Study setting {9}
The study will be conducted in three states selected from the six geopolitical zones in Nigeria comprising of Abia (South East), Kano (North West), and Oyo (South West) states. A state in Nigeria comprises a number of LGAs and each LGA is made up of 10 to 12 wards.
Two Local Government Areas (LGAs) (One urban and one rural) each were selected from each state based on participation in past hypertension survey and good cooperation received from the community members in past studies. Thus: in Abia State - Umuahia North (urban) and Isuikwuato (rural) with population of 292,300. and151,700; in Kano state, -Tarauni (Urban) and Bichi (Rural) with population of 387100 and 308,600 and in Oyo state- Ibadan North (Urban) and Ona-Ara (Rural) with population of 473,900 and 373,100 respectively will be studied. [32] Figure 1 is the Map of Nigeria showing selected states visited.
In the urban sites the predominant economic activities are white- and blue-collar jobs, trading and other commercial activities. There are small, medium and large-scale industries and very little farming activities. Whereas, in the rural sites, the people are predominantly farmers with few small-scale industries and trading.
The Local Government in each of the states has a Secondary/Comprehensive health facility, while each ward has a primary health facility (PHC). The PHCs are manned by a team of medical officer, nurses, Community health extension workers, Junior Community health extension workers and pharmacy assistants headed by the medical officer or senior nurse where there is no medical officer.
Existing within the wards are trained lay persons who have served as community health workers at some point or participated in previous community-based studies such as the home management of malaria using artemisinin-based combination therapy study. Some will be selected from them to serve as CORPs. Where there are no CORPs, communities shall nominate persons who meet selection criteria to represent their communities.
Eligibility criteria {10}
The study will involve two groups of participants. The community members and the CORPs.
Community members
The community members will participate at the three phases of the study.
For the base- and end- line surveys, participants will be consenting residents of the community aged ≥ 18 years. A resident will be someone who has been living in the community for 6 months or more. Those who are sick at time of survey, mentally challenged or have communication challenge and pregnant women will be excluded from the survey. In addition, at end-line survey, a sub-group of participants in the intervention arm will be randomly selected to participate in focus group discussions and in-depth interviews to explore their acceptability and perception of quality of the CORPs delivered follow-up care, as well as perceived challenges to implementation and sustainability.
For recruitment into the intervention, those found at community screening to have elevated blood pressure and same confirmed in the health facility, old patients receiving treatment and not controlled or not on treatment will be eligible for recruitment. They must plan to reside in the community for at least one year after enrollment and willing to participate in the home-based follow-up care by CORPs. To be excluded are patients with clinically established complications and other cardiovascular diseases, patients needing or on special medical services and pregnant women. The health workers to recruit at the health facilities will be medical officers of health and nurses involved in the care of adults in the health facilities. They will be trained on diagnosis, treatment and prevention of hypertension as well as use of the National guideline for treatment of hypertension.
Community oriented resources persons (CORPs)
The set of inclusion criteria to be met by any persons to be nominated by the community to participate as a CORP include the following i. an adult > 18 years (Male or Female] ii. have completed at least primary level education with ability to read and write iii. may have worked as a volunteer on community project especially in the area of health and must have performed well while serving on the project. iv. may be an unemployed healthcare worker such as trained junior community health worker (JCHEWs), or retired nurse/health care professional, retired civil servant with interest in providing care v. where married, the spouse must be supportive vi. must be acceptable to other members of their community vii. must have been resident in the community for at least one year. Two nominees will be from each community. The nominated members will participate in a 4-day training and the final selection of CORPs to participate in the study will be based on their performance at the training which will be assessed using pre and post training test and score at practical exercises.
Who will take informed consent? {26a}
Informed consent will be obtained at the different level/phases of implementation. For the baseline study, informed consent will be taken from participants by the interviewing research assistants during the survey and qualitative studies. At the health facility, informed consent will be obtained from those found to be hypertensive and eligible to be recruited including consent to receive home based follow-up care.
Additional consent provisions for collection and use of participant data and biological specimens {26b}
The informed consent form will have a paragraph seeking for the later use of data collected with assurance of confidentiality.
Interventions
Explanation for the choice of comparators {6b}
Comparators will be adults aged 18 years and above who are living in the control communities and receiving usual care for the management of hypertension.
Intervention description {11a}
The highlights of the activities and assessments for intervention and control arm is shown in Table 1. The components of the intervention include the following.
i. Training of CORPs
A 4-day training will be conducted for selected persons to serve as CORPs using a training manual developed by the team. A pre and post-test will be conducted to assess the knowledge gained during the training and to select those with high score and practical ability who will eventually participate in the project. At the training, draft health education materials and messages shall be revised with input by the CORPs and finalised for use (Participatory approach). A refresher training will be conducted 6 weeks into the intervention and on the job refresher training shall be conducted by the supervisors as found necessary.
ii. Community-based education on hypertension, risk factors, complications and healthy lifestyle
The CORPs will provide health education to raise awareness on hypertension, risk factors, importance of screening, adherence to medication and healthy lifestyle practices in the community and during home visits. They will also mobilise the community to come out for screening. The pre-tested health education materials will be used to facilitate the community health education and will be distributed to the participants for their reference.
iii. Community based screening, referral and linkage to health facility
The CORPs will be equipped with a tool kit consisting an OMRON digital sphygmomanometer, a weighing scale, tape rule and recording forms. They will visit homes, religious houses, organisational meetings in the community to screen for hypertension. In the intervention arm, trained CORPs will screen and refer individuals found to have high blood pressure to the primary health care center in the community. Referral forms will be provided.
iv. Initial treatment and counselling of individuals confirmed to have hypertension in a health facility
Health workers will be provided and trained on application of the national guideline for hypertension treatment being recommended by the Federal Ministry of Health for primary health facilities across the country. At the health facility, the attending physician/health worker will confirm diagnosis of hypertension among individuals referred by the CORPs and those found to be hypertensive among persons visiting the health facility for other reasons or self-referred. The physician/health worker will commence anti-hypertensive medications based on the National guideline for the treatment of hypertension and provide initial counselling on medication adherence and healthy lifestyle. Thereafter, the patient will be referred back to the CORP in their community for home-based follow-up care. The patients in the intervention sites will be given one-month clinic follow-up appointment at first visit to ascertain the follow-up process is in place, then every two months thereafter by the attending physician/healthcare worker. However, the physicians can use their discretions depending on the clinical status of the patient. A SMS voice messaging for treatment adherence, reminders and health messaging will be sent to participants weekly [33]
iv. Community-based hypertension follow-up care by CORPs
The CORPs will conduct routine follow-up patients in their homes monthly checking their blood pressure, adherence to medication and providing health education/counselling support. In addition, the CORPs will ask about their attendance to health facility as they were scheduled/advised and sought reasons for non-attendance among those who may not have adhered. The CORP will organise group lifestyle education session weekly where experiences will be shared and patients will engage in group exercises among other relevant activities. Follow up record form will be used by CORPs to detail information on patients’ compliance with drug, the health education provided and BP measurements. A CORP will be attached to 20 hypertensive patients for follow-up care. The intervention will be for six months.
Table 1: Highlights of the activities and assessments for intervention and control arm
|
Activity
|
Intervention
|
Control
|
1
|
Baseline survey
|
Yes
|
Yes
|
2
|
Selection, screening and standard training of CORPs on blood pressure screening
|
Yes
|
Yes
|
3
|
Training on additional information on follow-up care for hypertensive patients and CORPs coordination
|
Yes
|
No
|
4
|
Trained CORPs screen and refer community members found to have high blood pressure
|
Yes
Referral to the designated primary health care center in the community
|
Yes
Referral will be to the community member’s health facility of choice
|
5
|
Train health facility staff in designated primary health care facilities on the National guideline for hypertension treatment
|
Yes
|
No
|
6
|
CORPs Monthly checking and recording of blood pressure as well as providing health education/counselling support by the CORPs
|
Yes
|
No
|
7
|
SMS messaging on medication and healthy lifestyle adherence to support follow up care
|
Yes
|
No
|
8
|
Anthropometry measurement e.g. weight, height and Body Mass Index (BMI)
Biochemical measurement
ECG
|
Yes
|
No
|
9
|
End-line survey
|
Yes
|
Yes
|
Criteria for discontinuing or modifying allocated interventions {11b}
Any patient in the intervention arm who does not achieve blood pressure control over 2 follow-up visits by the CORPS or who develop complication of hypertension or found to be at risk of complication based on risk assessment may be withdrawn from the study after investigators review the case. Any CORP found not to perform effectively will be disengaged.
Strategies to improve adherence to interventions {11c}
To enhance adherence to the intervention we have proposed the following strategies i. short message services on healthy life style and medication adherence which will be sent to patients weekly; monthly monitoring of CORPS by supervisors, and pill counting by CORPs at home follow-up visits. There is a plan to engage drug pharmaceuticals to supply antihypertensives to patients at discounted price as much as possible.
Relevant concomitant care permitted or prohibited during the trial {11d}
Provisions for post-trial care {30}
No harm is envisaged from this trial.
Outcomes {12}
The Primary outcomes are i. change in baseline proportion of patients with controlled blood pressure ii. the mean change in blood pressure at six months between patients in the intervention and control communities. The secondary outcome measures are i. change from baseline in proportion of patients adhering to medication ii. Change in proportion of patients who are overweight/obese, smoke, take alcohol, practice unhealthy dietary habit and are physically inactive. In addition are iii. mean improvement in quality-of-life score iv. percentage increase in satisfaction with care score v. change in awareness, knowledge, perception and practice vi. proportion of CORPs assessed to have good competency score vii. Perception about quality and acceptability of home-based follow-up care delivered by CORPs, viii incidence of cardiovascular events among patients ix. Change in baseline proportion of patients assessed to have high cardiovascular risk and x. Mean cost of treatment of hypertension and xi. Mean change in lipid level, urinary sodium and food sodium content.
Participant timeline {13}
The project timeline showing schedule of enrolment, intervention and assessment is shown in Table 2. The project is for a two-year period which has been divided into eight quarters and activities for each quarter indicated and the corresponding year.
Table 2: The Project Timeline
S/N
|
Description of Activity
|
Duration
|
Year
|
Quarter
|
|
|
|
|
|
|
|
|
1st
|
2nd
|
3rd
|
4th
|
5th
|
6th
6nd
|
7th
|
8th
8nd
|
1
|
Formation of team and coordination
Planning and need assessment
|
3 Months
|
1
|
X
|
|
|
|
|
|
|
|
2
|
Finalizing protocol and manuals
|
2 Months
|
1
|
|
X
|
|
|
|
|
|
|
3
|
Hiring staff; selection and training of CORPs; identification of health Facilities and training of health workers
|
1 month
|
1
|
|
X
|
|
|
|
|
|
|
4
|
Baseline studies and data analysis and interim report
|
2 months
|
1
|
|
X
|
|
|
|
|
|
|
5
|
Preparation for intervention, Development of IEC
|
1 Month
|
1
|
|
X
|
|
|
|
|
|
|
6
|
Recruitment of patients
|
3months
|
1
|
|
|
X
|
|
|
|
|
|
7
|
Conducting follow-up visits
|
6 Months
|
1 &2
|
|
|
|
X
|
X
|
|
|
|
8
|
Laboratory samples collected
|
|
1&2
|
|
|
X
|
|
|
X
|
|
|
9
|
Mid-study report
|
1 month
|
1
|
|
|
|
X
|
|
|
|
|
10
|
Post-intervention survey
|
3 months
|
2
|
|
|
|
|
|
|
X
|
|
11
|
Final data analysis
|
2 months
|
2
|
|
|
|
|
|
|
X
|
|
12
|
Final report writing
|
1 months
|
2
|
|
|
|
|
|
|
|
X
|
Sample size {14}
The sample size will be determined using the superiority trial formula [34], power of 90% (Zβ=1.28) and standard normal deviate (Zα/2=1.96) corresponding to a 95% level of confidence.
Current literature indicates that only 30.0% [19] of those living with hypertension are controlled (p1). It is anticipated that the implementation of the intervention package will raise the percentage to 60.0% (p2). Based on these parameters, and adjusting for 10.0% attrition, a sample size of 50 persons living with hypertension will be required for each arm. This translates to 100 per LGA and 200 per State. Overall, 600 participants will be recruited for the intervention phase.
Recruitment {15}
Persons found to be hypertensive during baseline survey will be noted and contact address taking including the phone contact. Subsequently, they will be invited to the primary health facility in their neighbourhood for recruitment into the study (Intervention arm). In addition, the trained CORPs will screen and refer community members found to have high blood pressure to the primary health care facilities in the community (intervention arm) or health facility of their choice (control arm). The CORPs will carry out sensitisation campaign in the community through visits to community stakeholders including the community chiefs, heads of religious bodies, leaders of artisans, head of community structures such as Chairman of Landlord Associations and talks in churches, mosques, and community meetings to intimate them of the program and conduct blood pressure screening. The CORPs shall be provided with identification poster for display in front of their houses to indicate that blood pressure screening service is available. If the required number of hypertensive patients to be recruited in a community is not achieved, the neighbouring community may be co-opted and the CORP mobilised to cover the community as well. At the health facility, patients presenting with other ailments or walk-in patients or self -referred patients who present at the health facilities found to be hypertensive shall be requested to participate in the study. the physician/healthcare worker will confirm diagnosis and commence anti-hypertensive medications.
Assignment of interventions: allocation
Sequence generation {16a}
The unit of randomization will be the community. A total of 10 communities (five from each LGA) will be randomly selected from the list of communities from a ward obtained from the Local Government secretariat. The selected communities from each LGA will be grouped into two non-contiguous groups based on geographical distance between communities. One group will be randomly assigned to intervention and another to control. This will ensure that intervention communities are closed together but at far distance from control communities to minimize contamination. The final randomization of intervention and control communities will be done by a statistician who is not involved in the implementation of field activities. Assignment of communities to either the intervention or control arm will be done after the baseline survey. Given the nature of the intervention, it is not possible to blind the CORPs who will be involved in the delivery of the intervention.
Concealment mechanism {16b}
Implementation {16c}
Assignment of interventions: Blinding
Who will be blinded {17a}
Given the nature of the intervention, it is not possible to blind the CORPs who will be involved in the delivery of the intervention. However, the interviewers who will collect data for final assessment and the statistician may be blinded.
Procedure for unblinding if needed {17b}
Data collection and management
Plans for assessment and collection of outcomes {18a}
Standard operating procedures will be developed for each of the data collection activities to guide the research assistants and standardized the collection methods. Survey interviews will be conducted by 10 trained interviewers who will be graduates of tertiary institutions with experience in conducting community-based surveys and qualitative studies. Interviews will be conducted in secluded areas in the participants' houses and at a convenient time of the day. Participants will be given a sachet of detergent to compensate for the time of the interview.
Quantitative data collection
Surveys will be conducted using the Research Electronic Data Capture (REDCap) software on Android mobile devices. The data collection tools will be developed using information from literature, consideration of variables in the study specific objectives and the conceptual framework, researchers’ knowledge of the topic and adaptation of questions from past related studies. A semi-structured question will be drafted and face validated by experts to ensure the questions are adequate to provide answers to the study objectives. The draft questionnaire will be pretested in a community not selected in each of the six LGAs to ensure that questions are clear, comprehensible by participants, concise and consistent in a local government different from the ones selected into the study. Cronbach Alpha acceptable value will be set at 0.7 and above. The questionnaire will be translated into the local language and back translated into English to ascertain the correctness of the translation.
The survey questionnaire will be divided into the following sections: a. Demographic characteristics b. Health status of the participants including, presence of chronic disease (s), knowledge of their blood pressure status, drug history c. Health seeking behaviour d. Disease screening practices e. Lifestyle including dietary habit f. Knowledge of hypertension, risk factors and its control including sources of information g. Cost of treatment of hypertension among those with hypertension h. Willingness to accept CORPs to screen for hypertension and carry out follow-up care for hypertension in the community
Clinical and Anthropometry Measurements
Blood pressure
Blood pressure will be measured using a fully automated digital device, the OMRON digital sphygmomanometer (OMRON HEM-712C). Interviewers will be trained to use the device according to the manufacturer’s recommended protocol, and BP will be measured using recommended methods and categories from standard guidelines such as the World Health Organization-International Society of Hypertension Guidelines for the Management of Hypertension. The first blood pressure reading will be measured on the left arm with the participant in a seated position after resting for at least 5 minutes. The second and third readings will be taken about two minutes interval. In this study, hypertension was defined as average of two measurements of systolic and/or diastolic BP (2nd and 3rd readings) that is ≥140/90 mmHg in any adult according to the Joint National Committee JNC7 classification or self-reported previous diagnosis of hypertension and treatment of hypertension with antihypertensive medication taken in the past 2 weeks. [35] Participants with elevated blood pressure will be referred to a health facility for further assessment and confirmation of the BP status.
Electrocardiogram examination
The electrocardiogram (ECG) is listed among the routine investigation for hypertensive patients according to international guidelines It has been used for the evaluation of subclinical cardiac damage in uncomplicated hypertensive patients [36]. The outcome could help with stratification of cardiovascular risk in hypertension. In this study, individuals confirmed to have high blood pressure shall have Electrocardiogram (ECG) examination at baseline and endline. Those with abnormality shall be referred to a cardiologist in the nearest hospital.
Behavioral risk factors
The WHO STEPwise data collection tool for surveillance of non-communicable diseases will be adapted to gather information on behavioral CVD risk factors including smoking, alcohol drinking, and dietary habits. [37] Questions will probe on current and past smoking as well as current and past alcohol drinking. Dietary assessment will include intakes of fruits, vegetables, salt, use of vegetable cooking oil, and consumption of whole grains.
Anthropometric measurements
Anthropometric measurements will include weight, height, and waist circumference taken using standard procedures. Briefly, all anthropometric measurements will be taken with the participant wearing light clothing and without shoes within the participant’s household compound. Body weight will be taken to the nearest 0.1 kg using a validated SECA digital scale placed on flat ground. Height will be taken in a standing position with heels perpendicular to the portable stadiometer, measured to the nearest 0.1 cm. BMI will be calculated as body weight divided by height squared (kg/m2. Overweight will be defined as BMI ≥ 25 kg/m2 but < 30 kg/ m2 and obesity is defined as BMI ≥ 30 kg/m2 [37]. Waist circumference will be measured and recorded to the nearest 0.1 cm using a non-stretchable measuring tape at the mid-point between the lower margin of the last rib in the mid-axillary line and the iliac crest according the WHO guidelines [38]. Abdominal obesity will be defined as waist circumference ≥ 102 cm. Waist-to-hip ratio will be calculated and a value of less than 0.85 is considered as normal for women and less than 1.0 for men is normal
Wealth index
The household wealth index of the participants will be generated as described in the demographic health survey using data on ownership of household items such as refrigerator, bicycle, radio, television, sofa, telephone, car, and house ownership, construction materials (floor, walls, and roofing materials); source of water supply for home use and drinking; source of fuel for cooking and lighting; having working electricity and sanitation facility [39].
Qualitative data collection
The guide will be developed for the Focus Group Discussion (FGD) and Key Informant Interview (KII). A pre-tested guide will be used to facilitate the FGD sessions and KII interviews. The sessions will be audiotape recorded after obtaining consent from the participants. The FGD will be conducted by a team of 2-3 research assistants – facilitator, note-taker / recorder. Snacks will be provided during the sessions.
Key informant interviews will be conducted among key people in the community, head of facilities, the physician or health workers involved in the management of hypertensive patients. The focus group will comprise 6-12 homogenous community members. Two research assistants will facilitate the session. Participants will be provided incentive to compensate for the time at the FGD
DEVELOPMENT OF INTERVENTION MATERIALS
Results from the preliminary analysis of the baseline study data will help to identify gaps in the awareness, knowledge, perception, attitude, preventive practices regarding hypertension. This information will be used for the development of the intervention materials by the team members. These materials include i. Training manual for CORPs and health workers ii. Information education communication/behaviour change communication (IEC/BCC) materials including Healthy lifestyle hand bills, Hypertension treatment guide iii. Home-based follow up care guide iv. Standard operating procedures vi Short Messaging System (SMS) messages
Training manual and guides
Training manuals will be designed adopting the relevant sections in the WHO training manual for the prevention of NCDS and health lifestyle [40] and manuals shared by researchers who have conducted similar studies. The training topics will include definition of hypertension, risk factors, detection and management, blood pressure screening procedures and interpretation of readings, anthropometric measurements, ethical issues, community mobilisation and effective communication for behaviour change, health education on hypertension and healthy lifestyle, follow up care for hypertension among others. Graphics and pictorials will be used as appropriate. The manual will be face validated by two researchers involved in hypertension studies. In addition, guides will be developed using algorithms and adapting the National Hypertension Control guidelines.
Health education materials
The health education materials will be developed by team members using illustrations from literature, adapted form IEC materials shared by other researchers and drawn by an artist. The draft will be presented to CORPs and health workers for their input after which it will be face validated by selected community members before final production The materials will be in form flyers/brochures with messages on hypertension as silent killer, the risk factors and how to prevent them such as reducing salt intake, reducing or maintaining normal/ideal body weight, smoking cessation, reducing alcohol intake, increasing consumption of fruits and green leafy vegetables, using vegetable cooking oil and engaging in exercise. Training modes will include didactic lecture, case study, role plays and practical sessions in the field.
SMS message
The content of reminders will be prepared based on literature search and consultations with communication expert. A SMS reminder content of about a minute duration will be designed. The message will be prepared in English and translated to local languages (Hausa, Igbo and Yoruba) version; thereafter back translated to English to verify accuracy of the translation by an expert in both English and the local languages. It will be validated and pretested among 10 selected members of communities not included in this study.
Plans to promote participant retention and complete follow-up {18b}
Participants will be provided adequate information on the project and their role as well as what is expected of them emphasizing completeness of follow-up. It will be ascertained at time of recruitment that the participant will be resident in the community for at least a year. The participants will be linked to the CORPs in their community who will provide follow-up care and visit them to check on adherence to clinic follow-up visit. The participant is recruited from the catchment area of the clinic; hence it is assumed that this will encourage clinic as distance to clinic will not be a barrier to follow-up visit. The proportion of participants who visit the clinic and those who had home follow-up visit by CORPs as scheduled shall be measured at the end of the six months follow up visit.
Data management {19}
The research assistants (data collectors) will upload the data collected on their android phone daily into the REDCap database server from where the data manager will retrieve and review the data daily for quality assurance and control. The data manager will provide feedback on entered data early the following morning they were collected so that research assistants can correct wrong entries and fill gaps or missing data as necessary.
For the qualitative data, the audio recording will be carried out using a good quality tape recorder and research assistants will ensure it is functioning, label the sides and pre-record to test before use for the sessions. The tapes will be kept in locked boxes to prevent destruction and for confidentiality. Analysis will be carried by two investigators independently. Where they differ, the transcribed notes will be revisited and analysed again till there is a consensus.
Confidentiality {27}
Handling and storage of data
The confidentiality of all participants information will be protected in accordance with national and international data protection laws. The study team will assure that participants’ anonymity will be maintained and that their identities are protected from unauthorized parties.
Participants will be assigned unique code as identification numbers for data collection. All information will be collected using the unique study participants’ code numbers except for consent forms, which will bear the name and signature of the participant. Only the statistician and data manager have access to the files in the REDCap. Documents (i.e. participant signed ICF, medical records, case record forms etc.) will be maintained in strict confidence in pass worded files on the computers and locked cabinets in the office. Any reports or publications or scientific presentations will not contain any participants’ identifying information. The data will be in storage for at least five years and any request to use them for secondary data analysis shall be made to the principal investigator after agreeing to conditions for data sharing and all data will be de-identified.
Plans for collection, laboratory evaluation and storage of biological specimens for genetic or molecular analysis in this trial/future use {33}
Ready-to-eat food samples will be collected randomly at unannounced visit to a participant’s home twice (including one weekend day) during the study and kept frozen in a sterile bottle. Biochemical analysis of food sodium content, will be carried in certified laboratories such as the International Institute of Tropical Agriculture, (IITA) Ibadan, Nigeria
Blood samples for estimation of urea, creatinine and lipid profile will be collected according to standard laboratory guideline under sterile conditions at recruitment and at the end of the six months intervention period in the health facility. Urine samples will also be collected and analysed using Uristix® at the same time. Blood sample analysis will be at the Chemical pathology laboratory of a tertiary institution in the study states.
Statistical methods
Statistical methods for primary and secondary outcomes {20a}
Data analysis will be carried out using Stata MP version 14 based on the CONSORT 2010 guideline [41]. Intention-to-treat analysis will be applied. Continuous variable will be presented as mean and standard deviations (SDs) or medians with their 25th and 75th percentiles when the distribution of the data does not follow a Gaussian distribution. Categorical variables shall be presented as frequencies and percentages.
Baseline characteristics of participants in the intervention and control arms will be compared to assess balance and identify any variable that need to be adjusted in the final analysis. The primary outcome is achievement of blood pressure control at 6 months post intervention. The effect of intervention within each of the study groups will be carried out comparing baseline and 6 months post-intervention using McNemar test. Depending on the distribution of baseline characteristics, random-effect logit model will be fitted to estimate treatment effect size comparing the two groups. Similar analysis will be done for categorical secondary outcomes such as treatment adherence, etc.
Numerical secondary outcomes such as mean change in systolic blood pressure will be analysed using two approaches. First, a difference-in-difference method [42] would be employed to compare mean SBP between baseline and six-month post-intervention. This will be an assessment of within-group changes in blood pressure. Secondly, a linear mixed model will be implemented to determine the treatment effect as a measure of between-group comparison of intervention and control arms.
The use of CORPS who are based in the study communities and monthly home visit will help to minimize the occurrence of missing data and losses to follow-up. During analysis, sensitivity analyses will be carried out to assess the patterns of missing data and loss-to-follow up so that appropriate decisions can be taken on whether multiple imputation methods need to be employed. The level of significance will be set at 5%. Cost-effectiveness analysis will also be carried out using the ingredient approach [43].
Qualitative Data
The audiotape recordings from the FGD and KIIs will be transcribed verbatim and translated into English. This will be analysed by content analysis using N-VIVO. The text will be entered into NVIVO and codes and themes on acceptability and performance of the CORPs and quality of the intervention will be generated.
Qualitative data Analysis of qualitative data from the FGDs will be done using N-vivo 9® software and manual coding. The audio recordings from FGDs will be transcribed verbatim and translated into English. Caution will be taken to ensure that no data will be lost during translation. The text data will be entered into Nvivo 9® software and analyzed for themes on perceptions about quality and acceptability of the CHWs intervention in the community
Interim analyses {21b}
Interim analysis will not be carried out
Methods for additional analyses (e.g. subgroup analyses) {20b}
Methods in analysis to handle protocol non-adherence and any statistical methods to handle missing data {20c}
Plans to give access to the full protocol, participant level-data and statistical code {31c}
The team plans to grant public access to the study protocol and de-identified data set after due request and commitment to adhere strictly to ethically consideration. This will only be available after 3 years of study completion.