Adherence to the medical regime in patients with heart failure.
OBJECTIVE
To assess adherence to medical treatment in patients with heart failure (HF) using a specific questionnaire and measurement of the serum concentration of digoxin.


RESULTS
Forty patients with symptomatic HF and a clinical indication for digoxin were included in this pilot study. The assessment of adherence to the medical regime was based on two different methods: (i) the CARDIA-Questionnaire and (ii) the measurement of serum digoxin concentration (SDC) at 1 and 6 months. All patients were placed on digoxin treatment (target SDC 0.6-0.8 ng/mL) at baseline. Poor adherence was defined if the patient self-reported taking < or =75% of the prescribed HF medication or had an SDC < 0.4 ng/mL (subtherapeutic range) at the follow-up visits. During the entire follow-up, the proportion of patients with poor adherence was 15% as assessed by the questionnaire, 20% as assessed by the SDC, and 25% if both methods were combined.


CONCLUSIONS
Although HF is a symptomatic disease, the proportion of patients with poor adherence to the medical regime in our study was high (up to 25%). The objective methodology based on the measurement of the SDC identified a higher number of patients with poor adherence when compared with the CARDIA-Questionnaire.
Muzzarelli
Stefano
S
Cardiology Department, University Hospital Basel, Petersgraben 4, Basel, Switzerland. muzzarellis@uhbs.ch
Brunner-La Rocca
Hanspeter
H
Pfister
Otmar
O
Foglia
Pietro
P
Moschovitis
Giorgio
G
Mombelli
Giorgio
G
Stricker
Hans
H
D000368:Aged; D002316:Cardiotonic Agents / Q000097:blood / Q000627:therapeutic use*; D004077:Digoxin / Q000097:blood / Q000627:therapeutic use*; D005260:Female; D015438:Health Behavior; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D008297:Male; D055118:Medication Adherence; D010865:Pilot Projects; D011446:Prospective Studies; D011594:Psychometrics; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013557:Switzerland
D002316:Cardiotonic Agents; D004077:Digoxin