Table 4.
Multivariable generalized linear model of healthcare expenditures on intravitreal anti-VEGF injections over the first 6 and 12 months after the index date
| Parameter | 6 Month analyses | 12 Month analyses | ||||||
|---|---|---|---|---|---|---|---|---|
| Cost Ratio | Lower 95% CI | Upper 95% CI | P | Cost Ratio | Lower 95% CI | Upper 95% CI | P | |
| Aflibercept (reference = ranibizumab) | 0.96 | 0.89 | 1.04 | 0.338 | 0.92 | 0.74 | 1.13 | 0.429 |
| Age 18–64 years (reference = 85 + years) | 1.03 | 0.90 | 1.17 | 0.684 | 0.89 | 0.66 | 1.20 | 0.457 |
| Age 65–74 years (reference = 85 + years) | 1.02 | 0.92 | 1.13 | 0.696 | 0.96 | 0.76 | 1.20 | 0.697 |
| Age 75–84 years (reference = 85 + years) | 1.04 | 0.97 | 1.12 | 0.276 | 0.95 | 0.80 | 1.13 | 0.583 |
| Male (reference = female) | 0.98 | 0.91 | 1.04 | 0.461 | 0.94 | 0.81 | 1.09 | 0.405 |
| Region: North Central (reference = Northeast) | 0.98 | 0.89 | 1.07 | 0.607 | 0.94 | 0.76 | 1.15 | 0.539 |
| Region: South (reference = Northeast) | 1.04 | 0.95 | 1.14 | 0.384 | 0.92 | 0.74 | 1.13 | 0.412 |
| Region: Unknown Central (reference = Northeast) | 0.90 | 0.61 | 1.32 | 0.578 | 0.29 | 0.07 | 1.25 | 0.098 |
| Region: West Central (reference = Northeast) | 0.99 | 0.88 | 1.12 | 0.885 | 0.93 | 0.71 | 1.21 | 0.593 |
| Plan type: HMO (reference = FFS) | 0.79 | 0.69 | 0.90 | 0.001 | 0.81 | 0.59 | 1.11 | 0.196 |
| Plan type: Other (reference = FFS) | 1.11 | 0.93 | 1.34 | 0.243 | 1.05 | 0.58 | 1.92 | 0.867 |
| Plan type: POS (reference = FFS) | 0.95 | 0.81 | 1.12 | 0.526 | 1.05 | 0.73 | 1.49 | 0.805 |
| Plan type: PPO (reference = FFS) | 0.96 | 0.89 | 1.04 | 0.320 | 1.02 | 0.85 | 1.22 | 0.821 |
| Rural residence (reference = urban or unknown) | 1.01 | 0.91 | 1.11 | 0.919 | 1.14 | 0.90 | 1.45 | 0.273 |
| Median household income | 1.00 | 1.00 | 1.00 | 0.615 | 1.00 | 1.00 | 1.00 | 0.353 |
| Non-melanoma cancer | 1.00 | 0.89 | 1.12 | 0.971 | 1.24 | 0.95 | 1.62 | 0.107 |
| Dyslipidemia | 0.99 | 0.92 | 1.06 | 0.734 | 0.95 | 0.82 | 1.12 | 0.558 |
| Retinal vein occlusion | 0.95 | 0.76 | 1.20 | 0.679 | 0.97 | 0.62 | 1.52 | 0.901 |
| Diabetic macular edema | 0.94 | 0.81 | 1.11 | 0.471 | 1.13 | 0.78 | 1.65 | 0.516 |
| Cataracts | 1.01 | 0.93 | 1.10 | 0.830 | 1.13 | 0.91 | 1.39 | 0.271 |
| Glaucoma | 0.98 | 0.90 | 1.06 | 0.631 | 1.09 | 0.91 | 1.30 | 0.340 |
| Non-steroidal anti-inflammatory drugs | 1.04 | 0.94 | 1.16 | 0.451 | 0.88 | 0.70 | 1.11 | 0.296 |
| Glucocorticoids | 1.17 | 1.05 | 1.30 | 0.005 | 1.15 | 0.88 | 1.50 | 0.321 |
| Photodynamic therapy | 0.76 | 0.45 | 1.28 | 0.301 | 0.67 | 0.24 | 1.90 | 0.455 |
| Laser photocoagulation therapy | 0.83 | 0.52 | 1.32 | 0.428 | 0.37 | 0.09 | 1.56 | 0.175 |
| Cataract surgery | 1.02 | 0.90 | 1.15 | 0.772 | 1.05 | 0.78 | 1.40 | 0.765 |
| Intravitreal steroid injection | 0.91 | 0.83 | 1.00 | 0.039 | 1.00 | 0.79 | 1.27 | 0.983 |
| Deyo-Charlson Comorbidity Index | 1.00 | 0.97 | 1.02 | 0.863 | 0.97 | 0.91 | 1.03 | 0.252 |
| Unique 3-digit ICD-9-CM diagnoses | 1.00 | 1.00 | 1.01 | 0.334 | 1.01 | 0.99 | 1.02 | 0.331 |
| Unique National Drug Codes | 1.00 | 0.99 | 1.00 | 0.082 | 1.00 | 0.99 | 1.02 | 0.442 |
| Total healthcare expenditures | 1.00 | 1.00 | 1.00 | 0.260 | 1.00 | 1.00 | 1.00 | 0.716 |
CI confidence interval, FFS fee-for-service, HMO health maintenance organization, ICD-9-CM International Classification of Diseases, 9th Revision, Clinical modification, POS point-of-service, PPO preferred provider organization