May Measurement Month 2022: an analysis of blood pressure screening results from Mauritius

Abstract

May Measurement Month (MMM) is a global campaign initiated by the International Society of Hypertension aimed at raising awareness of high blood pressure (BP) and to act as a temporary solution to the lack of screening programmes worldwide. We provide the results of the MMM 2022 (MMM22) campaign in Mauritius. Adults aged ≥18 years were recruited opportunistically at workplaces and community centres, in both rural and urban areas across Mauritius. Three seated BP readings were taken for each participant, along with completion of a questionnaire on demographics, lifestyle factors, and comorbidities. Hypertension was defined as a systolic BP ≥140 mmHg and/or a diastolic BP ≥90 mmHg or being on antihypertensive medication. Controlled BP was defined as being on antihypertensive medication with a BP <140/90 mmHg. Multiple imputation was used to estimate any missing BP readings. In total, 8953 were screened, with a mean age of 43.6 years and 62.2% of whom were female. Out of 8953 participants, 2024 participants (22.6%) had hypertension, of whom 1066 (52.7%) were aware, and 884 (43.7%) were on antihypertensive medication. Of those on antihypertensive medication, 550 (62.2%) had controlled BP, and of all participants with hypertension, 550 (27.2%) had controlled BP. The MMM campaign in Mauritius identified significant numbers of participants with either untreated or inadequately treated hypertension. May Measurement Month 2022 was the largest BP screening campaign undertaken in Mauritius. These results suggest that MMM22 was useful in the identification of patients with raised BP for further investigation and follow-up.

Introduction

Raised blood pressure (BP) is one of the largest contributors to the global burden of disease.¹ Hypertension is one of the principal causes of Mauritians attending community hospitals, area health centres, and Mediclinic in Mauritius.² In 2021, the prevalence of hypertension among Mauritian adults aged 25–74 years was reported to be 27.2%³ which marked a significant decrease in the prevalence of hypertension compared with 38.0% reported in 2009 and 28.4% in 2015.

May Measurement Month (MMM) was initiated in 2017 by the International Society of Hypertension and has since run annually, except for 2020/2021 due to the COVID-19 pandemic. Having participated in MMM in 2017, 2018, and 2019, Mauritius again contributed in 2022, with the aim of continuing to raise awareness of the dangers of raised BP.⁴ In this paper, we report on the findings of the MMM22 campaign in Mauritius.

Methods

May Measurement Month is a cross-sectional opportunistic survey of consenting adults aged 18 years or over. The programme in Mauritius was co-ordinated by Non-Communicable Diseases, Health Promotion and Research Unit, which is under the aegis of the Ministry of Health and Wellness over the months of May to June 2022. Screening sites were set up in workplaces and community centres, in both rural and urban areas across Mauritius.

In accordance with the standard MMM protocol, participants ideally had three seated BP readings measured at 1-min intervals.⁴ Automated Omron devices were used to measure BP. A questionnaire was also completed, collecting information on demographics, comorbidities, lifestyle risk factors, and antihypertensive medication use. Hypertension was defined as a raised BP (a systolic BP ≥140 mmHg or a diastolic BP ≥90 mmHg based on the mean of the second and third readings), or being on antihypertensive medication. Controlled BP was defined as being on medication with a BP <140/90 mmHg. Participants found to have raised BP were provided with diet and lifestyle advice, and the hypertensive cases are referred to the nearest healthcare centre.

Data were collected locally via questionnaire and submitted to the central MMM team for cleaning and analysis. In cases where any BP reading was missing, to ensure comparability between participants, the average of the second and third readings was estimated by multiple imputation using chained equations, based on global data as described previously.⁴ For comparison with other countries participating in MMM, the results are also presented after age and sex standardization using the World Health Organization world standard population, and assuming an equal gender split.⁵ The study received ethical approval from the Ethics Committee of Ministry of Health and Wellness.

Results

In total, 8953 were screened during MMM22 in Mauritius. The mean (standard deviation) age was 43.6 (14.6) years, and 5573 (62.2%) were female. Among the participants, 6924 (77.3%) were of South Asian, 1623 (18.1%) of Black, and 49 (0.5%) of East/South East Asian ethnicities. Of all participants, 536 (6.0%) reported never having had a BP measured before.

Multiple imputation was used to estimate missing BP readings for 297 (3.3%) participants missing data on the second and/or third BP reading. Of all participants, 2024 (22.6%) were found to have hypertension, of whom 1066 (52.7%) were aware, and 884 (43.7%) were on antihypertensive medication (Table 1). Of those on antihypertensive medication, 550 (62.2%) had controlled BP, and of all hypertensives, 27.2% had controlled BP. Of participants who were not taking antihypertensive medication, 1140 (14.1%) were found to have raised BP. In total, 1474 (16.5%) were found to have either untreated or inadequately treated hypertension.

Table 1.

Total participants and numbers with hypertension, awareness, on medication, and with controlled blood pressure, before and after age and sex standardization

	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
Actual	8953	2024 (22.6)	1066 (52.7)	884 (43.7)	550 (62.2)	550 (27.2)
Standardized	8923a	2061 (23.1)	1101 (53.5)	931 (45.2)	637 (68.5)	637 (30.9)

^aStandardized total lower than actual total, as 30 participants did not have information recorded on age or sex.

After age and sex standardization, 2061 (23.1%) were found to have hypertension, of whom 1101 (53.5%) were aware and 931 (45.2%) were on antihypertensive medication. Among those participants on antihypertensive medication, 637 (68.5%) had controlled BP (Table 1). The prevalence of hypertension for males (24.2%) was higher than for females (21.6%). Furthermore, the prevalence was seen to be higher for participants aged 70 years and above (57.3%).

Discussion

During the MMM22 campaign, the project was well promoted which consequently increased the number of participants from 8262 in MMM19 to 8953 in MMM22.⁶ The small increase suggests that Mauritians were becoming more health conscious and are benefitting for all the health facilities provided to them. Moreover, the number of participants having hypertension had also decreased from 29.4 to 22.6%, which may indicate a change towards a healthier lifestyle or of differential non-representative sampling.⁶ The MMM22 programme identified a total of 1474 (16.5%) participants with untreated or inadequately treated hypertension, suggesting a relatively low rate of hypertension in Mauritius.

Compared with other studies conducted locally, MMM22 was the most successful hypertension screening campaign in terms of numbers screened and was carried out in collaboration with the Mauritian government following a standardized protocol. The MMM campaign was effective, as it took hypertension to the front line of our health agenda, reminding both health professionals and the population of the need for regular BP measurement. The simplicity of the MMM study and its low cost, associated with large numbers screened, contributed greatly to the considerable success of the campaign in our country.

Strengths and limitations

A strength of the MMM campaign is the use of a standardized protocol across countries, which aids comparability of findings. Participants in MMM were recruited opportunistically using convenience sampling, and as a result, estimates should not be interpreted as estimates of national prevalence. Hypertension was defined based on three BP readings at a single visit for pragmatic reasons which is not the optimal method of diagnosis at the individual level as recommended in guidelines.⁷ Consequently, the rate of hypertension detected is likely to represent an overestimate.⁷

Conclusions

MMM22 is important to policy-makers as it demonstrates the scale of untreated and inadequate treatment in Mauritius and so provides impetus to improve the existing pathways for the diagnosis and management of hypertension.

Funding

This study was funded by the Ministry of Health and Wellness of the Government of Mauritius and no other grants.

Data availability

Data are not publicly available but access can be requested with permission from the MMM Management Board, on request through the MMM website: maymeasure.org.