Abstract
Purpose: :
To determine persistency rates of patients started on topical intraocular pressure (IOP) lowering monotherapy at a Singapore tertiary eye hospital.
Methods: :
This was a retrospective review of pharmaceutical dispensing records of patients who were commenced on a single IOP lowering medication between 1 October 2005 and 30 September 2006. Pharmacy dispensing records were traced from the date of first prescription for a 12-month period. Patients were defined as persistent if they were prescribed the same medication before, or within 14 days after, the previous prescription had lapsed. Patients were considered non persistent if they have defaulted, changed medication, or re-started therapy.
Results: :
2781 patients met the eligibility criteria. The sample mean age was 61.1±15.7 years; 50.2% were males; and the majority were Chinese (81.1%) and Singaporean residents (85.4%). Timolol 0.5% was the most frequently prescribed medication (62.2%), followed by travoprost 0.004% (10.4%), latanoprost 0.005% (10.4%) and brimonidine 0.15% (9.5%). At the end of 1 year, only 239/2781 (8.6%) patients were considered persistent having remained on the same therapy. Of these, 70.3% maintained the same medication, while 29.7% required additional IOP lowering medication(s). Persistency rates stratified for medication at 1 year included: travoprost (12.8%), latanoprost (10.8%), timolol (9.2%), brinzolamide (5%), brimonidine (3.0%), pilocarpine (1.9%) and dorzolamide (0.9%). Of the 2542 subjects (91.4%) who were non-persistent at the end of 1 year, 47.9% defaulted and were never subsequently prescribed any IOP lowering medication; 28.7% were re-started on the same medication; 4.4% were re-started on a different medication, while 0.8% were re-started on other medication(s) in addition to the initial one. Those who were non-persistent tended to be younger (p<0.01); non-Singapore residents (p=0.03); and on unilateral therapy (p<0.01).
Conclusions: :
In this hospital-based study from Singapore, the persistency rate of patients commenced on topical IOP lowering monotherapy was very low (8.6%) after 1 year. There is a need to for more research into risk-factors and interventions for this problem.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • anterior segment