Table 2

Final calibration of the six diagnostic groups after the splitting of the DIF items into two main groups: asymmetric disorders (CS, CP) and symmetric disorders (RA, SSc, NMDc, NMDa)

	Hands involvement	Responded by						Difficulty* (logits)	SE (logits)
Item	Hands involvement	CS	CP	RA	SSc	NMDc	NMDa	Difficulty* (logits)	SE (logits)
a01 Hammering a nail	2C	x						3.60	0.23
a02 Cutting one's nails	2C	x	x					3.32	0.15
a03 Threading a needle	2C	x						3.31	0.23
a04 Peeling potatoes with a knife	2C	x						3.28	0.23
a05 Wrapping up gifts	2C	x						3.20	0.25
a06 Filing one's nails	2C	x						2.82	0.21
a07 Peeling onions	2C	x						2.67	0.24
s08 Shelling hazel nuts	2C			x	x			2.38	0.14
a08 Shelling hazel nuts	2C	x						2.23	0.24
a09 Winding up a wristwatch	2B	x						2.08	0.20
a10 Using a screwdriver	2B	x						2.04	0.22
s01 Hammering a nail	2C			x	x			1.88	0.15
s11 Taking the cap off a bottle	2B			x	x		x	1.84	0.12
a12 Screwing on a nut	2B	x						1.81	0.25
s04 Peeling potatoes with a knife	2C			x	x		x	1.56	0.12
a13 Sharpening a pencil	2C	x	x					1.31	0.16
a11 Taking the cap off a bottle	2B	x						1.09	0.23
s07 Peeling onions	2C			x	x			0.91	0.14
a14 Spreading butter on a slice of bread	2B	x	x					0.74	0.16
b15 Fastening a snap (eg, jacket, bag)	2A	x	x	x	x	x	x	0.68	0.09
a16 Replacing a light bulb	2B	x						0.59	0.30
s06 Filing one's nails	2C			x	x			0.59	0.14
s16 Replacing a light bulb	2B			x	x			0.48	0.15
s05 Wrapping up gifts	2C			x	x			0.46	0.15
a17 Opening mail	2B	x	x					0.41	0.16
a18 Handling a stapler	2A	x						0.19	0.30
b19 Peeling a banana	2B		x			x		−0.19	0.15
b20 Filling a glass with water	2A		x			x	x	−0.20	0.12
b21 Opening a pack of biscuits	2B		x			x	x	−0.20	0.13
s22 Turning on a tap	1					x	x	−0.21	0.15
b23 Opening a car door	1		x		x			−0.48	0.15
a24 Opening a bread box	2A		x					−0.56	0.22
s25 Picking up a can	1			x	x	x	x	−0.93	0.12
b26 Throwing a ball	1		x			x		−0.99	0.16
b27 Brushing one's hair	1	x	x	x	x			−1.20	0.13
a28 Unwrapping candy	2C		x					−1.20	0.23
a22 Turning on a tap	1		x					−1.41	0.26
b29 Washing one's face	1	x	x	x	x			−1.63	0.14
a30 Placing a glass of water on a table	1	x	x					−1.70	0.22
s31 Dealing cards	2B					x		−1.80	0.25
a32 Drinking a glass of water	1	x	x					−1.87	0.25
a33 Handling a four-colour ballpoint pen with one hand	1	x						−2.02	0.37
a34 Counting banknotes	2A	x						−2.20	0.29
b35 Turning on a radio	1	x		x	x	x		−2.28	0.18
a36 Wiping one's hands	2A		x					−2.32	0.26
s37 Using a fork	1		x			x	x	−2.51	0.21
s38 Turning on a television	1			x	x	x	x	−2.56	0.18
b39 Piling up Lego blocks	2A		x			x		−2.74	0.21
b40 Using a spoon	1	x		x	x			−3.35	0.17
a38 Turning on a television	1	x	x					−3.43	0.38
a41 Turning off a tap	1	x						−3.54	0.56
s42 Blowing one's nose	1			x	x			−3.93	0.23

*Higher logit values indicate a greater manual ability for more difficult activities.
a, asymmetric disorders (CS, CP); s, symmetric disorders (RA, SSc, NMDc, NMDa); b, both symmetric and asymmetric disorders; 1 indicates unimanual activities; 2 indicates bimanual activities manageable in several unimanual steps (2A); requiring stabilisation with one hand and digital activity with the other (2B); requiring digital activity from both hands (2C). CP, cerebral palsy; CS, chronic stroke; NMDa, neuromuscular adults; NMDc, neuromuscular children; RA, rheumatoid arthritis; SE, standard error; SSc, systemic sclerosis.