Inter-observer reproducibility of blood pressure measurements in the clinic in a tertiary hospital in Nigeria by nurses and physicians: A cross-sectional study

Abstract

Accuracy of blood pressure measurement is critical to management of hypertension and stratification of patients. We observed marked variations in blood pressure readings obtained by the nurses and those obtained by the physicians at the time of the consultation.

Objective: To assess inter-observer reproducibility of blood pressure measurements in the clinics by nurses and physicians.

Method: This was a cross-sectional study. Blood pressure recordings of patients attending the cardiology clinics were obtained using validated electronic devices by the nurses and again by the attending physicians during consultation. The results obtained were analysed and coefficient of variation (COV) in percentage, inter-class correlation coefficient with 95% confidence interval (ICC), Bland-Altman limits of agreement of 95% and prevalence-adjusted and bias-adjusted kappa (PABAK) were used to determine inter-observer variability of the blood pressure measurements.

Results: Majority of the participants were aged between 51-70 years (44.2%) and females (53.8%). The mean systolic BP obtained by the nurses was 131.86±23.20 and 126.70±21.94 for those by the physicians while diastolic were 78.40±14.48 and 75.97±12.67 for the nurses and physicians respectively with overall significant p values. When subjected to test of COV (SBP 16.40, DBP 15.83), Bland Altman analysis (SBP 5.16, DBP 2.43) and PABAK (SBP 0.031, DBP 0.040), there was poor reproducibility of BP measurements by nurses and physicians.

Conclusion: There was poor reproducibility of blood pressure measurements taken by nurses and physicians in this study. Adherence to standardized guidelines for blood pressure measurement may improve blood pressure reproducibility among health care workers.