Table. Characteristics of Medicare Patients Undergoing Cataract Surgery, Stratified by Preoperative Testing in the Month After Biometry.
| Characteristic | No. (%) | ||
|---|---|---|---|
| Preoperative Testing (n = 211 034) | No Preoperative Testing (n = 212 676) | All Patients (n = 423 710) | |
| Age, mean (SD), y | 76.5 (6.3) | 75.8 (6.2) | 76.1 (6.2) |
| Sex | |||
| Male | 86 221 (40.9) | 83 903 (39.5) | 170 124 (40.2) |
| Female | 124 813 (59.1) | 128 773 (60.5) | 253 586 (59.8) |
| Race/ethnicity | |||
| White | 185 327 (87.8) | 190 627 (89.6) | 375 954 (88.7) |
| Black | 13 546 (6.4) | 12 114 (5.7) | 25 660 (6.1) |
| Other | 12 161 (5.8) | 9935 (4.7) | 22 096 (5.2) |
| Charlson Comorbidity Index | |||
| 0-1 | 112 551 (53.3) | 147 091 (69.2) | 259 642 (61.3) |
| 2 | 35 208 (16.7) | 29 565 (13.9) | 64 773 (15.3) |
| ≥3 | 63 275 (30.0) | 36 020 (16.9) | 99 295 (23.4) |
| Location of surgerya | |||
| Ambulatory surgery center | 136 784 (64.8) | 149 603 (70.3) | 286 387 (67.5) |
| Outpatient hospital department | 70 157 (33.2) | 61 319 (28.8) | 131 476 (31.0) |
| Unknown | 4093 (1.9) | 1754 (0.8) | 5847 (1.4) |
| US region of operating ophthalmologista | |||
| Northeast | 47 442 (22.5) | 24 787 (11.6) | 72 229 (17.0) |
| Midwest | 47 955 (22.7) | 54 258 (25.5) | 102 213 (24.1) |
| South | 80 327 (38.1) | 94 507 (44.4) | 174 834 (41.3) |
| Mountain West | 9329 (4.4) | 16 813 (7.9) | 26 142 (6.2) |
| Pacific West | 25 981 (12.3) | 22 311 (10.5) | 48 292 (11.4) |
| Population density of operating ophthalmologista | |||
| Urban | 177 126 (83.9) | 172 120 (80.9) | 349 246 (82.4) |
| Rural | 33 908 (16.1) | 40 556 (19.1) | 74 464 (17.6) |
| Primary care physicians per 100 000 population, rangea,b | |||
| 43.9-63.3 | 47 846 (22.7) | 59 382 (27.9) | 107 228 (25.3) |
| 63.5-69.0 | 48 181 (22.8) | 57 647 (27.1) | 105 828 (25.0) |
| 69.1-77.9 | 54 497 (25.8) | 51 203 (24.1) | 105 700 (25.0) |
| 78.4-117 | 60 510 (28.7) | 44 444 (20.8) | 104 954 (24.8) |
| Ophthalmologists per 100 000 population, rangea,b | |||
| 1.6-4.2 | 51 052 (24.2) | 62 572 (29.4) | 113 624 (26.8) |
| 4.3-4.7 | 46 872 (22.2) | 58 889 (27.7) | 105 761 (24.9) |
| 4.8-5.6 | 49 370 (23.4) | 50 994 (24.0) | 100 364 (23.7) |
| 5.7-10.6 | 63 740 (30.2) | 40 221 (18.9) | 103 961 (24.5) |
| Ophthalmologist surgical volume, 2011, rangea,b | |||
| 1-39 | 59 971 (28.4) | 42 352 (19.9) | 102 323 (24.1) |
| 40-68 | 55 797 (26.4) | 50 831 (23.9) | 106 628 (25.2) |
| 69-120 | 51 267 (24.3) | 56 099 (26.4) | 107 366 (25.3) |
| 121-662 | 43 999 (20.8) | 63 394 (29.8) | 107 393 (25.3) |
| Medicare expenditures per beneficiary in hospital referral regiona,b | |||
| 6911-8689 | 52 094 (24.7) | 54 301 (25.5) | 106 395 (25.1) |
| 8691-9674 | 51 223 (24.3) | 54 695 (25.7) | 105 918 (25.0) |
| 9693-10 311 | 55 626 (26.4) | 51 271 (24.1) | 106 897 (25.2) |
| 10 341-13 824 | 52 091 (24.7) | 52 409 (24.6) | 104 500 (24.6) |
a
US region, population density, primary care physicians/ophthalmologists per 100 000 population, and hospital referral regions were derived from the operating ophthalmologist's zip code.
b
Ranges of numbers represent the first, second, third, and fourth quartiles of the range of values in each category.