May Measurement Month 2021: an analysis of blood pressure screening results from Australia

Abstract

May Measurement Month (MMM) is a global and national blood pressure (BP) screening campaign initiated by the International Society of Hypertension to improve awareness of BP worldwide. This study reports on the findings of the MMM21 campaign in Australia. Adult participants (≥18 years) were screened through opportunistic sampling across Australia between 1 May and 30 November 2021. Trained volunteers recorded standardized BP measurements from community volunteer participants along with demographic data, lifestyle factors, comorbidities, and history of COVID-19 infection and vaccination. Hypertension was defined as systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg and/or taking antihypertensive medication. Data were collated and analysed centrally using the current MMM protocol and presented after the imputation of missing BP readings. A total of 1307 participants were screened in 2021, comprising 652 (49.9%) females and 654 (50.0%) males with a mean age of 48 years (SD 20.1). Of all 1307 participants, 524 (40.1%) had hypertension. Of participants with hypertension, 65.4% were aware and 59.3% were on antihypertensive medication. Of 311 participants on antihypertensive medication, 54.7% had controlled BP. Of all 524 participants with hypertension, 32.5% had controlled BP. The current 2021 data may indicate some progress in creating BP awareness; however, consecutive Australian data obtained since 2017 demonstrated stagnating treatment, and control rates compared with global rates and those in other high-income countries. Concerted efforts from all stakeholders will be required to further improve BP awareness, treatment, and control rates in Australia.

Introduction

Raised blood pressure (BP) is the major contributing risk factor to deaths in Australia and worldwide. About 22.8% of Australians aged 18 years and over have hypertension with stagnating rates of BP control since 2011.^1,2 The Australian Burden of Disease Database shows that high BP contributes to 65% of heart disease, 43% of coronary heart disease, 41% of stroke, 38% of chronic kidney disease, 32% of atrial fibrillation and flutter burden, and 3.6% of dementia and has been identified as a major risk factor for premature death and disability in Australians.³ Hypertension contributed to 5.8% of the total disease burden in Australia, with an estimated expenditure of more than AUD $131 million for related hospitalizations in 2015–16.⁴ The Australian May Measurement Month (MMM) campaigns from 2017 to 2019 screened a total of 10 046 participants, demonstrating a hypertension prevalence of 31.0%, awareness rate of 48.5%, treatment rate of 44.4%, and a hypertension control rate of 53.2%.⁵ The MMM campaign was deferred in 2020 due to COVID 19; however, MMM recommenced in 2021 adapting to the ever-changing landscape of COVID 19 to continue its mission of creating BP awareness. In this study, we report on findings from the MMM21 campaign in Australia.

Methods

In 2021, the MMM cross-sectional survey screened all adults (≥18 years) between 1 May and 30 November, with an extended time period to allow flexibility in view of the COVID 19 pandemic. Screening sites were set up in a wide range of outdoor locations and indoor public areas and in various pharmacies, hospitals, and health care facilities across Australia. The Dobney Hypertension Centre (DHC) at the University of Western Australia/Royal Perth Hospital has been serving as the national MMM coordinating centre and in turn coordinated with the other local screening sites across Australia. Ethics approval was obtained centrally through the Human Research and Ethics Committee of the Alfred Hospital, Melbourne, and further approved locally where required. The MMM questionnaire, training, and marketing materials were developed and shared by MMM via the MMM website (www.maymeasure.com). The Australian campaign was promoted via various social media outlets across all states. Informed consent was obtained from all MMM participants, and anonymized data were recorded in line with the MMM protocol.⁵

Data including demography, weight, medical history, and previous MMM participation were collected in the MMM questionnaire. Medical history included information regarding pre-existing conditions such as diabetes mellitus, history of stroke and myocardial infarction (MI), pregnancy, and hypertension in previous pregnancy. Data regarding medication such as aspirin, statins, hormonal contraceptive, and hormone replacement therapy, in addition to antihypertensive medications, were recorded. The details of the physical activity of participants were also explored and checked if meeting World Health Organization (WHO) physical activity guidelines. The details of previous COVID-19 infection and vaccination status and its influence on the hypertension management of participants were additionally explored in the 2021 campaign. Other details such as the social history of alcohol consumption, smoking, and education status of participants were also collected.

Automated BP machines kindly provided by Omron, Welch Allyn, and A&D were made available by the DHC to those sites where machines were required. Blood pressure was measured by trained volunteers using validated BP devices ensuring appropriate cuff sizes to suit the individual physique of screened participants to obtain correct readings. Blood pressure measurements included three seated recordings taken on the left arm (preferably) or right arm (where using the left arm was impractical) with 1-min intervals between readings. Hypertension was defined as systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg based on the mean of the second and third BP readings and/or in those on antihypertensive medication. All participants who had high BP were provided with evidence-based diet and lifestyle modification advice for BP lowering and those with untreated or uncontrolled hypertension were advised to follow-up with their general practitioner. The data collected were collated, cleaned, and analysed centrally by the MMM project team as described previously.⁵ In cases where any BP reading was missing, multiple imputation was used to estimate the mean of the second and third BP reading, based on global data.⁵

Results

During the MMM21 campaign, a total of 1307 Australian participants were screened. The mean age was 47.6 (20.1) years, comprising multiple ethnicities including 792 White participants (60.6%), 189 from South East Asia (14.5%), 120 from South Asia (9.2%), 34 Black participants (2.6%), 22 Middle Eastern (1.7%), 48 mixed (3.7%), 70 other (5.4%), and 32 of unknown origin (2.4%) with a total of 652 female (49.9%) and 654 male (50.0%) participants. Of all participants screened, 60 (4.6%) had previously participated in MMM17, MMM18, or MMM19, 1009 (77.2%) were new to MMM, and the status of 238 (18.2%) was unknown. Most of the screening took place in public places both indoors (n = 503; 38.5%) and outdoors (n = 159; 12.2%). The remainder of screening occurred in hospitals/clinics or pharmacies (n = 435; 33.3%), workplace environments (n = 187; 14.3%), and other sites (n = 23; 1.8%). Of all participants screened, 640 (49%) had received COVID-19 vaccination and 2 (0.2%) reported a previous positive COVID-19 test. Of all participants, 25 (1.9%) had a history of previous stroke and 49 (3.7%) had a history of previous MI.

A total of 80 participants (6.1%) reported having diabetes, 49 (3.7%) had a history of MI, 25 (1.9%) had a history of stroke, 108 (8.3%) reported aspirin usage, 204 (15.6%) reported statin use, 77 (11.8%) reported using hormonal contraceptives, and 28 (4.3%) were using hormone replacement therapy. Smoking was reported by 92 (7.0%) respondents and 35 (2.7%) reported daily alcohol consumption, 314 (24.0%) 1–6 times/week, and 314 (24.0%) reported alcohol consumption once or more per month. The mean weight of the participants was 75.1 (16.5) years and 7 (1.1%) of female respondents reported being pregnant.

Following imputation, of all the 1307 participants, 524 (40.1%) had hypertension (Table 1). Of those 524 participants with hypertension, 65.4% were aware of their diagnosis, and 59.3% were on antihypertensive medication. Of the 311 participants on antihypertensive medication, 54.7% had their BP controlled to <140/90 mmHg. Of all hypertensives, 32.5% were controlled to <140/90 mmHg. Of those for whom the number of medications was known, 159 (51.1%) were taking a single medication, 89 (28.6%) two medications, 27 (8.7%) three medications, 22 (7.1%) four medications, and 14 (4.5%) five or more medications. Of the 996 participants who were not taking antihypertensive medication, 21.4% were found to have hypertension.

Table 1.

Total participants and proportions with hypertension, awareness, on medication and with controlled blood pressure

Total participants	Number (%) with hypertension	Number (%) of hypertensives aware	Number (%) of hypertensives on medication	Number (%) of those on medication with controlled BP	Number (%) of all hypertensives with controlled BP
1307	524 (40.1%)	343 (65.4%)	311 (59.3%)	170 (54.7%)	170 (32.5%)

Discussion

As part of the MMM21 Australian campaign, 1307 participants of multi-ethnic background were screened, mostly from the community rather than from health care facilities. The prevalence of hypertension across the Australian sites was 40.1% (524 participants), which is higher when compared with previous Australian MMM2017, 2018, and 2019 campaigns (31.2%, 30.6%, and 31%, respectively) and the global MMM17, 2018, 2019, and 2021 campaigns (34.9%, 33.4%, 34.0%, and 35.2%, respectively).⁵ However, unlike previous years, BP awareness amongst hypertensive participants was higher, 65.4% compared with 50% or lesser in the previous years.⁵ Furthermore, of the 524 participants with hypertension, 311 (59.3%) were on BP-lowering medication compared with 44.4% in MMM17–19. Of those on treatment, only 54.7% had controlled BP, leaving 45.3% treated participants with uncontrolled hypertension, similar to findings from previous MMM17–19 campaigns.⁵

The MMM21 findings continue to demonstrate a high prevalence of hypertension in Australia. The higher BP awareness rate and treatment rate in 2021 is encouraging and may reflect a positive impact of the MMM screening and awareness campaign. However, the hypertension control rate in Australia remains lower than global rates.

The MMM limitations include the potential of selection bias from convenience sampling. Although the majority of screening took place in major cities, genuine attempts have been made to include regional and remote Australian towns. Owing to the cross-sectional design of the study, the potential impact of lifestyle advice provided to the participants could not be assessed. Nevertheless, despite the lower recruitment rates due to COVID-19 and the above-mentioned limitations, the estimates at the national and global level across the years have been remarkably consistent across the MMM campaigns and highlight the need for continued screening and awareness activities.

Funding

The International Society of Hypertension provided significant core funding for MMM in 2017 and 2018. This has been supplemented since 2018 by a generous annual donation from Servier Pharmaceuticals Co, which has enabled the campaign to happen in 2019 and 2021. However, most of the financial burden of MMM within each country falls on local resources and as ever we are indebted to those who have provided the necessary financial and logistical support within each country and to all those who have volunteered their time to deliver the project. We shall continue to seek further sources of funding to at least offset a greater proportion of the local costs of running MMM. We must also thank OMRON Healthcare for their continued support with their very generous supply of validated BP measuring devices.

Data availability

The data underlying this article can be shared on reasonable request to the corresponding author.