The value of routine sinus roentgenograms in the diagnostic evaluation of the patient with chronic cough

Purpose: The purpose of the study was to determine the diagnostic (dx) value of routinely obtaining sinus x-rays in the evaluation of patients with chronic cough. Methods: 35 consecutive patients with cough of 4 weeks or > duration underwent initial sinus xrays. They were divided into 2 groups (productive cough >loz or non-productive cough <loz). Patients with air-fluid levels or sinus opacification (but not mucosal thickening alone) were initially rxed for sinusitis (including antibiotic rx). Empiric antihistamine and decongestant therapy was given to all other pts without definitive sinusitis as part of a standard diagnostic protocol. Standard dx criteria for cause(s) of chronic cough were used. Results: 11/35 pts had abnormal (abn) sinus xrays (8 thickening, 2 opacified, 1 air-fluid level). 5/11 had a final dx of chronic sinusitis, The positive predictive value of an abnormal xray was .45, the negative predictive value was 1.0. 8/17 pts with a productive cough had abn xrays. The +pred.value in this group was .5, -pred value 1.0. 3/18 pts with a non-productive cough had an abn xray and 2/3 were false+. The presence of a productive cough alone had a +pred value for sinusitis of .24. The presence of a non-productive cough alone had a -pred value of .94. Only 3/8 pts with thickening had sinusitis as dx for cough. Conclusions: In the dx evaluation of chronic cough, routine sinus xrays are not indicated. They are rarely useful in non-productive cough. Even in pts with productive cough, the +pred value is only .45 and mucosal thickening alone does not prove sinusitis is dx. Clinical Implications: The standard dx protocol for the evaluation of chronic cough should not included routine sinus xrays. In pts with productive cough, the early use of sinus xrays is reasonable.