<p>Impacts of Different Spirometry Reference Equations and Diagnostic Criteria on the Frequency of Airway Obstruction in Adult People of North China</p>

Abstract

Background and Objective: The reference equations and diagnostic criteria play a critical role in the interpretation of pulmonary function tests (PFTs). The aim was to investigate the impacts of different reference equations and diagnostic criteria on the frequency of airway obstruction in adult people of a large teaching hospital of North China. Methods: The spirometry data of all adult people who underwent PFTs in Qilu hospital from April 2012 to November 2015 were collected. Two spirometry reference equations, namely, Zhongshan-2011 and Global Lung Function Initiative 2012 (GLI-2012) were compared. The frequency of airway obstruction using different spirometry prediction equations and diagnostic criteria including forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <92% of predicted value and FEV1/FVC <lower limits of normal (LLN) were investigated. Results: A total of 57,888 subjects were recruited with a mean age of 55.5 ± 13.72. There were significant differences in LLN and predicted value between the GLI-2012 and Zhongshan-2011. The average age of those who had an LLN of FEV1/FVC below 0.7 was 66.59 ± 6.05 years using GLI-2012, which was significantly lower than that in Zhongshan-2011 (77.46±2.63, P<0.001). Using FEV1/FVC<LLN as diagnostic criteria, Zhongshan-2011 identifies more obstructive subjects than GLI-2012 in each age group. In 45-59 or 60-80 age group, more participants were defined as obstructive using FEV1/FVC<92%pred than FEV1/FVC<LLN (both P<0.001). Conclusion: Zhongshan-2011 identifies more airway obstruction than GLI-2012 in adult people of North China. Compared to FEV1/FVC<LLN, FEV1/FVC<92%pred may lead to overdiagnosis of airway obstruction in elderly people.

Airway obstruction can be better predicted using Global Lung Function Initiative spirometry reference equations in Marfan syndrome

“…The need of more precise LF calculations considering more aspects arose as published by Quanjer et al in 2012. Diagnostic thresholds must account for age-and gender-related changes for LF [20,21]. Potential misidentification of respiratory disease, especially in aging populations is a major public health concern.…”

Asymptomatic Patients with Airflow Limitation are at Higher Risk of Postoperative Pulmonary Complications After Lung Surgeries: An Ambispective Cohort Study

“…A total of up to 11.4% (126/535) patients undergoing lung surgeries were spirometrically diagnosed as AFL using the fixed ratio (FEV 1 /FVC <70%) though preoperative spirometry and the incidence were in accordance with previous studies. 3,4,6,19 Generally, elderly males with higher levels of tobacco exposure tended to suffer from AFL. Our study confirmed that asymptomatic patients with AFL were at higher risk of PPCs than the general population in those who had undergone lung surgeries, accompanied by an GOLD guidelines recommended the use of postbronchodilator spirometry test and the fixed ratio as cutoff point (instead of lower limit of normal (LLN)) to confirm the presence of persistent airflow limitation.…”

“…Previous evidence has shown that the incidence of newly diagnosed AFL is far more higher than expected. [3][4][5][6][7] Additionally, GOLD (Global Initiative for Chronic Obstructive Lung Disease) guidelines have indicated that never smokers with chronic airflow limitation may have no increased risk of lung cancer or cardiovascular comorbidities. 1,4,8,9 Postoperative pulmonary complications (PPCs), whose majority are postoperative pneumonia (POP) and respiratory failure, are common and frequently life-threatening in patients who have undergone lung surgeries, [10][11][12][13] with an incidence ranging from 9% to 40% due to the lack of recognized definitions.…”

Pulmonary and renal long COVID at two-year revisit

“…Patients with ventilation and/or diffusion dysfunction are diagnosed with abnormal pulmonary function. A ventilation dysfunction can be obstructive (FEV1/FVC <92% of the predicted value (pred)) 38 or restrictive (TLC <80% pred, and for patients who did not have TLC records, FVC < LLN or <80% of pred accompany with FEV1/FVC ≥92% pred 39 , 40 ). Patients with two of the three indicators in FEF50%, FEF75%, and FEF 25%–75% lower than the pred of 65% were diagnosed with small airway dysfunction.…”