title: Differences between clinic blood pressure and morning home blood pressure, as shown by Bland-Altman plots, in a large observational study (HONEST study).
abstract: When interpreting home blood pressure (BP) measurements in hypertensive patients, differences between clinic and home BP should be noted. To investigate the differences between clinic and morning home BP in hypertensive patients, we analyzed clinic systolic BP (CSBP) and morning home systolic BP (MHSBP) data from the large-scale observational HONEST (Home BP measurement with Olmesartan Naive patients to Establish Standard Target blood pressure) study (n=21 340), using BP measurements obtained before starting olmesartan administration. We generated Bland-Altman plots, with the horizontal axis representing mean CSBP and MHSBP ([CSBP+MHSBP]/2) and the vertical axis representing the difference between CSBP and MHSBP (CSBP-MHSBP). We also did simulation experiments to explore factors affecting the results of the Bland-Altman plots. The difference between CSBP and MHSBP increased as the mean of the two values increased, and when the mean of CSBP and MHSBP was close to 140 mm Hg, the difference was theoretically 0 in average, although large interindividual BP variability existed in this BP range. Results were unaffected by factors such as previous antihypertensive treatment, age and concomitant diabetes or chronic kidney disease. Bland-Altman plots generated from simulated data of normal distribution showed that the slope of the regression line sloped upward, consistent with the results of the HONEST study, when the interindividual BP variability of MHSBP was less than that of CSBP. In conclusion, differences between mean CSBP and MHSBP may be caused by large interindividual variability in CSBP. Therefore, the differences between MHSBP and CSBP may vary between patient groups, which should be noted in the management of hypertension.
authors.affiliation: Shin-Oyama City Hospital, Oyama, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Shimada
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Jichi Medical University School of Medicine, Shimotsuke, Japan.
authors.forename: Kazuomi
authors.initials: K
authors.lastname: Kario
authors.affiliation: The Life Planning Center Foundation, Tokyo, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Kushiro
authors.affiliation: Department of Biostatistics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Teramukai
authors.affiliation: Daiichi Sankyo, Tokyo, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ishikawa
authors.affiliation: Daiichi Sankyo Development, Gerrards Cross, UK.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Kobayashi
authors.affiliation: Keio University, Yokohama, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Saito
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D007093:Imidazoles / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D013599:Systole; D013777:Tetrazoles / Q000627:therapeutic use
chemical_list: D007093:Imidazoles; D013777:Tetrazoles; C437965:olmesartan