Gut instinct for the diagnosis of cancer in general practice: a diagnostic accuracy review

Problem

Overcoming diagnostic delay in cancer is challenging in primary care. While screening tests are useful in breast, colon, and cervix, symptom-based diagnosis is often difficult because of uncertainty due to patients' concerns, doctor-patient relationship, and psychosocial context.

According to the past literatures, cancer-related gut instinct may improve access to specialists, but it might have been under-rated. The consensus statement of gut instinct by Stoppers at el defined it as ‘a physician’s intuitive feeling that something is wrong with the patient, although there are no apparent clinical indications for this, or a physician’s intuitive feeling that the strategy used in relation to the patient is correct, although there is uncertainty about the diagnosis’.

Diagnostic accuracy studies of the performance of gut instinct for the diagnosis of cancer in primary care have yielded variable results. For example the positive predictive value for the use of gut instinct to diagnose cancer has varied widely from 3 - 35 % in General Practice populations.

The purpose of this presentation is to determine the diagnostic accuracy of ‘gut instinct’ compared with reference standards for the diagnosis of cancer in general practice.

Approach

Design: Systematic review with meta-analysis with hierarchical summary receiver operating characteristic models following Cochrane methods. Methodological quality was appraised using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS2) criteria.

Data sources: MEDLINE, EMBASE, Cochrane, DARE, Medion databases were searched.

Eligibility criteria: Cross-sectional, randomised and cohort studies of test accuracy that compared gut instinct with an appropriate reference standard (MDT conference cancer diagnosis.

Findings

Results: 1231 potentially relevant papers were identified. 4 studies met the inclusion criteria. No studies satisfied all QUADAS2 criteria. Compared with the reference MDT confirmed cancer gut instinct had a sensitivity of 0.112 (0.037 to 0.292) and a specificity of 0.990 (0.928 to 0.999); The false positive rate was 0.010 (0.001 to 0.072)

Consequences

Conclusions: Gut instinct when used in general practice has a low sensitivity and high specificity. Future studies should try to meet the STARD criteria. Assuming a prevalence 30 per 1000 population for all cancers in England the PPV of 4% meets the NICE criteria of 3%for urgent action if present.