Characteristics of studies included in the review
| Author, year | Country | Study design | Diagnostic criteria of RH | Sample size | Mean age (years) RH/T | Male (%) RH/T | Mean SBP/DBP±SD (mm Hg) | Antihypertensive treatment | Prevalence of RH (%) | Associated factors* |
|---|---|---|---|---|---|---|---|---|---|---|
| Bachir Cherif et al, 201531 | Algeria | CS | Office blood pressure above the goal in spite of the concurrent use of 3 antihypertensive agents of different classes, including a diuretic, at full dose | 2175 | NM/49.71±13.56 | NM/46.8 | NM | NM | 19% (95% CI 17.4% to 20.7%) | Older age (65.7±12.6 vs 57.7±13.4 years, p<0.001); sedentary status (87.1% vs 74.5% p<0.05); previous cardiovascular events (36.9% vs 17.7%, p<0.001); diabetes (41.8% vs 26.5%, p<0.001); hypercholesterolaemia (20.8% vs 11.4%, p<0.05); obesity (35.5% vs 16.3%, p<0.001); metabolic syndrome (48.2% vs 22.6%, p<0.03), chronic kidney disease (24.9% vs 14.1%, p<0.05) |
| Thinyane et al, 201530 | Lesotho | CS | BP>160/100 mmHg despite use of at least 3 different antihypertensive drugs with complementary mechanisms of action, 1 of which being a diuretic | 70 | NM/57.7±13.2 | NM/10 | NM | Hydrochlorothiazide, captopril, atenolol, nifedipine | 14.3 (95% CI 7.9 to 24.6) | NM |
| Yaméogo et al, 201415 | Burkina Faso | CS | BP≥140/90 mm Hg despite at least 3 antihypertensive drugs including a diuretic; then after ambulatory BP monitoring:≥135/85 mm Hg in the morning and/or≥120/70 mm Hg in the night | 692 | 64.2±5.4/54.8±11.1 | 48.5/39.7 | 166.4±10.7/98.8±5.5 | Diuretics (100%), converting enzyme inhibitors (85.1%), calcium channel blockers (77.2%), β-blockers (66.3%), central antihypertensives (15.8%), angiotensin II receptor antagonists (12.9%), α-blockers (5%), antirenine (3%) | 14.6 (95% CI 12.2 to 17.4) | Age ≥45 for men or ≥55 for females: 101 (100%) vs 300 (50.8%); p=0.0001 Male sex; 49 (48.5%) vs 226 (38.2%); p=0.003 Dyslipidaemia: 32 (31.7%) vs 164 (27.8%); p=0.01 Obesity/overweight: 34 (33.7%) vs 142 (24%); p=0.007 Physical inactivity: 45 (44.6%) vs 54 (9.1%); p=0.0001 Smoking: 12 (11.9%) vs 44 (7.4%) |
| Salako and Ayodele, 200329 | Nigeria | CS | BP≥140/90 mm Hg in the presence of use of 3 antihypertensive drugs including a diuretic at near maximum doses for at least 1 month | 566 | 51.8±9.7/56±14.3 | 25/38.5 | 176.4±43/109.6±14 | Calcium channel blockers, diuretics, central antihypertensives, β-blockers | 4.9 (95% CI 3.4 to 7.1) | Mean age: 51.8 vs 54.6 years; p<0.04 Non-compliance with treatment: 14 (50%) vs 73 (18.6%); p<0.001 |
| Youmbissi et al, 199428 | Cameroon | CS | BP≥160/95 mm Hg despite a well-conducted treatment with 3 medications or more taken by a compliant patient for at least 1 month | 565 | 49.4±11.6 (men); 54.6±7 (women)/NM | 62.1/51.9 | 190±27/116±20 (men) 200±29/124±22 (women) | NM | 11.7 (95% CI 9.3 to 14.6) | Family history of hypertension 33 (50%) vs 274 (55%); regular alcohol intake 34 (52%) vs 274 (55%), heavy smoking 7 (10%) vs 65 (13%), associated diseases (gout and/or diabetes mellitus: 21 (32%) vs 205 (41%), compliance with a low-salt diet 33 (50%) vs 250 (50%); poor compliance with treatment 30 (46%) vs 284 (57%) |
*Comparison of the proportions of resistant versus non-resistant hypertensive patients (by the χ2 test).
BP, blood pressure; CS, cross-sectional; DBP, diastolic blood pressure; NM, not mentioned; ref, reference number; RH, resistant hypertension; SBP, systolic blood pressure; T, total (study population).