Table 2. Quantitative analysis of prospective studies investigating the association between spirometry prior to upper abdominal surgery and postoperative pulmonary complications*¹.

Study		Index test	Reference standard
First author,year (reference)	Number of patients	Standards for spirometry	Prevalence of PPC (%)	Index parameter cut-off value	Sensitivity	Specificity	PPV	NPV	For/against spirometry*2
Kocabas 1996 (e17)	60	ATS	35%	FEV1 < 1,25 l	50%	70%	38%	70%	against*4
				FEV1 % < 50%	62%	70%	38%	70%
				FEV1/FVC < 50%	38%	65%	14%	65%
				Abnormal spirometry*3	67%	76%	67%	76%
Barisione 1997 (e19)	361	ATS, ERS	14%	Abnormal spirometry*3	84%	99%	95%	98%	for
Kanat 2007 (e27)	60	ATS, ERS	58%	Abnormal spirometry*3	66%	55%	71%	55%	for
Jeong 2013 (e33)	538	GOLD	2%	Abnormal spirometry*3	6%	99%	60%	99%	for*5

= Univariate analysis, = multivariate analysis; study design: findings/conclusions based on: univariate analysis, multivariate analysis.

*¹ Only studies with a low risk of selection bias in QUADAS-2 analysis were included.

*² Conclusions drawn by the authors based on published study findings and clinical considerations

*³ According to the definition given in the study concerned

*⁴ Clinical parameters appeared to be non-inferior to spirometry.

*⁵ Multivariable analysis was performed only for the outcome measure “postoperative morbidity” (this includes surgical complications such as anastomosis leakage and wound complications)

ATS, American Thoracic Society; ERS, European Respiratory Society; FEV ₁, forced expiratory volume in one second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; NPV, negative predictive value; PFT, pulmonary function tests; PPC, postoperative pulmonary complications; PPV, positive predictive value; QUADAS, Quality Assessment of Diagnostic Accuracy Studies