ASA physical status classification and Duke activity scale index

ASA physical status classification:

  • ASA Ⅰ, No systemic disease, no smoking, no or minimal alcohol use
  • ASA Ⅱ, Mild to moderate systemic disease, well-controlled disease states; e.g., well-controlled DM, mild asthma or epilepsy, pregnancy, current smoker, social alcohol use, BMI 30–40
  • ASA Ⅲ, Severe systemic disease that limits activity but is not incapacitating; e.g., uncontrolled DM, history of CVA, MI, or CAD with stents >3 mo ago, mild COPD, BMI > 40, alcohol abuse or dependence, cardiac pacemaker, ESRD on dialysis
  • ASA Ⅳ, Severe systemic disease that limits activity and is a constant threat to life; e.g., CVA or MI within the past 3 mo, severe CHF, severe COPD, ongoing cardiac ischemia or valve dysfunction, sepsis
  • ASA Ⅴ, Patients not expected to survive 24 h
  • ASA Ⅵ, Organ donors

(CVA: cerebrovascular accident; MI: myocardial infarction; CHF: congestive heart failure; COPD: chronic obstructive pulmonary disease; DM: diabetes mellitus; ESRD: end-stage renal disease; CAD, Coronary Artery Disease)

McCarthy and Malamed1 adapted the ASA PS system for use in dentistry:

  • PS 1. A patient in the PS 1 category is defined as normal and healthy. After reviewing the available information, the dentist determines that the patient’s heart, lungs, liver, kidneys and central nervous system are healthy and his or her blood pressure is below 140/90 millimeters of mercury. The patient is not unduly phobic and is younger than 60 years. A patient in the PS 1 category is an excellent candidate for elective surgical or dental care, with minimal risk of experiencing an adverse medical event during treatment.

  • PS 2. Patients in the PS 2 category have a mild systemic disease or are healthy patients (PS 1) who demonstrate extreme anxiety and fear toward dentistry or are older than 60 years. Patients classified as PS 2 generally are somewhat less able to tolerate stress than are patients classified as PS 1; however, they still are at minimal risk during dental treatment. Elective dental care is warranted in a patient classified as PS 2, with minimal increased risk during treatment. However, the dentist should consider possible treatment modifications (see Stress Reduction Protocols below).

  • PS 3. A patient in the PS 3 category has severe systemic disease that limits activity but is not incapacitating. At rest, a patient in the PS 3 category does not exhibit signs and symptoms of distress (such as undue fatigue, shortness of breath, chest pain); however, when stressed, either physiologically or psychologically, the patient does exhibit such signs and symptoms. An example is a patient with angina who is pain free while in the waiting room but develops chest pain when seated in the dental chair. Like PS 2, the PS 3 classification indicates that the dentist should proceed with caution. Elective dental care is not contraindicated, though the patient is at an increased risk during treatment. The dentist should give serious consideration to implementing treatment modifications.

  • PS 4. A patient in the PS 4 category has an incapacitating systemic disease that is a constant threat to life. Patients with this classification have a medical problem or problems of greater significance than the planned dental treatment. The dentist should postpone elective dental care until the patient’s physical condition has improved to at least a PS 3 classification. A patient in the PS 4 category exhibits clinical signs and symptoms of disease at rest. The risk in treating this patient is too great to permit elective care. In dental emergencies, such as cases of infection or pain, clinicians should treat patients conservatively in the dental office until their conditions improve. When possible, emergency treatment should be noninvasive, consisting of drugs such as analgesics for pain and antibiotics for infection. When the dentist believes that immediate intervention is required (for example, incision and drainage, extraction, pulpal extirpation), I suggest that the patient receive care in an acute care facility (that is, a hospital) whenever possible.

  • PS 5. A PS 5 classification indicates a moribund patient not expected to survive 24 hours without surgery. Patients in this category almost always are hospitalized and terminally ill. In many institutions, these patients are not to be resuscitated if they experience respiratory or cardiac arrest. Elective dental treatment is contraindicated; however, emergency care, in the realm of palliative treatment (that is, relief of pain, infection or both) may be necessary. (PS 6 refers to a patient declared brain-dead and whose organs are being removed for donor purposes.9)

The ASA PS classification system is not meant to be inflexible; rather, it is meant to function as a relative value system based on a dentist’s clinical judgment and assessment of the available relevant clinical data. When the dentist is unable to determine the clinical significance of one or more diseases, I recommend he or she consult with the patient’s physician or other medical or dental colleagues. In all cases, however, the treating dentist makes the final decision regarding whether to treat or postpone treatment. The ultimate responsibility for the health and safety of a patient lies solely with the dentist who decides to treat or not treat the patient. 2

Duke Activity Scale Index

Functional class Metabolic equivalents Specific activity scale
>7 Patients can perform heavy housework such as moving furniture or scrubbing floors, and can participate in moderate recreational activities such as bowling, dancing, skiing, or doubles tennis.
>5 Patients can do light housework such as dusting or washing dishes, can climb one flight of stairs, and can walk on level ground at 4 mph.
>2 Patients can dress themselves, shower, make the bed, and walk indoors.
<2 Patients cannot perform activities of daily living without assistance and may be bedbound.
  1. McCarthy FM, Malamed SF. Physical evaluation system to determine medical risk and indicated dental therapy modifications. J Am Dent Assoc. 1979 Aug;99(2):181-4. doi: 10.14219/jada.archive.1979.0271. PMID: 287736.

  2. Malamed SF. Knowing your patients. J Am Dent Assoc. 2010 May;141 Suppl 1:3S-7S. doi: 10.14219/jada.archive.2010.0350. PMID: 20436083.