The treatment of hypertension in hospital outpatients and community populations in Dar es Salaam

Abstract

Hypertension is a rapidly increasing problem in Tanzania (1). It presents earlier in life and with much more severe complications than in White patients (2). Its impact is seen in the increasing work-load in our hospital outpatient clinics and in the increasing number of malignant hypertension, heart failure, stroke and chronic renal failure among hospital admissions. A study was carried out to identify all hypertensive patients within a randomly selected community in a Oar es Salaam urban population and to follow them up prospectively for 12 months using pharmacological and non-pharmacological treatment. Their monthly mean blood pressures and one year morbidity were calculated and compared between hypertensive patients who were treated with the ussual step-care pharmacological treatment and those who were followed up on non-pharmacological treatment only. Similarly, monthly mean blood pressures for the hypertensive patients who completed 12 months of regular follow-up in the community were compared with mean blood pressures for the patients who did not complete 12 months of follow up. Factors which were associated with good or poor patient compliance to treatment in the hypertensive populations were elucidated.

2 A similar study was done using the Records Department in Muhimbili Medical Center to assess the prevalence of hypertension among our hospital outpatient clinic population in 1983 and 1984. Blood Pressure records of identified hypertensive patients were documented for a period of 5 years up to 1988 and the degree of blood pressure control as well as compliance compared with the results obtained in the community studY• A total of 797 community subjects were screened for hypertension during the initial survey which was done at the beginning of the community study. 138 subjects out of this community population qualified for follow up in the community studY. Of the 138 community subjets 70 patients were hypertensive using world Health organization definition, the remaining 6B patients had borderline hypertension. prevalence of hypertension in th< community studied therefore, was found to be 8.8%. out of the 138 community patients 20 patients with borderline hypertension and 8 patients with blood pressure above 160/95 mmHg were lost for follow up. The remaining 110 patients were followed up monthly for one year in the community study Of these 48 (43.6%) patients had borderline hypertension, 50(45.5% patients had mild hypertension, 11(10%) patients had moderate hypertension and 1 (0.9%) patient had severe hypertension. --- ----- 3 The median age for the 62 hypertensive community patients (blood pressure> 160/95 mmHg) was 45 years (range 25-80 years). Their mean blood pressure at the beginning of study was 180/106 mmHg (range 160/94-236/132 mmHg). Only patients who had initial systolic blood pressure of 160 mmHg and above and/or initial diastolic blood pressure of 95 mmHg were considered for treatment in the community study. The borderline hypertensive patients in the community population were included in the study in order to determine the behaviour of borderline hypertension when followed up regularly without treatment for one year. The median age for the borderline group was 40 years (range 17-77 years) and their mean blood pressure was 151/93 mmHg. The hospital study consisted of 420(18.4%) hypertensive patients out of the 2287 new patients refered to Muhimbili Medical outpatient clinics from January 1983 to December 1984. Of the 420 hypertensive patients 349 (83.1%) patients had never been on anti-hypertensive treatment before. Their mean blood pressure was 170/108 mmHg with range 140/90 - 200/134 mmHg). 22(6.3%) of the 349 patients who had not been on treatment were started on anti-hypertensive treatment in the medical outpatient clinic with blood pressure below

160/95 mmHg.

156(44.7%) and 157(45.0%) patients who had

4 not been on treatment had mild and moderate hypertension respectively. Only 14 (4.0% of this group had severe hypertension. Isolated systolic hypertension was not found in the hospital and community population in this study. Non-compliance was a problem both in the hospital and in the community study population presenting with 379 (90%) and 77(70%) hospital and community patients respectively discontinuing follow up before the end of study period. Better compliance in treatment in the community patients was associated with having Islamic religious education (P=0.04) and aged 40 years and above (P=0.08). There was no significant difference in compliance between males and females and between those who were illiterate and those who had formal education. There were 2 heart failure and I stroke cases observed among the 42 community hypertensive patients who did not complete 12 months of follow up. Only 1 of the 33 compliant community hypertensive patients developed heart failure during the whole study period. The overall one year morbidity in the community study population was 2.4 times higher in the group which did not complete 12 months of follow up than in group which compli