Measures of promptness of cancer diagnosis in primary care: secondary analysis of national audit data on patients with 18 common and rarer cancers

Background: Evidence is needed about the promptness of cancer diagnosis and associations between its measures. Methods: We analysed data from the National Audit of Cancer Diagnosis in Primary Care 2009–10 exploring the association between the interval from first symptomatic presentation to specialist referral (the primary care interval, or ‘interval’ hereafter) and the number of pre-referral consultations. Results: Among 13 035 patients with any of 18 different cancers, most (82%) were referred after 1 (58%) or 2 (25%) consultations (median intervals 0 and 15 days, respectively) while 9%, 4% and 5% patients required 3, 4 or 5+ consultations (median intervals 34, 47 and 97 days, respectively) (Spearman’s r=0.70). The association was at least moderate for any cancer (Spearman’s r range: 0.55 (prostate)−0.77 (brain)). Patients with cancers with a higher proportion of three or more pre-referral consultations typically also had longer median intervals (e.g., multiple myeloma) and vice versa (e.g., breast cancer). Conclusion: The number of pre-referral consultations has construct validity as a measure of the primary care interval. Developing interventions to reduce the number of pre-referral consultations can help improve the timeliness of cancer diagnosis, and constitutes a priority for early diagnosis initiatives and research.