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Article
Mean Dietary Salt Intake in Vanuatu: A Population
Survey of 755 Participants on Efate Island
Katherine Paterson 1, *, Nerida Hinge 2, Emalie Sparks 3, Kathy Trieu 3, Joseph Alvin Santos 3,
Len Tarivonda 2, Wendy Snowdon 4, Jacqui Webster 3and Claire Johnson 3
1World Health Organization, Vanuatu Office, Ministry of Health Iatika Complex, Cornwall Street,
Port Vila, Vanuatu
2Vanuatu Ministry of Health, Iatika Complex, Cornwall St, Port Vila, Vanuatu; itahinge@gmail.com (N.H.);
ltarivonda@vanuatu.gov.vu (L.T.)
3The George Institute for Global Health, The University of New South Wales, Sydney 2006, NSW, Australia;
esparks@georgeinstitute.org.au (E.S.); ktrieu@georgeinstitute.org.au (K.T.);
jsantos@georgeinstitute.org.au (J.A.S.); jwebster@georgeinstitute.org.au (J.W.);
cjohnson@georgeinstitute.org.au (C.J.)
4World Health Organization, Division of Pacific Technical Support, South Pacific Office, Level 4,
Provident Plaza One, Downtown Boulevard, 33 Ellery Street, Suva, Fiji; snowdonw@who.int
*Correspondence: katherine.paterson@outlook.com.au; Tel.: +614-11-153-114
Received: 6 March 2019; Accepted: 8 April 2019; Published: 24 April 2019
Abstract:
Non-communicable diseases are responsible for 63% of global deaths, with a higher burden in
low- and middle-income countries. Hypertension is the leading cause of cardiovascular-disease-related
deaths worldwide, and approximately 1.7 million deaths are directly attributable to excess salt intake
annually. There has been little research conducted on the level of salt consumption amongst the
population of Vanuatu. Based on data from other Pacific Island countries and knowledge of changing
regional diets, it was predicted that salt intake would exceed the World Health Organization’s
(WHO) recommended maximum of 5 g per day. The current study aimed to provide Vanuatu
with a preliminary baseline assessment of population salt intake on Efate Island. A cross-sectional
survey collected demographic, clinical, and urine data from participants aged 18 to 69 years in
rural and urban communities on Efate Island in October 2016 and February 2017. Mean salt intake
was determined to be 7.2 (SD 2.3) g/day from spot urine samples, and 5.9 (SD 3.6) g/day from 24-h
urine samples, both of which exceed the WHO recommended maximum. Based on the spot urine
samples, males had significantly higher salt intake than females (7.8 g compared to 6.5 g; p<0.001)
and almost 85% of the population consumed more than the WHO recommended maximum daily
amount. A coordinated government strategy is recommended to reduce salt consumption, including
fiscal policies, engagement with the food industry, and education and awareness-raising to promote
behavior change.
Keywords:
humans; sodium chloride; salt; Vanuatu; non-communicable diseases; prevention and
control; nutrition policy
1. Introduction
High salt intake increases blood pressure, which is recognized as a risk factor for non-communicable
diseases (NCDs), in particular cardiovascular diseases (CVDs), including heart attack and stroke [
1
].
Sixty-three percent of global deaths are attributable to NCDs, with a higher burden in low- and
middle-income countries [
2
]. In 2015, there was an estimated 17.9 million deaths related to CVDs
worldwide, with high blood pressure being the leading cause [
3
]. Further, CVD-related deaths
attributable to excess salt intake have been estimated at 1.7 million deaths annually worldwide [4].
Nutrients 2019,11, 916; doi:10.3390/nu11040916 www.mdpi.com/journal/nutrients
Nutrients 2019,11, 916 2 of 12
A reduction in population salt intake is one of the single most effective public health strategies
to reduce the burden of NCDs worldwide [
5
], prompting the World Health Assembly to adopt a
population salt intake reduction target of 30% by 2025, in 2013 [
2
]. Salt reduction has also been
named as one of the World Health Organization’s (WHO) NCD “best buy” strategies, which defines
interventions that are affordable, feasible, and cost-effective [
6
], as reducing salt intake lowers blood
pressure, and thereby the risk of CVDs [
1
]. The WHO recommends a reduction in salt intake to less
than 5 g per day to prevent NCDs [
7
]. Globally, populations are consuming excessive amounts of salt,
with the worldwide estimated mean salt intake being almost 10 g/day, double the recommendation [
8
].
Vanuatu is a lower middle-income country in the Pacific Islands [
9
] and has a high prevalence
of deaths from NCDs, estimated at 70% in 2008, with 36% attributable to CVDs [
10
]. The 2013 WHO
STEPwise approach to surveillance of non-communicable disease risk factor (STEPS) survey reported
almost 30% of the Vanuatu population had raised blood pressure or was on medication for high blood
pressure [
11
]. High blood pressure and CVDs place a large economic burden on the government: it
was estimated that the average inpatient hospital expenditure on admissions related to arterial diseases
was approximately $2516 USD per person per stay in 2012 [
12
]. It has also been estimated that the
government could save up to US $75 per person per year in pharmaceutical costs if hypertensive
people were able to control their blood pressure through lifestyle choices [13].
The rise in NCDs in many of the Pacific Island Countries (PICs) occurred during the latter half of
the twentieth century, coinciding with the changing dietary patterns of the region [
14
]. There has been
a shift away from the traditional diets of the PICs, consisting primarily of root crops, starchy fruit and
vegetables, seafood, and coconut products, toward a more Western-style diet, including refined cereals
and grains, edible fats and oils, processed foods and higher quantities of land animals [
14
]. Today, high
salt containing foods are commonly consumed in PICs, including bread, instant noodles, packaged
snack foods, such as crisps and crackers, canned foods, and salty sauces, such as soy sauce [
15
].
Furthermore, as the availability of processed foods and commercially prepared meals increase, salt
intake is also likely to increase [
16
,
17
]. The use of discretionary salt added during cooking and at the
table may also be increasing as this practice becomes more common [15].
The increased accessibility and availability of high salt foods is suggested to be a contributor to
the high prevalence of NCDs found in Vanuatu [
4
]. While increased salt intake has previously been a
topic of discussion [
11
,
18
], it has never before been a government priority, and as such, there is not
yet a population measurement of salt intake for Vanuatu. Therefore, the main objective of the current
study was to provide Vanuatu with a preliminary baseline assessment of population salt intake on
Efate Island, estimated using spot urine samples and validated with measured 24-h salt excretion from
a subsample. Whilst 24-h urine samples are the gold standard methodology [
19
], spot urine samples
validated by a subsample of 24-h urine collections are often utilized in low resource settings, such as
Vanuatu [
20
], in order to obtain a viable result. The secondary aim was to identify the proportion of
the population with salt intake above the WHO recommended maximum intake of 5 g per day. Based
on data from Samoa and Fiji, which show population salt intake exceeding the WHO’s recommend
maximum of 5 g per day [
21
,
22
], and knowledge of changing diets in the Pacific [
14
], it was predicted
that salt intake in Vanuatu would also exceed the WHO’s recommended salt consumption limit.
2. Materials and Methods
This cross-sectional survey collected data from rural and urban communities on Efate Island
during two time periods, October 2016 and February 2017, due to administrative delays part way
through the survey. Ethical approval was obtained through the Vanuatu Ministry of Health. Written
informed consent was obtained from all participants as well as the freedom to withdraw from the
survey at any time.
Nutrients 2019,11, 916 3 of 12
2.1. Survey Population and Sampling
The population was divided into two strata (urban and rural) by mapping of Enumeration Areas
(EA), which was previously undertaken by the Vanuatu National Statistics Office (VNSO) [
23
]. A total
of 28 EAs were randomly selected using the WHO STEPS sampling frame [
24
], including 14 urban and
14 rural areas.
During the October 2016 data collection period, 50 households were listed in the selected EAs
and 27 were randomly selected using the lottery method [
25
]. Participant selection was undertaken
via a convenience sampling method, such that eligible household members at home at the time of
interviewing were invited to participate in the survey. Participants were eligible to participate in the
study if they were aged between 18–69 years and not pregnant or menstruating at the time of urine
collection. Only one person from each household was interviewed. During the February 2017 data
collection, the number of households selected in each EA increased from 27 to 36 due to a low response
rate in 2016. In 2017, both households and participants were selected via convenience sampling due
to lower than expected participant and household response rates. Low response rates have been
previously documented as a challenge for data collection in the Pacific [21].
2.2. Data Collection
The survey was conducted in communities on Efate Island, the most populous island in Vanuatu.
As migration from outer islands to Efate is high, the population of Efate can be seen as somewhat
representative of the country’s population. Local field researchers were appropriately trained in
order to undertake data collection, as per the WHO STEPS survey protocol [
24
]. These research
methods have also been used successfully in neighboring PICs, including Samoa and Fiji [
21
,
22
].
All questionnaires, consent forms, information sheets, and urine collection instructions were translated
in Bislama, the national language of Vanuatu.
Demographic data was collected via a questionnaire and included questions relating to age,
education level, gender, employment, NCD risk factors, and history of disease. Clinical data, including
recording of weight, height, blood pressure, and measurement of sodium and potassium levels by spot
and 24-h urine samples, were also obtained.
Weight was measured in kilograms to the nearest 100 g using digital bathroom scales on a flat
surface and height was measured in centimeters to the nearest millimeter using a stadiometer [
24
].
Blood pressure was measured using the OMRON Automatic Blood Pressure Machine, in millimeters
of mercury (mmHg). Three measurements were performed on the participant’s left arm with 3-min
intervals in between. Final blood pressure was calculated as an average of the second and third
measurements. High blood pressure was defined as systolic blood pressure greater than 140 mmHg or
diastolic blood pressure greater than 90 mmHg.
Spot urine samples were collected from each participant after they completed the interview.
All participants were given a 100 mL spot urine container and estimated mean salt intake was
calculated using the INTERSALT with potassium equation, validated in the estimation of mean
population levels of 24-h sodium and potassium excretion [26–28].
A random subsample of participants were asked to provide a 24-h urine sample. Participants
were given verbal and written instructions for the process in Bislama. They were asked to discard the
first void of urine collected in the morning and provide the time that this occurred, and then begin
collection with the following urine onwards for the next 24 h, including the first urine of the following
morning. Participants were asked to provide the time of the final urine and report any issues with
collection, such as missed collection or spillage. Urine collected was stored in a provided 5-L container
and participants were asked to store it in a cool, dry area, with the lid on tight. The urine samples were
collected by field researchers one to two days after completion.
Participants who did not meet the eligibility criteria, had incomplete demographic data,
or suspected inaccurate urine collection based on the urine volume and urinary creatinine excretion,
were excluded [22]. The process of determining the final participant number is outlined in Figure 1.
Nutrients 2019,11, 916 4 of 12
Nutrients 2019, 11, x FOR PEER REVIEW 4 of 12
Figure 1. Process of determining the final participant number.
Starting participants (n = 774)
Age and sex exclusions:
Didn’t meet age criteria: 18-69 years (n = 2)
Missing age data (n = 17)
Missing sex data (n = 0)
Remaining participants (n = 755)
SPOT URINE 24-HOUR URINE
Spot urine exclusions:
Missing spot sodium data (n = 211)
Missing spot creatinine data (n = 3)
Remaining participants (n = 541)
Additional exclusion:
Missing height or weight (n = 5)
Remaining participants (n = 536)
Remaining participants
24-hour urine exclusions:
Without 24-hour urine data (n = 634)
Additional exclusion:
Questionable data (n = 1)
Remaining participants
Suspected incomplete collections:
Volume <500 mL (n = 29)
Creatinine <6mmol/day for males (n = 9)
Creatinine <4mmol/day for females (n=8)
Participants included in the analysis
(n = 71)
Suspected incomplete collections:
Creatinine <1.8 or >32.7mmol/L for males
(n = 22) and creatinine <1.8 or >28.3mmol/L
for females (n = 31)
Participants included in the analysis
(n = 483)
Figure 1. Process of determining the final participant number.
Nutrients 2019,11, 916 5 of 12
2.3. Biochemical Assessment
The spot and 24-h urine samples were analyzed to determine the level of sodium, creatinine, and
potassium at the Laboratory Department at Vila Central Hospital in Port Vila using a Cobas C311
urine analyzer.
2.4. Statistical Analyses
Statistical analyses were undertaken by The George Institute for Global Health in Sydney, Australia.
All analyses were weighted to reflect the age, sex, and area distribution of the Efate population based
on the 2016 mini census [
23
]. Statistical testing was conducted in STATA 13 for Windows (StataCorp
LP, Texas), with a significance level of p<0.05.
3. Results
A total of 774 participants completed the survey, of which 541 provided spot samples and 121
provided 24-h urine samples. After applying the criteria in Figure 1, 483 and 71 participants had
complete spot and 24-h urine samples, respectively, and were included in these analyses, giving a final
participation rate of 62.4%.
The mean age was approximately 37 years and 49% of all participants were female. Most
participants were urban dwellers (66%) and just over half (53%) were employed. The majority of
participants reported completing either primary (44%) or secondary schooling (42%; Table 1). Sixty
percent of the participants were found to have a body mass index (BMI) in the overweight or obese
category (66% in women versus 55% in men). The mean BMI was 27.3 kg/m
2
(overweight), and
men had a lower mean BMI than women (26.6 compared to 28.1 kg/m
2
). Mean blood pressure
was 122/78 mmHg. Only 10% of the participants reported having previously been diagnosed with
hypertension, however 21.6% were found to have raised blood pressure, with a further 2.4% taking
anti-hypertensive medication (Table 1).
Table 1. Weighted sample characteristics.
Characteristics Overall Female Male
Age in years, mean (SD) 36.6 (12.6) 35.6 (12.3) 37.5 (12.8)
Female, % 49.2 - -
Area, %
Rural 34.1 34.7 33.4
Urban 66.0 65.3 66.6
Completed education, %
No formal schooling 2.5 2.8 2.2
Primary level 43.6 47.9 39.6
Secondary level 41.7 38.7 44.7
Tertiary level 12.1 10.7 13.5
Employed, % 52.8 43.7 61.6
Height in cm, mean (SD) 164.1 (7.9) 158.9 (5.7) 169.1 (6.3)
Weight in kg, mean (SD) 73.6 (15.6) 71.1 (16.3) 76.0 (14.6)
Body mass index in kg/m2, mean (SD) 27.3 (5.4) 28.1 (5.9) 26.6 (4.8)
Overweight or obese, % 60.3 54.8 65.9
Systolic blood pressure in mmHg, mean (SD) 121.7 (19.2) 116.5 (18.1) 126.8 (19.0)
Diastolic blood pressure in mmHg, mean (SD) 77.9 (12.7) 76.4 (11.4) 79.3 (13.8)
History of hypertension, % 10.3 10.9 9.8
Measured hypertension, % 21.6 16.1 26.9
Nutrients 2019,11, 916 6 of 12
Table 1. Cont.
Characteristics Overall Female Male
Pre-existing hypertension (those who had measured
high blood pressure OR were taking Western
hypertension medication prior to the survey), %
24.0 18.8 29.0
History of high cholesterol in blood, % 3.7 5.1 2.4
History of heart attack, % 1.8 0.8 2.9
History of stroke, % 1.1 0.4 1.7
History of diabetes, % 2.0 1.0 3.1
History of chronic kidney disease, % 1.8 1.0 2.6
Estimated Salt Intake from Urine Samples
Mean salt intake was estimated to be 7.2 (SD 2.3) g/day derived from spot urine samples. Males
had significantly higher salt intake than females (Difference 1.3 g/day; 95% CI 0.9 to 1.7 g/day;
p<0.001
).
Almost 85% of the population consumed more than the WHO’s recommended amount of 5 g salt per
day, with 87.6% of men and 81.1% of women exceeding the guideline. Mean salt intake using 24-h
urine samples was found to be 5.9 (SD 3.6) g/day, and no sex differences were determined (Table 2).
There was no statistical difference observed between the characteristics of participants who completed
a spot urine and 24-h urine sample (Appendix A). A Bland-Altman plot showed all but two data
points (97%) fell within the limits of agreement (
−
5.8 and 9.1; +/
−
2SDs of the mean difference of
1.6 g/day), indicating that there is little variability between the results of the spot and 24-h urine for
those participants who provided both samples (n=65; Appendix B).
Table 2. Weighted results for salt intake.
nOverall Female Male p-Value
24-h urine in g/day, mean (SD) 71 5.9 (3.6) 5.6 (3.7) 6.2 (3.5) 0.496
Spot urine using “INTERSALT with
potassium” equation in g/day, mean (SD) 483 7.2 (2.3) 6.5 (1.7) 7.8 (2.6) <0.001
Salt intake above the 5 g WHO target, % 483 84.4 81.1 87.6
WHO, World Health Organization.
4. Discussion
The Vanuatu Salt Intake Survey is the first cross-sectional study to provide a baseline estimate of
salt intake using urinary analysis. The majority of the study population, almost 85%, consumed more
than the WHO recommended amount of 5 g, and 8% of the population consumed over 10 g/day; double
the guideline. Estimated mean salt intake was found to be 7.2 g/day from spot urine samples in the
sub-national study population, with men consuming significantly more salt than women. Mean salt
intake using 24-h urine samples was found to be 5.9 g/day, 1.3 g/day less than the spot urine estimate.
The characteristics of participants who provided spot urine samples were not significantly different
to those providing 24-h urine samples, suggesting it is possible to estimate mean salt intake from spot
urines. The sample size of 24-h urine samples was small, and therefore estimates may not be precise,
as indicated by the large standard deviation. However, the smaller standard deviation given from spot
urine samples is likely a result of the equation used, which incorporates age, sex, and BMI; variables
which are relatively constant, and thereby generate less variability [
29
]. As there was a larger sample of
spot urine samples, this may be a more precise estimate, however this method is known to overestimate
population mean intake at lower levels and underestimate at higher intake levels [
29
,
30
], and has not
yet been validated in this population. The WHO recommends the collection of spot urine samples
in countries where low capacity and resources impede the ability to collect 24-h urine samples, after
validation of spot urine in the population [
20
]. Our intention was to validate the spot urine samples
Nutrients 2019,11, 916 7 of 12
with the 24-h urine samples as per the recommended procedure, however, the low 24-h urine sample
size prevented this. Taking all of these factors into account, we can surmise that the result from the
spot samples in this population may reflect a more accurate measurement of population salt intake
under these circumstances. Future research will still require a sub-sample of 24-h urine collection to
validate spot urine samples and may provide a better estimate.
While an exact estimate of mean salt intake cannot be obtained from spot urine samples in this
study, it is known that spot urine estimates are able to accurately classify population salt intake as
above or below the 5 g/day maximum salt target set by the WHO [
30
]. From this, we can conclude that
the Vanuatu population are consuming excess amounts of salt and salt reduction strategies should be a
priority for the country.
Mean salt intake from 24-h urine samples was similar to previous estimates in Vanuatu. The 2010
Global Burden of Diseases (GBD) modelling study estimated salt intake as 5.6 g/day in Vanuatu [
31
],
and the Household Income and Expenditure Survey (HIES), 2010, estimated mean salt intake as 5.2
g per person per day [
32
]. However there are notable shortcomings of HIES data, which include
underestimation of staple foods and overestimation of infrequently consumed foods [
33
] and processed
foods, which tend to be high in salt [
34
]. While the 24-h urine estimate from this study is similar to these
previous estimates, the spot urine samples suggest salt intake may be higher than previously recorded.
Salt intake estimated from spot urine was 7.2 g/day, which was similar to a nationally representative
sample in Samoa in 2013 (7.09 g/day), though this was measured from 24-h urine samples [
35
].
The similarity of these results is highly likely given the demographic, environmental, and cultural
similarities between the two countries [
9
,
36
]. Likewise, gender differences were also found in this study
(male salt intake was significantly greater than female), mirroring the Samoa study [
35
]. In contrast,
salt consumption was lower than Fiji’s most recently recorded salt intake data from 24-h urine samples
in 2016 [
21
]. This may be due to the increased urbanization and differences in food culture in Fiji, for
example Fijian Indian cuisine having a high salt content [37].
Financial constraints resulted in multiple study limitations. Due to limited financial resources
and administrative delays, a common occurrence in the Pacific, the sampling was conducted at two
time points, which may have induced seasonal bias. Further, the method of sampling was also
modified from random sampling of households in 2016 to convenience sampling in 2017 due to a lack
of finances, personnel, and time restraints. However, the estimated intakes from both samples are
likely comparable [
38
]. Financial limitations meant that the study was only conducted in one island of
Vanuatu, Efate Island, which was chosen because it has the highest population density and rate of
urbanization of all the islands.
The greatest strength of this study was the ability to determine the proportion of the population
with a salt intake of greater than 5 g/day. This research was also the first to provide an estimate of
population salt intake from urinary analysis and provides a baseline from which to monitor population
salt intake. Furthermore, the protocol used is detailed enough to be replicated and improved upon
for future data collection. An additional strength is the inclusion and empowerment of local people.
The data collection teams were entirely comprised of, and led by, ni-Vanuatu, and all questionnaires
and procedures were culturally sensitive and inclusive towards ni-Vanuatu people and their customs.
This fostered a sense of community ownership and encouraged participation. Given the limited health
research previously carried out in Vanuatu, and lack of local people’s exposure to research of this
kind, it is vital that the importance of this research is conveyed to people in order for the results to be
implemented. As such, we ensured that outcomes of this research were appropriately disseminated to
the relevant ministries and also the general population through local media, creating conversation and
awareness about salt intake. This research has highlighted the need for action to reduce salt consumption
in Vanuatu, where previously there was little awareness in the general population of a need for change.
Future research in the region should anticipate the difficulties in data and urine sample collection
in the Pacific, including low response rates, and plan for a larger number of survey teams collecting data
from more communities. Additionally, raising awareness of research within communities should be
Nutrients 2019,11, 916 8 of 12
extensive to increase and support participation. It should be comprised of varied media forms, including
TV, radio, and newspapers, in addition to speaking to, and involving, chiefs and community leaders.
Recommendations
A large proportion of the Vanuatu population are consuming more than 5 g of salt per day. This
baseline assessment of salt intake in Vanuatu provides the required evidence for the implementation of
a national salt reduction initiative. Previous interventions have demonstrated that a multi-sectorial,
multi-factored approach is most effective in lowering population salt intake [
39
]. Components of
this approach might include fiscal policies, such as a salt tax, engagement with food industry to
reduce salt levels in foods, and education and awareness-raising interventions to promote behavior
change regarding low salt food choices and discretionary salt use [
40
]. To appropriately direct these
components, additional research will be needed, particularly the identification of major sources of
salt in the diet, which can be obtained by conducting two 24-h diet recalls [
41
,
42
]. Results from a
knowledge, attitudes, and behavior questionnaire conducted at the same time-points as the urine
collection could also be used to identify population subgroups that should be targeted for education
and awareness-raising campaigns [
42
]. Furthermore, the SHAKE the Salt Habit Technical Package
for Salt Reduction [
43
] provides instruction on the most effective ways to develop, implement, and
monitor salt reduction strategies and could be a useful tool for Vanuatu to achieve a reduction in
population salt intake via a variety of methods.
Due to the multi-factorial nature of NCDs, prevention and control strategies need the partnership
and engagement of multi-sectoral stakeholders both inside and outside the health sector, including
relevant government ministries, non-government organizations, the food industry, private sector,
and the communities themselves. Future actions point to political commitment on the part of the
government to mobilize resources for salt reduction programs, while additionally creating a monitoring
plan to track changes in salt intake, which could be completed through the already established WHO
STEPs protocol [24].
5. Conclusions
This is the first study to assess salt intake in Vanuatu using urine samples and confirms that the
majority of the Vanuatu population are consuming salt intakes greater than the WHO recommended
maximum intake. Introducing a national salt reduction strategy could decrease salt intake, or prevent
the likely increase in salt consumption, and reduce the burden of NCDs in Vanuatu. Future studies in
Vanuatu and other PICs should consider the challenging environment and other lessons learned from
this study to improve research efficiency and effectiveness.
Author Contributions:
Conceptualization, W.S., J.W., and C.J.; data curation, K.T.; formal analysis, K.T. and J.A.S.;
funding acquisition, L.T., J.W., and C.J.; investigation, K.P. and N.H.; methodology, K.P.; project administration,
N.H.; software, J.A.S.; supervision, K.P., N.H., K.T., and C.J.; validation, K.T. and W.S.; visualization, K.P. and E.S.;
writing—original draft, K.P. and E.S.; writing—review and editing, K.P., E.S., K.T., J.A.S., L.T., W.S., J.W., and C.J.
Funding:
The World Health Organization funded the survey. J.W. is supported by a joint National Health
and Medical Research Council and National Heart Foundation Career Development Fellowship, (APP1082924);
K.T. was supported by a National Health and Medical Research Council of Australia postgraduate scholarship
(APP1115169) during this work. C.J. was supported by an NHMRC postgraduate scholarship (APP1074678)
during this work.
Acknowledgments:
Tsogy Bayandorj, Myriam Abel, Clare Farrand, Graham Tabi, Jacob Kool, Vila Central
Hospital Laboratory Team, Vanuatu Ministry of Health.
Conflicts of Interest:
J.W. is Director of the World Health Organization Collaborating Centre on Population Salt
Reduction at the George Institute for Global Health. All other authors declare no conflict of interest.
Disclaimer:
The author W.S. is a staffmember of the World Health Organization, K.P. was a volunteer with the
World Health Organization. The authors alone are responsible for the views expressed in this publication and
they do not necessarily represent the views, decisions or policies of the World Health Organization.
Nutrients 2019,11, 916 9 of 12
Appendix A
Table A1. Comparison of characteristics of subjects with spot vs. 24-h urine samples.
Characteristics Spot Urine 24-h Urine p-Value
(n=483) (n=71)
Age in years, mean (SD) 36.6 (12.6) 36.4 (12.6) 0.898
Female, % 49.2 49.2 1.000
Area, %
Rural 34.1 34.0 1.000
Urban 66.0 66.0
Completed Education, %
No formal schooling 2.5 1.8
Primary level 43.6 54.4 0.386
Secondary level 41.7 36.1
Tertiary level 12.1 7.8
Employed, % 52.8 48.4 0.540
Height in cm, mean (SD) 164.1 (7.9) 165.2 (9.3) 0.284
Weight in kg, mean (SD) 73.6 (15.6) 76.4 (15.1) 0.162
Body mass index in kg/m2, mean (SD) 27.3 (5.4) 28.1 (5.8) 0.271
Systolic blood pressure in mmHg, mean (SD) 121.7 (19.2) 123.9 (19.2) 0.385
Diastolic blood pressure in mmHg, mean (SD) 77.9 (12.7) 79.9 (13.2) 0.224
History of hypertension, % 10.3 12.2 0.634
History of high cholesterol in blood, % 3.7 4.3 0.799
History of heart attack, % 1.8 2.5 0.766
History of stroke, % 1.1 0.0 0.413
History of diabetes, % 2.0 0.0 0.243
History of chronic kidney disease, % 1.8 2.6 0.741
Appendix B
Nutrients 2019, 11, x FOR PEER REVIEW 9 of 12
Appendix A
Table A1. Comparison of characteristics of subjects with spot vs. 24-h urine samples.
Characteristics Spot Urine
(n = 483)
24-h Urine
(n = 71) p-Value
Age in years, mean (SD) 36.6 (12.6) 36.4 (12.6) 0.898
Female, % 49.2 49.2 1.000
Area, %
Rural
Urban
34.1
66.0
34.0
66.0
1.000
Completed Education, %
No formal schooling
Primary level
Secondary level
Tertiary level
2.5
43.6
41.7
12.1
1.8
54.4
36.1
7.8
0.386
Employed, % 52.8 48.4 0.540
Height in cm, mean (SD) 164.1 (7.9) 165.2 (9.3) 0.284
Weight in kg, mean (SD) 73.6 (15.6) 76.4 (15.1) 0.162
Body mass index in kg/m
2
,
mean (SD) 27.3 (5.4) 28.1 (5.8) 0.271
Systolic blood pressure in mmHg, mean (SD) 121.7 (19.2) 123.9 (19.2) 0.385
Diastolic blood pressure in mmHg, mean (SD) 77.9 (12.7) 79.9 (13.2) 0.224
History of hypertension, % 10.3 12.2 0.634
History of high cholesterol in blood, % 3.7 4.3 0.799
History of heart attack, % 1.8 2.5 0.766
History of stroke, % 1.1 0.0 0.413
History of diabetes, % 2.0 0.0 0.243
History of chronic kidney disease, % 1.8 2.6 0.741
Appendix B
Figure A1. Bland-Altman plot for 24-h sodium excretion estimated from spot urine using the
INTERSALT with K method.
References
-20 -1 5 -10 -5 0 5 10 15 20
Difference (salt_INTERSALT_K-salt_24HU)
510 15 20
Average of salt_INTERSALT_K and salt_24HU
Average bias
95% upper limit
95% lower limit
Figure A1.
Bland-Altman plot for 24-h sodium excretion estimated from spot urine using the
INTERSALT with K method.
Nutrients 2019,11, 916 10 of 12
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