Thank you for your inquiry. For CMS 66 (Total Knee Arthroplasty), age is calculated at the start of the measurement period for patients “who had a primary [TKA] in the year prior to the measurement period and who had an outpatient encounter during the measurement period”. The intent of the measure is to include only patients that are 18 at the time of the TKA. To ensure that patients are at least 18 at the time of the TKA, in the year prior to the measurement period, we have to include people that are 19 of age or older at the beginning of the measurement period.

Please clarify - The eSpec Description in the top portion states: "Percentage of patients 18 years of age and older who received an elective primary total knee arthroplasty (TKA) and completed a functional status assessment within 90 days prior to the surgery and in the 270-365 days after the surgery" This is a contradiction to the bottom portion criteria which states: "and exists ( ["Patient Characteristic Birthdate"] Birthdate where Global."CalendarAgeInYearsAt"(Birthdate.birthDatetime, start of "Measurement Period")>= 19)" Is this a typo and should we be following the bottom portion for >=19?