Table 1. Characteristics of studies by country
Study identifier and reference / Country / Year of field work / Study population / Age range (years) / Sample size / Response rate (%) / Device / Measures/ visits / Preparation / Age-adjusted/ age-specific prevalence /11-3 / Nigeria / 1992 / Urban / 20-64 / 799 / 84 / Standard mercury / 3/3 / 5-minute rest / No/no
24 / Nigeria / Not stated / Urban / >15 / 5200 / 98 / Standard mercury / 2/1 / 5 minute-rest / No/yes
35 / Nigeria / Not stated / Urban / 18-64 / 917 / 95 / Standard mercury / 3/1 / 10 minute-rest / Yes¶/yes
46 / Nigeria / Not stated / Urban / 19-70 / 998 / 86.4 / Standard mercury / 1/1 / No information available / No/no
57 / Tanzania / Not stated / Rural / 25-64 / 608 / 86 / Random zero / 2/1 / 10 minute-rest / No/no
68, 9 / Tanzania / 1987/1998 / Urban/rural/ semi-nomadic / 47-57 / 496 in 1987 and 446 in 1998 / 82.7 and 74.3 / Electronic / 3/1 / 5-10 minute-rest / No/yes
710 / Tanzania / Not stated / Rural / >=15 / 8581 / 72.5-96 / Standard mercury / 2/1 / Standard procedure- / Yes||/yes
811 / Tanzania / 1996/97 / Urban/rural / >15 / 1698 / 63.5-84.5 / Standard mercury / 2/1 / Standard procedure / Yes*/yes
912, 13 / South Africa / 1989/90 / Rural / >=15 / 1240 / 81.6 / Standard mercury / 3/1 / Standard procedure / Yes‡/no
1014 / South Africa / 1998 / National / >=15 / 13802 / 92 / Electronic / 3/1 / 5 minutes rest / Yes*,‡/yes
1115 / Ghana / 1998 / Urban/rural / >=25 / 4733 / 75 / Standard mercury / 2/1 / 10 minutes-rest / Yes*/no
1216, 17 / Ghana / 2004 / Urban/rural / >15 / 1431 / 82-99 / Electronic / 2/1 / 5 minutes-rest / No/yes
1318 / Sudan / Urban / Mean 35 / 510 / 93 / Random zero / 1/1 / 10 minutes-rest / No/no
1419-22 / Nigeria/ Cameroon / 1991-1995 / Urban/rural / 25-74 / 2574 Nigeria /2832 Cameroon / 90-99 / Standard mercury / 3/1 / 10 minutes rest / yes†/no
1523 / Cameroon / Urban/rural / 25-74 / 1798 / 91/95 / Standard mercury / 3/1 / 30 minutes-rest / Yes§/no
1624, 25 / Cameroon / Urban/rural / 25-74 / 1780 / 91/95 / Standard mercury / 3/1 / 15 minutes-rest / yes†/no
1726, 27 / Cameroon / Urban/rural / >=15 / 2465 / 96/98 / Standard mercury / 2/1 / 10 minutes-rest / yes||/no
1828 / Cameroon / 2003 / Urban / >=15 / 10011 / 92.5 / Electronic / 3/1 / 5 minutes-rest / Yes*/yes
1929 / Liberia / 1989 / Rural / >=20 / 3588 / 84 / Electronic / 2/1 / 5 minutes-rest / No/no
2030 / Eritrea / 2004 / National / 15-64 / 2352 / 95.6 / Electronic / 2/1 / 5 minutes-rest / No/yes
2131 / Senegal / Urban / >=15 / 1869 / 97 / Standard mercury / 2/1 / 5 minutes-rest / No/yes
2232 / Senegal / Urban / >= 15 / 2300 / 77 / Standard mercury / 2/2 / 5 minutes -rest / No/yes
2333 / Gambia / 1996 / National / >=15 / 6048 / 94.9 / Electronic / 2/2 / No information available / No/no
2434-36 / Gambia / 1996/97 / Urban/rural / >=15 / 5389 / 78.1 / Electronic / 2/1 / 5 minutes-rest / No/no
2537 / Gambia / 1998 / Urban/rural / >=15 / 2538 / 83.5 / Electronic / 2/1 / 5 minutes-rest / No/no
* Age adjusted to the WHO New World Population
† Age adjusted to the entire study population
‡ Age adjusted to the population of the country
§ Age adjusted to WHO old world standard population
|| Not stated
¶ Adjusted readings said to have been obtained by MANOVA techniques
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Excluded references and reasons for exclusion
Participants included those aged less than 15 years 38-44
Hospital or clinic based or where visitors to hospitals were included45-57
Editorials and reviews58-63
Participants included non blacks or blacks living outside Africa64-66
Sample size less than 40067-78
Results not presented in a way that could be extracted easily for the review79-90
Low response rate or no mention of response rate 91-118
Classification of hypertension different or diastolic blood pressure defined as Korotkoff IV7, 119-129
Longitudinal study130-132
Prevalence of hypertension not reported133,134
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References
1. Bunker CH, Ukoli FA, Matthews KA, Kriska AM, Huston SL, Kuller LH. Weight threshold and blood pressure in a lean black population. Hypertension. 1995;26:616-623.
2. Forrest KY, Bunker CH, Kriska AM, Ukoli FA, Huston SL, Markovic N. Physical activity and cardiovascular risk factors in a developing population. Med Sci Sports Exerc. 2001;33:1598-1604.
3. Markovic N, Olomu IN, Bunker CH, Huston SL, Ukoli FA, Kuller LH. Adequacy of a single visit for classification of hypertensive status in a Nigerian civil servant population. Int J Epidemiol. 1994;23:723-729.
4. Ekpo EB, Udofia O, Eshiet NF, Andy JJ. Demographic, life style and anthropometric correlates of blood pressure of Nigerian urban civil servants, factory and plantation workers. J Hum Hypertens. 1992;6:275-280.
5. Kadiri S, Walker O, Salako BL, Akinkugbe O. Blood pressure, hypertension and correlates in urbanised workers in Ibadan, Nigeria: a revisit. J Hum Hypertens. 1999;13:23-27.
6. Olatunbosun ST, Kaufman JS, Cooper RS, Bella AF. Hypertension in a black population: prevalence and biosocial determinants of high blood pressure in a group of urban Nigerians. J Hum Hypertens. 2000;14:249-257.
7. Vaughan JP. Blood pressure and heart murmurs in a rural population in the United Republic of Tanzania. Bull World Health Organ. 1979;57:89-97.
8. Njelekela M, Negishi H, Nara Y, Tomohiro M, Kuga S, Noguchi T, Kanda T, Yamori M, Mashalla Y, Jian Liu L, Mtabaji J, Ikeda K, Yamori Y. Cardiovascular risk factors in Tanzania: a revisit. Acta Trop. 2001;79:231-239.
9. Njelekela M, Sato T, Nara Y, Miki T, Kuga S, Noguchi T, Kanda T, Yamori M, Ntogwisangu J, Masesa Z, Mashalla Y, Mtabaji J, Yamori Y. Nutritional variation and cardiovascular risk factors in Tanzania--rural-urban difference. S Afr Med J. 2003;93:295-299.
10. Swai AB, McLarty DG, Kitange HM, Kilima PM, Tatalla S, Keen N, Chuwa LM, Alberti KG. Low prevalence of risk factors for coronary heart disease in rural Tanzania. Int J Epidemiol. 1993;22:651-659.
11. Edwards R, Unwin N, Mugusi F, Whiting D, Rashid S, Kissima J, Aspray TJ, Alberti KG. Hypertension prevalence and care in an urban and rural area of Tanzania. J Hypertens. 2000;18:145-152.
12. Daniels A, Hoffman M, Lombard C, Steyn K, Levitt N, Katzenellenbogen J. Blood pressure and social support observations from Mamre, South Africa, during social and political transition. J Hum Hypertens. 1999;13:689-693.
13. Metcalf CA, Hoffman MN, Steyn K, Katzenellenbogen JM, Fourie JM. Design and baseline characteristics of a hypertension intervention program in a South African village. J Hum Hypertens. 1996;10:21-26.
14. Steyn K, Gaziano TA, Bradshaw D, Laubscher R, Fourie J. Hypertension in South African adults: results from the Demographic and Health Survey, 1998. J Hypertens. 2001;19:1717-1725.
15. Amoah AG. Hypertension in Ghana: a cross-sectional community prevalence study in greater Accra. Ethn Dis. 2003;13:310-315.
16. Agyemang C. Rural and urban differences in blood pressure and hypertension in Ghana, West Africa. Public Health. 2006;120:525-533.
17. Agyemang C, Bruijnzeels MA, Owusu-Dabo E. Factors associated with hypertension awareness, treatment, and control in Ghana, West Africa. J Hum Hypertens. 2006;20:67-71.
18. Elbagir M, Ahmed K. Blood pressure in a multiracial urban Sudanese community. Journal of Human Hypertension. 1990;4:621-624.
19. Cooper R, Rotimi C, Ataman S, McGee D, Osotimehin B, Kadiri S, Muna W, Kingue S, Fraser H, Forrester T, Bennett F, Wilks R. The prevalence of hypertension in seven populations of west African origin. Am J Public Health. 1997;87:160-168.
20. Okosun IS, Cooper RS, Rotimi CN, Osotimehin B, Forrester T. Association of waist circumference with risk of hypertension and type 2 diabetes in Nigerians, Jamaicans, and African-Americans. Diabetes Care. 1998;21:1836-1842.
21. Okosun IS, Forrester TE, Rotimi CN, Osotimehin BO, Muna WF, Cooper RS. Abdominal adiposity in six populations of West African descent: prevalence and population attributable fraction of hypertension. Obes Res. 1999;7:453-462.
22. Okosun IS, Rotimi CN, Forrester TE, Fraser H, Osotimehin B, Muna WF, Cooper RS. Predictive value of abdominal obesity cut-off points for hypertension in blacks from west African and Caribbean island nations. Int J Obes Relat Metab Disord. 2000;24:180-186.
23. Mbanya JC, Minkoulou EM, Salah JN, Balkau B. The prevalence of hypertension in rural and urban Cameroon. Int J Epidemiol. 1998;27:181-185.
24. Mennen LI, Mbanya JC, Cade J, Balkau B, Sharma S, Chungong S, Cruickshank JK. The habitual diet in rural and urban Cameroon. Eur J Clin Nutr. 2000;54:150-154.
25. Cruickshank JK, Mbanya JC, Wilks R, Balkau B, Forrester T, Anderson SG, Mennen L, Forhan A, Riste L, McFarlane-Anderson N. Hypertension in four African-origin populations: current 'Rule of Halves', quality of blood pressure control and attributable risk of cardiovascular disease. J Hypertens. 2001;19:41-46.
26. Sobngwi E, Mbanya JC, Unwin NC, Kengne AP, Fezeu L, Minkoulou EM, Aspray TJ, Alberti KG. Physical activity and its relationship with obesity, hypertension and diabetes in urban and rural Cameroon. Int J Obes Relat Metab Disord. 2002;26:1009-1016.
27. Sobngwi E, Mbanya JC, Unwin NC, Porcher R, Kengne AP, Fezeu L, Minkoulou EM, Tournoux C, Gautier JF, Aspray TJ, Alberti K. Exposure over the life course to an urban environment and its relation with obesity, diabetes, and hypertension in rural and urban Cameroon. Int J Epidemiol. 2004;33:769-776.
28. Kamadjeu RM, Edwards R, Atanga JS, Unwin N, Kiawi EC, Mbanya JC. Prevalence, awareness and management of hypertension in Cameroon: findings of the 2003 Cameroon Burden of Diabetes Baseline Survey. J Hum Hypertens. 2006;20:91-92.
29. Giles WH, Pacque M, Greene BM, Taylor HR, Munoz B, Cutler M, Douglas J. Prevalence of hypertension in rural west Africa. Am J Med Sci. 1994;308:271-275.
30. Mufunda J, Mebrahtu G, Usman A, Nyarango P, Kosia A, Ghebrat Y, Ogbamariam A, Masjuan M, Gebremichael A. The prevalence of hypertension and its relationship with obesity: results from a national blood pressure survey in Eritrea. J Hum Hypertens. 2006;20:59-65.
31. Lang T, Pariente P, Salem G, Tap D. Social, professional conditions and arterial hypertension: an epidemiological study in Dakar, Senegal. J Hypertens. 1988;6:271-276.
32. Astagneau P, Lang T, Delarocque E, Jeannee E, Salem G. Arterial hypertension in urban Africa: an epidemiological study on a representative sample of Dakar inhabitants in Senegal. J Hypertens. 1992;10:1095-1101.
33. van der Sande MA, Bailey R, Faal H, Banya WA, Dolin P, Nyan OA, Ceesay SM, Walraven GE, Johnson GJ, McAdam KP. Nationwide prevalence study of hypertension and related non-communicable diseases in The Gambia. Trop Med Int Health. 1997;2:1039-1048.
34. van der Sande MA, Milligan PJ, Nyan OA, Rowley JT, Banya WA, Ceesay SM, Dolmans WM, Thien T, McAdam KP, Walraven GE. Blood pressure patterns and cardiovascular risk factors in rural and urban gambian communities. J Hum Hypertens. 2000;14:489-496.
35. van der Sande MA, Walraven GE, Milligan PJ, Banya WA, Ceesay SM, Nyan OA, McAdam KP. Family history: an opportunity for early interventions and improved control of hypertension, obesity and diabetes. Bull World Health Organ. 2001;79:321-328.
36. van der Sande MA, Ceesay SM, Milligan PJ, Nyan OA, Banya WA, Prentice A, McAdam KP, Walraven GE. Obesity and undernutrition and cardiovascular risk factors in rural and urban Gambian communities. Am J Public Health. 2001;91:1641-1644.
37. van der Sande MA, Milligan PJ, Walraven GE, Dolmans WM, Newport M, Nyan OA, Banya WA, Thien T, Ward R, McAdam KP. Geographical variation in prevalence of hypertension within The Gambia. J Hum Hypertens. 2001;15:733-739.
38. Beiser M, Collomb H, Ravel JL, Nafziger CJ. Systemic blood pressure studies among the Serer of Senegal. J Chronic Dis. 1976;29:371-380.
39. Adams-Campbell LL, Wing R, Ukoli FA, Janney CA, Nwankwo MU. Obesity, body fat distribution, and blood pressure in Nigerian and African-American men and women. J Natl Med Assoc. 1994;86:60-64.
40. Kesteloot H, Ndam N, Sasaki S, Kowo M, Seghers V. A survey of blood pressure distribution in Pygmy and Bantu populations in Cameroon. Hypertension. 1996;27:108-113.
41. Ahren B, Mutembei DS. Blood pressure distribution in a selected Tanzanian population. East Afr Med J. 1984;61:444-448.
42. Alakija W. A pilot study of blood pressure levels in Benin City, Nigeria. East Afr Med J. 1979;56:182-187.
43. Bertrand E, Serie F, Kone I, Le Bras M, Boope JL, Beda B, Assamoi MO, Thomas JY. [Prevalence and certain epidemiologic aspects of arterial hypertension in the Ivory Coast]. Bull World Health Organ. 1976;54:449-454.
44. M'Buyamba-Kabangu JR, Fagard R, Staessen J, Lijnen P, Amery A. Comparison of blood pressure and prevalence of hypertension in rural and urban Zaire. Bibl Cardiol. 1987:80-87.
45. Abengowe CU, Jain JS, Siddique AK. Pattern of hypertension in the northern savanna of Nigeria. Trop Doct. 1980;10:3-8.
46. Azinge NO. The changing pattern of hypertension in Benin City, Nigeria. Trop Doct. 1980;10:154-156.
47. Koate P. [Arterial hypertension in black Africa]. Bull World Health Organ. 1978;56:841-848.
48. Levitt D. Hypertensive heart disease in the Zambian. East Afr Med J. 1977;54:174-180.
49. Mokhobo KP. Arterial hypertension in rural societies. East Afr Med J. 1976;53:440-444.
50. Mufunda J, Nyarango P, Kosia A, Obgamariam A, Mebrahtu G, Usman A, Ghebrat J, Gebresillosie S, Goitom S, Kifle A, Tesfay A, Gebremichael A. Noncommunicable diseases in Africa: a silent hypertension epidemic in Eritrea. J Hum Hypertens. 2005;19:255-256.