association’s (AMA) Physician Masterfile, to be included in our study. Of the 7,890 total contacts included on the AMA list, 2,931 were excluded due to missing demographic and/or contact information such as age, sex, and/or phone number. Of the remaining 4,959 with complete information, 354 were over age 75 and were also excluded. Our sample for randomization therefore included 4,605 potential respondents. Eligible respondents were family physicians, general internists, and general practitioners actively practicing in Los Angeles County, California in January 2015. The randomization procedure was performed using a random seed algorithm in SAS to stratify and select survey recipients based on age group, sex and area of specialty. Of the 1,840 physicians randomized, 456 were excluded from the study due to one of the following criteria: (1) we were unable to successfully mail the introductory letter and questionnaire to the physician (n=120); (2) the physician lacked valid current contact information (n=242); or (3) the physician was located outside Los Angeles County, unlicensed, sanctioned, retired, or deceased (n=94). This resulted in a final sample of 1,384 eligible primary care physicians. From this sample, 250 physicians (18% response rate) completed the survey, while the remaining 1,134 physicians received the survey but elected not to participate. Methods of survey and data collection are described elsewhere.1 This study was reviewed and approved by the City of Hope Institutional Review Board (COH IRB #14228). Surveys included an information sheet on the study and an experimental subject’s bill of rights.
Questionnaire Items and Methods
The survey contained a total of 54 questions organized into four sections to determine perceived efficacy of LDCT and chest X-ray (CXR) to prevent death from lung cancer, knowledge of guidelines for LCS, utilization of LCS by PCPs, and perceived barriers to LDCT. We previously reported data on the utilization and perceived efficacy of LDCT and chest X-ray (CXR) in preventing lung cancer death, the knowledge of LCS guidelines, and potential barriers to LDCT. Here we analyze results according to understanding of guidelines. We asked PCPs whether LDCT was recommended by the USPSTF, NCCN, or ACS to measure awareness of the guidelines. We also presented three clinical scenarios of asymptomatic patients of varying ages and tobacco exposure history and asked whether these patients should undergo annual LDCT, CXR or no screening (Table 1) to measure understanding of the guidelines.
Table 1:
Choice of screening test according to clinical scenarios
| LDCT, n (%) | CXR, n (%) | No screening, n (%) | No answer, n (%) | |
|---|---|---|---|---|
| 1. An asymptomatic 60 year-old with a 30 pack-year history who quit 5 years ago (USPSTF RECOMMENDED) | 180 (72%) | 36 (14%) | 33 (13%) | 1 (0%) |
| 2. An asymptomatic 60 year-old with a 30 pack-year history who quit 20 years ago (NOT RECOMMNEDED) | 63 (25%) | 56 (22%) | 130 (52%) | 1 (0%) |
| 3. An asymptomatic independent 80 year-old former smoker with a 40 pack-year history who quit 10 years ago (USPSTF RECOMMENDED) | 77 (31%) | 53 (21%) | 120 (48%) | 0 |
Abbreviations: United States Preventive Services Task Force (USPTF)
Statistical Methods
Summary data were tabulated using total counts and frequencies. In addition, data were stratified across the following 3 areas:
-
Knowledge of Task Force Guidelines, defined as answering “YES” to the following question:
“To the best of your knowledge, does the U.S. Preventative Services Task Force (USPSTF) recommend the use of low-dose radiation CT scanning for lung cancer screening for high-risk individuals?”
Number of correct responses in the patient scenarios (Table 1) to the question: “Which, if any lung cancer screening test would you recommend for the following hypothetical patients? Assume no history of occupational exposures to known carcinogens.”
The percent of high risk patients, defined as those aged 55–80 with a >30 pack-year smoking history, who the PCP referred in the last 12 months for low dose radiation chest CT for lung cancer screening. These percentages were grouped as: a) none, few, or some (<25%), versus b) half, most, or almost all of patients (about 50% or greater).
For the 3 areas listed above, dichotomized data were summarized across physician demographic characteristics (e.g. age, sex), practice information (e.g. years in practice, practice size), and survey responses. Survey questions revolved around the following themes: physician beliefs, physician practices, patient influences, and knowledge of lung cancer screening guidelines and recommendation.
All data were analyzed using chi-square statistics along with univariate and multivariate logistic regression. Statistical significance was set at a two-sided alpha of 0.05. Due to multiple comparisons, a Bonferroni adjustment sets the statistically significant alpha at 0.004 rather than 0.05. Analyses were performed using SAS version 9. Results were not adjusted to account for multiple testing. Missing data, while infrequent, were excluded.
Results
Overall, 116 (46%) respondents answered that they were aware that the USPSTF recommends LDCT for high-risk current and former smokers. Provider characteristics were analyzed by awareness of USPSTF guidelines for LCS and are summarized in Table 2. Responses to choice of LDCT, CXR, or no screening for various clinical scenarios are summarized in Table 1. 123 (49%) respondents correctly answered 2 or 3 scenarios, using USPSTF recommendations, compared with 129 (51%) respondents who answered 0 or 1 scenarios correctly.
Table 2:
Primary Care Physician Characteristics by Awareness of USPSTF Guidelines
| Characteristic | Yes (N=116) | No/Unsure (N=129) | |
|---|---|---|---|
| Age | |||
| <40 | 9 (7.8) | 6 (4.7) | 0.5058 |
| 40–49 | 36 (31.0) | 36 (27.9) | |
| 50–59 | 41 (35.3) | 41 (31.8) | |
| 60–69 | 24 (20.7) | 36 (27.9) | |
| ≥70 | 6 (5.2) | 10 (7.8) | |
| Male | 75 (64.7) | 83 (64.3) | 0.9591 |
| Years in practice | |||
| >30 | 27 (23.3) | 31 (24.2) | 0.914 |
| 21–30 | 32 (27.6) | 39 (30.5) | |
| 11–20 | 43 (37.1) | 42 (32.8) | |
| 0–10 | 14 (12.1) | 16 (12.5) | |
| Board certification | |||
| Family Practice | 53 (46.5) | 57 (44.2) | 0.7186 |
| Internal Medicine | 61 (53.5) | 72 (55.8) | |
| Practice type | |||
| Full/part owner | 52 (44.8) | 70 (54.7) | 0.0417 |
| Physician-owned | 10 (8.6) | 8 (6.3) | |
| Large medical group/system | 23 (19.8) | 19 (14.8) | |
| Staff/group model HMO | 10 (8.6) | 15 (11.7) | |
| University affiliated | 18 (15.5) | 7 (5.5) | |
| Other non-university affiliated | 3 (2.6) | 9 (7.0) | |
| Specialty mix | |||
| Single specialty | 66 (56.9) | 80 (64.0) | 0.2595 |
| Multi-specialty | 50 (43.1) | 45 (36.0) | |
| Practice size | |||
| 1 | 27 (23.3) | 34 (26.6) | 0.3052 |
| 2–5 | 34 (29.3) | 50 (39.1) | |
| 6–15 | 26 (22.4) | 17 (13.3) | |
| 16–49 | 18 (15.5) | 16 (12.5) | |
| 50–99 | 6 (5.2) | 4 (3.1) | |
| ≥100 | 5 (4.3) | 7 (5.5) | |
| Type of health record system used | |||
| Paper chart | 12 (10.3) | 22 (17.3) | 0.4754 |
| Partial EMR | 6 (5.2) | 6 (4.7) | |
| Transitioning from paper to full EMR | 20 (17.2) | 19 (15.0) | |
| Full EMR | 78 (67.2) | 80 (63.0) | |
| Percent patients insured | |||
| 0–5 | 85 (73.3) | 78 (60.5) | 0.1966 |
| 6–25 | 20 (17.2) | 34 (26.4) | |
| 26–100 | 6 (5.2) | 8 (6.2) | |
| Not answered | 5 (4.3) | 9 (7.0) | |
| Percent patients insured by Medi-Cal | |||
| 0–5 | 56 (50.9) | 57 (46.0) | 0.1623 |
| 6–25 | 36 (32.7) | 33 (26.6) | |
| 26–50 | 11 (10.0) | 13 (10.5) | |
| 51–75 | 5 (4.5) | 16 (12.9) | |
| 76–100 | 2 (1.8) | 5 (4.0) | |
| Patient volume during typical week | |||
| ≤25 | 12 (10.6) | 10 (8.0) | 0.6022 |
| 26–50 | 14 (12.4) | 22 (17.6) | |
| 51–75 | 33 (29.2) | 30 (24.0) | |
| 76–100 | 32 (28.3) | 35 (28.0) | |
| 101–125 | 16 (14.2) | 16 (12.8) | |
| >125 | 6 (5.3) | 12 (9.6) |
Abbreviations: United States Preventive Services Task Force (USPTF); Low dose computed tomography (LDCT); Chest x-ray (CXR).
5 primary care physicians did not respond to the question about USPSTF recommendations.
We analyzed responses to the clinical scenarios by whether the respondent was aware of the USPSTF recommendations. Overall, knowledge of USPSTF guidelines was correlated with correctly identifying the scenarios. For scenario 1, 102 (87%) of respondents aware of USPSTF guidelines correctly answered LDCT, compared with 75 (57%) of respondents not aware of guidelines (p<0.001). For scenario 2, 66 (56%) of respondents aware of USPSTF guidelines correctly answered LDCT, compared with 64 (48%) of respondents not aware of guidelines (p=0.009). For scenario 3, 52 (44%) of respondents aware of USPSTF guidelines correctly answered LDCT, compared with 25 (19%) of respondents not aware of guidelines (p<0.001).
Next, we analyzed the responses to questions regarding perceived efficacy of LDCT in preventing death from lung cancer and the self-reported utilization of LDCT and CXR for lung cancer screening during the prior 12 months, stratified by awareness of USPSTF recommendations. As summarized in Table 3, PCPs familiar with USPSTF recommendations were significantly more likely to have ordered LDCT and initiate a discussion about LCS. A larger number of PCPs familiar with USPSTF recommendations reported referring to a lung cancer screening program, but the result did not meet the Bonferroni adjusted p value we set. Similarly, perceived barriers to screening with LDCT were analyzed by awareness of USPSTF guidelines. PCPs who were aware of USPSTF were much less likely agree or strongly agree that the benefits of LDCT weren’t clear, but responses to other potential barriers were similar between groups (Table 4).
Table 3:
PCP Responses to questions according to awareness of USPSTF recommendations*
| For current or former smokers aged 55–80 with a | Yes | No | p value |
|---|---|---|---|
| > 30 pack-year history of smoking:1 | |||
| LDCT is an effective screening option, n (%) | 109 (97%) | 104 (90%) | 0.02 |
| CXR is an effective screening option, n (%) | 31 (28%) | 59 (47%) | 0.002 |
| Over the past 12 months have you:2 | |||
| Ordered LDCT for lung cancer screening, n(%) | 80 (71%) | 47 (38%) | <0.001 |
| Ordered CXR for lung cancer screening, n(%) | 48 (42%) | 56 (46%) | 0.6 |
| Referred a patient to a lung cancer screening program | 20 (18%) | 10 (8%) | 0.029 |
| Initiated a discussion about benefits and risks of lung cancer screening | 97 (86%) | 76 (62%) | <0.001 |
Abbreviations: United States Preventive Services Task Force (USPTF); Low dose computed tomography (LDCT); Chest x-ray (CXR).
5 primary care physicians did not respond to the question about USPSTF recommendations.
Missing and Don’t Know responses were excluded from these analyses.
Missing and Not Sure responses were excluded from these analyses.
Table 4:
Barriers to lung cancer screening according to awareness of USPSTF recommendations*
| Physicians who strongly or somewhat that they may not order | Yes | No | p value |
|---|---|---|---|
| LDCT due to the following reasons:1 | |||
| LDCT is not covered by insurance, n(%) | 59 (52%) | 74 (58%) | 0.34 |
| I don’t have time to discuss risks and benefits, n(%) | 13 (11%) | 10 (8%) | 0.34 |
| The risks are too high, n(%) | 8 (7%) | 15 (12%) | 0.21 |
| The benefits are not clear to me, n(%) | 16 (14%) | 57 (45%) | <0.001 |
| LDCT is too expensive for our healthcare system, n(%) | 27 (23%) | 34 (26%) | 0.6 |
Abbreviations: United States Preventive Services Task Force (USPTF); Low dose computed tomography (LDCT); Chest x-ray (CXR).
5 primary care physicians did not respond to the question about USPSTF recommendations.
Compared to those ‘Strongly Disagree’, ‘Somewhat Disagree’ or ‘Neither Agree nor Disagree; Missing responses were excluded from these analyses.
We performed a multi-variate analysis of physician factors associated with awareness of USPSTF recommendations. We found that that there was a non-significant lower odds of awareness of guidelines with a higher percentage of uninsured patients (OR 0.69, p=0.056) and higher patient volume per week (OR 0.42, p=0.18 for >125 patients per week). Practice type, board certification type, and years in practice were not associated with awareness of USPSTF LCS guidelines. We repeated this analysis comparing 0–1 and 2–3 correct clinical scenarios and observed similar results. We then performed multi-variate analysis of factors predicting ever-ordering LDCT over the prior 12 months for LCS (Table 5). We found that knowledge of USPSTF guidelines and correctly identifying 2–3 clinical scenarios were each independently associated with significantly higher odds (3.30, p<0.001; 5.09, p<0.001, respectively) of ordering LDCT. Having a practice with a majority of patients insured by Medi-Cal was strongly associated with lower odds of ordering LDCT (OR 0.11, p=0.004). There was a non-significant increase in odds of higher utilization among internal medicine boarded PCPs (OR 1.61, p=0.14). Other physician and patient factors were not significantly associated with LDCT utilization.
Table 5:
Univariate and Multivariate Predictors of Asymptomatic Patient LDCT Referral
| Univariate | Multivariate** | |||||
|---|---|---|---|---|---|---|
| N (%) | OR (95% CI) | p-value | OR (95% CI) | p-value | ||
| Does USPSTF Recommend LDCT?** | No/Not Sure | 128 (52.7) | 1.00 (reference) | - | 1.00 (reference) | - |
| Yes | 115 (47.3) | 3.94 (2.31 – 6.73) | <0.001 | 3.30 (1.71 – 6.36) | <0.001 | |
| Number correct for asymptomatic patient guidelines | 0–1 correct | 126 (50.8) | 1.00 (reference) | - | 1.00 (reference) | - |
| 2–3 correct | 122 (49.2) | 4.28 (2.51 – 7.29) | <0.001 | 5.09 (2.56 – 10.11) | <0.001 | |
| Years in practice | 0–10 | 30 (12.1) | 0.91 (0.38 – 2.18) | 0.82 | 0.63 (0.19 – 2.08) | 0.44 |
| 11–20 | 86 (34.8) | 1.03 (0.53 – 2.01) | 0.92 | 0.60 (0.24 – 1.48) | 0.27 | |
| 21–30 | 72 (29.1) | 1.53 (0.77 – 3.07) | 0.23 | 1.40 (0.56 – 3.52) | 0.47 | |
| >30 | 59 (23.9) | 1.00 (reference) | - | 1.00 (reference) | - | |
| Specialty | Family Practice | 112 (45.5) | 1.00 (reference) | - | 1.00 (reference) | - |
| Internal Medicine | 134 (54.5) | 1.29 (0.78 – 2.13) | 0.33 | 1.66 (0.84 – 3.28) | 0.14 | |
| Primary practice arrangement | Full/part owner | 43 (17.4) | 1.00 (reference) | - | 1.00 (reference) | - |
| Physician-owned | 125 (50.6) | 1.18 (0.59 – 2.35) | 0.65 | 1.70 (0.66 – 4.39) | 0.27 | |
| Large medical group/system | 16 (6.5) | 0.95 (0.30 – 3.01) | 0.94 | 0.71 (0.17 – 2.96) | 0.64 | |
| Staff/group model HMO | 25 (10.1) | 1.03 (0.39 – 2.77) | 0.95 | 1.72 (0.49 – 5.97) | 0.40 | |
| University affiliated | 25 (10.1) | 1.21 (0.45 – 3.27) | 0.70 | 0.53 (0.15 – 1.85) | 0.32 | |
| Non-university affiliated | 13 (5.3) | 0.29 (0.07 – 1.19) | 0.085 | 1.33 (0.18 – 9.73) | 0.78 | |
| Patient volume during typical week | <=25 | 23 (9.5) | 1.00 (reference) | - | 1.00 (reference) | - |
| 26–50 | 36 (14.9) | 0.96 (0.33 – 2.76) | 0.94 | 0.75 (0.17 – 3.37) | 0.70 | |
| 51–75 | 63 (26.0) | 0.85 (0.32 – 2.21) | 0.73 | 0.49 (0.12 – 2.04) | 0.32 | |
| 76–100 | 69 (28.5) | 0.84 (0.32 – 2.17) | 0.72 | 0.87 (0.21 – 3.59) | 0.85 | |
| 101–125 | 31 (12.8) | 0.93 (0.32 – 2.77) | 0.90 | 1.00 (0.21 – 4.74) | 0.99 | |
| 126+ | 20 (8.3) | 0.63 (0.19 – 2.10) | 0.45 | 0.36 (0.06 – 2.20) | 0.27 | |
| % of patients insured by Medi-Cal† | 0–5 | 115 (48.3) | 1.00 (reference) | - | 1.00 (reference) | - |
| 6–25 | 70 (29.4) | 0.76 (0.42 – 1.39) | 0.38 | 0.79 (0.39 – 1.63) | 0.53 | |
| 26–50 | 26 (10.9) | 0.64 (0.27 – 1.51) | 0.31 | 0.80 (0.27 – 2.34) | 0.68 | |
| 51–100 | 27 (11.3) | 0.11 (0.04 – 0.34) | <0.001 | 0.11 (0.02 – 0.49) | 0.004 | |
An OR of > 1 indicates higher odds that within the last year the physician recommended LDCT to an asymptomatic patient.
2 primary care physicians did not respond to the question about ordering a LDCT for an asymptomatic patient.
5 primary care physicians did not respond to the question about USPSTF recommendations.
The 51–75% and 76–100% groups were merged due to small sample sizes in the 79–100% category.
Discussion
Our results demonstrate that less than half of PCPs are aware of USPSTF criteria, and that a large proportion of PCPs cannot correctly identify clinical scenarios where LDCT is recommended or not recommended. We found that understanding LDCT guidelines was associated with a higher likelihood of discussing LCS with patients, utilization of LDCT, and referral to a LCS program. Surprisingly, most barriers, including concern regarding risks, costs, and insurance coverage of LDCT were similar regardless of whether PCPs were aware of guidelines. A major strength of our study is that the sample of PCPs was population-based, surveying physicians in a wide range of practices settings.
We analyzed physician factors associated with knowledge of USPSTF guidelines. We found that only academic practice was significantly associated with knowledge of guidelines, although there was a non- significant decrease in utilization for patient mix with fewer uninsured or Medi-Cal patients. Years in practice, internal medicine board certification, and patient volume were not significantly associated with knowledge of guidelines. This suggests that the gap in knowledge of LCS guidelines is pervasive across PCP practices.
Meanwhile, awareness and knowledge of guidelines was independently associated with ordering LDCT for high-risk patients. This suggests that improving understanding of LCS guidelines may increase utilization of LDCT. On the other hand, a high percentage of Medi-Cal patients was strongly associated with not ordering LDCT. This finding suggests potential socioeconomic disparities for high-risk patients with respect to LCS. Further investigation on the impact of socioeconomic disparities and barriers to LDCT is needed.
Other investigators have similarly found that utilization of LDCT is low and that a number of important physician, patient, and system barriers exist to implementing LCS guidelines.8,9,11,12,14–17 Several groups have specifically examined physician barriers by interviewing or surveying PCPs.1,2,9,10 It is clear that PCP utilization of LDCT is low in various practice settings and that knowledge of LCS guidelines is poor. Lewis and colleagues surveyed PCPs at a single academic center regarding LDCT for LCS. They reported that 53% of PCPs correctly identified less than half or none of the USPSTF LCS screening criteria. Like our study, they found that providers who knew most of the USPSTF LCS guidelines had a greater odds of ordering LDCT.2 Begna and colleagues reported that education of PCPs regarding LCS eligibility at one medical center resulted in an increase in volume, suggesting that PCP education is effective at improving guidelines adherence.14
This study has important implications. We previously reported that utilization of LDCT by PCPs was low, a finding other investigators have identified. These results suggest that educating PCPs regarding LDCT guidelines may improve utilization of LDCT for high-risk current and former smokers. Although we only show an association between knowledge of guidelines and utilization of LDCT, research on the effect of educational interventions to improve understanding of LCS guidelines for PCPs is warranted. In addition, health care system interventions may be effective. We previously demonstrated that incorporation of automated identification of patients eligible for screening using the electronic medical record increased utilization of LCS at our institution.18 Use of automatic notifications, a LCS nurse or coordinator, and incentives for physicians to comply with guidelines are other possible interventions that may improve adherence with LCS guidelines.
This study has several limitations. The response rate to the survey was only 18%. We previously reported that PCP characteristics, including training background, years in practice, and sex were similar between responders and non-responders. Although this does not eliminate the potential of bias in the responders, it suggests that the responders were likely to be representative of the surveyed population of PCPs. Next, we focused here on USPSTF recommendations. Medicare (CMS) guidelines, which differ from USPSTF guidelines in that the upper age limit for coverage is 77 instead of 80, dictate what may be ordered because of insurance coverage. We included a clinical scenario of an 80 year-old smoker who would be eligible by USPSTF criteria but not CMS criteria. In our analysis of factors associated with understanding of LCS guidelines, we utilized USPSTF guidelines. We recognize that many physicians will adhere to CMS guidelines for practical reasons and may respond to the survey accordingly. For this reason, we analyzed data by answering 0–1 or 2–3 scenarios correctly, and we analyzed data by knowledge that USPSTF recommended screening. Both methods of analysis yielded similar results. Finally, this study is limited to PCPs in Los Angeles County and may not be representative of other geographic regions in the United States. Los Angeles County, with a population of more than 10 million is ethnically and socioeconomically diverse and practices are likely to be representative of most major population centers in the United States.
Conclusions
In summary, our study demonstrated that knowledge of LCS guidelines among PCPs is poor across practice settings, but that understanding of guidelines is strongly associated with increased utilization of LCS. Additional research and policy efforts to improve PCP knowledge of LCS guidelines are needed.
Clinical Practice Points.
Lung cancer screening (LCS) with low-dose computed tomography (LDCT) is effective at reducing lung cancer mortality in high-risk current and former smokers and is recommended by the US Preventive Services Task Force (USPSTF), however a minority of patients of eligible people is screened. We previously reported that only half of primary care physicians are aware of the USPSTF recommendations.1 The extent to which knowledge of LDCT guidelines affects utilization is unclear. Lewis and colleagues reported that knowledge of guidelines by PCPs at a single academic institution was associated with a higher odds of ordering LDCT.2
In this study, we sought to understand in a population-based survey across multiple type of PCP practice settings, whether knowledge of LDCT guidelines was associated with LDCT utilization. We also sought to determine what physician factors were associated with knowledge of guidelines, and whether barriers to LDCT differed among those physicians who were aware of guidelines. We found that knowledge of guidelines was clearly associated with LDCT utilization. LDCT guidelines knowledge was poor across a variety of practice settings, and especially poor among providers caring for socioeconomically underserved patients.
Our results suggest that efforts at educating PCPs on LDCT guidelines are needed. In addition, health system interventions aimed at improving utilization of LDCT are needed.
Acknowledgements:
We acknowledge the City of Hope Survey Research Core for assistance with this study.
Funding Sources:
Research reported in this publication is supported by the Lung Cancer Research Foundation, and the National Cancer Institute of the National Institutes of Health under award numbers NIH 5K12CA001727-20 (Raz) and P30CA33572 through the use of the City of Hope Survey Research Core. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. We also acknowledge the generous support of the Baum Family Foundation in support of this research.
Sources of Funding:
Lung Cancer Research Foundation, NIH 5K12CA001727-20, and P30CA33572.
Disclosures:
DR: Cireca (consultant), Merck (grant funding), neither related to the study.
Footnotes
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