Population and data description
Data for analysis were collected from January 2009 to December 2016. The study base population consisted of 407 patients from each unit. While 407 was the actual number of consecutive patients evaluated at the Secondary Unit during the 8-year period, we selected a random sample of 407 from 6,960 consecutive patients evaluated at the unit of the tertiary center during the same period. By using online random sampling software (https://www.randomizer.org/), randomization was performed for each year of the study to match the annual number of patients of the secondary hospital unit.
Computerized medical records stored in the information systems of the hospitals were compiled. Demographic, clinical, and economic data were analyzed to determine the patient sample and calculate the costs. Data collected included age, gender, referral sources, time-to diagnosis, ratio of successive/first visits, clinical indications for referral, and final diagnosis. For the study purpose, indications for referral were dichotomized into symptoms suggestive of cancer vs. other symptoms and final diagnosis was subdivided into malignant vs. nonmalignant diseases. The study was carried out in line with the principles of the Declaration of Helsinki. Approvals were granted by the research ethics committee of the tertiary university hospital and the network of hospitals to which the second-level hospital belongs to (Comitè d’Ètica de la Investigació Clínica [CEIC]-Unió Catalana d’Hospitals). Need for informed consent was waived due to the retrospective design of this study.