Purpose:
To assess the relationship of Mean Deviation (MD) scores with resource utilization among glaucoma patients from a medical chart review across 12 sites in the United States, using simple linear and logistic regression analysis.
Methods:
Patient records (N=151) from a US chart review of glaucoma patients (mean age 66.3, minimum follow–up four years) were analyzed to calculate the number of office visits, glaucoma medications and visual field exams per six–month time increment and the probability of trabeculoplasty and trabeculectomy per one–year time increment. MD scores from the worst eye were associated with the appropriate time increment and observations were grouped into MD score categories. Simple linear regression was performed to describe the relationship between the mean MD score in each category and the mean number of office visits, medications and visual field exams. Logistic regression was performed to describe the relationship between MD scores and the one–year probability of trabeculoplasty or trabeculectomy.
Results:
Resource utilization significantly increased with worsening MD scores (office visits: p = 0.001; visual field exams: p= 0.05; glaucoma medications: p = 0.01). MD scores were also found to be a significant predictor of trabeculoplasty and trabeculectomy (Table 1); for every 1.0 dB worsening in MD score, the odds of trabeculoplasty increased by 4% and the odds of trabeculectomy increased by 10%. Of the trabeculoplasty patients, 81.1% of patients will have one surgery and 18.9% will have two surgeries within one year, while for trabeculectomy patients, 73.8% of patients will have one trabeculectomy, 19.1% will have two and 7.1% will have three within one year.
Conclusions:
These analyses demonstrate an increasing resource consumption associated with worsening MD scores. Therapies and treatments aimed at stabilizing MD scores may reduce some of the costs associated with managing glaucoma.
Keywords: visual fields • clinical (human) or epidemiologic studies: outcomes/complications • clinical (human) or epidemiologic studies: risk factor assessment