Diagnostic delay in cancer is a difficult subject to study with many confounder factors. Several papers have been published with controversial results about the relationship between delay and survival, although there is a clear tendence for a worse prognosis with longer delays. We will expose some of the confounder factors and biases that can interact with the association between delay and survival.
This is real good news. Putting Diagnostic Improvement in practice. I,m sure The Center will be a reference for all who are working in the field 0f clinical reasoning and improving diagnosis. Dr.Newman-Toker is a brilliant and clever communicator and an expert in the field of Diagnostic error. Congratulations.
There are three basic models of cancer care in the literature, two of them derived from the world of the psychology , the Safer model and the Andersen model , widely used in publications, and the third one coming from the medical general practice world, the Olesen model  developed in Denmark. Based on her publication we think is also worth to introduce a fourth model, the Walter model , a refinement of the Andersen model, that introduces the term “time interval” rather than delay.
The time between symptom recognition and a definitive diagnosis have been described in many terms including ‘Time-to-Diagnosis’ (TtD), delay to diagnosis, pre-diagnostic interval and duration of symptoms in the literature  and we will use TtD across this paper. The concept of the term “delay” assumes that there is an ideal period of time to arrive to a diagnosis in a patient with cancer
There is a good rational to assume that the smaller a tumor the better the outcome. However, there are several variables and prognostic factors involved in the clinical evolution of a patient, not only time. The process of diagnostic in cancer have been artificially divided in different segments related to the patient, the appointment with a doctor and the pattern of referral. In all these models the physician looks like the perfect machine prepared for a perfect diagnosis….