Increasing Medical Attention to High Blood Pressure

Executive Summary

Nudge Lebanon, in collaboration with B4Development (formerly known as QBIU) and Smart Science, conducted a two-phase intervention to identify individuals with hypertension and nudge them to seek medical care. In phase I, 1227 participants attending the 2018 Beirut International Marathon in Lebanon were screened for hypertension. While in Phase II, 266 eligible participants (e.g. measurements indicated hypertension, consented to the trial and provided valid contact details) were randomly assigned into control and treatment groups, with the treatment group receiving a behaviorally informed reminder via WhatsApp to seek medical care. Follow up data via a phone call revealed that Those who received the WhatsApp reminder were 17.5 percentage points more likely to seek medical care, compared to the control group (45.5% treatment group vs 28.0% control group). This study reveals that high blood pressure can be prevalent across a health-conscious population and that informing them that they have hypertension can successfully prompt them to follow up with a physician.

Policy Challenge

High blood pressure or hypertension is one of the leading risk factors contributing to cardiovascular diseases. If left uncontrolled, it may lead to strokes, vision loss, heart failures, and fatal heart attacks.

In Lebanon, the prevalence of hypertension increased threefold in the past decade^[1]. Evidence from a recent study conducted in the greater Beirut area suggests that 36.4% of the study participants were hypertensive^[2], while a cross-sectional study conducted between December 2014 and May 2015 in five districts across Lebanon revealed a prevalence rate of 29.3%.^[3]

Similar figures were also observed among runners participating in Beirut International Marathon in 2014. The study which screened 30 runners participating in the 42 km race, and 295 runners participating in the 10 km race revealed an incidence rate of 46.7% and 31.2% respectively.^[4]

Against this background, Nudge Lebanon in collaboration with B4Development and Smart Science conducted a behavioural insights intervention offering free blood pressure (BP) readings to participants in the Beirut International Marathon 2018. The intervention was designed to assess the prevalence of hypertension among runners and spectators, as well as nudge those who are diagnosed as hypertensive to seek medical care.

Intervention Design

The intervention consisted of two phases. In Phase 1, trained volunteers measured the BP of 1277 participants attending the 2018 Beirut International Marathon, while collecting data regarding their age, gender, smoking and drinking habits, health conditions, family history of hypertension, and their awareness of their condition (if any). Participants diagnosed with hypertension (as defined by the American Heart Association^[5]) were asked for verbal consent to receive further communication from Nudge Lebanon.

In Phase 2, 266 hypertensive participants with a valid Lebanese mobile number, and who consented to receive further communication, were randomly assigned to one of two groups:

• • Treatment group: participants in this group received a personalized message via WhatsApp messenger, 25 days following the Marathon day. The behaviorally-informed message, which was communicated in Arabic, including the participant’s first name, their measured BP, and a statement urging them to seek medical attention.

    

“Dear [First name],
Your BP reading during Beirut Marathon was [Reading].
This indicates that you have an elevated blood pressure.
You should seek medical attention at your earliest convenience. Your wellbeing matters to us.
Nudge Lebanon team”

• • Control group: participants in this group did not receive any WhatsApp communication.

Both groups received a phone call one month following the dissemination of the WhatsApp message, to enquire whether they sought further medical attention.

 Results

Phase 1

A total of 1,227 participants, aged 18 or above were screened between the 7^th and 11^th of November 2018. The majority were less than 40 years old and were males. Moreover, 44% were regular consumers of alcohol, 32% were smokers, and 50% had a family history of hypertension.

Around 25% of the screened participants were diagnosed with hypertension (n = 309), of which 76% were unaware of their condition. Interestingly, 54% of those diagnosed with hypertension claimed that they checked their BP regularly. This could suggest that participants misreported their screening habits, or BP readings were overestimated due to environmental factors (e.g. excessive movement, loud music, temperature, …).

Phase 2

A total of 266 participants were contacted one month following the WhatsApp message to check whether they sought medical attention. Of those, 219 answered the follow up call.^[6]

According to the results of the logistic regression analysis, individuals who received the behaviourally-informed WhatsApp message, and answered the follow up call, had a 17.5 percentage points higher probability of seeking medical attention compared to the control group (p-value = 0.01).^[7] These results were robust to adding covariates such as age, gender, smoking, alcohol consumption, diabetes, cholesterol level and BMI.

Descriptively, 45.5% (n = 51) of the treatment group sought medical attention compared to 28% (n = 30) in the control group.

To further assess the impact of the intervention, participants in the treatment group were asked whether they sought medical attention before or after receiving the behaviourally-informed message. Of the 51 participants, only 18 sought medical attention before receiving the message compared to 33 afterwards.^[8]

Conclusion

The current study reveals that high BP can be widely prevalent even across a health-conscious population such as the one participating in the Beirut Marathon. The intervention proves to be significant in raising awareness among people suffering from hypertension, thereby generating an intention to seek medical attention.

Similar interventions can be implemented to test the prevalence of other types of NCDs, such as diabetes. For instance, in Qatar, a team from Hamad Medical Corporation ran a pilot study during the month of Ramadan screening 2,177 people, with one-third unaware that they were diabetic or pre-diabetic (5.3% and 26.5% respectively).

This study also shows that implementing a simple nudge in the form of a personalised WhatsApp reminder can prompt hypertensive individuals to seek medical attention, and thereby reduce their risk of experiencing cardiovascular diseases. Note that, the findings of this study remain contingent on participants’ honesty in self-reporting their follow-up visits as it was not possible to verify these claims with hard evidence.

Endnotes

[1] Yamout, Rouham, et al. “Peer reviewed: screening for cardiovascular risk in asymptomatic users of the primary health care network in Lebanon, 2012–2013.” Preventing chronic disease 11 (2014).

[2]Noubani, Aya, et al. “Prevalence, Awareness, and Control of Hypertension in Greater Beirut Area, Lebanon.” International journal of hypertension 2018 (2018).

[3] Mouhtadi, Bouchra Bakr, et al. “Prevalence, awareness, treatment, control and risk factors associated with hypertension in Lebanese adults: A cross sectional study.” Global cardiology science & practice 2018.1 (2018).

[4] Tatari, Souzan, et al. “The Prevalence of High Blood Pressure among Marathon Runners during Beirut-Marathon 2014.” Open Journal of Epidemiology 7.03 (2017): 279.

[5] Refer to: https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings

[6] Contact was successfully established in both the control and treatment groups, yielding similar response rates (Chi Squared Test: N_Control = 107; N_Treatment = 112; p-value = 0.624)

[7] Both linear probability models and maximum likelihood estimation (probit and logit) yielded nearly identical results.

[8] Given that there was no visibility on the actions of the control group prior to the intervention, we assume that due to randomization, an equal number of treatment and control participants would have sought medical attention before the WhatsApp message was sent. Therefore, the only detected difference between the two groups refers to post-intervention medical attention.