Table S4. Patient demographic, clinical, and hospital characteristics of comparable cohort identified by propensity score matching, by different surgical approaches, for all hospitals and hospitals with >25 annual VL or RL cases.
| Variables | Among all hospitals, N/N (%) | Hospitals with >25 annual VL or RL cases, N/N (%) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2008–2012a | 2013–2015 Septemberb | 2008–2012c | 2013–2015 Septemberd | ||||||||||||
| VL | RL | P valuee | VL | RL | P valuee | VL | RL | P valuee | VL | RL | P valuee | ||||
| No. of cases | 1,136 | 1,136 | 1,729 | 1,729 | 269 | 269 | 607 | 607 | |||||||
| Age (years) | 0.7 | 0.82 | 0.67 | 0.5 | |||||||||||
| 18–44 | 15 (1.32) | 21 (1.85) | 26 (1.50) | 28 (1.62) | 3 (1.12) | 4 (1.49) | 13 (2.14) | 9 (1.48) | |||||||
| 45–64 | 408 (35.92) | 398 (35.04) | 562 (32.50) | 543 (31.41) | 104 (38.66) | 93 (34.57) | 192 (31.63) | 173 (28.50) | |||||||
| 65–80 | 594 (52.29) | 605 (53.26) | 970 (56.10) | 995 (57.55) | 136 (50.56) | 149 (55.39) | 348 (57.33) | 366 (60.30) | |||||||
| >80 | 119 (10.48) | 112 (9.86) | 171 (9.89) | 163 (9.43) | 26 (9.67) | 23 (8.55) | 54 (8.90) | 59 (9.72) | |||||||
| Gender | 0.97 | 0.97 | 0.1 | 0.69 | |||||||||||
| Female | 585 (51.50) | 583 (51.32) | 910 (52.63) | 908 (52.52) | 134 (49.81) | 154 (57.25) | 326 (53.71) | 318 (52.39) | |||||||
| Male | 551 (48.50) | 553 (48.68) | 819 (47.37) | 821 (47.48) | 135 (50.19) | 115 (42.75) | 281 (46.29) | 289 (47.61) | |||||||
| Race | 0.83 | 0.21 | 0.56 | 0.8 | |||||||||||
| Black | 69 (6.07) | 60 (5.28) | 105 (6.07) | 99 (5.73) | 20 (7.43) | 18 (6.69) | 38 (6.26) | 30 (4.94) | |||||||
| White | 873 (76.85) | 878 (77.29) | 1,239 (71.66) | 1,283 (74.20) | 211 (78.44) | 218 (81.04) | 413 (68.04) | 418 (68.86) | |||||||
| Hispanic | 17 (1.50) | 20 (1.76) | 6 (0.35) | 2 (0.12) | 4 (1.49) | 1 (0.37) | 2 (0.33) | 2 (0.33) | |||||||
| Other | 177 (15.58) | 178 (15.67) | 379 (21.92) | 345 (19.95) | 34 (12.64) | 32 (11.90) | 154 (25.37) | 157 (25.86) | |||||||
| Insurance type | 0.87 | 0.54 | 0.64 | 0.53 | |||||||||||
| Medicare | 699 (61.53) | 707 (62.24) | 1,108 (64.08) | 1,137 (65.76) | 170 (63.20) | 181 (67.29) | 393 (64.74) | 406 (66.89) | |||||||
| Medicaid | 52 (4.58) | 47 (4.14) | 92 (5.32) | 85 (4.92) | 14 (5.20) | 11 (4.09) | 45 (7.41) | 41 (6.75) | |||||||
| Commercial | 337 (29.67) | 340 (29.93) | 480 (27.76) | 469 (27.13) | 74 (27.51) | 70 (26.02) | 152 (25.04) | 150 (24.71) | |||||||
| Others/Self–pay | 48 (4.23) | 42 (3.70) | 49 (2.83) | 38 (2.20) | 11 (4.09) | 7 (2.60) | 17 (2.80) | 10 (1.65) | |||||||
| Malignancy indication | 0.85 | 0.75 | 0.6 | 0.9 | |||||||||||
| Primary neoplasm of lung | 1,080 (95.07) | 1,077 (94.81) | 1,649 (95.37) | 1,644 (95.08) | 249 (92.57) | 253 (94.05) | 575 (94.73) | 573 (94.40) | |||||||
| Metastases other than lung | 56 (4.93) | 59 (5.19) | 80 (4.63) | 85 (4.92) | 20 (7.43) | 16 (5.95) | 32 (5.27) | 34 (5.60) | |||||||
| Charlson comorbidity score | 0.76 | 0.83 | 0.6 | 0.86 | |||||||||||
| 0 | 385 (33.89) | 384 (33.80) | 623 (36.03) | 625 (36.15) | 101 (37.55) | 97 (36.06) | 230 (37.89) | 238 (39.21) | |||||||
| 1–2 | 501 (44.10) | 488 (42.96) | 733 (42.39) | 745 (43.09) | 103 (38.29) | 114 (42.38) | 253 (41.68) | 244 (40.20) | |||||||
| ≥3 | 250 (22.01) | 264 (23.24) | 373 (21.57) | 359 (20.76) | 65 (24.16) | 58 (21.56) | 124 (20.43) | 125 (20.59) | |||||||
| Obese status | 1 | 0.46 | 0.46 | 0.93 | |||||||||||
| Without obesity diagnosis | 1,005 (88.47) | 1,004 (88.38) | 1,484 (85.83) | 1,500 (86.76) | 241 (89.59) | 247 (91.82) | 532 (87.64) | 534 (87.97) | |||||||
| Obese (BMI ≥30) | 131 (11.53) | 132 (11.62) | 245 (14.17) | 229 (13.24) | 28 (10.41) | 22 (8.18) | 75 (12.36) | 73 (12.03) | |||||||
| Previous/current smoker | 0.79 | 0.93 | 0.55 | ||||||||||||
| No | 398 (35.04) | 405 (35.65) | 506 (29.27) | 520 (30.08) | 103 (38.29) | 101 (37.55) | 150 (24.71) | 160 (26.36) | |||||||
| Yes | 738 (64.96) | 731 (64.35) | 1,223 (70.73) | 1,209 (69.92) | 166 (61.71) | 168 (62.45) | 457 (75.29) | 447 (73.64) | |||||||
| Year | 0.59 | 0.36 | 0.6 | 0.37 | |||||||||||
| 2008 | 34 (2.99) | 42 (3.70) | – | – | 10 (3.72) | 18 (6.69) | – | – | |||||||
| 2009 | 68 (5.99) | 81 (7.13) | – | – | 12 (4.46) | 11 (4.09) | – | – | |||||||
| 2010 | 173 (15.23) | 181 (15.93) | – | – | 53 (19.70) | 56 (20.82) | – | – | |||||||
| 2011 | 365 (32.13) | 361 (31.78) | – | – | 70 (26.02) | 69 (25.65) | – | – | |||||||
| 2012 | 496 (43.66) | 471 (41.46) | – | – | 124 (46.10) | 115 (42.75) | – | – | |||||||
| 2013 | – | – | 664 (38.40) | 635 (36.73) | – | – | 195 (32.13) | 218 (35.91) | |||||||
| 2014 | – | – | 608 (35.16) | 648 (37.48) | – | – | 263 (43.33) | 246 (40.53) | |||||||
| 2015 Jan–Sep | – | – | 457 (26.43) | 446 (25.80) | – | – | 149 (24.55) | 143 (23.56) | |||||||
| Attending surgeon specialty | 0.82 | 0.37 | 0.33 | 0.72 | |||||||||||
| Thoracic surgeon | 660 (58.10) | 646 (56.87) | 953 (55.12) | 912 (52.75) | 200 (74.35) | 199 (73.98) | 342 (56.34) | 329 (54.20) | |||||||
| Cardiovascular surgeon | 264 (23.24) | 275 (24.21) | 480 (27.76) | 502 (29.03) | 41 (15.24) | 50 (18.59) | 172 (28.34) | 177 (29.16) | |||||||
| Others | 212 (18.66) | 215 (18.93) | 296 (17.12) | 315 (18.22) | 28 (10.41) | 20 (7.43) | 93 (15.32) | 101 (16.64) | |||||||
| Attending surgeon volume in previous 12 months | 0.15 | 0.49 | 0.31 | 0.23 | |||||||||||
| ≤10 | 670 (58.98) | 655 (57.66) | 854 (49.39) | 820 (47.43) | 81 (30.11) | 80 (29.74) | 136 (22.41) | 159 (26.19) | |||||||
| 11–25 | 246 (21.65) | 225 (19.81) | 466 (26.95) | 491 (28.40) | 68 (25.28) | 83 (30.86) | 155 (25.54) | 137 (22.57) | |||||||
| >25 | 220 (19.37) | 256 (22.54) | 409 (23.66) | 418 (24.18) | 120 (44.61) | 106 (39.41) | 316 (52.06) | 311 (51.24) | |||||||
| Bed size | 0.19 | 0.67 | 0.73 | 0.59 | |||||||||||
| 0–199 | 36 (3.17) | 32 (2.82) | 84 (4.86) | 84 (4.86) | – | – | – | – | |||||||
| 200–399 | 299 (26.32) | 264 (23.24) | 411 (23.77) | 389 (22.50) | 46 (17.10) | 42 (15.61) | 32 (5.27) | 27 (4.45) | |||||||
| 400+ | 801 (70.51) | 840 (73.94) | 1,234 (71.37) | 1256 (72.64) | 223 (82.90) | 227 (84.39) | 575 (94.73) | 580 (95.55) | |||||||
| Hospital geographic location | 0.62 | 0.76 | 0.97 | 0.4 | |||||||||||
| Midwest | 89 (7.83) | 89 (7.83) | 191 (11.05) | 193 (11.16) | – | – | 30 (4.94) | 27 (4.45) | |||||||
| Northeast | 273 (24.03) | 250 (22.01) | 430 (24.87) | 422 (24.41) | 74 (27.51) | 76 (28.25) | 197 (32.45) | 219 (36.08) | |||||||
| South | 650 (57.22) | 679 (59.77) | 956 (55.29) | 944 (54.60) | 154 (57.25) | 151 (56.13) | 380 (62.60) | 361 (59.47) | |||||||
| West | 124 (10.92) | 118 (10.39) | 152 (8.79) | 170 (9.83) | 41 (15.24) | 42 (15.61) | |||||||||
| Hospital teaching status | 0.85 | 0.18 | 0.73 | 0.56 | |||||||||||
| Academic | 857 (75.44) | 852 (75.00) | 1,084 (62.70) | 1,123 (64.95) | 223 (82.90) | 227 (84.39) | 585 (96.38) | 580 (95.55) | |||||||
| Community | 279 (24.56) | 284 (25.00) | 645 (37.30) | 606 (35.05) | 46 (17.10) | 42 (15.61) | 22 (3.62) | 27 (4.45) | |||||||
| Hospital metropolitan location | 0.66 | 0.38 | N/A | N/A | |||||||||||
| Rural | 70 (6.16) | 64 (5.63) | 76 (4.40) | 88 (5.09) | – | – | – | – | |||||||
| Urban | 1,066 (93.84) | 1,072 (94.37) | 1,653 (95.60) | 1,641 (94.91) | 269 (100.00) | 269 (100.00) | 607 (100.00) | 607 (100.00) | |||||||
| Hospital annual VL/RL volumea | 0.08f | 0.07 | N/A | N/A | |||||||||||
| ≤25 | 652 (57.39) | 592 (52.11) | 971 (56.16) | 917 (53.04) | – | – | – | – | |||||||
| >25 | 484 (42.61) | 544 (47.89) | 758 (43.84) | 812 (46.96) | 269 (100.00) | 269 (100.00) | 607 (100.00) | 607 (100.00) | |||||||
a, the propensity score has been generated from multivariate logistic regression adjusted for age (18-44/45-64/65-80/80+), gender (female/male), race (black/white/Hispanic/other), insurance type (Medicare/Medicaid/commercial/other or self-pay), malignancy indication (primary neoplasm of lung/metastases other than lung), Charlson comorbidity score (0/1–2/≥3), obesity status (obese/without obese diagnosis), previous/current smoker (yes/no), year (2008/2009/2010/2011/2012), attending surgeon specialty (thoracic/cardiovascular/other surgeons), surgeon volume in previous 12 months (≤10/11–25/>25), bed size (0–199/200–399/≥400), hospital geographic location (Midwest/Northeast/South/West), hospital teaching status (academic/community), hospital metropolitan location (rural/urban), hospital annual VL/RL hospital (≤5/6–15/16–25/>25). b, the propensity score has been generated from multivariate logistic regression adjusted for age (18–44/45–64/65–80/80+), gender (female/male), race (black/white/Hispanic/other), insurance type (Medicare/Medicaid/commercial/other or self-pay), malignancy indication (primary neoplasm of lung/metastases other than lung), Charlson comorbidity score (0/1–2/≥3), obesity status (obese/without obese diagnosis), previous/current smoker (yes/no), year (2013/2014/2015), attending surgeon specialty (thoracic/cardiovascular/other surgeons), surgeon volume in previous 12 months (≤10/11–25/>25), bed size (0–199/200–399/≥400), hospital geographic location (Midwest/Northeast/South/West), hospital teaching status (academic/community), hospital metropolitan location (rural/urban), hospital annual VL/RL hospital (≤25/>25). c, the propensity score has been generated from multivariate logistic regression adjusted for age (18–44/45–64/65–80/80+), gender (female/male), race (black/white/Hispanic/other), insurance type (Medicare/Medicaid/commercial/other or self-pay), malignancy indication (primary neoplasm of lung/metastases other than lung), Charlson comorbidity score (0/1–2/≥3), obesity status (obese/without obese diagnosis), previous/current smoker (yes/no), year (2008/2009/2010/2011/2012), attending surgeon specialty (thoracic/cardiovascular/other surgeons), surgeon volume in previous 12 months (≤10/11-25/>25), bed size (0-199/200-399/≥400), hospital geographic location (Midwest/Northeast/South/West), hospital teaching status (academic/community), hospital metropolitan location (rural/urban). d, the propensity score has been generated from multivariate logistic regression adjusted for age (18–44/45–64/65–80/80+), gender (female/male), race (black/white/Hispanic/other), insurance type (Medicare/Medicaid/commercial/other or self-pay), malignancy indication (primary neoplasm of lung/metastases other than lung), Charlson comorbidity score (0/1–2/≥3), obesity status (obese/without obese diagnosis), previous/current smoker (yes/no), year (2013/2014/2015), attending surgeon specialty (thoracic/cardiovascular/other surgeons), surgeon volume in previous 12 months (≤10/11–25/>25), bed size (0–199/200–399/≥400), hospital geographic location (Midwest/Northeast/South/West), hospital teaching status (academic/community), hospital metropolitan location(rural/urban). e, Chi-square test and Wilcoxon rank-sum test were used to test for significance. f,.P value was generated from Chi-square test to exam the difference of hospital annual VL/RL volume (≤5/6–15/16–25/>25) among VL and RL from 2008–2012. BMI, body mass index; N/A, not applicable; RL, robotic-assisted lobectomy; VL, video-assisted thoracoscopic lobectomy.