Table 3.

COPD* and its potential overdiagnosis using postbronchodilator spirometry: COPD case series in primary healthcare settings

Author year Citation	Study name location	Participant no† (%eligible) ‡, Selection, no/type of GP practices	Gender Age (mean (SD) years)	COPD cases (COPD±ACO)	Prevalence of spirometry-defined COPD (%, (n/N))§	Overdiagnosis in those labelled with COPD (%, (n/N))§
Fisk et al, 201950	Welsh COPD Primary Care Audit, UK	N=8957 (18.6%) Patients on the QOF COPD register used by 280 (61%) of 462 Welsh GP practices who had post-BD FEV1/FVC read-coded*	54% male 72 (12) years range 36–105	COPD	74.8% (6702/8957)	25.2% (2255/8957)
Ghattas et al, 201351	USA	N=80† Consecutive patients either with COPD or clinically managed for COPD symptoms; Single health centre	40.0% male 52.9 (7.7) years	COPD and ACO	35.0% (28/80)	65.0% (52/80)¶
Walters et al 201152	TAS, Australia	N=341 (28%) Non-consecutive adult patient 40–80 years managed for COPD with >10 pack-years and ≥1 GP visit last 12 months; from 31 urban/rural practices	48.8% male Non-COPD 59 (9) COPD 64 (8) years	COPD	68.6% (234/341)	31.4% (107/341)
Zwar et al 201153	PELICAN study, NSW Australia (prior to randomisation)	N=445 (38.9%) Non-consecutive adults 40–80 years clinically managed for COPD; 56 GPs from 44 practices	No COPD: 44% males; 62 (11) COPD±asthma: 52% males; 67 (10)	COPD and ACO	57.8% (257/445)	42.2% (188/445)¶
Sichletidis et al, 200754	Northern Greece	N=319 (87.4%) Non-consecutive adult patients >40 years treated with a COPD diagnosis; 8 health centres	Symptomatic COPD cases 83.8% male Age-N/A	COPD and ACO (n=5)	50.1% (160/319)	49.9% (159/319)

*COPD as defined by post-BD airflow obstruction on spirometry testing.

†COPD prevalence could be inaccurate due to insufficient sample size (online supplemental results E4), so study has been omitted from the forest plot in a sensitivity analysis.

‡All % eligible figures were calculated.

§COPD was defined by airflow obstruction detected by postbronchodilator spirometry using the GOLD criterion (forced expiratory ratio <0.70)

¶Data needed to be deduced and calculated from the figures given (by the present authors).

ACO, asthma-COPD overlap; BD, bronchodilator; COPD, Chronic obstructive pulmonary disease; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; GP, general practitioner; QOF, quality and outcomes framework.