Accuracy of indirect measures of medication compliance in hypertension


  • Heather M. Craig MScN

    Assistant Professor, Corresponding author
    • McMaster University, School of Nursing, 1200 Main Street West, Hamilton, Ontario, Canada L8N 3Z5
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    • Ms. Heather M. Craig is assistant professor and clinical specialist in cardiac rehabilitation in the School of Nursing, McMaster University, Hamilton, Ontario.


The purpose of this study was to identify the most accurate indirect measure of medication compliance in primary hypertension through comparison with a recently developed direct measure of the antihypertensive agent, hydrochlorothiazide. A convenience sample of 40 subjects was seen by the investigator twice in an office setting and once in their homes. Data were collected by an interview schedule, blood pressure measurement, pill counts, urine analysis, and hospital record review. Patient interview was the most sensitive and accurate measure of compliance; this measure correctly classified 85% of patients as to compliant or noncompliant.