Vital8 Methods and Scoring System

This methods document is the technical companion to the Vital8 methodology white paper. It describes the current scoring rules used by the Vital8 calculator. You can try the tool from the Vital8 page.

Vital8 is educational only. It is adapted from the American Heart Association's Life's Essential 8 (LE8) framework, but it is not itself a validated clinical risk calculator, diagnosis, treatment recommendation, or emergency tool.

Overall Score

Vital8 uses eight domains:

• Daily Fuel
• Movement
• Nicotine
• Sleep Rhythm
• Body Size
• Cholesterol Particles
• Blood Sugar
• Blood Pressure

Each completed domain receives a score from 0 to 100. The total score is the rounded average of completed domains.

Vital8 score = round(sum(completed domain scores) / number of completed domains)

Missing domains are excluded from both the numerator and denominator. The app displays how many of the eight domains were included.

Score categories:

80-100 = High cardiovascular health
50-79 = Moderate cardiovascular health
0-49 = Low cardiovascular health

Daily Fuel

Daily Fuel is a simplified diet estimate, not a formal DASH, Mediterranean, or 24-hour dietary recall score.

The score sums eight inputs to 100 points:

fruits and vegetables: 0, 5, 15, or 25
whole grains: 0, 5, 10, or 15
sugary drinks: 10, 7, 3, or 0
processed meals: 10, 7, 3, or 0
protein pattern: 15, 10, 5, or 0
fish/seafood: 10, 7, 3, or 0
nuts/legumes: 10, 7, 3, or 0
sodium pattern: 5, 3, or 0

All diet inputs must be answered for the diet domain to score.

Movement

Movement uses moderate-equivalent minutes per week:

moderate-equivalent minutes = moderate minutes + 2 x vigorous minutes

Scoring uses linear interpolation:

150+ minutes = 100
120-149 = linear from 80 to 100
90-119 = linear from 60 to 80
60-89 = linear from 40 to 60
30-59 = linear from 20 to 40
1-29 = linear from 0 to 20
0 = 0

Nicotine

Nicotine scoring:

Never used = 100
Former user, quit 5+ years ago = 75
Former user, quit 1-4 years ago = 50
Former user, quit less than 1 year ago = 25
Current non-combustible nicotine = 10
Current combustible tobacco = 0
Current combustible plus another nicotine product = 0

Regular secondhand smoke or vapor exposure subtracts 5 points, with a floor of 0.

Sleep Rhythm

Sleep scoring:

7 to <9 hours = 100
9 to <10 hours = 90
6 to <7 hours = 70
5 to <6 hours = 40
>=10 hours = 40
4 to <5 hours = 20
<4 hours = 0

Body Size

Body Size uses BMI:

BMI = weight_lbs / height_inches^2 x 703
BMI = weight_kg / height_m^2

Scoring:

<18.5 = 30
18.5 to <25 = 100
25 to <30 = linear decline from 100 to 30
30 to <35 = linear decline from 30 to 15
35 to <40 = linear decline from 15 to 0
>=40 = 0

BMI is an imperfect screening signal and does not measure muscle, body composition, or overall health by itself.

Cholesterol Particles

Cholesterol uses non-HDL cholesterol (a low-cost proxy for apolipoprotein B, or ApoB):

non-HDL = total cholesterol - HDL cholesterol

Scoring:

<130 mg/dL = 100
130 to <160 = linear decline from 100 to 60
160 to <190 = linear decline from 60 to 40
190 to <220 = linear decline from 40 to 20
>=220 = 0

If the user reports taking cholesterol-lowering medication, subtract 20 points, with a floor of 0.

Blood Sugar

Blood Sugar uses either A1c or fasting glucose. Known diabetes changes the scoring track.

A1c without known diabetes:

<5.7% = 100
5.7 to <6.5% = linear decline from 100 to 60
>=6.5% = 40

A1c with known diabetes:

<7.0% = 40
7.0 to <8.0% = linear decline from 40 to 30
8.0 to <9.0% = linear decline from 30 to 20
>=9.0% = 10

Fasting glucose without known diabetes:

<100 mg/dL = 100
100 to <126 = linear decline from 100 to 60
>=126 = 40

Fasting glucose with known diabetes:

<130 mg/dL = 40
130 to <160 = linear decline from 40 to 30
160 to <200 = linear decline from 30 to 20
>=200 = 10

If the user reports glucose-lowering medication and is not already on the diabetes-specific track, subtract 20 points, with a floor of 0.

Blood Pressure

Systolic and diastolic blood pressure are scored independently. The lower score is used.

Systolic scoring:

<120 = 100
120 to <130 = 75
130 to <140 = 50
140 to <160 = 25
>=160 = 0

Diastolic scoring:

<80 = 100
80 to <90 = 50
90 to <100 = 25
>=100 = 0

If the user reports taking blood-pressure medication, subtract 20 points, with a floor of 0.

Mean arterial pressure is shown as context:

MAP = (SBP + 2 x DBP) / 3

MAP below 65 is flagged as a cautionary signal but does not directly change the score.

Optional Fitness Layer

The fitness layer does not replace the raw Vital8 score. It contributes one multiplier to a separate exploratory adjusted score.

The input is age- and sex-specific cardiorespiratory fitness percentile, not raw VO2max alone. The anchors are derived from the Kokkinos veterans cohort and use the 50th percentile as the neutral reference point.

<=10th percentile = multiplier 0.71
30th percentile = multiplier 0.88
50th percentile = multiplier 1.00
70th percentile = multiplier 1.15
90th percentile = multiplier 1.29
>=98th percentile = multiplier 1.44

Values between anchors are linearly interpolated.

crf multiplier = interpolate(percentile anchors)

The 1.44 ceiling reflects the upper anchor used by the model. It is not a claim that fitness benefit biologically stops there.

Optional Biomarker Layer

The biomarker layer uses hsCRP and Lp(a). It contributes multipliers to the same exploratory adjusted score and does not change the raw Vital8 score.

Each multiplier is derived as:

multiplier = sqrt(1 / hazard ratio or relative risk anchor)

The square-root transform intentionally softens the published risk estimate because this is an educational ordinal layer, not a calibrated hazard model.

hsCRP:

<1 mg/L = multiplier 1.00
1 to <2 = multiplier 0.95
2 to <3 = multiplier 0.91
3 to <10 = multiplier 0.86
>=10 = multiplier 1.00 and retest-when-well flag

Lp(a):

<20 nmol/L = multiplier 1.00
20 to <75 = interpolate 1.00 to 0.91
75 to <125 = interpolate 0.91 to 0.85
125 to <250 = interpolate 0.85 to 0.71
250 to <350 = interpolate 0.71 to 0.58
350 to <430 = interpolate 0.58 to 0.50
>=430 = multiplier 0.50

Lp(a) is scored internally in nmol/L. If the user enters mg/dL, the app uses the guideline-paired approximate values:

50 mg/dL ~= 125 nmol/L
100 mg/dL ~= 250 nmol/L
180 mg/dL ~= 430 nmol/L

Direct mass-to-molar conversion is isoform-dependent, so this is labeled as approximate.

Combined Exploratory Adjustment

product = Lp(a) multiplier x hsCRP multiplier x CRF multiplier
adjusted score = round(max(raw Vital8 score x product, 0))

The product is used because the source anchors are hazard-ratio or relative-risk estimates, and the dyslipidemia guideline describes Lp(a)-derived relative risk as multiplicative with other risk factors.

There is no arbitrary upper clamp. The analytic maximum is:

100 x 1.00 x 1.00 x 1.44 = 144

The adjusted score is shown only when at least 6 of 8 raw domains are entered. This prevents a large multiplier from being applied to an unstable partial raw score.

Display labels:

>100 = Exceptional fitness reserve, only when biomarker multipliers are neutral
>100 with non-neutral biomarkers = Very high exploratory score
80-100 = High cardiovascular health
50-79 = Moderate cardiovascular health
0-49 = Low cardiovascular health

The raw Vital8 score is always displayed first. The adjusted score is secondary, explicitly exploratory, and accompanied by each multiplier and the combined product.

If Lp(a) is at least 125 nmol/L, the app displays a fixed interpretation note: Lp(a) is largely genetically determined, so lifestyle goals generally do not lower the Lp(a) value itself. The useful response is early, intensified management of modifiable risk factors. The app does not attenuate the Lp(a) multiplier for statin or PCSK9 inhibitor use because Lp(a)-mediated risk can persist even at low achieved LDL-C.

This product combines anchors from related but non-identical outcomes: ASCVD for Lp(a), MACE for hsCRP, and all-cause mortality for CRF. It should therefore be interpreted as an ordinal risk-ranking signal, not a calibrated prediction of one specific event. CRF may also partly overlap with the Movement and Body Size domains already present in the raw score; that possible double counting should be tested empirically before validation claims are made.

Appropriate Use

Vital8 is educational only. Results do not replace professional medical evaluation. The optional layers are exploratory and unvalidated. Single self-entered blood pressure readings may not reflect true average blood pressure. Clinically relevant results should be discussed with a healthcare professional.

For the evidence and scientific rationale behind these rules, see the Vital8 methodology white paper.