Does changing healthcare use signal opportunities for earlier detection of cancer? A review of studies using information from electronic patient records

Abstract

Background: It has been proposed that changes in healthcare use before cancer diagnosis could signal opportunities for quicker detection, but systematic appreciation of such evidence is lacking. We reviewed studies examining pre-diagnostic changes in healthcare utilisation (e.g. rates of GP or hospital consultations, prescriptions or diagnostic tests) among patients subsequently diagnosed with cancer.

Methods: We identified studies through Pubmed searches complemented by expert elicitation. We extracted information on the earliest time point when diagnosis could have been possible for at least some cancers, together with variation in the length of such 'diagnostic windows' by tumour and patient characteristics.

Results: Across twenty-eight studies, changes in healthcare use were observable at least six months pre-diagnosis for many common cancers, and potentially even earlier for colorectal cancer, multiple myeloma and brain tumours. Early changes were also identified for brain and colon cancer sub-sites.

Conclusion: Changing healthcare utilisation patterns before diagnosis indicate that future improvements in diagnostic technologies or services could help to shorten diagnostic intervals for cancer. There is greatest potential for quicker diagnosis for certain cancer types and patient groups, which can inform priorities for the development of decision support tools.

Keywords: Early detection of cancer[MeSH Term]; Early diagnosis; Health records; Healthcare use; Signs and symptoms[MeSH Term].

Fig. 1

Exemplar evidence by Hansen et al examining healthcare utilisation changes before diagnosis of cancer. Illustrated for primary care consultations among women subsequently diagnosed with colorectal cancer, compared with controls. Reproduced with permission from John Wiley & Sons ©2015 UICC.

Fig. 2

Flow diagram of numbers of studies identified and included in review.

Fig. 3

Longest diagnostic window* for patients diagnosed with each cancer, by study and event type, ranked by diagnostic window length. *The earliest point in time before diagnosis when a change was observed in a relevant clinical event type. Where multiple values were given by a study for an event type or patient groups, the earliest single value is shown. Therefore, the value shown may only apply to specific groups of patients with that cancer. For studies using longer/ shorter time intervals than months (e.g. quarters, days), the equivalent range of months are highlighted **Study included two different methods yielding different results; the results of primary focus in the study conclusions are shown here. ***Study examined 'GP' and 'specialist' consultations; these were assigned to primary and secondary care consultations, respectively. i Estimated by literature review authors using graphs or tables provided. ii No change before diagnosis.