WHAT’S IT WORTH TO HEAL THE SICK? OR TO PROVIDE PREVENTIVE CARE? OR TO DO NOTHING?

QALY’S (Quality-adjusted life year(s)) PROVIDE “OBJECTIVE” GUIDANCE.

This post takes the Author into dark and deep water. This post takes on healthcare economics straight on. Right between the eyes. The Author, as many readers know, was formerly a healthcare law and economics geek. He would have remained one, but grew ill watching the nation in the 1990s eschew healthcare cost containment.

QALY (quality-adjusted life years) is a formula for measuring the long-term effectiveness of a healthcare treatment or intervention. QALYs are often combined with a cost factor to assess and compare the relative value of a treatment or intervention. QALYs give healthcare economists and policy makers an important, if somewhat limited, method of valuing the cost and effectiveness of treatments across populations.

HERE’S HOW TO CALCULATE A QALY:

If a treatment or intervention provides one year of “good health”, it yields one QALY. Such a treatment could also yield more than one (or sometimes less than one), QALY(s).

As most of you know, the Author just underwent open-heart surgery. This intervention saved his life and he is now in “good health” again. Given an estimated life expectancy of 80, the Author has 30 more years of good health to expect (at least from the heart surgery), so the heart surgery can be assigned a QALY of 30.

QALYs can also be less than one, and many interventions yield less than perfect health. Death is assigned a factor of 0. Some health states are considered worse than death (consider Terry Schaivo). Below is a graph of QALY health state valuations using the EQ-5D weighting system:

Health state Description Valuation

11111 No problems 1.000

11221 No problems walking about; no problems with self-care; some problems with performing usual activities; some pain or discomfort; not anxious or depressed 0.760

22222 Some problems walking about; some problems washing or dressing self;
some problems with performing usual activities; moderate pain or discomfort;
moderately anxious or depressed 0.516

12321 No problems walking about; some problems washing or dressing self; unable to perform usual activities; some pain or discomfort; not anxious or depressed 0.329

21123 Some problems walking about; no problems with self-care; no problems
with performing usual activities; moderate pain or discomfort; extremely
anxious or depressed 0.222

23322 Some problems walking about, unable to wash or dress self, unable to perform usual activities, moderate pain or discomfort, moderately anxious or depressed 0.079

33332 Confined to bed; unable to wash or dress self; unable to perform usual
activities; extreme pain or discomfort; moderately anxious or depressed
-0.429

Note that the last condition yields a QALY of less than 0. Also remember that this scale is much generalized. This health state scale was taken from “What is a QALY”, published by Hayward Medical Communications.

LESS THAN ONE, LESS THAN A QALY?

Many interventions, as you can see from the health state scale above, yield QALY factors of less than one. For simplicity, let’s say that an intervention will provide someone with four years of health state .75. We then multiply 4 (life years) * .75 (health state) and get a QALY of 3. So this intervention (or treatment) provides 3 QALYs.

DARE TO COMPARE?

The intervention above yields 3 QALYs. If we know how many QALYs this intervention yields, we can compare it to other interventions for the same condition. A competing treatment for the same condition as above yields five years of health state .50. So we multiply 5 (life years) * .5 (health state) and get a QALY of 2.5. Ceteris paribus, the first treatment is a “better treatment” Or is it?

MORE YEARS OR BETTER YEARS?

The question above involves a topic close to the hearts’ of healthcare economists. (Or close to the spot where their hearts would otherwise be.) It is the Time-trade off. Below is a definition of the Time-trade off lifted from Wikipedia.

Time-Trade-Off (TTO) is a tool used in Health Economics to help determine the quality of life of a patient or group. The individual will be presented with a set of directions such as:

Imagine that you are told that you have 10 years left to live. In connection with this you are also told that you can choose to live these 10 years in your current health state or that you can choose to give up some life years to live for a shorter period in full health. Indicate with a cross on the line the number of years in full health that you think is of equal value to 10 years in your current health state.

The Time-Trade Off illustrates a problem with QALYs. They are only generalizations that do not account well for individual preferences. But as tools for economists and policy makers, they provide useful formulas to compare treatment efficacies. And when combined with cost-utility ratios, they allow cost-based efficacy comparisons to be made; turning health care decision making from the game of “whatever the doctor orders” to the science of what is most cost-effective.

MORE NEXT TIME…

In the next couple of posts we will discuss how to use QALYs to make cost-effectiveness determinations and how to address some well recognized problems with QALYs.

STAY HEALTHY OR HEAL FAST IN THE DESERT OF THE REAL!