Article Figures & Data
Tables
Characteristic Value, Mean (SD) [range]a Age, yb 64 (8) [24–78] Sex, female, % (No.) 53 (152) Body mass index, kg/m2 29.4 (4.8) Waist-hip ratio 0.95 (0.48) Antihypertensive medications (daily defined dose), No. 2.4 (1.4) Measures of target organ disease Aortic stiffness, m/s 9.4 (2.1) Left ventricular relative wall thickness, cm 0.47 (0.20) Left ventricular mass index, g/m2.7 31.3 (5.5) Left ventricular ejection fraction, % 62 (5) Left atrial area, cm2 20.4 (4.2) Left ventricular filling pressure, E/e′ 11.6 (3.6) Clinic blood pressure, mm Hg Systolic 134 (14) Diastolic 78 (10) 24-hour ambulatory blood pressure, mm Hg Systolic 133 (12) Diastolic 77 (8) 7-day home blood pressure, mm Hg Systolic 128 (13) Diastolic 74 (8) - Table 2
Indices of the Diagnostic Accuracy of Classification of Patients as Having vs Not Having Uncontrolled Blood Pressure Based on the Number of SBP Elevations
Definition of Uncontrolled Blood Pressure and Index Unadjusted Adjusteda Cut Point Value Cut Point Value 24-hour ABP SBP ≥130 mm Hg AUCb ≥3 elevations 0.712 ≥3 elevations 0.722 NRIc ≥3 elevations 0.005 ≥3 elevations 0.004 Category-free NRIc ≥3 elevations 0.010 ≥2 elevations 0.192 rIDId ≥3 elevations 1.021 ≥3 elevations 1.018 Deviancee ≥3 elevations 321.9 ≥3 elevations 321.1 24-hour ABP daytime SBP ≥135 mm Hg AUCb ≥2 elevations 0.717 ≥2 elevations 0.724 NRIc ≥2 elevations 0.072 ≥2 elevations 0.072 Category-free NRIc ≥2 elevations 0.144 ≥2 elevations 0.137 rIDId ≥2 elevations 1.306 ≥2 elevations 1.237 Deviancee ≥2 elevations 331.9 ≥2 elevations 330.3 ABP = ambulatory blood pressure; AUC = area under the receiver operating characteristic curve; NRI = net reclassification index; rIDI = relative integrated discrimination improvement; SBP = systolic blood pressure.
↵a For age, sex, and body mass index.
↵b Criterion: largest value for receiver operating characteristic curve produced from all 10 cut points (≥1 elevations, ≥2 elevations, ≥3 elevations, …, ≥9 elevations, 10 elevations).
↵c Criterion: last classification before that producing first negative value.
↵d Criterion: last classification before that producing first value below unity.
↵e Model deviance, criterion: last classification before that producing first higher value.
Note: Elevated systolic blood pressure was defined as 24-hour ABP SBP ≥130 mm Hg or 24-hour ABP daytime SBP ≥135 mm Hg. Number of elevations was defined as number of elevations ≥135 mm Hg among the last 10 recordings of morning and evening home SBP.
- Table 3
Differences in Indicators of Target Organ Disease for Patients Not Attaining vs Attaining the Cut Point in Number of SBP Elevations During Home Blood Pressure Monitoring
Target Organ Disease Indicator and Cut Point Value, Mean (SD) Unadjusted Difference (95% CI)a Adjusted Difference (95% CI)a, b Did Not Attain Cut Point Attained Cut Point Aortic stiffness, m/s ≥2 elevations 8.82 (1.79) 9.87 (2.25) 1.05 (0.57 to 1.54)c 0.72 (0.27 to 1.18)d ≥3 elevations 8.92 (1.87) 9.94 (2.26) 1.02 (0.53 to 1.51)c 0.71 (0.25 to 1.17)d Relative wall thickness in cm × 10 ≥2 elevations 4.49 (0.75) 4.74 (0.63) 0.26 (0.09 to 0.04)d 0.26 (0.09 to 0.43)d ≥3 elevations 4.51 (0.74) 4.75 (0.63) 0.02 (0.01 to 0.04)d 0.25 (0.07 to 0.42)d Left ventricular ejection fraction, % ≥2 elevations 62.57 (5.18) 60.46 (5.40) −2.11 (−3.48 to −0.74)d −2.00 (−3.43 to −0.56)d ≥3 elevations 62.54 (5.28) 60.11 (5.22) −2.43 (−3.83 to −1.03)d −2.34 (−3.80 to −0.89)d Left ventricular mass, g/m2.7 ≥2 elevations 30.91 (5.11) 31.60 (5.83) 0.69 (−0.64 to 2.03) 0.71 (−0.61 to 2.35) ≥3 elevations 30.71 (5.17) 31.99 (5.83) 1.28 (−0.05 to 2.61) 1.03 (−0.29 to 2.35) Left atrial area, cm2 ≥2 elevations 19.91 (3.78) 20.72 (4.57) 0.80 (−0.23 to 1.84) 0.28 (−0.75 to 1.32) ≥3 elevations 19.72 (3.84) 21.08 (4.56) 1.36 (0.33 to 2.39)d 0.77 (−0.26 to 1.79) ≥4 elevations 19.86 (3.87) 21.14 (4.69) 1.28 (0.22 to 2.34)e 0.76 (−0.29 to 1.80) Left ventricular filling pressure, E/e′ ≥2 elevations 11.36 (3.17) 11.84 (3.79) 0.48 (−0.39 to 1.36) 0.81 (−0.05 to 1.67) ≥3 elevations 11.28 (3.22) 12.04 (3.87) 0.76 (−0.11 to 1.63) 1.10 (0.24 to 1.95)e ≥4 elevations 11.12 (3.28) 12.48 (3.93) 1.36 (0.47 to 2.25)d 1.63 (0.77 to 2.49)c E/e′ = the ratio of mitral inflow to mitral annular early diastolic velocity; SBP = systolic blood pressure.
↵a Difference in means between patients who did vs did not attain cut point.
↵b Adjusted for age, sex, and body mass index.
↵c P <.001.
↵d P <.01.
↵e P <.05.
Note: Number of elevations ≥135 mm Hg among the last 10 recordings of morning and evening home SBP. Results are shown for ≥4 elevations only if the difference between means is similar to or higher than that for ≥3 elevations.
Additional Files
The Article in Brief
Pragmatic Method Using Blood Pressure Diaries to Assess Blood Pressure Control
James E. Sharman , and colleagues
Background Home blood pressure (HBP) is superior to clinic blood pressure in assessing blood pressure control. However, averaging all HBP values from patient records in order to assess blood pressure control is impractical in busy clinical practice. This study offers a new method for clinicians to assess a patient's home blood pressure.
What This Study Found If three or more of the last 10 home blood pressure readings are at least 135 mm Hg (the threshold for elevated blood pressure based on HBP), there is a tendency towards uncontrolled blood pressure and greater risk of total organ disease associated with hypertension. hypertension there is a propensity toward having uncontrolled blood pressure according to 24-ABP, as well as greater risk of target organ disease associated with hypertension (increased aortic stiffness, left ventricular relative wall thickness, and left atrial area, but lower left ventricular ejection fraction).
Implications
- According to the authors, this pragmatic approach using a summary statistic is a valid method for assessing blood pressure control.
- This approach could also encourage greater use of HBP monitoring and help patients achieve better blood pressure control.
Annals Journal Club
Jan/Feb 2016: Pragmatic Method to Assess Blood Pressure Control From Home Blood Pressure Diaries
The Annals of Family Medicine encourages readers to develop a learning community of those seeking to improve health care and health through enhanced primary care. You can participate by conducting a RADICAL journal club and sharing the results of your discussions in the Annals online discussion for the featured articles. RADICAL is an acronym for Read, Ask, Discuss, Inquire, Collaborate, Act, and Learn. The word radical also indicates the need to engage diverse participants in thinking critically about important issues affecting primary care and then acting on those discussions.1
HOW IT WORKS
In each issue, the Annals selects an article or articles and provides discussion tips and questions. We encourage you to take a RADICAL approach to these materials and to post a summary of your conversation in our online discussion. (Open the article online and click on "TRACK Discussion: Submit a comment.") You can find discussion questions and more information online at: http://www.AnnFamMed.org/site/AJC/.
CURRENT SELECTION
Article for Discussion
Sharman JE, Blizzard L, Kosmala W, Nelson MR. Pragmatic method using blood pressure diaries to asses blood pressure control. Ann Fam Med. 2016;14(1):63-69.
Discussion Tips
This article proposes a pragmatic approach to quickly interpret home blood pressure readings in the clinic setting. The investigators compare their method with 24-hour ambulatory blood pressure monitoring and show a correlation with sonographic measures of target organ damage.
The study by Sharman et al finds that the percentage of the last 10 home systolic blood pressures ≥135 mm HG provides a reasonable estimate of the reference standard of 24-hour ambulatory blood pressure.
Discussion Questions
- What question is asked by this study and why does it matter?
- How strong is a cross-sectional study design for answering this question? What other study designs could be used?
- To what degree can the findings be accounted for by:
- How patients were selected or excluded?
- How the main variables were measured? Could the intensity of the study protocol affect the quality of the blood pressure diaries? How good are 24-hour ambulatory blood pressure and the end-organ biomarkers as reference standards?
- Confounding (false attribution of causality because 2 variables discovered to be associated actually are associated with a 3rd factor)?
- How the findings were interpreted? Does the timing of measuring predictors (eg, home blood pressures) and outcomes (eg, target organ damage) affect your interpretation of the causal relationship between the 2?
- What are the main study findings?
- How comparable is the study sample to your practice? What would be some barriers to implementing this pragmatic method for other clinicians & patients?
- What contextual factors are important for interpreting the findings? How might the findings relate to recent and evolving recommendations for blood pressure control in different age-groups?
- How might this study change your practice? Is the main outcome of interest patient oriented? What are the limitations of using disease-oriented outcomes?
- What are the next steps in interpreting or applying the findings?
- What researchable questions remain?
References
- Stange KC, Miller WL, McLellan LA, et al. Annals Journal Club: It's time to get RADICAL. Ann Fam Med. 2006;4(3):196-197 http://annfammed.org/content/4/3/196.full.
