Office Spirometry Before Lung Resection

Supplemental Table 1: List of variables included in the propensity score model, excluding interactions where applicable. Variables with p<0.05 in univariate analysis or biologic plausibility as true confounders were included. Reference group: 40-50 year old male, white, American Society of Anesthesiologist (ASA) class 1-2, Zubrod 0, no comorbidities, normal body mass index, never smoker, FEV1 90-100%, benign indication, wedge resection, via thoracoscopic approach.

Variable Description / Variable Type
Age, in years / Categorical, 10-year increments
ASA classification / Categorical, range 1-4
Body mass index (kg/m2) / Categorical, per Centers for Disease Control
Comorbidity cerebrovascular disease / Binary
Comorbidity chronic obstructive pulmonary disease / Binary
Comorbidity congestive heart failure / Binary
Comorbidity coronary artery disease / Binary
Comorbidity current dialysis / Binary
Comorbidity diabetes mellitus / Binary
Comorbidity dysrhythmia / Binary
Comorbidity dysrhythmia / Binary
Comorbidity hypertension / Binary
Comorbidity hypertension / Binary
Comorbidity prior cancer diagnosis / Binary
Comorbidity pulmonary hypertension / Binary
Forced expiratory volume in 1 second (FEV1) / Categorical, 10% predicted increments
Forced vital capacity (FVC) / Continuous, in percent predicted
Gender / Binary
Malignant disease indication / Binary
Race / Binary
Smoking, current status / Categorical (never, current, past)
Smoking, exposure history / Continuous, in pack-years
Surgical incision type / Categorical (wedge, lobectomy, bullectomy)
Surgical resection type, intention to treat / Categorical (thorascopic, open, sternotomy)
Zubrod score <1 / Binary

Supplemental Table 2: Univariate analysis of low-risk lung resection patients who received office spirometry compared to those who received laboratory spirometry, who did not match via propensity score. Censoring performed for missing values. SD; standard deviation. ASA, American Society of Anesthesia; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; SD, standard deviation.

Unmatched cohort
(N=1053)
No. of patients (%)
Characteristics / Office spirometry (N=11) / Laboratory spirometry (N=1042) / p value
Age, mean (SD), in years / 56.88 (15.63) / 62.89 (12.21) / 0.106
Male sex / 5 (45.45) / 611 (58.64) / 0.377
Race / White / 7 (63.64) / 918 (88.10) / *0.014
Other / 4 (36.36) / 124 (11.90) / *0.014
Body mass index, mean (SD) / 29.12 (6.91) / 27.94 (6.37) / 0.544
Smoking / Never smoker / 5 (45.45) / 279 (26.78) / 0.165
Former smokera / 4 (36.36) / 492 (47.22) / 0.473
Current smoker / 2 (18.18) / 271 (26.01) / 0.556
Smoking exposure, mean (SD), in pack-years / 25.27 (27.62) / 32.46 (32.96) / 0.471
FEV1% predicted, mean (SD) / 85.88 (19.29) / 88.13 (16.49) / 0.708
FVC% predicted, mean (SD) / 88.08 (36.95) / 96.04 (16.17) / 0.112
Number of preoperative comorbidities, mean (range) / 1 (0-3) / 0.99 (0-5) / 0.979
ASA classification / 1-2 / 6 (54.55) / 283 (27.16) / *0.043
3 / 4 (36.36) / 759 (72.84) / *0.007
4b / 1 (9.09) / 0 / *<0.001
Disease Category / Benign / 2 (18.18) / 152 (14.59) / 0.737
Malignant / 9 (81.82) / 890 (85.41) / 0.737
Surgery type / Wedge resection / 4 (36.36) / 352 (33.78) / 0.857
Segmentectomy / 0 / 49 (4.70) / 0.461
Lobectomy / 7 (63.64) / 605 (58.06) / 0.709
Bilobectomy / 0 / 28 (2.69) / 0.582
Bullectomy / 0 / 8 (0.77) / 0.771
Incision typec / Thoracoscopy / 10 (90.91) / 784 (75.24) / 0.230
Thoracotomy / 0 / 258 (24.76) / 0.058
Sternotomy / 1 (9.09) / 0 / *<0.001
aQuit >1 month prior. bShould have been screen fail. cIntention to treat.