Table 1.

Items on the ALSFRS-R that did not discriminate well as identified by GRM [19]

Domain item	Response options that do not discriminate well
Bulbar domain Salivation	Time 1 R1 ‘marked excess of saliva with some drooling’ vs R0 ‘marked drooling; requires constant tissue or handkerchief’ R2 ‘moderately excessive saliva; may have minimal drooling’
Bulbar domain Swallowing	Time 0 R1 ‘needs supplemental tube feeding vs R0 ‘nothing by mouth; exclusively parenteral or enteral’ R2 ‘dietary consistency changes’
Fine Motor domain Cutting food and handling utensils	All times 0, 1, 2 All responses far exceeded the threshold for acceptable item discrimination This item may potentially be redundant May be over discriminating between individuals with different levels of severity as assessed by this item
Fine Motor domain Dressing and hygiene	Time 0 All responses exceeded the threshold for acceptable item discrimination
Gross Motor domain Turning in bed and adjusting bed clothes	Time 0 R0 ‘helpless’ vs R1 ‘can initiate but cannot adjust sheets alone’
Gross Motor domain Climbing stairs	All times 0, 1, 2 R2 ‘mild unsteadiness or fatigue’ vs R1 ‘needs assistance’ R3 ‘ slow’ Most problematic item
Respiratory domain Respiratory insufficiency	At all times 0, 1, 2 Patients responded with either 4 ‘none’ or 2 ‘continuous use of BiPAP’ rather than 3 ‘intermittent use of BiPAP, suggesting that response 3 did not assess a unique level of severity
Respiratory domain Orthopnea Respiratory insufficiency	Fit very poor for these items and lowest threshold ‘0’ could not be estimated due to lack of responses in that score category

GRM: Grade Response Modeling, [Source: Bacci 2016], [19]