The relationship of self-report and medication possession with success of glaucoma medication administration

Abstract

Purpose : Even among experienced eye drop users, many are unable to successfully self-administer their drops. Observing patients’ drop technique can be time consuming. Thus, physicians may seek a surrogate marker of drop administration success to inform clinical decision-making. We examined the usefulness of surrogate markers for drop administration success. We tested the hypotheses that there was an association between 1) patient self-reported success with eye drop administration and observed drop administration success in a University and VA population, and 2) glaucoma medication possession and observed drop administration success in a VA population.

Methods : Participants (n=135) included adults with glaucoma from a University and from a VA site. Participants answered the question “How confident are you that you can get the medication into your eye?” with a three-category scale, and responses were dichotomized into “very confident” and all other responses. Participants were also observed administering drops and scored on correct technique, defined as the ability to get drops into the eye and to only put one drop into the eye at a time. Glaucoma medication possession ratio (MPR) for 6 months following enrollment was calculated from the site with a closed pharmacy system (VA site, n=79). MPR was defined as the amount of eye drop available according to pharmacy refill data divided by the amount of drop required according to the physician order, and was analyzed as a three-level variable. Associations between variables were examined via Fisher’s exact and chi-squared tests.

Results : Of participants who stated they were “very confident” they could administer eye drops correctly (n=117), 95 participants (81%) displayed correct drop technique. Of those who reported being less than “very confident” (n=18), 11 participants (61%) displayed correct drop technique (Fisher’s exact, p=0.07). The MPR among only the veterans also showed no significant relationship to observed drop administration success (chi-squared, p=0.18).

Conclusions : Our results suggest self-reported success with eye drop administration and medication possession ratio are not strongly associated with and may be inadequate surrogates for successful drop administration. Direct observation of patients’ self-administration of drops may be the most effective means of determining success and warrants the time required.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.