Interventions for improving adherence to ocular hypotensive therapy

Poor adherence to therapy is a significant healthcare issue, particularly in patients with chronic disease such as open angle glaucoma. Treatment failure may necessitate unwarranted changes of medications, increased healthcare expenditure and risk to the patient if surgical intervention is required. Simplifying eye drop regimes, providing adequate information and ongoing support according to patient need, may have a positive effect on improving adherence.

To summarise the effects of interventions for improving adherence to ocular hypotensive therapy in people with ocular hypertension (OHT) or glaucoma.

We searched CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science, ZETOC and OpenSIGLE. In addition, we searched research registers of ongoing studies. We contacted pharmaceutical manufacturers to request unpublished data and searched conference proceedings for the Association for Research in Vision and Ophthalmology (ARVO), and the Annual Congress for the Royal College of Ophthalmologists (RCO). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 15 January 2009.

We included randomised controlled trials (RCTs) and quasi RCTs that compared interventions to improve adherence to ocular hypotensive therapy for patients with OHT or glaucoma.

At least two authors independently assessed the search results for eligibility and extracted data for included trials onto specifically designed forms. We calculated the mean difference for continuous data and relative risks for dichotomous data. Where appropriate, we pooled data using a fixed-effect model.

Eight trials met the inclusion criteria. There was considerable heterogeneity of interventions and reported outcome measures and therefore, meta-analysis was limited to two studies. Overall, studies were not of high quality due to small sample sizes, missing data and short term follow-up. Three of five drug comparison studies provided evidence that reducing the frequency of drops can improve adherence. However, the study that compared the least frequent regime with one of the most complicated, showed no difference in reported adherence. A small study of thirteen patients found a reminder device beneficial to adherence levels yet only one of two studies involving education and individualised care planning was found to be successful.

Interventions involving simplified dosing regimes, reminder devices, education and individualised care planning, did show improvements in adherence rates. However, due to inadequate methodological quality and heterogeneity of study design we are unable to advocate any particular interventions at this time.