In 2019, the National Academy of Medicine indicated that lowering dietary sodium (Na) intake for people who consume more than 2300 mg/d could reduce blood pressure and CVD risk(1). However, mean intake in the USA population exceeds this level(Reference Cogswell, Loria and Terry2). A 10-year graduated reduction in Na in the USA food supply to achieve a mean population intake of ≤ 2300 mg/d could prevent 252 500 CVD deaths and save $37 billion in health care costs(Reference Dehmer, Cogswell and Ritchey3).
Health care providers have an important role to play in educating and supporting patients to reduce dietary Na intake(4). Current guidelines recommend that health care providers counsel their patients who have or are at risk for hypertension on lifestyle modification, including dietary Na reduction, to reduce their CVD risk(Reference Whelton, Carey and Aronow5). Although the extent to which receiving advice from a health care provider to reduce Na intake results in clinically meaningful reductions in actual Na intake is unknown(Reference Rees, Dyakova and Ward6), receiving advice from a health care provider has been shown to be associated with increased likelihood of reporting taking action to reduce Na intake(Reference Jackson, Coleman King and Park7,Reference Va, Thompson-Paul and Fang8) , improvements in dietary behaviours linked to CVD risk (e.g. fruit and vegetable intake, dietary fibre intake and dietary fat intake)(Reference Rees, Dyakova and Ward6) and reduced blood pressure(Reference Rees, Dyakova and Ward6). Documenting consumer action to reduce Na intake and the prevalence of receiving advice from a health professional to reduce Na intake can help inform the development and implementation of Na reduction interventions. However, the prevalence of consumers who report receiving advice from a health professional to reduce Na intake and the prevalence of trying to reduce Na intake have not been estimated in all US states, territories and jurisdictions.
The Behavioral Risk Factor Surveillance System (BRFSS) optional Na module allows US states, territories and other jurisdictions to monitor receiving advice and taking action to reduce Na intake. This analysis uses 2017 BRFSS data to update prevalence estimates in seven states and the District of Columbia (DC), and generate first-ever estimates in New York state and the US territory of Guam, which have both implemented several initiatives to reduce dietary Na intake(9–Reference Jackson, VanFrank and Lundeen11).
Materials and methods
The Behavioral Risk Factor Surveillance System is a cross-sectional state-based telephone survey among a representative sample of non-institutionalised adults aged ≥ 18 years (median response rates: 45·2 % landlines, 44·3 % cell phones). In 2017, Iowa, Maine, New York, North Carolina, Ohio, Oregon, West Virginia, DC, Guam and Purto Rico opted to use the two-item Na module, which assesses whether respondents are currently watching or reducing their Na or salt intake or have received advice from a doctor or other health professional to reduce Na or salt intake. All BRFSS respondents residing in these jurisdictions were asked the Na module items. Among the 49 536 module participants, 85·3 % were included in this analysis. Participants were excluded if they had missing data on module items (11·8 %); hypertension status or medication use (0·3 %); age, sex, or race or Hispanic ethnic group (1·2 %) or comorbidities (1·8 %). Excluded participants differed from included participants on all measured characteristics except for total number of comorbid conditions and were more likely to be male or younger and less likely to be in the Hispanic ethnic group or report having hypertension as compared with included participants.
We estimated the weighted prevalence of receiving advice from a healthcare professional and taking action to reduce Na intake among adults overall and by jurisdiction, select demographic characteristics, hypertension status and number of CVD comorbidities linked to high blood pressure (i.e. diabetes, kidney disease, stroke, myocardial infarction and coronary heart disease) using SAS-callable SUDAAN (version 11). We also estimated the prevalence of taking action to reduce Na intake by receipt of advice from a health care professional among adults overall and by subgroup, as well as the prevalence difference (PD). Respondents were coded as having hypertension if they self-reported the condition; those who reported hypertension only during pregnancy, borderline hypertension or no hypertension were classified as not having hypertension. All prevalence estimates were weighted to account for the complex sampling design and non-response, and χ 2 tests were used to assess the uniformity of the prevalence distribution within each subgroup using a type I error rate of 5 %.
Results
Overall, 53·6 % (95 % CI 52·7, 54·5) of respondents reported taking action to reduce Na intake (Table 1). The prevalence ranged from 43·0 % (95 % CI 41·1, 44·8) in Oregon to 69·6 % (95 % CI 67·6, 71·5) in Puerto Rico and was 54·8 % (95 % CI 52·8, 56·7) in New York and 61·2 % (95 % CI 57·6, 64·7) in Guam. Overall, the prevalence was highest among adults with self-reported hypertension (72·5 %; 95 % CI 71·2, 73·7), females (55·3 %; 95 % CI 54·1, 56·5), adults aged ≥ 65 years (69·2 %; 95 % CI 67·9, 70·6), non-Hispanic blacks (69·6 %; 95 % CI 66·7, 72·4) and those with ≥ 2 comorbidities (80·5 %; 95 % CI 77·7, 83·0). The prevalence was lowest among adults with no self-reported hypertension (43·9 %; 95 % CI 42·7, 45·0), males (51·8 %; 95 % CI 50·5, 53·1), adults aged 18–44 years (40·8 %; 95 % CI 39·3, 42·3), non-Hispanic whites (48·6 %, 95 % CI 47·5, 49·6), and those with no comorbidities (48·9 %; 95 % CI 47·9, 49·9). Among adults with hypertension, the prevalence of taking action was higher among those who report taking medication (76·4 %; 95 % CI 75·2, 77·6) as compared with those not taking medication (59·0 %; 95 % CI 55·7, 62·2; P < 0·0001).
Table 1 Prevalence of adults aged ≥ 18 years who reported taking action to reduce sodium intake or receiving advice from a doctor or health professional to reduce sodium intake overall and by subgroup – Behavioral Risk Factor Surveillance System, seven states, the District of Columbia, Puerto Rico, and Guam, 2017*
* Note. This table reports the unweighted number of respondents and weighted prevalence and 95 % CI, which accounts for the complex sampling design. Wald Chi-Square tests were used to generate P-values testing the uniformity of the prevalence distributions within each subgroup.
† Diabetes, kidney disease, stroke, myocardial infarction, coronary heart disease.
Overall, 24·0 % (95 % CI 23·3, 24·7) of adults reported receiving advice from a health professional to reduce Na intake (Table 1). The prevalence ranged from 14·9 % (95 % CI 13·6, 16·3) in Iowa to 42·7 % (95 % CI 40·8, 44·7) in Puerto Rico and was 21·5 % (95 % CI 20·1, 23·0) in New York and 33·4 % (95 % CI 30·1, 36·8) in Guam. Across all locations, the prevalence was highest among adults with self-reported hypertension (51·6 %; 95 % CI 50·2, 52·9), adults aged ≥ 65 years (37·5 %; 95 % CI 36·1, 38·9), non-Hispanic blacks (34·0 %; 95 % CI 31·3, 36·9) and those with ≥ 2 comorbidities (63 %; 95 % CI 59·8, 66·1). The prevalence was lowest among adults with no self-reported hypertension (9·9 %; 95 % CI 9·2, 10·4), adults aged 18–44 years (13·7 %; 95 % CI 12·8, 14·8), non-Hispanic whites (20·1 %; 95 % CI 19·4, 20·9) and those with no comorbidities (17·9 %; 95 % CI 17·2, 18·6). Among adults with hypertension, the prevalence of receiving advice was higher among those who reported taking medication (55·7 %; 95 % CI 54·2, 57·1) as compared with those not taking medication (37·5 %; 95 % CI 34·4, 40·7; P < 0·0001).
Overall, the prevalence of taking action to reduce Na intake was significantly higher among those who received advice from a health professional (82·6 %; 95 % CI 81·3, 83·9) as compared with those who did not receive advice (44·4 %; 95 % CI 43·4, 45·5; P< 0·0001; Table 2). This pattern of results was consistent across subgroups, though the magnitude of the difference in prevalence varied. The largest difference between the prevalence of taking action among adults who reported receiving advice compared with those who did not report receiving advice was among residents of the District of Columbia (PD: 52·5 %), Ohio (PD: 48·4 %) and Oregon (PD: 41·3 %) and non-Hispanic Whites (PD: 40·7 %). The smallest prevalence differences were among residents of Guam (PD: 18·9 %), adults with hypertension who were not taking medication (PD: 23·7 %) and adults with ≥ 2 comorbidities (PD: 25·0 %).
Table 2 Prevalence of adults aged ≥ 18 years who reported taking action to reduce sodium intake by receipt of advice from a doctor or health professional to reduce sodium intake – Behavioral Risk Factor Surveillance System, seven states, the District of Columbia, Puerto Rico, and Guam, 2017*
DC, District of Columbia; HTN, hypertension; NH, non-Hispanic.
* This table reports the unweighted number of respondents and weighted prevalence and 95 % CI, which accounts for the complex sampling design.
† Diabetes, kidney disease, stroke, myocardial infarction, coronary heart disease.
Discussion
The majority of adults in seven US states, two territories and DC, and nearly three-quarters of adults with hypertension reported taking action to reduce Na intake. Consistent with prior results(Reference Jackson, Coleman King and Park7,Reference Va, Thompson-Paul and Fang8,Reference Fang, Cogswell and Park12) , the prevalence of taking action was highest among adults who reported receiving advice from a health professional to reduce Na intake. However, only one-quarter of adults overall and one-half of adults with hypertension reported receiving such advice in 2017. These results highlight a potential missed opportunity for health professionals to provide Na reduction advice during clinical visits, especially among adults with hypertension.
The American College of Cardiology/American Heart Association hypertension guidelines recommend that all adults with hypertension and those who are at risk of developing hypertension be counseled on lifestyle modification(Reference Whelton, Carey and Aronow5). However, this study and others have found that not all patients with hypertension recall receiving advice to reduce Na intake(Reference Jackson, Coleman King and Park7,Reference Va, Thompson-Paul and Fang8) , nor do all health care providers report advising their patients with hypertension to reduce Na intake(Reference Fang, Cogswell and Keenan13,Reference Quader, Cogswell and Fang14) . Barriers that health care providers report prevent them from advising patients to reduce dietary Na intake include perceptions that patients are unlikely to comply, lack of resources for patient education and insufficient scientific evidence(Reference Fang, Cogswell and Keenan13,Reference Quader, Cogswell and Fang14) . Epidemiologists, health promotion specialists and public health and healthcare organisations can use data from the BRFSS optional Na module along with the strong scientific evidence supporting scientific Na reduction(1) to document the need to train health care professionals about the benefits of Na reduction. Increasing understanding about the importance of Na reduction can augment public health strategies to reduce Na in the food supply and support patients in lowering their intake, as recommended by the National Academy of Medicine(4). The need for clinical counseling on dietary Na reduction is likely to become increasingly important given that 52 million US adults have been newly classified as having elevated blood pressure or Stage I hypertension under the expanded blood pressure cutoffs used in the American College of Cardiology/American Heart Association hypertension guidelines released in 2017(Reference Whelton, Carey and Aronow5,Reference Ritchey, Gillespie and Wozniak15) .
According to a systematic review, although evidence suggests that receiving advice from a health care provider is associated with reductions in blood pressure and improvements in other dietary behaviors, evidence for the association between provider advice and reduced Na intake is mixed(Reference Rees, Dyakova and Ward6). Reducing actual Na intake may be difficult for even highly motivated consumers to achieve, given the ubiquity of added Na in the US food supply(Reference Harnack, Cogswell and Shikany16). For this reason, reducing Na added to the food supply and expanding access to lower-Na food options are needed to assist consumers in lowering their Na intake(4,Reference Ide, Ajenikoko and Steele17) . Public health professionals and food industry partners can use data from the BRFSS optional Na module to demonstrate that the majority of adults report taking action to reduce Na intake, demonstrating potential demand for policies, interventions and products that facilitate Na reduction efforts.
Multiple Na reduction initiatives are currently being implemented throughout the USA. For example, the Centers for Disease Control and Prevention and other federal partners support Na reduction efforts through multiple initiatives, including the Sodium Reduction in Communities Program(9), the State Physical Activity and Nutrition Program(18) and the Million Hearts Initiative(19). Additionally, many jurisdictions that participated in the BRFSS optional Na module have ongoing Na reduction initiatives, including New York State and Guam, which participated in the module for the first time in 2017. New York has implemented food service guidelines and offered lower-Na food options in corrections, education and healthcare settings; conducted consumer sensory testing of lower-Na products; and required chain restaurants with fifteen or more locations nationwide to post warning icons next to menu items that contain ≥ 2300 mg of Na to assist consumers in lowering their intake(9,Reference Anekwe, Lent and Kennelly10) . In Guam, Na reduction was included a component of the territorial noncommunicable disease strategic plan and the Department of Health launched an initiative in collaboration with the restaurant industry to remove salt shakers from tables at local restaurants(Reference Jackson, VanFrank and Lundeen11). Educating health care providers about current Na reduction initiatives may increase uptake of these interventions among their patient populations.
A strength of this analysis is that it represents the first-ever prevalence estimates for New York and Guam. Limitations of this study include that responses are self-reported and median response rates of < 50 %, indicating possible recall, social desirability or response biases. Additionally, self-reported action to reduce Na intake may not necessarily equate to lower mean daily Na intake(Reference Ayala, Gillespie and Cogswell20). Finally, results are limited to jurisdictions that opted to participate in the Na module and may not generalise to the US adult population overall.
Conclusions
These results document that a majority of US adults in participating jurisdictions report taking action to reduce Na intake and highlight an opportunity to increase Na reduction advice during clinical visits to encourage all adults, and especially those with hypertension, to take action to reduce sodium intake to prevent and control CVD.
Acknowledgements
Acknowledgements: The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. Financial support: No financial support was received to support this analysis. Conflicts of interest: The authors declare no conflict of interest. Authorship: Conceptualisation, RW, KO, MC; methodology, RW, KO, JF, SJ, MC; software, KO; formal analysis, KO; writing – original draft preparation, RW, KO; writing – reviewing & editing, RW, KO, JF, SJ, MC; visualisation, RW, KO; supervision, MC, SJ; project administration, RW. Ethics of human subject participation: This study was conducted according to the guidelines laid down in the Declaration of Helsinki. This is a secondary analysis of publicly available surveillance data, and human subjects review was not required.
Supplementary material
For supplementary material accompanying this paper visit https://doi.org/10.1017/S1368980021002019
