title: Improving adherence to glaucoma medication: a randomised controlled trial of a patient-centred intervention (The Norwich Adherence Glaucoma Study).
abstract: BACKGROUND
  Improving adherence to ocular hypertension (OH)/glaucoma therapy is highly likely to prevent or reduce progression of optic nerve damage. The present study used a behaviour change counselling intervention to determine whether education and support was beneficial and cost-effective in improving adherence with glaucoma therapy.
  
  
  METHODS
  A randomised controlled trial with a 13-month recruitment and 8-month follow-up period was conducted. Patients with OH/glaucoma attending a glaucoma clinic and starting treatment with travoprost were approached. Participants were randomised into two groups and adherence was measured over 8 months, using an electronic monitoring device (Travalert® dosing aid, TDA). The control group received standard clinical care, and the intervention group received a novel glaucoma education and motivational support package using behaviour change counselling. Cost-effectiveness framework analysis was used to estimate any potential cost benefit of improving adherence.
  
  
  RESULTS
  Two hundred and eight patients were recruited (102 intervention, 106 control). No significant difference in mean adherence over the monitoring period was identified with 77.2% (CI, 73.0, 81.4) for the control group and 74.8% (CI, 69.7, 79.9) for the intervention group (p = 0.47). Similarly, there was no significant difference in percentage intraocular pressure reduction; 27.6% (CI, 23.5, 31.7) for the control group and 25.3% (CI, 21.06, 29.54) for the intervention group (p = 0.45). Participants in the intervention group were more satisfied with information about glaucoma medication with a mean score of 14.47/17 (CI, 13.85, 15.0) compared with control group which was 8.51 (CI, 7.72, 9.30). The mean intervention cost per patient was GB£10.35 (<US$16) and not cost-effective.
  
  
  CONCLUSIONS
  Adherence with travoprost was high and not further increased by the intervention. Nevertheless, the study demonstrated that provision of information, tailored to the individual, was inexpensive and able to achieve high patient satisfaction with respect to information about glaucoma medication. Measurement of adherence remains problematic since awareness of study participation may cause a change in participant behaviour.
  
  
  BACKGROUND
  Current Controlled Trials, ISRCTN89683704.
authors.affiliation: Norfolk & Norwich University Hospital NHS Trust, Glaucoma Research Unit, Level 2, West Block, Colney Lane, Norwich NR4 7UY, UK. heidi.cate@nnuh.nhs.uk.
authors.forename: Heidi
authors.initials: H
authors.lastname: Cate
authors.forename: Debi
authors.initials: D
authors.lastname: Bhattacharya
authors.forename: Allan
authors.initials: A
authors.lastname: Clark
authors.forename: Richard
authors.initials: R
authors.lastname: Fordham
authors.forename: Richard
authors.initials: R
authors.lastname: Holland
authors.forename: David C
authors.initials: DC
authors.lastname: Broadway
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D003008:Cloprostenol / Q000031:analogs & derivatives* / Q000627:therapeutic use; D003376:Counseling / Q000379:methods; D005260:Female; D005901:Glaucoma / Q000188:drug therapy*; D017048:Health Care Costs; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy*; D010353:Patient Education as Topic / Q000191:economics / Q000379:methods / Q000592:standards; D017060:Patient Satisfaction; D018802:Patient-Centered Care / Q000379:methods*; D000069557:Travoprost; D016903:Drug Monitoring
chemical_list: D000959:Antihypertensive Agents; D003008:Cloprostenol; D000069557:Travoprost