May Measurement Month 2022: an analysis of blood pressure screening results from the Republic of the Congo

Abstract

The May Measurement Month (MMM) campaign was carried out in the Republic of the Congo in 2022 with the aim of raising awareness of raised blood pressure (BP). Here, we report on the findings of the campaign. Adults aged ≥18 years were recruited opportunistically in rural areas and some cities in Congo. 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 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, 8619 were screened, with a mean age of 44.8 years and 49.8% were female. Of those screened, 2596 (30.1%) reported previous COVID-19 vaccination, 476 (5.5%) reported diabetes, 422 (4.9%) reported previous myocardial infarction, 124 (1.4%) reported previous stroke, 1211 (14.1%) were current smokers, and 1237 (14.4%) reported daily alcohol intake. Of all participants, 3054 (35.4%) had hypertension, of whom 1331 (43.6%) were aware, and 944 (30.9%) were on antihypertensive medication, of whom 801 (84.9%) were on monotherapy and 116 (12.3%) on dual therapy. Of those on antihypertensive medication, 235 (24.9%) had controlled BP, and of all participants with hypertension, 7.7% had controlled BP. The MMM campaign in the Republic of the Congo identified significant numbers of participants with either untreated or inadequately treated hypertension. Therapeutic education must be more active, in addition to enhanced screening, facilitating access to care and making medication available.

Introduction

Raised blood pressure (BP) is one of the largest contributors to the global burden of disease.¹ Worldwide, 88% of deaths attributable to hypertension occur in low- and middle-income countries.¹ In Africa, 54% of the adult population is hypertensive, and it is a major cause of premature death.² In the Republic of the Congo, the prevalence of hypertension is high and growing. These complications often occur early, at a young age. This is due to the lack of awareness of the disease and limited access to care.³

May Measurement Month (MMM) was initiated in 2017 by the International Society of Hypertension and has since run annually, except for 2020 due to the COVID-19 pandemic. In 2022, the MMM campaign continued, with an aim of continuing to raise awareness of the dangers of raised BP and included 757 350 participants worldwide.⁴

The proportion of hypertension during the different screenings in Congo varied depending on the rural or urban environment and the social context with the COVID-19 pandemic. Thus, the frequency was 41, 22.2, 33.5, and 34.1% in 2017, 2018, 2019, and 2021, respectively.^5-8 In this paper, we report on the findings of the MMM22 campaign in the Republic of the Congo.

Methods

The MMM is a cross-sectional opportunistic survey of consenting adults aged 18 years or over. The programme in the Republic of the Congo was coordinated by the Congolese Society of Hypertension and Internal Medicine (SCHAMI) over the months of June–August 2022. Screening sites were set up in urban (cities of Brazzaville and Pointe-Noire in southern), semi-urban (localities of Mouyondzi, Nkayi, Dolisie, and Owando in southern and central region), and rural (county of Epena in northern) areas of the Republic of the Congo. These localities are distributed in the southern, central, and northern regions of Congo. The testing locations were hospitals, clinics, churches, and other public places. Volunteer investigators received information on the different screening procedures. The campaign was advertised via the media and by criers in the neighbourhoods with megaphones.

In accordance with the standard MMM protocol, participants ideally had three seated BP readings measured at 1-min intervals.⁴ OMRON M-3 HEM-7131-E® 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 and/or 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 referred to health centres for further assessment and appropriate treatment.

Data were collected locally via paper forms and then onto electronic spreadsheets 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, results are also presented after age and sex standardization using the World Health Organization (WHO) world standard population and assuming an equal gender split.⁹ The study received authorization from the Directorate of Health Services of the Ministry of Health and population (Republic of the Congo) and ethical approval from Ethics Committee for Health Science Research (CERSSA). Funding was received from many organizations (listed at the end).

Results

In total, 8619 adults were screened during MMM22 in the Republic of the Congo. The mean (standard deviation) age was 44.8 (16.3) years, and 4288 (49.8%) were female. The majority of the participants identified as Black 7317 (84.9%). About a third (3074, 35.7%) had between 7 and 12 years of education while 27.8% (2396) had more than 12 years. The screening locations were primarily indoor public areas 5337 (61.9%). Of those screened, 2596 (30.1%) reported previous COVID-19 vaccination, 476 (5.5%) reported diabetes, 422 (4.9%) reported previous myocardial infarction, 124 (1.4%) reported previous stroke, 1211 (14.1%) were current smokers, and 1237 (14.4%) reported daily alcohol intake. Of all participants, 1174 (13.6%) reported never having had their BP measured before.

Multiple imputation was used to estimate missing BP readings for 6753 (78.4%) participants missing data on the second and/or third BP reading. Of all participants, 3054 (35.4%) were found to have hypertension, of whom 1331 (43.6%) were aware, and 944 (30.9%) were on antihypertensive medication (Table 1). Of those on antihypertensive medication, 235 (24.9%) had controlled BP, and of all hypertensives, 7.7% had controlled BP. Of the participants who were not taking antihypertensive medication, 2110 (27.5%) were found to have raised BP. In total, 2819 (32.7%) 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	8619	3054 (35.4)	1331 (43.6)	944 (30.9)	235 (24.9)	235 (7.7)
Standardized	8184a	2768 (33.8)	1159 (41.9)	801 (28.9)	220 (27.5)	220 (7.9)

^aStandardized total lower than actual total, as 435 participants did not have information recorded on age or sex. BP, blood pressure.

After age and sex standardization, 2768 (33.8%) were found to have hypertension, of whom 1159 (41.9%) were aware, 801 (28.9%) were on antihypertensive medication, and 220 (7.9%) were controlled (Table 1).

Discussion

This screening campaign was carried out in the context of COVID-19.⁸ Thus, 30.1% of those screened were vaccinated against COVID-19 vs. only 4.4% in 2021.⁸ This aspect denotes the effects of the national response to this pandemic. The MMM22 programme identified a total of 2819 (32.7%) participants with untreated or inadequately treated hypertension, highlighting the scale of hypertension in the Republic of the Congo.

This proportion is close to that reported during screenings in 2019 and 2021,^7,8 but higher than the proportion found in 2018 (22.2%).⁶ This difference is linked to the fact that the population screened in 2018 was predominantly young with 67.8% aged between 18 and 29 years.⁶

Also, the level of awareness of hypertension is similar to that of 2018, but the level of control of BP is lower than that of 2018 (16% vs. 7.7%). Blood pressure control levels remain close to those reported in 2019 and 2021.^5,6 This observation shows that efforts must be undertaken in order to improve the rate of hypertensive patients who are treated and controlled. Actions with key priorities have been issued to achieve well-defined objectives²; these actions include, among others, mandatory BP measurement regardless of the consultation, implementation of treatment protocols, improvement of access to treatment by encouraging local production, and government involvement in imposing a healthy diet and promoting physical activity, as provided for in the ACHIEVE-WHO-HEARTS guide for the control of hypertension.² To be effective, these actions must benefit from the support and assistance of public authorities.

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, prevalence 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 recommended in guidelines.¹⁰ Consequently, the rate of hypertension detected is likely to represent an overestimate.¹⁰

Conclusion

The MMM campaign in the Republic of the Congo identified significant numbers of participants with either untreated or inadequately treated hypertension. Therapeutic education must be more active, in addition to making medication available and facilitating access to care.

Funding

This study was supported by the University Hospital of Brazzaville, Denis Sassou-Nguesso University, National Institute of Health Sciences, EMR-Pharma, Biogaran Congo, ETHICA-Congo, GHPL-Congo, Ajanta Pharma Congo, Foundation Charlotte Opimbat, and Denk-Pharma Congo.

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.