🧮 Clinical Calculators

Calculators

Clinical calculators for everyday general practice: Wells, FIB-4, CHA2DS2-VASc and more, with each result explained.

AQ-10 autism screening

Flags whether an adult may warrant an autism assessment. Ten questions, listed by NICE CG142 as an Autism Research Centre resource that it points to rather than hosts.

AUDIT-C alcohol screening

The three consumption questions from the full Alcohol Use Disorders Identification Test (AUDIT), scored 0 to 12. This is the UK version and it asks about units, not drinks.

Adult ADHD self-report scale (ASRS v1.1)

Opens the Adult ADHD Self-Report Scale (ASRS v1.1) screener on MDCalc: six Part A questions, where 4 or more in the shaded range is highly consistent with adult ADHD and warrants further assessment. The ASRS is World Health Organization (WHO) copyright, so the items are not reproduced here.

Body mass index (BMI)

Places an adult BMI in the NICE NG246 categories. NG246 sets lower thresholds for several family backgrounds.

CHA2DS2-VASc stroke risk in atrial fibrillation

Estimates stroke risk in atrial fibrillation. The score NICE NG196 uses to frame whether anticoagulation is offered, considered or not offered.

CRB65 score in community-acquired pneumonia

Grades 30 day mortality risk in community-acquired pneumonia. NICE NG250 uses it alongside your own judgement to inform where someone is treated. Also written CRB-65.

Centor criteria for acute sore throat

The other sore throat antibiotic score NICE NG84 offers. An alternative to FeverPAIN for deciding who is more likely to benefit. Derived in adults. Children under 5 with a fever are assessed under NICE NG143, fever in under 5s, instead.

FIB-4 index

Estimates the risk of advanced liver fibrosis in metabolic dysfunction-associated steatotic liver disease (MASLD). The first-line test for whether a fatty liver stays in primary care, needs a second-line test, or goes to a liver clinic. Not the test for someone drinking at harmful levels: they need transient elastography.

FRAX fracture risk

Ten year probability of a major osteoporotic fracture and of a hip fracture. The algorithm is not published, so it is run on the official FRAX site or in software licensed to use it.

FeverPAIN score for acute sore throat

Scores who with a sore throat may benefit from an antibiotic. NICE NG84 groups adults and children as unlikely, more likely, or most likely to benefit. Children under 5 with a fever are assessed under NICE NG143, fever in under 5s, instead.

GAD-7 anxiety severity

Seven questions about the last 2 weeks, scored 0 to 21. It measures the severity of anxiety symptoms in someone already being assessed for it. It does not diagnose.

HbA1c to estimated average glucose

Converts an HbA1c in International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) units, the mmol/mol used in the UK, to an estimated average glucose in mmol/L, so a result can be discussed against the numbers a person sees on their own meter.

MEWS national maternity early warning score

The national maternity early warning score, with the response each total asks for.

NEWS2 national early warning score

The adult early warning score, with the response each total asks for.

ORBIT bleeding risk in atrial fibrillation

Estimates major bleeding risk in atrial fibrillation. The bleeding tool NICE NG196 recommends in place of HAS-BLED.

Ottawa ankle and foot rules

Decides whether an ankle or foot X-ray is needed after injury. The rules NICE NG38 supports, in anyone over 5. The answer is met or not met, not a severity.

PEWS national paediatric early warning score

NHS England's national early warning score for children in hospital, with a chart for each age band.

PHQ-9 depression severity

Nine questions about the last 2 weeks, scored 0 to 27. NICE NG222 draws its line at 16. It measures severity in someone already being assessed, and does not diagnose.

QRISK3 cardiovascular risk

Estimates 10 year cardiovascular risk. NICE NG238 names QRISK3 for people aged 25 to 84 without cardiovascular disease, including type 2 diabetes. NG238 says not to use a risk tool where risk is already high: type 1 diabetes, an estimated glomerular filtration rate (eGFR) below 60 or albuminuria, and familial hypercholesterolaemia. Tools underestimate risk in people already treated for risk factors, and qrisk.org says it is not valid for anyone on a statin.