Adherence to glaucoma medication: the effect of interventions and association with personality type

To determine whether multiple interventions influence adherence to glaucoma medication and to study the relationship between personality type and adherence.

Eighty patients with glaucoma using prostaglandin monotherapy were prospectively randomized to an intervention or a nonintervention group. Over a 5-month period, the intervention group received monthly automated telephone calls reminding them to take their glaucoma medications. At month 3, the intervention group had an office visit with their physician and received education regarding their disease and treatment. The nonintervention group returned at the end of the study period. Adherence was directly measured with an electronic monitoring cap. Outcome measures were adherence rate and therapeutic coverage. Patients completed the Minnesota Multiphasic Personality Inventory-2.

Thirty-eight patients were randomized to the intervention group and 42 were randomized to the nonintervention group. Mean adherence rate for the intervention group over 5 months was 76% and for the nonintervention group, 81%. For the intervention group, adherence did not change significantly after the midstudy visit (P=0.233). No difference existed between the intervention and nonintervention groups before (P=0.456) or after (P=0.134) the midstudy intervention visit. The Minnesota Multiphasic Personality Inventory-2 personality scales for depression (P=0.01) and hypochondriasis (P>0.0001) were significantly associated with poorer adherence.

Monthly automated telephone reminders, a 1-time educational session, and increased contact with a physician did not improve adherence rate with glaucoma medications. Depression and hypochondriasis personality types were related to poor adherence and highlight the role of psychosocial factors in medication adherence.