Prediagnostic primary care consultations and imaging in emergency-diagnosed versus referred patients with lung cancer: a population-based linked data study.

Abstract

Emergency diagnosis of lung cancer is common and associated with worse prognosis. To compare prediagnostic healthcare use between emergency-diagnosed patients and patients referred routinely or urgently. Population-based linked English primary care, hospital admission, imaging, and cancer registration data were analysed for patients with lung cancer (2007-2018). Monthly prediagnosis rates of consultations (for any clinical reason and selected symptoms) and chest imaging by diagnostic route (emergency, routine referral, and urgent referral) were measured. Multivariable Poisson regression estimated route-specific event rates and inflection points. The study examined 4473 patients with lung cancer with features representative of the nationwide incident cohort, of whom 33% (<i>n</i> = 1491) were emergency diagnosed. Most (emergency diagnosis, <i>n</i> = 1473/1491; routine referral, <i>n</i> = 1023/1026; urgent referral, <i>n</i> = 1252/1259; and other, <i>n</i> = 684/697) had consulted in primary care in the year prediagnosis, independent of diagnostic route. Consultation and imaging rates increased from 5- and 4-months prediagnosis, respectively, with shorter diagnostic windows in emergency-diagnosed than referred route patients. Compared with emergency-diagnosed patients, referred route patients had higher prediagnostic consultations rates for cough (adjusted incidence rate ratio [aIRR] compared with emergency-diagnosed 1.90, 95% confidence interval [CI] = 1.58 to 2.30 for routinely and 1.94, 95% CI = 1.61 to 2.33 for urgently referred) and chest X-ray use (aIRR 1.91, 95% CI = 1.53 to 2.38 for routinely and 1.77, 95% CI = 1.42 to 2.21 for urgently referred). Similar or shorter diagnostic windows suggest similar potential for earlier diagnosis among emergency-diagnosed and referred route patients alike. Earlier detection may be supported through improved management of non-specific symptoms, timely follow-up of imaging, and greater access to chest computed tomography. Future research should measure missed diagnostic opportunities to identify clinical actions to further reduce emergency lung cancer diagnoses.