Early Adherence to Glaucoma Medication Predicts Future Treatment Patterns

Anne Cathrine Falch-Joergensen, PhD

Credit: LinkedIn

A new investigation into treatment adherence among a national registry of patients with glaucoma revealed the first years of care may predict future treatment patterns for the progressive vision condition.¹

The observational analysis, involving approximately 30,000 patients with glaucoma in Denmark, showed increasing age, female sex, and a low Charlson comorbidity (CCI) index score were the factors most correlated with better adherence to glaucoma treatment.

“This finding may be of importance for physicians informing of the clinical value of adherence in the first and the first two years of treatment and may lead physicians to investigate other intraocular pressure (IOP)-lowering options sooner in patients with poor adherence, particularly among those that are progressing at unsafe rates,” wrote the investigative team, led by Anne Cathrine Falch-Joergensen, PhD, Real World Evidence, Signum Life Science.

Rates of glaucoma are expected to increase dramatically in the coming years, owing to the rapidly aging global population. Often asymptomatic, current rates of affected individuals are presumed to be much higher than what is reported, making adherence to management strategies crucial to curb the long-reaching effects of the chronic disease.

Glaucoma medications have been affected by adherence challenges, resulting from both the asymptomatic nature of the disease and difficulties with eye-drop administration. Poor medication adherence has been linked with a faster progression of visual field loss and could place an undue economic burden on the healthcare system.

This analysis, led by Falch-Joergensen, investigated patterns in treatment adherence in glaucoma, related to predictors of adherence, long-term patterns, and economic consequences of poor adherence. Using the Danish National Patient Register (DNPR), all Danish adults with glaucoma alive and residing in Denmark between 2000 and 2009 were included for analysis.

Glaucoma presence was determined by a minimum of 3 redeemed prescriptions of glaucoma medication or a registered diagnosis of primary open-angle glaucoma (POAG) Patients were followed from their index date for the next 10 years—after exclusions, the baseline population consisted of 30,100 individuals.

Medication adherence was determined by calculating the proportion of days covered (PDC) using the redeemed defined daily dose for 10 years, divided by 365 days. High adherence was defined as a PDC ≥80% and poor adherence as a PDC <80%. Patient comorbidities were obtained from the DNPR, estimated from 5 years before and up to the index date, and operationalized as a CCI score.

Falch-Joergensen and colleagues found that 54.7% of participants adhered to their glaucoma treatment within the first year from the index date. In the first two years from the index date, 51.8% of patients adhered to glaucoma medication.

Upon analysis, high adherence in the first year of treatment was found to be less likely among men (odds ratio [OR], 0.78; 95% CI, 0.75 to 0.82), younger participants, and those with a positive CCI score ≥3 (OR, 0.71; 95% CI, 0.63 to 0.80).

First-year adherence and adherence in the first two years were strongly associated with adherence in the fifth and 10th years from the index date. The most notable association estimates were identified after applying adherence over the first two years, with a strong association in fifth-year adherence (OR, 6.47; 95% CI, 6.10 to 6.86) and slightly lower estimates in the 10th year.

Poorer adherence in the first years of treatment was correlated with higher healthcare costs after 5 and 10 years from the index date. Patients with poor adherence in the first two years had an average cost increase in hospital contacts of €190.77 per patient in the fifth year and €205.16 in the 10th year from the index, compared with those with high adherence. These associations remained statistically significant after adjustment for age, sex, and CCI score.

In their conclusion, Falch-Joergensen and colleagues stressed the need for further investigations into the association between the severity and progression of glaucoma, and poor adherence to treatment, to enhance the current study findings.

“The understanding of the interplay is likewise highly relevant for enhancing the glaucoma treatment, and thus, seeking to prevent the negative consequences of poor medical adherence to glaucoma treatment,” they wrote.

References

1. _{Kolko M, Faergemann Hansen R, G Dal L, et alPredictors and long-term patterns of medication adherence to glaucoma treatment in Denmark—an observational registry study of 30 100 Danish patients with glaucomaBMJ Open Ophthalmology 2024;9:e001607. doi: 10.1136/bmjophth-2023-001607}