Table 3.
Univariate and Multivariate Cox Proportional Regression Models Assessing Risk of Developing Open-Angle Glaucoma
| Covariates | Univariate Analysis | Multivariate Analysis | ||
|---|---|---|---|---|
| HR (95% CI) | P Value | HR (95% CI) | P Value | |
| Age at plan enrollment, y | ||||
| 40 to <45 | 1 [Reference] | … | 1 [Reference] | … |
| 45 to <50 | 1.34 (1.10–1.64) | .004 | 1.24 (0.92–1.67) | .16 |
| 50 to <55 | 1.69 (1.40–2.04) | <.001 | 1.74 (1.33–2.26) | <.001 |
| 55 to <60 | 1.88 (1.57–2.26) | <.001 | 1.88 (1.43–2.46) | <.001 |
| 60 to <65 | 2.07 (1.72–2.49) | <.001 | 2.23 (1.67–2.98) | <.001 |
| ≥65 | 2.24 (1.88–2.67) | <.001 | 2.98 (2.20–4.02) | <.001 |
| Sex | ||||
| Male | 1 [Reference] | … | 1 [Reference] | … |
| Female | 1.03 (0.95–1.12) | .47 | 0.96 (0.84–1.10) | .56 |
| Race/ethnicity | ||||
| European ancestry | 1 [Reference] | … | 1 [Reference] | … |
| African ancestry | 2.18 (1.94–2.46) | <.001 | 1.95 (1.61–2.35) | <.001 |
| Latino | 1.21 (1.04–1.42) | .02 | 1.26 (1.03–1.55) | .03 |
| Asian American | 1.46 (1.16–1.82) | .001 | 1.53 (1.11–2.10) | .008 |
| Other | 0.88 (0.63–1.25) | .48 | 1.43 (0.89–2.30) | .13 |
| Education | ||||
| <High school | 1 [Reference] | … | 1 [Reference] | … |
| High school diploma | 0.86 (0.71–1.03) | .10 | 0.94 (0.72–1.24) | .68 |
| Some college | 0.83 (0.69–1.00) | .06 | 0.93 (0.70–1.25) | .64 |
| College diploma | 0.74 (0.60–0.90) | .003 | 0.72 (0.51–1.02) | .06 |
| Advanced degree | 1.11 (0.46–2.69) | .81 | 1.11 (0.19–6.37) | .90 |
| Geographic region of residence | ||||
| Northeast | 1 [Reference] | … | 1 [Reference] | … |
| Southeast | 1.06 (0.96–1.18) | .24 | 1.15 (0.95–1.38) | .16 |
| Midwest | 0.84 (0.75–0.94) | .003 | 1.01 (0.82–1.25) | .93 |
| West | 1.13 (0.98–1.31) | .10 | 1.25 (0.90–1.73) | .18 |
| Net worth, $ | ||||
| 0 to <25 000 | 1 [Reference] | … | 1 [Reference] | … |
| 25 000 to <75 000 | 0.83 (0.68–1.02) | .08 | 1.10 (0.80–1.51) | .58 |
| 75 000 to <150 000 | 1.06 (0.91–1.24) | .46 | 1.02 (0.79–1.31) | .88 |
| 150 000 to <500 000 | 0.87 (0.77–0.99) | .03 | 0.88 (0.71–1.11) | .28 |
| ≥500 000 | 0.87 (0.75–1.00) | .04 | 0.92 (0.69–1.23) | .57 |
| Ocular comorbiditiesa | ||||
| Nonexudative AMD | 1.12 (1.00–1.26) | .04 | 0.87 (0.69–1.11) | .26 |
| Exudative AMD | 1.19 (0.97–1.46) | .10 | 0.58 (0.33–1.02) | .06 |
| Cataract | 1.09 (0.99–1.19) | .07 | 0.91 (0.78–1.06) | .21 |
| Pseudophakia or aphakia | 1.27 (1.16–1.39) | <.001 | 0.91 (0.73–1.14) | .42 |
| NPDR | 1.04 (0.95–1.13) | .39 | 0.89 (0.75–1.05) | .16 |
| PDR | 1.37 (1.22–1.53) | <.001 | 0.93 (0.74–1.18) | .55 |
| Cataract surgery | 1.26 (1.15–1.39) | <.001 | 1.20 (0.96–1.50) | .11 |
| Retina surgery | 1.53 (1.37–1.71) | <.001 | 1.10 (0.87–1.40) | .43 |
| Other comorbiditiesa | ||||
| Hyperlipidemia | 0.86 (0.73–1.00) | .049 | 0.82 (0.56–1.22) | .34 |
| Obesity | 0.94 (0.85–1.03) | .16 | 0.94 (0.80–1.09) | .40 |
| Dementia | 1.02 (0.82–1.27) | .87 | 0.87 (0.50–1.52) | .63 |
| Depression | 0.80 (0.69–0.94) | .006 | 0.89 (0.68–1.16) | .39 |
| Hypertension | 1.20 (1.00–1.44) | .05 | 1.37 (1.04–1.81) | .03 |
| Type 1 diabetesb | 0.97 (0.89–1.05) | .44 | 0.84 (0.72–0.97) | .02 |
| Adapted CCI scorec | 0.92 (0.89–0.94) | <.001 | 0.86 (0.81–0.92) | <.001 |
| Other covariates | ||||
| Eye-related visits, No. | 1.06 (1.06–1.07) | <.001 | 1.07 (1.06–1.08) | <.001 |
| HbA1c level, % of total hemoglobin | 1.03 (0.98–1.08) | .20 | 1.08 (1.03–1.13) | .003 |
| Metformin use, g | ||||
| Never used | 1 [Reference] | … | 1 [Reference] | … |
| 0–315 | 0.89 (0.78–1.01) | .08 | 0.85 (0.69–1.04) | .11 |
| 316–660 | 0.92 (0.81–1.04) | .19 | 0.89 (0.72–1.09) | .25 |
| 661–1110 | 0.92 (0.80–1.05) | .22 | 1.03 (0.84–1.27) | .78 |
| >1110 | 0.84 (0.74–0.96) | .01 | 0.75 (0.59–0.95) | .02 |
| Use of other diabetes medications | ||||
| Sulfonylureas | 1.01 (0.91–1.11) | .88 | 1.03 (0.88–1.22) | .68 |
| Thiazolidinediones | 1.01 (0.91–1.12) | .88 | 1.09 (0.91–1.31) | .34 |
| Meglitinides | 0.88 (0.63–1.23) | .47 | 0.85 (0.56–1.28) | .43 |
| Insulin | 0.92 (0.81–1.03) | .14 | 0.86 (0.71–1.03) | .10 |
| Others | 1.07 (0.85–1.35) | .56 | 1.11 (0.84–1.47) | .47 |
Abbreviations: AMD, age-related macular degeneration; CCI, Charlson comorbidity index; HbA1c, glycated hemoglobin; HR, hazard ratio; NPDR, nonproliferative diabetic retinopathy; PDR, proliferative diabetic retinopathy; ellipses, not applicable.
SI conversion factor: To convert HbA1c to proportion of total hemoglobin, multiply by 0.01.
Some individuals may have more than 1 comorbidity, so percentages for comorbidities do not total 100%.
Characteristics of patients assigned this code suggest that this code may also be used for some patients with type 2 diabetes who are using insulin.
The adapted CCI score is an index of general health, with diabetes and dementia removed so they are not counted twice during analysis.