The Andersen Model of Total Patient Delay: a systematic review of its application in cancer diagnosis

OBJECTIVE Patient pathways to presentation to health care professionals and initial management in primary care are key determinants of outcomes in cancer. Reducing diagnostic delays may result in improved prognosis and increase the proportion of early stage cancers identified. Investigating diagnostic delay could be facilitated by use of a robust theoretical framework. We systematically reviewed the literature reporting the application of Andersen's Model of Total Patient Delay (delay stages: appraisal, illness, behavioural, scheduling, treatment) in studies which assess cancer diagnosis. METHODS We searched four electronic databases and conducted a narrative synthesis. Inclusion criteria were studies which: reported primary research, focused on cancer diagnosis and explicitly applied one or more stages of the Andersen Model in the collection or analysis of data. RESULTS The vast majority of studies of diagnostic delay in cancer have not applied a theoretical model to inform data collection or reporting. Ten papers (reporting eight studies) met our inclusion criteria: three studied several cancers. The studies were heterogeneous in their methods and quality. The review confirmed that there are clearly identifiable stages between the recognition of a symptom, first presentation to a health care professional, subsequent diagnosis and initiation of treatment. There was strong evidence to support the existence and importance of appraisal and treatment delay as defined in the Andersen Model, although treatment delay requires expansion. There was some evidence to support scheduling delay which may be contributed to by both patient and the health service. Illness delay was often difficult to distinguish from appraisal delay. It was less clear whether behavioural delay exists as a separate significant stage. CONCLUSIONS Greater consistency is required in the conduct and reporting of studies of diagnostic delay in cancer. We propose refinements to the Andersen Model which could be used to increase its validity and improve the consistency of reporting in future studies.