eTable 1. Qualitative synthesis of identified retrospective studies dealing with spirometry*1.
| Study | Cohort | Findings | |||
| First author,year (reference) | Number of patients | Preselection: type of surgery | Preselection: demographics and existing diseases | For/against spirometry*2 | Positive index test |
| Kispert 1992 (e11) | 147 | Major vascular surgery | − |
 for |
FEV1, FEV1/FVC |
| Kroenke 1992 (e12) | 89 | Mixed | Severe COPD, FEV1 < 50% |
against |
− |
| Kroenke 1993 (e15) | 130 | Thoracic and major abdominal surgery*5 | 78 with COPD, 52 without COPD |
 against*4
|
− |
| Moriyama 1994 (e16) | 103 | Aneurysm surgery | − |
for |
VC % |
| Lawrence 1996 (e18) | 164 | Abdominal surgery*6 | Only men |
against |
− |
| Fuso 2000 (e22) | 480 | Abdominal surgery | > 70 years, obesity, smokers, cough, any pulmonary disease |
for |
FEV1 %, FEV1/FVC |
| Joo 2009 (e28) | 111 | Partial laryngectomy | − |
against |
FEV1/FVC % |
| Silva 2010 (e29) | 521 | Mixed | At discretion*3 |
against |
FVC % |
| Ferguson 2011 (e30) | 516 | Esophagectomy | − |
for |
FEV1 %, DLCO % |
| Huh 2013 (e32) | 213 | Laparoscopic gastrectomy | ≥ 60 years |
against |
FEV1 %, FEF25–75, FEF25–75%, FEV1/FVC % |
| Inokuchi 2014 (e34) | 1053 | Gastrectomy | − |
for |
VC % |
| Clavellina-Gaytán 2015 (e36) | 602 | Obesity surgery | − |
against*7
|
FEV1 %, FVC % |
| Jeong 2014 (e35) | 2059 | Mixed | At discretion*3 |
for |
airflow obstruction |
| Kim HJ 2016 (e37) | 405 | Mixed | COPD |
for*8
|
FEV1 % |
| Kim TH 2016 (e38) | 387 | Abdominal surgery | ≥ 40 years, comorbidities or abnormal lung function, at discretion*3 |
against*9
|
− |
| Miki 2016 (e39) | 750 | Gastrectomy | − |
for |
abnormal PFT |
| Reinersmann 2016 (e40) | 136 | Esophagectomy | − |
for |
FEV1 %, DLCO % |
| Tajima 2017 (e43) | 1236 | Colorectal | − |
for |
FEV1, FEV1 %, VC % |
| Hirosako 2018 (e44) | 386 | Mixed | At discretion*3 |
for |
FEV1 % |
| Oh 2018 (e45) | 898 | Laparoscopic gastrectomy and colorectal | > 60 years, chronic pulmonary disease, smokers |
for |
FEV1 %, FVC %, DLCO
|
= Univariate analysis, = multivariate analysis; study design: findings/conclusions based on: univariate analysis, multivariate analysis.
*1 in genera,l retrospective studies are suspicious for selection bias, as the indication for PFT typically relies on non-reproducible individual clinical consideration or is at the discretion of a physician (referral pattern);
*2 Conclusions drawn by the authors based on published study findings and clinical considerations
*3 Patients were preselected at the discretion of a physician (in most cases a surgeon or anesthetist) and referred to an internist, pulmonologist, respiratory physician, or specialized department (referral pattern must be considered)
*4 Clinical variables appeared to be non-inferior to spirometry
*5 Study design: matched cohort
*6 Study design: case–control
*7 ”Abnormal spirometry” was no longer an independent predictor in the multivariable model when ”obstructive sleep apnoea” and ”respiratory symptoms” were subtracted.
*8 Only GOLD groups A/B versus C/D, which are based on clinical data, were used in the multivariable model, while GOLD grades 1–4, determined by spirometry, were evaluated in a descriptive/univariable analysis.
*9 Patients with mild to moderate COPD (FEV 1 ≥ 50% predicted) were compared with a control group
COPD, Chronic obstructive pulmonary disease; D LCO , diffusing capacity for carbon monoxide; FEF25–75%, mean forced expiratory flow over 25–75% of FVC; FEV 1, forced expiratory volume in one second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; PFT, pulmonary function tests; VC, vital capacity