Sensitivity of alternative measures of functioning and wellbeing for adults with sickle cell disease: comparison of PROMIS® to ASCQ-Me℠

Table 2 Reliability and validity of ASCQ-Me fixed and short forms^a

	Number of items	Cronbach’s Alpha	Full ASCQ-Me item bank	Similar PROMIS short form(s)^b
ASCQ-Me short forms
Emotional impact	5	0.901	0.96	−0.69 to −0.73^c
Pain impact	5	0.942	0.99	−0.72 to −0.80
Sleep	5	0.930	0.98	−0.54 to −0.80
Social	5	0.921	0.98	0.58 to 0.65
Stiffness	5	0.918	0.97	0.64
ASCQ-Me pain episode fixed forms
Pain episode frequency	2	0.799	−0.54^d	0.42 to 0.47
Pain episode severity	3	0.727	−0.26	0.26 to 0.26

^aWe use the term “fixed form” to indicate that these are not adaptive measures because all respondents are presented with the same items in the same sequence. All ASCQ-Me short forms are subsets of items from the corresponding ASCQ-Me item banks. The Pain Episodes items are not short forms because they are not drawn from the ASCQ-Me item banks, but they are fixed forms because the items are presented in a fixed sequence
^bThere is more than one PROMIS score to correspond to the first five ASCQ-Me scores (see Table 1) and for those, there will be a range of correlations reported. These correlations are negative consistent with differences between the way ASCQ-Me and PROMIS scores are calculated
^cPROMIS measures of symptoms (i.e. anxiety, depression, pain, sleep disturbance) are scored such that higher scores mean more of the symptom; whereas, all of the ASCQ-Me measures – with the exception of the pain episodes – are scored such that higher scores mean better health. The negative correlation reflects the difference in the direction of scoring
^dThe negative correlation between the ASCQ-Me Pain Episode measures and the ASCQ-Me Pain Impact item bank is an artifact of the direction of scoring: a high score for Pain Episodes means more pain whereas a high score for the Pain Impact item bank means less pain

ISSN: 1477-7525