North Star Ambulatory Assessment (NSAA)
Clinician reported outcome. Designed to capture the construct of ambulatory function in DMD. 17-item scale that grades performance of various functional skills on a scale from 0 (unable), 1 (completes independently but with modifications), and 2 (completed without compensation). Total score 0 – 34 with a higher score denoting a higher level of function. It includes two timed tests. Timed rise from floor (RFF) and timed 10 metre walk / run test (10MWR). Validated and regularly used in clinical trials as well as clinic. Well understood by families.
DMD but may be of use in weaker ambulant subjects with other NMD or in undiagnosed neuromuscular patients. If they are stronger – better to use the NSAD.
Level of function:
Suitable for use even in very young DMD boys where items can be attempted or scored based on observation as they move around the clinic. See the NSAA Observed / Family Report NSAA_OR resource below.
As they get older or weaker and items get harder, more assistance can be given by the evaluator or only the easier items attempted. Alternatively, the Transitioning Assessment North Star (TANS) can be used, which consists of the easier items on the NSAA and adapted observed items from the Egen Klassifikation Scale to create a novel yet unvalidated measure for subjects where ambulation is becoming more difficult and independence for transfers and self-care become more important to capture.
Training / training material
NSAA – Training advised to ensure accurate delivery of the scale. Need a stopwatch, box step and 12 metre space to conduct the test. Manual and worksheets are available as well as comprehensive audio guided training slides.