Physician perceived barriers and solutions to DASH diet recommendations for hypertension prevention and management

The Dietary Approach to Stopping Hypertension (DASH) is proven to lower systolic and diastolic blood pressure up to 7.8 and 3.7 mmHg, respectively and is considered rst-line therapy per national guidelines. Yet, implementation into clinical practice remains suboptimal. We designed a provider survey to identify and characterize physician-identied barriers to providing DASH diet to eligible primary care patients to reduce blood pressure. The survey assessed four domains: (1) provider beliefs/knowledge of DASH benets (2) patient characteristics inuencing likelihood of recommendation, (3) practice barriers to provision of DASH diet advice/education, and (4) resources necessary to facilitate use. We conducted qualitative interviews with 4 primary care physicians and designed a 7-item Likert scale-based survey. Participants: University of Colorado aliated primary care clinics and School of medicine faculty providers working in Denver metro.

(88%) and low ability to implement DASH diet into patient's lifestyle (88%) as patient factors in uencing their decision to provide DASH diet education. The most signi cant practice barriers were lack of time (71%) and lack of patient-directed educational resources (67%). Resources providers would nd useful included resources accessible through the electronic medical record, (88%), a dietician (83%), and printed patient education materials (59%).

Conclusion
Most physicians believe DASH diet is effective at lowering blood pressure. The most common barriers to providing DASH education are low perceived patient ability or motivation, lack of provider time, and lack of patient-directed educational resources. Providers identi ed that readily available electronic and printed materials and access to dieticians would help improve DASH counseling in practice.

Background:
Chronic hypertension contributes to 25% of cardiovascular-related morbidity and mortality (stroke, chronic heart Disease, coronary revascularization, or heart failure) 1 , and affects 29% of the US population 2 . Hypertension control is an area of focus for many healthcare systems, driven in part by quality measurement within many value-based programs, including the Medicare Incentive Payment Program (MIPS) 3 .According to the American College of Cardiology 2017 guideline for high blood pressure in adults, lifestyle modi cation is rst-line therapy for patients with elevated BP (SBP 120-129 and DBP < 80), or stage 1 hypertension (SBP 130-139 or DBP 80-89) with an ASCVD 10-year risk of < 10% 1 .The Dietary Approach to Stopping Hypertension (DASH), rst published in 1997, is proven to lower systolic and diastolic blood pressures by 4.5 to 7.8 mmHg and 2.6 to 3.7 mmHg, respectively, compared to usual diet controls in treated and untreated hypertensive patients 4 . This compares to blood pressure lowering of 6-9/4-5 mmHg for addition of a blood pressure such as lisinopril, amlodipine, or chlorthalidone 5,6,7 .
Despite the DASH Diet's effectiveness, DASH diet education implementation into clinical practice is suboptimal. The National Health and Nutrition Examination Survey (NHANES) from 1998 to 2004 studies showed that less than 1% of U.S population consumes a diet consistent with DASH 8,9 . An NHANES study examined an individual's degree of adherence to target for the nine food categories outlined within the DASH regimen (total fat, saturated fat, protein, ber, cholesterol, calcium, magnesium, potassium, and sodium) by using DASH accordance score. Depending on speci c target values of the nine DASH nutrients, points were added to one, half, or no points. Americans with diagnosed and undiagnosed hypertension met less than 3 out of 9 of these targets 10 . A manual chart review of outpatient visits where blood pressures were in the elevated stage 1 hypertensive range at an internal medicine clinic in our own system found documentation of DASH diet counseling in only 2 out of 330 visits within a one-month period.
Multiple factors contribute to the low level of DASH diet implementation, including the US food environment, socioeconomic factors, clinical factors, and patient knowledge. The rst step to a patient making lifestyle changes to reduce blood pressure is often advice from their physician. However, a host of barriers prevent physicians from recommending dietary and other lifestyle changes 11 . Physicians cite lack of time to provide proper counseling on general nutrition, perception that patients lack interest and motivation in making lifestyle changes, and lack of training in nutritional counseling as barriers to consistent provision of life-style advice to patients, though data speci c to DASH diet is lacking 8,11,12,13 .
One observational study showed provision of lifestyle counseling was associated with longer clinic visits (r=-0.32, P < 0.001). Speci cally, each additional lifestyle counseling point (e.g. smoking cessation, lowsodium diet) was associated with 2.05 min increase in visit length 14 .
Regular provision of lifestyle advice, including DASH diet, has the potential to positively impact a large number of patients, and provider advice is a potentially in uential rst step. Clarity of the most important provider reported barriers related to patient characteristics, practice setting, and resources could facilitate development of more effective/ useful educational materials. This study aimed to identify provideridenti ed barriers to provision of DASH diet to patients who may bene t for lowering of blood pressure.

Methods:
This cross-sectional study was conducted from December 2019 to January 2020 at the University of Colorado Anschutz Medical Campus with General Internal Medicine, Family Medicine, and geriatrics providers. This study was reviewed by the Colorado Multiple Institution Review Board and granted exempt status.

Population and setting:
The University of Colorado School of Medicine faculty providers who care for patients at 149 different family medicine, general internal medicine, and geriatric clinics across the Denver/Boulder metro area.
The system uses Epic as an electronic medical record. Within this platform, patient educational materials related to hypertension, low sodium diet, DASH diet, and anti-hypertensive medication are available through a third-party vendor Survey Questionnaire and Data Collection

Data Collection and Analysis
Survey data was collected electronically and anonymously. Descriptive statistics were used to describe provider-identi ed barriers to the provision of lifestyle advice, including the DASH diet. All survey results were reported as percentages.

Results:
Among 149 primary care providers who received the email, 49 (33%) responded to the survey [ Table 1]. About two thirds (n=32, 65%) of physicians believe that the DASH diet is at least as effective at lowering BP in adherent patients as adding a medication. The most commonly identi ed patient-related barriers reported were low perceived patient motivation (90%) and low patient ability to implement the DASH diet (86%), while the most commonly identi ed practice setting barriers were lack of time and lack of patientdirected educational resources, with 71% and 66%, respectively, reporting these as somewhat to very signi cant factors.
When physicians were asked about methods or resources they frequently use to educate patients about DASH diet, most reported verbal education (39%), and sometimes electronic resources currently available through the EMR (27%). The resources they reported would be most useful were electronic materials accessible through the EMR (88%), dieticians (82%), and printed materials (59%).
The work ow physicians considered most appropriate for DASH diet education was one where patients with hypertension and pre-hypertension who are interested and motivated to make lifestyle changes receive referral to a group class led by a dietician (86%), with the majority of physicians (57%) also approving of a process where all hypertension and pre-hypertension patients receive a short description of the DASH diet with the written materials during a hypertension or preventative visit.
Finally, 88% of the providers believe that DASH diet advice should be provided to patients who might bene t from the DASH diet and for those who might only learn DASH diet education through a healthcare provider (Figure 1).

Discussion:
Overall, this study demonstrates that most primary care providers believe that the DASH diet effectively reduces blood pressure compared to adding a medication. However, provider-perceived patientcharacteristics, time, and lack or perceived lack of accessible patient education materials limit the provision of DASH diet counseling in pre-hypertension and hypertension patients likely to bene t.
Most physicians perceived lack of patient motivation (90%) and ability to implement the DASH diet (86%) as signi cant barriers, which is consistent with previous studies of physician views towards nutritional advice. 11,12 Although physician perceptions do not necessarily re ect actual patient motivation and ability, there is evidence of some truth to this viewpoint, at least in some populations. A study evaluating DASH diet acceptability and adherence in an African American community of low socioeconomic status patients identi ed cost, personal preference of food, poor availability of healthier food stores, and cultural aspects as barriers to DASH diet adherence 15 . However, such barriers may be surmountable. A randomized pilot trial assessing DASH diet adherence for under-resourced communities reported that an intervention involving multiple peer-group sessions involving shared DASH diet meal plans, grocery shopping ideas, and budget management increased fruit and vegetable intake compared to a control group who only received a DASH diet educational packet 16 . Thus, to improve the patient's ability to implement the DASH diet, a healthcare team and even supportive peer programs should be developed to provide individualized plans for patients to follow.
Lack of time for patient education is a frequent barrier, with 71% of providers reporting it as a barrier to DASH diet counseling comparable to other studies where 76-81% of providers report this as a barrier to dietary counseling 12-14, 17-19, 21 . One study estimated that providing USPSTF recommended nutritional counseling points requires 8 minutes 18 , which is one third to one half of a general clinic visit, which takes 16-30 minutes according to 2016 CDC statistics 20 . This indicates that lack of time is a signi cant practice barrier, and delivery all the services recommended by USPSTF may simply not be feasible 18 . Thus, developing a toolkit and resources are potential sources to facilitate the physician's nutritional counseling efforts in limited time.
Development of effective and accessible educational resources seems like a logical solution to this issue and was supported by survey respondents. Interestingly, educational resources, including the DASH diet, already existed in their EHR, in Spanish and English, with the ability to attach to an after visit summary or print out directly, but were apparently unknown to the 32 survey respondents, given 66% reported their absence as a signi cant practice barrier. This study did not examine why physicians were not utilizing resources that already exist, but this is likely not unique to our institution. One study reported the resources and tools are not individualized to the institutions or easily disseminated to the patient, providers, and all other practices 21 , causing di culties for practitioners to locate resources. More focused research should evaluate the low uptake of existing tools and resources.
De ciencies in nutrition training was identi ed as a barrier by just 38% of the physicians, which is somewhat less than the 46-59% of primary care providers in Croatia and Switzerland considering this a signi cant barrier 11,12 . In U.S medical schools, students and most educators consider current nutritional education inadequate, despite the efforts and developments of nutritional counseling programs for the past decades 19,21 . Providers universally endorsed access to dieticians to provide nutritional counseling, in accordance to a previous study where 84.9% of physicians considered dietician involvement to be bene cial for sodium counseling in hypertension patients 17 . In addition to more detailed dietary and nutrition expertise, a dietician also provides an extension to provider education, addressing the barrier of provider time. In one study demonstrated that dietician's involvement in outpatient settings for DASH diet and exercise counseling program improved patient's cholesterol, blood pressure, and weight management 22 . Similarly, a PREMIER study showed better uptake of the DASH diet, achieved dietary reference index (DRI) recommendation in most nutrients, and reduced blood pressure in participants with multiple group sessions led by dietitians compared to control group 30-minute counseling session 23 . Thus, dieticians provide positive outcomes to patient's DASH diet uptake. Meanwhile, further research should be conducted to identify strategies and the bene ts in dietician's participation in the U.S primary care settings.
This study is limited by a relatively small sample of university-based primary care practitioners. Second, this survey was built and responded by the provider's perspective, limiting the view of the patients' side. A provider's perceived patient barriers may be in uenced by their own biases, and may not accurately re ect the motivation, means, grit, and resourcefulness of their patients. More studies need to focus on the patient's perceived barriers and the actual patient barriers to con rm the result that we found. Third, the cross-sectional survey does not provide the relationship between the cause and effect of the response, limiting analysis of the result. However, this study has multiple supportive studies to mitigate this problem.

Conclusion:
Providers identify perceived patient inability or unwillingness to implement DASH diet, lack of time, and real or perceived lack of accessible resources as signi cant barriers to advising patients to follow DASH. Interventions to increase provision of DASH dietary advice should focus on identifying eligible and willing patients, easy or automated dispensing of appropriate educational materials, and expanded access to dieticians.

Declarations
Acknowledgements and Con icts of Interest: This study does not have contributors who are not authors, and received no external funding. The authors no con icts of interests to declare. This work was presented in abstract form at the Pharmacy Quality Alliance (PQA) Annual Conference on May 7, 2020. Author's contributions: HP conducted focus groups, performed the background chart review to assess baseline provision of DASH diet advice, designed the survey, compiled the results, and drafted the manuscript. SB supervised the focus groups, contributed to survey design, and analyzed and interpreted the results, and was a major contributor in writing the manuscript. LS contributed to the design of the survey and analysis of the results. All authors read and approved the nal manuscript