Selected markers that could be used to determine the natural history of patients with chronic obstructive pulmonary diseases

Strength of evidenceValue in helping to determine disease extentCommentRef.
 Spirometry (FEV1 and FVC)AAGold standard of disease severity and progression[33, 34, 48–50, 60]
 Lung volumesCAClinically valid
Poor data about use over time
 Diffusion capacity for COCAClinically valid
Poor data about its natural course
 Chest radiographyABClinically valid
Poor data bout its natural course
 Chest tomographyAAClinically valid
Some data over time
Useful for emphysema
Functional Capacity
 Timed walking distanceAAPredictor of outcome
Moderate evidence of longitudinal change
[80, 81]
 Cardiopulmonary exercise testAAUseful to determine reserve and endurance
No longitudinal data
[70, 82]
Perceptive domain
 Dyspnoea scalesAAPredictors of outcome
Significant data about its change over time
 Health status or quality of lifeAAGood determinant of disease effect
Good data for evolution over time
[65, 66, 86]
 SystemicBCNo biomarker has been identified as clinically useful[87–89]
 Breath condensateCCLimited experimental use[87]
 BODEAAPredicts outcome
Some longitudinal data, supports its clinical use
[55, 90–92]
 ADOBBPredicts outcome
No longitudinal data
 DOSEBBPredicts outcome
No longitudinal data

Strength of evidence (A–C): this strength represents the evidence from the literature. Value for helping to determine disease extent (A–C): this qualifier relates to the help it offers to evaluate disease extent. FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; BODE: body mass index, obstruction, dyspnoea and exercise; ADO: age, dyspnoea and obstruction index; DOSE: dyspnoea, obstruction, smoking and exacerbations.