CASE IDENTIFICATION, RETENTION AND BLOOD PRESSURE CONTROL: LESSONS 1 FROM A LARGE-SCALE HYPERTENSION PROGRAMME IN KENYA.

30 Background: The prevalence of hypertension in sub-Saharan Africa has been on the rise but remains 31 underdiagnosed, undertreated and poorly controlled. In Kenya, 92% of patients are not on treatment and 32 3% controlled. This study aimed to assess the performance of a hypertension screening and treatment 33 program in five counties in Kenya with reference to identification of individuals at risk, retention on 34 treatment and blood pressure (BP) control. 35 Methods: We conducted a retrospective cohort study using data routinely collected between March 36 2015 and December 2018. All patients 18 years and older screened and/or treated for hypertension at 37 any of the program supported sites were included in the study. We calculated prevalence of high BP 38 (systolic BP equal or more than 140 mmHg, diastolic BP equal or more than 90 mmHg) and related risk 39 in the screening episodes, retention on treatment, BP control and related factors among patients enrolled 40 for treatment of hypertension. 41 Results: A total of 663,028 screening encounters were recorded of which 70.4% were female, median 42 age was 34 years and majority (73.9%) were screened at the community level. Of the encounters, 19% 43 had high BP, significantly higher among males and older individuals. A total of 66,981 patients were 44 enrolled on treatment with majority being females (71.2%), median age 55 years, 40.4% aged 60+ years 45 and 36.2% enrolled in Level 5 health facilities (county referral hospitals). Only 12% of patients were 46 retained in care at 12 months with younger patients and individuals treated at higher level facilities 47 (levels 4 and 5) having the lowest retention rates (p<0.05). By 12 months of treatment, BP was 48 controlled in 48.6% of patients retained on treatment. Over a 36-month follow-up period, the mean 49 systolic and diastolic BP gradually reduced by 8.9mmHg and 2.5mmHg, respectively. 50 Conclusions: The program screened primarily females and younger individuals at lower risk of 51 developing hypertension. Retention in care was poor especially among younger patients and those 52 enrolled at higher level facilities. Close to half of the patients retained, attained blood pressure control 53 by one year. Hypertension programs should target high risk populations, decentralize care and include retention and follow-up strategies.


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The hypertension screening programme 111 The Healthy Heart Africa (HHA) project was implemented by Amref Health Africa in five counties in 112 Kenya (Kiambu, Kirinyaga, Nairobi, Kajiado and Nakuru). These counties were selected purposively 113 mainly due to relatively higher prevalence of high blood pressure and high population levels compared This study utilized data which had been entered monthly into a custom-built Microsoft Excel file, as 129 part of routine project monitoring. Screening data were extracted from routine screening registers used 130 at the hypertension screening service points and treatment data from patient records at facility level.
health system level where the service was offered ((Level 1, 2, 3, 4 and 5) and systolic and diastolic BP 135 readings of each hypertension screening and treatment encounter. BP measurements were taken after 136 the client had sat quietly for 3-5 minutes using validated automated BP machines (Omron M3). The BP 137 was measured while the client was seated upright on a chair with back support and legs outstretched.

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With the arm relaxed and supported at the level of the heart, two measurements were taken at least 2-3 139 minutes apart. For the first visit, BP from both arms was taken and the highest recorded. Hypertension 140 screening outcomes of interest include prevalence of HBP among those screened, retention on treatment 141 and blood pressure control. Definitions of theses outcomes are described in Table 1   Hypertension screening encounter: defined as blood pressure screening service offered to an individual at any of the program sites. It does not necessarily represent unique individuals screened by the program.
Enrolled on treatment: defined as patients diagnosed to have hypertension who are registered into the program and initiated or continued pharmacological and non-pharmacological therapy.
High blood pressure (HBP) † : defined as SBP equal to or more than 140mmHg and/or DBP equal to or more than 90 mmHg (7) or more.
Hypertension † : An individual was considered hypertensive if they had 3 HBP readings at separate occasions within a 2-month period, if the initial SBP and/or DBP readings were equal or more than 160mmHg and 100mmHg respectively or if they had been previously on treatment for hypertension.
Retention in care (RIC): defined as proportion of patients on hypertensive treatment who were receiving treatment.
12-month BP Control: defined as proportion of patients who visited the facility between 10.5 -13.5months after enrollment whose SBP less was than 140mmHg and/or DBP less than 90mmHg. 146 The data collected in the Microsoft Excel files were cleaned and exported to STATA v14.2 (StataCorp, 147 College Station, TX, USA) for analysis. The data were described in terms of episodes/ encounters (for 148 screening) and per-patient (for those on treatment). Summary statisticsfrequencies and proportions 149 for categorical variables and mean (standard deviations, SD) or median (interquartile range, IQR) for 150 continuous variableswere used to describe the characteristics of the screening episodes and patients.

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The prevalence rate (PR) of high blood pressure, together with their 95% confidence interval (CI) and 152 chi-square P-values were calculated for the screening episodes. Retention in care (RIC) over time for 153 patients on treatment was calculated using Kaplan Meier survival curves, overall and adjusted by the 154 available variables. Log-rank test was used to estimate the differences in the curves, as appropriate.

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Factors associated with RIC and blood pressure control at 12 months were calculated using binary 156 regression models and presented as relative risks (RR)unadjusted and adjusted (using the available 157 variables), and 95% CI. P<0.05 were considered statistically significant.

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Demographic characteristics 165 A summary of the demographic characteristics and blood pressure status of the screening encounters is 166 described in Table 2. A total of 663,028 screening encounters were recorded of which 70.4% of those 167 with documented sex were from females. Approximately one-third (31%) of the screening episodes had 168 no documented sex. The median age was 34 years (IQR: 26-47) with 50.2% aged between 18 -34 years.

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Majority of the screening encounters (73.9%) occurred at level 1 (community) of the health system 170 while the least occurred at level 5 (county referral hospitals) (1.0%). Prevalence of pre-hypertension and high blood pressure was 13.0% and 18.7% respectively. The average SBP and DBP was 123mmHg 172 (SD 18.2) and 75mmHg (SD 11.4) respectively.     The majority of patients enrolled had only one clinic visit recorded (76.9%) with the total number of 201 visits ranging from 1 to 36. The median duration between clinic visits was 5.9 weeks (IQR: 3.9 -12).     to be effectives should be incorporated within hypertension and other NCD programs (24).

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Just under half of patients who could be followed up had controlled blood pressure 12 months after 283 enrollment. This is similar to a national survey that reported blood pressure control rates of 51.7% (95% CI: 33.5 -69.9) among those on treatment (12). Other studies in SSA have reported lower BP control 285 rates ranging from 7-20% (5,23). A multinational survey which included 17 countries from low-income, 286 middle-income and high-income counties reported overall control rates of 33% with rates of 26.9% in 287 low-and middle-income countries, 40.7% in high-income countries and 40.2 in low-income counties.

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Lowering blood pressure substantially reduces CVD morbidity and mortality (25). Therefore, 289 hypertension treatment programs should not only ensure individuals with high blood pressure are 290 initiated on treatment but should also monitor the BP control rates (26).

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This study found that males were less likely to have controlled blood pressure. This is similar to other 292 studies in SSA which found that women had higher blood pressure control rates (20). Poor blood  Availability of data and materials 363 The datasets used and/or analysed during the current study are available from the corresponding author 364 on reasonable request.