title: Electronic pillboxes (MEMS) to assess the relationship between medication adherence and blood pressure control in primary care.
abstract: OBJECTIVE
  To investigate the relationship between blood pressure and medication adherence using electronic pillboxes (MEMS).
  
  
  METHODS
  Five general practices in Bristol, UK.
  
  
  METHODS
  A total of 239 individuals with a clinical diagnosis of hypertension and being prescribed at least one blood pressure-lowering medication. Participants were asked to use the electronic pillbox as their drug bottle for at least one month.
  
  
  METHODS
  "Timing adherence" (correct inter-dose intervals) as measured through MEMS and systolic (SBP) and diastolic (DBP) office blood pressure.
  
  
  RESULTS
  Mean (+/-SD) timing adherence was 88% (+/-17),>80% in 175 (73%), and less than 50% in 11 (5%) participants. Adherence was monitored for a mean of 33 (+/-6) days. Mean (+/-SD) SBP was 147.9+/-19.1 mmHg and DBP 82.3+/-10.1 mmHg. There was no evidence to suggest that timing adherence was associated with SBP or DBP (overall correlation coefficients -0.01 and -0.02 respectively). According to current guidelines, about one in four of all participants had controlled SBP (only 6% of diabetic patients). DBP was under control in 66% of the individuals.
  
  
  CONCLUSIONS
  No relationship between adherence and blood pressure in patients with hypertension recruited from primary care was found. Average timing adherence measured by electronic monitors was high (88%) and blood pressure was controlled in a minority of patients. Our findings suggest that in terms of poor blood pressure control pharmacological non-response to or insufficient intensity of blood pressure-lowering medication might be more important than poor adherence to antihypertensive drug therapy.
authors.affiliation: Academic Unit of Primary Health Care, Department of Community Based Medicine, University of Bristol, Bristol, UK. zellera@uhbs.ch
authors.forename: Andreas
authors.initials: A
authors.lastname: Zeller
authors.forename: Knut
authors.initials: K
authors.lastname: Schroeder
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Peters
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D016903:Drug Monitoring / Q000295:instrumentation / Q000379:methods; D004349:Drug Packaging / Q000295:instrumentation; D005194:Family Practice; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008509:Medication Systems; D017063:Outcome Assessment, Health Care; D010349:Patient Compliance; D011320:Primary Health Care; D011446:Prospective Studies
chemical_list: D000959:Antihypertensive Agents