Predictive value of abnormal blood tests for detecting cancer in primary care patients with nonspecific abdominal symptoms: A population-based cohort study of 477,870 patients in England.

BACKGROUND: Identifying patients presenting with nonspecific abdominal symptoms who have underlying cancer is a challenge. Common blood tests are widely used to investigate these symptoms in primary care, but their predictive value for detecting cancer in this context is unknown. We quantify the predictive value of 19 abnormal blood test results for detecting underlying cancer in patients presenting with 2 nonspecific abdominal symptoms. METHODS AND FINDINGS: Using data from the UK Clinical Practice Research Datalink (CPRD) linked to the National Cancer Registry, Hospital Episode Statistics and Index of Multiple Deprivation, we conducted a population-based cohort study of patients aged ≥30 presenting to English general practice with abdominal pain or bloating between January 2007 and October 2016. Positive and negative predictive values (PPV and NPV), sensitivity, and specificity for cancer diagnosis (overall and by cancer site) were calculated for 19 abnormal blood test results co-occurring in primary care within 3 months of abdominal pain or bloating presentations. A total of 9,427/425,549 (2.2%) patients with abdominal pain and 1,148/52,321 (2.2%) with abdominal bloating were diagnosed with cancer within 12 months post-presentation. For both symptoms, in both males and females aged ≥60, the PPV for cancer exceeded the 3% risk threshold used by the UK National Institute for Health and Care Excellence for recommending urgent specialist cancer referral. Concurrent blood tests were performed in two thirds of all patients (64% with abdominal pain and 70% with bloating). In patients aged 30 to 59, several blood abnormalities updated a patient's cancer risk to above the 3% threshold: For example, in females aged 50 to 59 with abdominal bloating, pre-blood test cancer risk of 1.6% increased to: 10% with raised ferritin, 9% with low albumin, 8% with raised platelets, 6% with raised inflammatory markers, and 4% with anaemia. Compared to risk assessment solely based on presenting symptom, age and sex, for every 1,000 patients with abdominal bloating, assessment incorporating information from blood test results would result in 63 additional urgent suspected cancer referrals and would identify 3 extra cancer patients through this route (a 16% relative increase in cancer diagnosis yield). Study limitations include reliance on completeness of coding of symptoms in primary care records and possible variation in PPVs if extrapolated to healthcare settings with higher or lower rates of blood test use. CONCLUSIONS: In patients consulting with nonspecific abdominal symptoms, the assessment of cancer risk based on symptoms, age and sex alone can be substantially enhanced by considering additional information from common blood test results. Male and female patients aged ≥60 presenting to primary care with abdominal pain or bloating warrant consideration for urgent cancer referral or investigation. Further cancer assessment should also be considered in patients aged 30 to 59 with concurrent blood test abnormalities. This approach can detect additional patients with underlying cancer through expedited referral routes and can guide decisions on specialist referrals and investigation strategies for different cancer sites.

Underlying disease risk among fatigued patients: a population-based cohort study in primary care.

Background Presenting to primary care with fatigue is associated with a wide range of conditions, including cancer, although their relative likelihood is unknown. Aim To quantify associations between new-onset fatigue presentation and subsequent diagnosis of various diseases, including cancer. Design and setting Cohort study of patients presenting in English primary care with new-onset fatigue during 2007-2017 (fatigue presenters (FPs)), compared to non-fatigue presenters (NFPs), using Clinical Practice Research Datalink data linked to hospital episodes and national cancer registration data. Method We described excess short-term incidence of 237 diseases in FPs compared to NFPs. We modelled disease-specific 12-month risk by sex and calculated age-adjusted risk. Results We included 304,914 FPs and 423,671 NFPs. 127 of 237 diseases studied were more common in male FPs than in male NFPs, and 151 were more common in female FPs. Diseases that were most strongly associated with fatigue included: depression; insomnia & sleep disturbances, and hypo/hyperthyroidism (women only). By 80 years, cancer was the 3rd most common disease and had the 4th highest absolute excess risk in male FPs (FPs: 7.0%, CI = 6.6 to 7.5; NFPs: 3.4%, CI = 3.1 to 3.7; AER: 3.7%). In women, cancer remained relatively infrequent; by age 80 it had the 13th highest excess risk in FPs. Conclusion Our study ranks the likelihood of possible diagnoses in fatigue presenters, to inform diagnostic guidelines and doctors' decisions. Age-specific findings support recommendations to prioritise cancer investigation in older men with fatigue, but not women.

The association between atrial fibrillation and dementia: A UK linked electronic health records cohort study.

BACKGROUND: We investigated the association between atrial fibrillation (AF) and dementia, and its subtypes (vascular-VaD, Alzheimer, mixed and rare dementia), and identified predictors for dementia in AF patients. METHODS: The analysis was based on 183,610 patients with new-onset AF and 367,220 non-AF controls in the United Kingdom between 1998 and 2016, identified in three prospectively collected, linked electronic health records sources. Time-to-event (dementia or subtypes) analyses were performed using Cox proportional hazards and weighted Cox. Sub-analyses performed: including & censoring stroke and age (median used as cut-off). RESULTS: Over a median follow-up of 2.67 years (IQR .65-6.02) for AF patients and 5.84 years for non-AF patients (IQR 2.26-11.80), incidence of dementia in the AF cohort was 2.65 per 100 person-years, compared to 2.02 in the non-AF cohort. After adjustment, a significant association was observed between AF and all-cause dementia (HR = 1.38, 95% CI: 1.31-1.45), driven by a strong association with VaD (HR = 1.55, 95% CI: 1.41-1.70). AF was also associated with mixed dementia (HR = 1.26, 95% CI: 1.01-1.56), but we could not confirm an association with Alzheimer (HR = 1.05, 95% CI: .94-1.16) and rare dementia forms (HR = 1.19, 95% CI: .90-1.56). Ischemic stroke (HR = 1.40, 95% CI: 1.26-1.56), subarachnoid haemorrhage (HR = 2.08, 95% CI: 1.47-2.96), intracerebral haemorrhage (HR = 1.95, 95% CI: 1.54-2.48) and diabetes (HR = 1.32, 95% CI: 1.24-1.41) were identified as the strongest predictors of dementia in AF patients. CONCLUSIONS: AF patients have an increased risk of dementia, independent of stroke, with highest risk of VaD. Management and prevention of the identified risk factors could be crucial to reduce the increasing burden of dementia.