A healthcare measure is a calculation made on the care activities of a provider that indicates the level of quality provided by the caregiver. As providers are increasingly being rewarded based on the quality rather than the quantity of services they provide, healthcare measures are playing a more important role in determining which care providers are rewarded or penalized. The Centers for Medicare and Medicaid Services (CMS) is just one of the federal-level agencies in the United States that publishes standardized measures; in addition, states publish measures as well. Providers calculate the measures using the data of their own patients and then submit their calculations to be audited by the issuing agency. The results partially determine how the providers are reimbursed by the agency.

A typical measure in healthcare is usually a ratio or percentage that correlates with care quality. There are typically two parts that make up a measure: a numerator and a denominator. The denominator is some quantification of the eligible population or number of encounters that were seen by the provider during a specific time range. Determining the denominator usually involves applying inclusion criteria and/or exclusion criteria to the overall provider population to reach the desired measurement population or encounter pool. Once the denominator is determined, the numerator is calculated based on the number of items in the denominator that received a certain positive or negative outcome or event.

This outcome or event is usually suggested by basic and/or clinical research as being a recommended part of patient care (or a marker for adverse care). Finally, dividing the numerator by the denominator yields the final percentage. This percentage may be used on a standalone basis or may be integrated into more complex formulas and weighting schemes with other measures to determine an overall quality score.

For example, an agency that wishes to measure the quality of diabetes care provided by outpatient facilities in a state could start composing a measure by surveying the literature for diabetes care recommendations. Among other things, diabetes patients are supposed to receive multiple foot examinations (to check for ulcers and nerve damage) and hemoglobin-A1c tests (to check for elevated blood glucose) during each year. To calculate the denominator, the inclusion criteria are that the patient has received an ICD code diagnosis of diabetes mellitus at least once in the past year. The agency only wants to consider the standard adult population; therefore, children less than 18 years of age and elderly adults greater than 65 years of age will be excluded. One clinic may have 4,000 patients overall, of which 500 meet these criteria; 500 is then the denominator for this measure. There are then two numerators to calculate:

• The number of these patients who received at least three foot exams in the past year
• The number of these patients who received at least two HgbA1c tests during the past year

For example, let's say that the numbers for our clinic are 350 and 400, respectively. The final measures are 350/500 = 0.70 for diabetic foot exam performance and 400/500 = 0.80 for diabetic blood work measurement. These can then be averaged together to give an overall rating of 0.75 for diabetes care at this clinic.

Measures have their share of problems; no measure is above loopholes that allow providers to manipulate their measurement scores without really improving care. Also, many measures may unfairly penalize providers who may have had patients act against medical advice or refuse proper treatment. However, if care quality is to be rewarded, then there must be a way to quantify care quality, and measures in healthcare are an important means of achieving that.