Developing a complex intervention for the outpatient management of incidentally diagnosed pulmonary embolism in cancer patients

BACKGROUND Most patients with pulmonary embolism (PE) spend 5-7 days in hospital even though only 4.5% will develop serious complications during this time. In particular, the group of patients with incidentally diagnosed PE (i-PE) includes many patients with low risk features potentially ideal for outpatient management; however the evidence for their optimal management is lacking hence relative practices may vary considerably. We describe the development process, components, links and function of a nurse-led service for the management of patients with i-PE, developed in accordance to the UK Medical Research Council complex intervention guidance. METHODS Phase 0 (Theoretical underpinning): The Pulmonary Embolism Severity Index (PESI) was selected for patient risk assessment and the American Society of Clinical Oncology (ASCO) guideline for the management of PE in cancer patients (2007) was selected as quality measure. Historical registry and audit data from our centre regarding i-PE incidence and management for the period between 2006 and 2009 illustrating the then current practices were reviewed. Phase 1 (Modelling): Modelling of the pathway included the following: a) Identification of training needs, planning and implementation of training schemes and development of transferable competencies and training materials. b) Mapping patient pathways and flow and c) Production of key documentation and Standard Operating Procedures for the delivery of the service. RESULTS Phase 2 (Implementation and testing of the intervention): During the initial 12 months of implementation, remedial action was taken to address identified deficiencies regarding patient referral to the pathway, compliance with treatment protocol, patient follow up, selection challenges from the use of PESI in cancer patients and challenges regarding the "first-pass" identification of i-PE. CONCLUSION We have developed and piloted a complex intervention to manage cancer patients with incidental PE in an outpatient setting. Adherence to evidence- based care, improvement of communication between professionals and patients, and improved quality of data is demonstrated.