Patterns of clinical investigation before cancer diagnosis in primary care

Introduction

Currently, we know little about how often and in what clinical circumstances investigations ordered by GPs tend to be used (or not used); the nature of investigations (including common test combinations); their impact on diagnostic timeliness and other aspects of the diagnostic process; if different GP practices differ in their use of investigations; and whether practice-level characteristics are associated with this.

Funding

Cancer Research UK £141,000 EDAG Project Award

Aims & objectives

To use data from the National Cancer Diagnosis Audit (NCDA) 2014 and 2018 to examine:

1. How often are primary care investigations used in patients before a cancer diagnosis, and which patient and disease factors are associated with their use?

2. How is use of investigations associated with length of diagnostic intervals, and process and outcome measures of the diagnostic process?

3. Is there variation between practices in the use of tests and to what extent does it relate to local health economy factors such as hospital policies or CCG protocols?

What practice characteristics are associated with greater/lower test use and can these be used for markers of need for quality improvement?

Methodology

This project will involve secondary analysis of cross-sectional data collected as part of the NCDA, which collected information on the diagnostic process from participating general practices for individuals diagnosed with cancer in 2014/2018. The dataset combines information from cancer registration and primary care records.

Research questions 1 and 2 will be led by UCL, and research questions 3 and 4 will be led by Exeter. Descriptive statistics and regression frameworks will be used to examine crude and adjusted associations of interest.

We will examine individuals diagnosed with all types of cancer, and include cancer site as a covariate of interest as we hypothesise that the associations being examined will vary by cancer type.

Output & impact

By examining patterns of investigation for symptomatic individuals subsequently diagnosed with cancer, this project will identify how diagnostic tests are used before cancer diagnosis, and how patient or practice level characteristics are associated with their use. This will inform health service improvement and health policy relating to cancer diagnosis in primary care.

The findings will be written up for publication in an academic journal, and shared with stakeholders through academic conferences and other opportunities for dissemination.