Keywords: systematic review, Africa, hypertension, raised blood pressure, non-pharmacological interventions, randomized controlled trials
Prevalence of hypertension is still rising in many African countries. However, the awareness remains low, hindering adequate screening, treatment and adherence to lower the long-term risk of organ damage.
This systematic review aimed to evaluate evidence on non-pharmacological strategies to decrease blood pressure (BP) in hypertensive patients from African countries.
We performed a systematic review (CRD42018075062) and searched Medline, Central, CINAHL and study registers until June 23, 2020 for randomized studies on interventions to decrease BP of patients with hypertension in African countries. We assessed the study quality using the Cochrane risk of bias tool and calculated random-effects meta-analyses for non-pharmacological interventions on BP.
A total of 5564 references were identified, of them 24 studies with altogether 18,376 participants from six African countries were included. These studies investigated educational strategies to improve adherence of patients (12 studies) and their treatment by health care professionals (5 studies), individualized treatment strategies (2 studies) and strategies to change lifestyle via enhanced physical activity (4 studies) or modified nutrition (1 study). Nearly all studies on educational strategies stated improved knowledge and adherence of patients, but only three studies showed a clinically relevant benefit on BP control. All studies on individualized strategies (renin/aldosterone profile; chronotherapy) and lifestyle behavior change (e.g. training programs, reduced salt consumption) resulted in clinically relevant effects on BP.
The identified studies offer effective low-cost interventions including education, task shifting strategies, individualized treatment and lifestyle modifications to improve BP control. All strategies were tested in African countries and can be used for recommendations in evidence-based guidelines on hypertension in African settings.
Points for discussion:
Available studies concentrate in urban areas of few African countries, which limits the generalizability of the results.
Internal validity might be restricted due to the partial unfeasibility of double-blinding.