The sensitivity and positive predictive value of GP two-week wait referrals for lung cancer

Abstract

Introduction: In 2012, lung cancer was responsible for >35,000 deaths in the UK. In the UK NHS, the two-week wait (2WW) pathway exists to facilitate urgent referral by general practitioners (GP) of patients in whom cancer is suspected to the appropriate specialist. This study examined the 2WW pathway for lung cancer at a London university hospital, analysing data included by referrers and calculating the sensitivity and positive predictive value for lung cancer diagnosis via this pathway. Methods: 156 GP 2WW referral forms were analysed between March and September 2014. Whole year (2014) data for confirmed lung cancer cases were analysed and their provenance identified. Results: The most common indication (46%) for 2WW referral is a chest x-ray suggestive of lung cancer. In 40% of cases, the fact that an urgent referral for suspected cancer has been made is not discussed with the patient. In 41% of cases, clinical information regarding symptoms is not included. Of 156 GP referrals, 23 were confirmed to have lung cancer; positive predictive value = 0.147. Of 134 lung cancers diagnosed in 2014, 57 arose from GP 2WW referrals; sensitivity = 0.428. Discussion A large minority of 2WW referral forms are incompletely filled by the referring clinician. The positive predictive value (0.147) and sensitivity (0.428) of 2WW referrals for lung cancer is in keeping with the national average for 2WW referrals for all cancers (0.11 and 0.43, respectively).