HDCN Article Review/Hyperlink

Chatellier G, Dutrey-Dupagne C, Vaur L, Zannad F, Genes N, Elkik F, Menard J

Home self blood pressure measurement in general practice: the SMART study

Am J Hypert (Jul) 29:644-652 1996

Although self home blood pressure monitoring is widely employed in clinical hypertension practice, the exact value and limitations of such a practice are not well studied. These authors wanted to assess the feasibility and practical value of self measured home BP, and office BP in a clinical trial in a French population.

The study design is an open label one based in General Practice involving 1710 patients with essential hypertension. After an initial 2 week washout of current antihypertensive therapy, subjects with diastolic BP between 95 to 115 mmHg were given trandolapril 2mg in the morning for 4 weeks. Office BP and self measured BP was performed to assess response to therapy. Home BP was planned during the last 4 days of the washout and also of the final week of treatment. The home BP device used in this study uses an oscillometric method and is also able to record BP and print values. The authors analyzed compliance with taking the home BP, and also compared home BP to office BP levels at baseline and after treatment with Trandolapril.

Compliance with taking home BP readings was only fair with 25% of subjects not taking any readings, and only 36% of all subjects taking the full complement of expected home readings. There were no good identifiers of compliance with home self BP measurement. A distinct digit preference for 0 and 5 was found among the physicians' office BP readings. The performance of 6 readings at home achieved most of the reduction of the standard deviation seen with the entire set of home readings. As expected home BP was significantly lower than office BP by 13/8 15/10 mmHg. Large differences were seen between the two methods especially at lower BP values. Office BP declined more with treatment than home BP.

Comment: Although the authors are optimistic about the use of home BP in the evaluation and treatment of hypertension, only 36% of all subjects performed all expected readings. Perhaps a period of education about anticipated value of the home BP would have improved compliance. Doctors continue to show observer bias in recording BP, a problem which has to be constantly guarded against. Home BP devices however are notoriously unreliable and should be calibrated at time of purchase against a mercury sphygmomanometer. Further work is necessary before home BP can substitute for office BP or ambulatory BP in clinical work or clinical research trials. (George Mansoor, M.D., University of Connecticut)