A pilot study to assess the feasibility of using the Travalert® dosing aid to measure adherence

A pilot study to assess the feasibility of using the Travalert® dosing aid to measure adherence Heidi Cate, 2011 Glaucoma is a chronic condition, leading to progressive visual field loss and eventual blindness if left untreated. With adequate medical therapy, progression of the disease can be reduced. Non-adherence to glaucoma medication is a significant issue requiring further research. However, rigorous evidence for novel adherence interventions requires a valid and reliable measure of adherence. A gold standard for measuring adherence to glaucoma therapy has yet to be established. This study evaluated the Travalert® dosing aid (TDA) as an effective measure of adherence to travoprost. One hundred patients prescribed travoprost for glaucoma or ocular hypertension, were approached and stratified by phase of travoprost use: newly prescribed or follow-up. At baseline, self-reported adherence to travoprost was obtained from follow-up participants using questionnaires (Morisky Medication Adherence Scale and Frequency of Missed Dose). All participants were given a TDA and daily adherence data were collected for 2 months. Self-reported adherence was obtained from both newly prescribed and follow-up participants. Satisfaction with information received about travoprost was assessed using the Satisfaction with Information about Medications Scale questionnaire. The results suggested that future adherence studies should monitor adherence in excess of 100 days to overcome initial monitoring effects. Furthermore, the use of intraocular pressure as a short-term clinical outcome measure to assess adherence to glaucoma medication was found to be unreliable and thus requires further investigation. This study has provided preliminary evidence that the TDA does not significantly alter patient eye drop use behaviour. It has been demonstrated as a feasible, objective adherence measure revealing that 40.9% of participants deviated from their prescribed treatment regimen. A further application of the TDA could be investigation of patient medication usage patterns to advance understanding of the complex area of non-adherence to glaucoma medication and aid the design of future adherence interventions.