Statistical analysis
lung cancer, lung cancers, cancers
LUNG CANCER, LUNG CANCERS, CANCERS
We originally anticipated that the intervention would confer a difference of 11 days in time to diagnosis of lung cancer, and a common SD of 14 days. For 80% power to detect this as significant (2-sided testing), we would need 54 cancers in total. This is approximately the number of lung cancers expected in a year at HUH, so the study was designed to run for a year.The primary analysis, comparison of times to diagnosis and discharge in those with possible lung cancer, was done using the t-test. We applied the test after log-transformation, after testing for departure from normality, since we observed that the distribution of times was strongly asymmetrical. For comparison with NUH, we compared times with diagnosis and discharge for each reporting group (immediate and standard) with the overall times to diagnosis and discharge in NUH (in which all reporting was standard) using the same method (t-test after log transformation). All tests were two-sided.The number of urgent respiratory referrals was compared between the two groups using the χComparison of ratings of radiologist and radiographer reports by the reviewing thoracic radiologist used McNemar methods, as they involved matched pair comparison (each case being reported by both and therefore being his or her own control).