COPD: high-yield clinical criteria did not predict chest X-ray abnormalities

Clinical bottom line (level 2b)

40% of patients with acute exacerbations of COPD had an abnormality on chest X-ray.
High-yield criteria did not usefully identify patients who will have an abnormality on chest X-ray.

Emerman and Cydulka: Annals of Emergency Medicine 1993; 22: 680-684

Expires November 2003

The study

Setting: emergency department, acute hospital, USA

254 patients (aged mean 62, 53% female) with 685 episodes of acute exacerbations of COPD

Excluded if

no medical records available

no chest X-ray taken

Independent blinded reference standard, applied in all patients from a consecutive appropriate spectrum.
Reference standard:

abnormality on chest X-ray diagnosed by radiologist

Diagnostic test: high-yield criteria

history of congestive heart failure or coronary artery disease
oedema
chest pain
while cell count > 15 x 10 ⁹

The evidence

pre-test probability of abnormality on chest X-ray: 43%, (95% CI: 37% to 49%)

diagnostic test	abnormality on chest X-ray	no abnormality	LR+ (95% CI)	post-test probability	LR- (95% CI)	post-test probability
high-yield criteria met	83	86	1.3 (1.1 to 1.5)	49%	0.59 (0.40 to 0.86)	31%
total	109	145

Comments

This study was a retrospective chart review to validate a clinical prediction rule.
The important question is the likelihood of harm to a patient when there is delay in detection of an abnormality on chest X-ray resulting in delay in treatment - it is difficult to extract this information from the study here.

Citation

Emerman CL, and Cydulka RK: evaluation of high-yield criteria for chest radiography in acute exacerbation of chronic obstructive pulmonary disease. Annals of Emergency Medicine 1993; 22: 680-684

Search Terms: ?
Contributor: Bob Phillips and Chris Ball, November 1999
Reviewer: Gerard Ryan

_{Clinical Question.}

_Patient	_{acute exacerbation of COPD}
_{Intervention or Exposure}	_{high-yield criteria}
_Outcome	_{abnormality on chest X-ray}