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Question: Clarification of CSTK-1 Measure Population Requirements

As of January 2019, Primary Stroke Centers are reporting on the CSTK-1 measure for NIHSS documentation within 12 hours of patient arrival.

When reviewing the specifications manual for this measure, the numerator statement states to complete an NIHSS within 12 hours of arrival on all patients who have recanalization therapy OR those that do not receive recanalization therapy. However, the included population statement states to include patients who have had t-PA OR reperfusion therapy (aka recanalization.

Does this mean we include all of our patients regardless of reperfusion therapy or does this mean to only include patients who received t-PA or reperfusion therapy?

Can you please clarify this?

Also, does this measure consider the patients' last known well or onset of symptoms? Or does it factor in if the symptoms occurred prior to arrival or after admission? For example, if a patient arrived to your facility and later had a stroke, the NIHSS would not be documented within 12 hours of arrival to the hospital.

Can you please clarify?

Thank you for your time! )


Jamie, 1. The denominator statement describes the patients to include in the CSTK-01 measure population. The denominator statement is: "Ischemic stroke patients." This means ALL ischemic stroke patients. Enter the total number of ischemic stroke cases for the reporting month for the denominator value.

The numerator statement is: Ischemic stroke patients for whom a NIHSS score is performed prior to any acute recanalization therapy in patients undergoing recanalization therapy and documented in the medical record, OR documented within 12 hours of hospital arrival for patients who do not undergo recanalization therapy.

In other words, of ALL ischemic stroke patients, how many patients had a NIHSS done and documented prior to IV/IA t-PA or a mechanical endovascular reperfusion procedure (thrombectomy) + the number of ischemic stroke patients who did not receive treatment but had a NIHSS done and documented within 12 hrs. Both patient counts combined will be the number of cases enter for the numerator.

2. Last Known Well is not collected for CSTK-01. If the patient has a reperfusion procedure any time during the hospital stay and a NIHSS was done and documented prior to initiation of treatment, then the case will be included in the numerator. For patients who do not receive treatment, the clock starts with the Arrival Time at the hospital. There must be a NIHSS done and documented within 12 hours of the Arrival Time in order to include the case in the numerator.

All of the above is described in the CSTK-01 Measure Information Form section of the specifications manual.

Hope this clarifies for you. Thank you for your inquiry.

Question Details
Focus area(s): Chart Abstracted Measure Specifications – Clinical
Related documents: CSTK-01, CSTK-1
Manual: Current Manual (current data collection period; prior to data transmission)

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