For example, if a person would prefer 9 yr of health to 10 yr of chronic pain (but would prefer the 10 yr of pain to only 8 yr of life), then each year of life with pain is credited with 9/10 = 0.9 QALY. [merckmanuals.com]

For example, if a person would prefer 9 years of health to 10 years of chronic pain (but would prefer the 10 years of pain to only 8 years of life), then each year of life with that particular pain is credited with 9/10 = 0.9 QALY. [msdmanuals.com]

The number needed to treat (NNT) or harm is another way to quantify patient outcome; NNT is the reciprocal of the absolute change in a dichotomous outcome (death, disability). [merckmanuals.com]

Marginal osteophytes are visible. There is attrition of the left medial tibial plateau. By permission of the publisher. From Myers S: Atlas of Rheumatology. Edited by G Hunder. Philadelphia, Current Medicine, 2005. [merckmanuals.com]

This analysis suggests that for an expensive therapy such as an ICD, an attempt should be made to identify subpopulations expected to reap the greatest benefit. [merckmanuals.com]