Removing the mask on hypertension (REMAH) study: Design; quality of blood pressure phenotypes and characteristics of the first 490 participants

Purpose: Previous studies that evaluated the prevalence of hypertension in Nigeria were either clinic based, non-standardized or did not include out-of-clinic blood pressure (BP) measurement. Materials and Methods: We selected a rural and an urban community in one state in each of the 6 geopolitical zones of Nigeria. Five consecutive BP of adults older than 18 years were measured in the clinic following which, each participant was provided with a home BP device to obtain duplicate morning and evening BP for 3 days. Result: Out of 556 invited from Anambra State, South-East Nigeria, 490 (88%) consented. Overall, more women participated in both rural (115 vs 61, p <.0001) and urban (213 vs 101; p <.0001) sites. About 35.9% of participants had their home BP monitored. Of the 4890 clinic BP readings, 29.8%, 16.3%, 16.6%, 16.4% and 20.8% ended in 0,2,4,6 and 8 digits respectively. Only 0.8% ended in odd numbers. Of the identical BP readings,5 (0.20%), 6 (0.25%), 56 (2.30%) and 316 (12.9%) SBP and 8 (0.33%), 17 (0.70%), 93 (3.80%), 319 (13.1%) DBP had no difference in five, four, three and two values of the five consecutive readings. Conclusion: REMAH is feasible and the quality of BP will ensure that the final results are robust.