Table 1.
Practice Characteristics of Surgical Specialties in SK&A Data, 2007 to 2017
| Characteristic | Total | Never integrated | Always integrated | Become integrated | p Value |
|---|---|---|---|---|---|
| Total practice years, n (%) | 303,930 (100) | 219,252 (72.1) | 30,077 (9.9) | 54,601 (18.0) | |
| Total provider years, n (%)* | 923,172 (100) | 568,170 (61.6) | 146,673 (15.9) | 208,329 (22.6) | |
| Provider characteristic† | |||||
| Male sex, n (%) | 815,082 (88.7) | 508,587 (90.0) | 123,653 (84.7) | 182,562 (87.9) | <0.001 |
| Missing, n | 4,120 | ||||
| Provider with NPI in 2007, n (%)‡ | 232,782 (0.765) | 166,723 (0.76) | 0.732 (0.362) | 54,481 (0.801) | <0.001 |
| Practice characteristic | |||||
| General surgery primary specialty, n (%) | 46,403 (15.3) | 27,297 (12.5) | 7,121 (23.7) | 11,985 (22.0) | <0.001 |
| Multispecialty surgical practice, n (%) | 20,534 (6.8) | 10,995 (5.0) | 4,099 (13.6) | 5,440 (9.9) | <0.001 |
| Plastic surgery primary specialty, n (%) | 32,584 (10.7) | 28,529 (13.0) | 1,473 (4.9) | 2,582 (4.7) | <0.001 |
| Physicians/practice, median (IQR) | 1 (1,3) | 1 (1,3) | 2 (1,5) | 2 (1,4) | <0.001 |
| Patient volume/d, median (IQR) | 40 (20, 120) | 35 (20, 100) | 60 (20, 200) | 50 (20, 150) | <0.001 |
| Payer mix | |||||
| Accepts Medicare, n (%)§ | 165, 911 (90.2) | 116,529 (88.7) | 16,370 (94.0) | 33,012 (93.8) | <0.001 |
| Accepts Medicaid, n (%)§ | 124,102 (67.5) | 79, 855 (60.8) | 15,742 (90.4) | 28,505 (81.0) | <0.001 |
| Missing, n | 12,397 | ||||
| Medicaid expansion, n (%) | 193,287 (63.6) | 138,343 (63.1) | 19,682 (65.4) | 35,262 (64.6) | <0.001 |
| Market characteristic, n (%) | |||||
| Rural | 29,244 (16.1) | 19,129 (15.4) | 3,057 (14.4) | 7,058 (19.3) | <0.001 |
| Market concentration | <0.001 | ||||
| Unconcentrated | 84,750 (27.9) | 65, 622 (29.9) | 6,857(22.8) | 12,271 (22.5) | |
| Moderately concentrated | 44, 501 (14.9) | 34,233 (15.6) | 4,078 (13.6) | 6,908 (12.7) | |
| Highly concentrated | 173, 961 (57.3) | 119,397 (54.5) | 19,142 (63.6) | 35,422 (64.9) | |
| Medicare use, mean (SD) | |||||
| Surgical discharges/1,000 enrollees | 82.93 (14.0) | 83.25 (14.1) | 79.88 (13.4) | 83.23 (13.8) | <0.001 |
| Surgical inpatient days/enrollees | 0.503 (0.11) | 0.508 (0.11) | 0.475 (0.11) | 0.496 (0.11) | <0.001 |
| Patient characteristic | |||||
| Percent uninsured, mean (SD) | 0.188 (0.073) | 0.193 (0.074) | 0.169 (0.070) | 0.176 (0.071) | <0.001 |
| Missing, n | 52,820 | ||||
*
From SK&A provider files.
†
From SK&A provider files and National Plan & Provider Enumeration System (NPPES).
‡
Provider experience obtained from provider NPI enumeration date from the NPPES. NPI numbers were not required before 2007, so we report percentage of providers with an NPI enumeration date in or before 2007.
§
Excludes 2007, 2017 data.
IQR, interquartile range; NPI, National Provider Identification number.