RT Journal Article SR Electronic T1 The dangers of widespread nitric oxide screening for primary ciliary dyskinesia JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 560 OP 561 DO 10.1136/thoraxjnl-2015-208056 VO 71 IS 6 A1 Samuel A Collins A1 Laura Behan A1 Amanda Harris A1 Kerry Gove A1 Jane S Lucas YR 2016 UL http://thorax.bmj.com/content/71/6/560.abstract AB Primary ciliary dyskinesia (PCD) is underdiagnosed and requires complex testing at specialist diagnostic centres. Measurement of nasal nitric oxide (nNO) has good sensitivity and specificity screening for PCD, but is currently usually measured at PCD centres rather than prior to referral. Proposals to include NO testing for asthma diagnoses could widen access to PCD screening if nasal mode analysers are available. Data from 282 consecutive referrals to our PCD diagnostic centre (31 PCD positive) were used to model predictive values for nNO testing with varying pretest probability and showed that predictive values were good in the referral population, but extending screening to more general populations would result in excessive false positives that may overwhelm diagnostic services. Although nNO remains a useful test, a ‘normal’ result with classical clinical history should still be considered for further testing.