DASI Calculator

What Is the Duke Activity Status Index (DASI)?

The Duke Activity Status Index, or DASI, is a short 12-question survey that measures how well a person can handle daily physical tasks. It was created in 1989 by Dr. Mark Hlatky and his team at Duke University.¹ Each question asks if you can do one activity, like walking, climbing stairs, doing housework, or playing sports. You answer only "Yes" or "No."

How the DASI Score Works

Every activity has its own MET weight. Harder tasks, like running or heavy housework, are worth more points. You add up the weights for every task you can do.⁴ The lowest score is 0 and the highest score is 58.2.⁵ A higher score means better fitness.

What Are METs?

A MET is a metabolic equivalent. It shows how much oxygen your body uses. One MET is the energy you use while sitting still and resting, which equals about 3.5 mL of oxygen per kilogram of body weight each minute.⁶ Walking very slowly, under 2 mph, is 2.3 METs.⁷ Climbing stairs at a slow pace is 4.5 METs.⁷ Running at 4 mph is 6.5 METs, and faster running takes more.⁸

Turning the Score Into Peak VO₂

The DASI score can estimate peak VO₂. Peak VO₂ is the most oxygen your body can use during hard exercise. The formula is: Peak VO₂ = (0.43 × DASI score) + 9.6.³ Then divide that number by 3.5 to get METs.⁴ This gives doctors a fitness estimate without a treadmill test. The estimate tends to run high. In a large study of patients before major surgery, the formula overstated peak VO₂ for most patients compared with a real exercise test, with a typical gap of 9.3 mL/kg/min in women and 7.7 mL/kg/min in men.³ In the same study, a DASI score of 34 matched about five METs on an exercise test, not the seven METs the formula gives.⁵ The study's authors advise doctors to judge risk before surgery from the DASI score itself, such as the 34-point mark, rather than from converted METs.⁵

Why Doctors Use the DASI

Doctors often use the DASI before surgery. Patients who can reach 4 METs or more usually handle surgery better.² Patients under 4 METs may face more risk and may need extra heart tests first.² A DASI score below 34 is linked to higher odds of death or heart attack within 30 days after surgery, and of serious complications in the hospital.⁵ A score above 34 is linked to lower odds of death or heart muscle injury within 30 days.⁵

Functional Capacity Groups

Heart guidelines for surgery sort functional capacity into four groups by METs.²

• Under 4 METs: Poor functional capacity, with higher risk around surgery.²
• 4 up to 7 METs: Moderate functional capacity.²
• 7 to 10 METs: Good functional capacity.²
• Over 10 METs: Excellent functional capacity.²

The DASI formula tops out at 9.89 METs when all 12 answers are Yes, so it never places anyone in the excellent group.

Good to Know

The DASI is short, and patients can fill it in on their own.¹ But it is based on what the patient says, not on a real exercise test. People may guess wrong about what they can do. Conditions other than heart disease, such as arthritis, chronic lung disease, or obesity, can also limit what a person can do.⁹ Low functional capacity (under 4 METs) is linked to a higher risk of heart problems around surgery, whatever its cause.⁹ The DASI is one piece of the picture, not a full diagnosis. Always talk with a doctor about your results.