COMBI >> Scales >> Moss Attention Rating Scale >> Syllabus


Tessa Hart , PhD, Moss TBI Model System at

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Hart, T. (2008). The Moss Attention Rating Scale. The Center for Outcome Measurement in Brain Injury.
combi/mars ( accessed ).





MARS Syllabus

The MARS is designed to be completed by clinicians on the basis of their everyday, routine interaction with the patient; no special tests or questions are administered. In studies thus far, clinicians have been asked to think of the 2 or 3 previous days in which they have treated/ interacted with the patient to form their ratings. It is not known whether ratings based on a shorter period of time would show equivalent reliability.

There is no manual for administering the MARS because it was developed to be usable by people from a variety of disciplines and backgrounds and to provide a simple, rapid assessment of attention behavior. The only special instruction to raters is not to skip any items, because doing so prevents calculating a score. If an item mentions a behavior that the rater has not observed directly during the rating period, s/he should extrapolate from other observations of the patient to make a best guess about how that item should be rated. For example, patients who are entirely non-verbal must still be rated on the item “Tends to speak less than he/ she is capable of.” The scale has shown adequate reliability with a variety of patients under these instruction conditions.

A focus group of clinicians from a variety of rehabilitation disciplines who were experienced MARS users revealed that nurses given the MARS found it easier to complete their ratings when they “scheduled” a specific time for themselves to spend with (or observing) the patient, e.g., a half hour over lunch, time spent passing meds, etc., to make their ratings more comparable to those of team members who had specific times scheduled with the patient. Team members agreed that it was most useful to balance their ratings by considering not the best nor the worst attention observed over the rating interval, rather trying to capture the average level of attention over the proscribed time period.


Each item is rated on a 5-point Likert type scale indicating the degree to which the item describes the patient’s behavior. Since items include both positive and negative behaviors, some items must be “flipped” in direction before any scores are summed. The total, raw MARS score is the sum of the 22 items (ranging from 22-110), with higher scores indicating better attention.

Half of the MARS items may also be used to compute 3 factor scores: Restlessness/ Distractibillity (items 1, 10, 12, 17, 22), Initiation (items 7, 13, 19), and Sustained/ Consistent Attention (items 6, 14, 15). Mean item ratings must be used to compare factor scores due to the unequal number of items that compose the factors.

The attached worksheets (MARS Scoring Worksheet.xls) allow for semi-automatic MARS scoring. The first tab aligns reverse-scored and direct-scored items into the same scoring direction and calculates the total raw MARS score and mean item Factor scores. The second tab provides a Table for looking up the logit scores that correspond to raw total MARS scores. These logit scores convert the MARS to an interval scale for parametric manipulations.

IMPORTANT: On 6-7-2010, it was discovered that the scoring sheet posted in November 2008 contained a typographical error that could affect the Initiation and Sustained/Consistent Attention subscale scores (but not the MARS total scores). The spreadsheet was replaced on 6-7-2010; please download the scoring spreadsheet again if you downloaded it prior to that date. The authors of the MARS regret this error.


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