Clinical Context

In the United States, more than 2 million adults older than 40 years have glaucoma. Interventions are needed to improve adherence to glaucoma treatment. Although there are a variety of educational materials, services, resources, tools, and devices intended to improve adherence, evidence is lacking regarding their effectiveness.

The Interactive Study to Increase Glaucoma Adherence to Treatment (I-SIGHT) is a randomized controlled trial aiming to assess the efficacy of an automated, interactive, telephone-based health communication intervention and accompanying printed materials for improving adherence to glaucoma treatment among clinic patients. The current study by Glanz and colleagues describes findings from the I-SIGHT trial regarding adherence to glaucoma medications, appointment attendance, and medication refills at 1 year after baseline evaluation.

Study Synopsis and Perspective

A telephone-based health communication intervention does not significantly improve treatment and appointment adherence compared with usual care among patients with glaucoma, a new randomized controlled study has found.

Karen Glanz, PhD, MPH, with the Perelman School of Medicine and School of Nursing, University of Pennsylvania, Philadelphia, and colleagues reported their findings published online June 11, 2012, in the Archives of Ophthalmology.

"Medication use can reduce the progressive visual field loss caused by glaucoma, but nonadherence with glaucoma medication remains a primary treatment challenge," Dr. Glanz and colleagues noted, with only approximately half of patients taking glaucoma medication adhering to treatment.

According to the researchers, longer and larger studies of interventions to improve patients' treatment adherence to both medication and follow-up appointments are needed.

The current study, called I-SIGHT, sought to evaluate the efficacy of an intervention to improve adherence to glaucoma treatment.

The study included 312 patients (18 - 80 years old) with glaucoma who were attending one of 2 hospital eye clinics in the southeastern United States. The treatment group (n = 150) received the intervention, and the control group (n = 152) received usual care, and both groups had 12-month follow-up data.

Usual care included a recommendation for medical appointments and physician-directed prescription refill scheduled. By contrast, the intervention consisted of a tailored telephone intervention and printed materials. The telephone intervention consisted of 12 educational telephone calls during a 9-month period: a call every 2 weeks during months 1 and 2; a call every 3 weeks during months 3, 4, and 5; and a call every 4 weeks during months 6, 7, 8, and 9.

"The objectives of the calls were to provide individually tailored messages to encourage adherence with medication taking, appointment keeping, and refills; provide information about glaucoma; and intervene on barriers to adherence," the authors noted. Participants had the option to call into the system if they missed a call.

Participants also received printed materials, consisting of 1-page, double-sided flyers written in large print at an eighth-grade reading level, after each phone call. These flyers provided tips and strategies to improve treatment adherence as well as additional glaucoma information.

Adherence to medication and appointment times for both the intervention group and the usual care group was measured by interviews, medical charts, appointment records, and pharmacy data.

Although a statistically significant increase was found for all adherence measures in both the intervention group and the usual care group, the current intervention did not significantly improve adherence measures vs usual care, Dr. Glanz and colleagues found.

Adherence increased for all measures and in both groups (all P < .01). Self-reported medication adherence increased from 10.2% to 30.2% in the treatment group and from 13.5% to 27.0% in the control group.

"The treatment group had greater improvements in adherence in 4 of 6 categories, but this did not reach statistical significance," the authors wrote. In addition, the percentage of patients who were adherent at 12 months was similar for those who received all 12 telephone calls and those who did not.

Study limitations were that the participants and interviewers were not masked to treatment groups. "There may have been a selection bias that contributed to a placebo effect in the control group," the authors note. "The 'control' patients may have already been highly motivated to seek further knowledge or involvement in managing their glaucoma."

They conclude: "The findings of the I-SIGHT trial suggest that motivated patients participating in an ongoing clinical trial may improve their adherence, even without tailored messages, but because there was not an untailored 'attention intervention' condition, this needs to be tested in future research."

The National Institutes of Health supported this study. This study was also supported in part by a National Eye Institute Core Grant for Vision Research and an unrestricted departmental grant from Research to Prevent Blindness. Dr. Glanz was supported in part by a Georgia Cancer Coalition Distinguished Scholar award and by the Leonard Davis Institute for Health Economics and the Center for Public Health Initiatives at the University of Pennsylvania.

Arch Ophthalmol. Published online June 11, 2012.

Clinical Implications

• In the I-SIGHT randomized controlled trial, patient adherence to glaucoma treatment and appointment keeping during the study period improved in both the treatment group and the control group, possibly because of participation in the study and in interviews.
• Investigators in I-SIGHT suggest that strategies addressing the individual patient's specific barriers and facilitators may enhance the effect of telephone calls, especially for keeping appointments and refilling prescriptions.

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