Validation of an iCare Health Monitor smartphone application in the assessment of vital signs among stroke survivors in a poor-resource country

Background Frequent and accurate monitoring of blood pressure (BP) is a vital part of stroke management. There is therefore the need for availability of simple, portable and accurate devices for monitoring BP at any point in time. Objective To determine the validity and reliability of the iCare Health Monitor (iCHM) smartphone application in the measurement of BP, heart rate (HR) and respiratory rate (RR) amongst stroke survivors in Anambra State. Methods This was a cross-sectional survey involving 86 stroke survivors (64.0% males; mean age = 65.23 ± 12.10 years) consecutively recruited from three conveniently selected centres in Anambra State. BP, PR and RR were assessed using both the standardised methods and iCHM. The parameters were reassessed with the iCHM after few minutes. Convergent validity and test-retest reliability of the iCHM were determined using Pearson product moment correlation and intra-class correlation coefficient respectively at an alpha level of 0.05. Results The convergent validity of the iCHM was excellent in measuring systolic BP (SBP) ( r = 0.96; p < 0.01), diastolic BP (DBP) ( r = 0.93; p < 0.01), HR ( r = 0.96; p < 0.01) but moderate in measuring RR ( r = 0.74; p < 0.01). The test-retest reliability of the iCHM was excellent in assessing SBP (ICC = 0.95; p < 0.01), DBP (ICC = 0.94; p < 0.01) and HR (ICC = 0.92; p < 0.01) but poor in assessing RR (ICC = 0.35; p = 0.03). Also, the iCHM displayed clinically insignificant bias. Conclusion The iCHM is a valid and reliable tool for assessing BP and HR (but not RR) among stroke survivors. Its use is therefore recommended especially in poor-resource countries where gadgets for assessing BP and PR might not easily be affordable and available.