Early-warning Intervention for Heat Waves and Cold Spells in Older Hypertensive Patients

A Health-risk Early-warning Intervention for Heat Waves and Cold Spells in Older Hypertensive Patients in Tianjin, China: an Open, Cluster-randomised Trial

This study was designed to explore the impact of health-risk early-warning interventions for heat waves and cold spells on older hypertensive patients.

From June 15th 2023 to August 31st 2023, and December 1st 2023 to February 28th 2024, researchers will conduct a double-blind, cluster randomised controlled trial involving 258 hypertensive patients aged 60 to 65 years in Wuqing District, Tianjin. For the sampling stage, three communities will be randomly selected in Wuqing District. The geographical distribution, urbanisation, population size, population structure, economic status, and health service resources of each selected community are in equilibrium. Meanwhile, the distance between the selected communities is greater than 5 km. Based on the list of chronic disease management records, 86 older hypertensive patients (male: female = 1:1) in each community will be involved in the intervention group, monitoring group, and blank control group, respectively. Eligible individuals for this trial will be a mean untreated systolic blood pressure of at least 140 mmHg or a mean untreated diastolic blood pressure of at least 90 mmHg, or a mean treated systolic blood pressure of at least 130 mmHg or a mean treated diastolic blood pressure of at least 80 mmHg. Patients with a history of coronary heart disease, heart failure, stroke or diabetes were exclueded. For the intervention stage, different groups have different intervention modalities including heat waves or cold spells warnings, monitoring of health indicators, questionnaire surveys, health checkups and biological sample collection. According to the heat waves or cold spells health warning systems conducted by National Institute of Environmental Health in the Chinese Center for Disease Control and Prevention, whenever a health risk warning for a heat waves or cold spells is issued, only the elderly in the intervention group will be alerted to the early warning information through the Wechat Mini Programme. The exposure temperature, electrocardiography (ECG), and blood pressure indicators will be monitored every day during the study period in the intervention group and monitoring group, respectively. The blank control group will only monitor the exposure temperature every day. Besides, the study period will be divided into two parts including pre-intervention and intervention periods, respectively, and all the patients will have questionnaire surveys, health checkups and biological sample collections once in the pre-intervention period and three times in the intervention period. Biological biomarkers of inflammation and oxidative stress in the cardiovascular system will be tested. The content of the questionnaire will include individual fundamental information, the perception of the health risk of heat waves and cold spells, sleep quality, hypertension medication.

The elderly in the intervention group will receive warning messages through WeChat mini programs and monitor daily exposure temperature, electrocardiogram (ECG), and blood pressure indicators

The exposure temperature, electrocardiography (ECG), and blood pressure indicators will be monitored every day during the study period in the monitoring group

Whenever a health risk warning for a heat waves or cold spells is issued, only the elderly in the intervention group will be alerted to the early warning information through the Wechat Mini Programme.

The electrocardiography (ECG) and blood pressure indicators will be monitored every day during the study period in the intervention group and monitoring group, respectively.

Inclusion Criteria: 60 ≤ 65 years old Volunteer to participate in this study Exclusion Criteria: Patients with a history of coronary heart disease, heart failure, stroke or diabetes were exclueded. Unable to cooperate with follow-up