TABLE 2.

Item Difficulty (P_i) and Discrimination (r_it)

Items and HRQoL Domains	N Valid	Mean (SD)	Difficulty (Pi)	Discrimination (rit)
Physical			0.65
1. I have been satisfied with my ability to:
a. bathe (ie, showering or sponging)	380	1.89 (1.23)	0.47	0.58
b. get dressed by myself	388	2.93 (1.10)	0.73	0.55
c. change my VAD dressing	247	1.81 (1.70)	0.45	0.44
d. go shopping	368	2.42 (1.25)	0.61	0.65
e. do housekeeping/minor household repairs	377	2.00 (1.28)	0.50	0.72
f. drive a car	331	2.50 (1.52)	0.63	0.56
2. I feel satisfied with the quality of my sleep.	387	2.14 (1.19)	0.54	0.51
3. I feel like my appetite is at a healthy level for me.	391	2.87 (1.05)	0.72	0.44
4. I feel like I can do activities that I enjoy.	388	1.99 (1.17)	0.50	0.63
5. I feel satisfied with my physical strength.	391	1.51 (1.08)	0.38	0.71
6. I feel satisfied with how long my energy lasts.	390	1.37 (1.07)	0.34	0.69
7. It frustrates me not being able to drink alcohol.	387	3.59 (0.81)	0.90	−0.06
8. In the past 2 weeks, I was bothered by:
a. swelling of the legs or ankles	386	3.37 (1.06)	0.84	0.37
b. difficulty breathing	388	2.96 (1.07)	0.74	0.49
c. nosebleed	383	3.37 (0.98)	0.84	0.19
d. infections related to my VAD	383	3.45 (1.07)	0.86	0.20
e. intestinal bleeding	382	3.89 (0.49)	0.97	0.23
f. malfunctions of the device (the VAD did not work properly)	382	3.82 (0.71)	0.96	0.08
g. hospitalization due to my heart or the VAD	383	3.50 (1.10)	0.88	0.18
9. It frustrates me that I can't fully submerge myself in water (eg, in the bathtub or while swimming).	390	1.62 (1.52)	0.41	0.13
10. I am comfortable working with my VAD equipment.	390	2.43 (1.19)	0.61	0.52
11. I have figured out some tricks for daily living with a VAD.	383	2.17 (1.17)	0.54	0.30
12. It bothers me how the VAD affects my sitting position on chairs or in the car.	391	2.21 (1.19)	0.55	0.55
13. Because of the VAD, it is difficult to maintain balance.	390	3.12 (1.07)	0.78	0.35
14. I feel like I cannot move freely…like I'm “tied down” by my VAD.	389	2.07 (1.18)	0.52	0.65
15. I have physical discomfort related to wearing equipment.	391	2.54 (1.26)	0.64	0.57
Emotional			0.65
16. I feel hopeful.	381	2.29 (1.22)	0.57	0.56
17. I feel sad.	386	2.99 (1.04)	0.75	0.64
18. I worry that my VAD might stop working properly.	390	2.53 (1.32)	0.63	0.53
19. I can laugh.	387	2.99 (1.08)	0.75	0.48
20. I am angry about my heart problems.	390	1.80 (1.28)	0.45	0.50
21. I have found ways to help cope with life's challenges.	392	2.51 (1.05)	0.63	0.52
22. I am confident my healthcare providers can help me if I have questions about living with my VAD.	391	2.97 (0.99)	0.74	0.45
23. I worry when I travel a distance from my VAD center.	380	2.98 (1.13)	0.75	0.54
24. I feel stressed by health issues not related to my VAD.	389	2.73 (1.26)	0.68	0.40
25. I am anxious about the uncertainty of my future.	392	2.35 (1.25)	0.59	0.69
Social			0.61
26. I am less likely to go places because of my supplies.	389	2.27 (1.38)	0.57	0.55
27. I am burdened by extra costs related to my VAD.	391	2.87 (1.21)	0.72	0.27
28. I can contribute to the well-being of others.	384	1.92 (1.23)	0.48	0.51
29. I have someone I can talk to about my condition.	392	3.18 (1.23)	0.80	0.31
30. It is difficult to talk with healthy people about the challenges I have living with my VAD.	391	2.73 (1.23)	0.68	0.39
31. I am bothered by how my VAD makes me look.	392	2.79 (1.19)	0.70	0.42
32. My VAD keeps me from working outside the home.	322	2.40 (1.44)	0.60	0.48
33. I can do the things I need to fulfill my role in my family.	371	2.29 (1.27)	0.57	0.61
34. I am satisfied with my ability to cuddle/hold loved ones.	367	2.55 (1.31)	0.64	0.62
35. I am satisfied with my ability to be intimate with my partner.	272	1.34 (1.38)	0.34	0.48
Cognitive			0.79
36. It is hard to remember things.	382	3.02 (1.07)	0.76	0.46
37. My mind is clear enough to do my everyday activities.	389	3.20 (1.11)	0.80	0.22
38. It is hard for me to concentrate for longer than 30 min.	389	3.21 (1.08)	0.80	0.50
Meaning/spiritual			0.63
39. I am a valuable human being.	376	3.02 (1.19)	0.76	0.55
40. My life has meaning and purpose.	379	3.04 (1.17)	0.76	0.58
41. I have peace no matter what happen.	378	2.60 (1.29)	0.65	0.58
42. I believe God or a higher power cares for me.	289	1.79 (1.63)	0.45	0.58
43. I feel support from others who share my faith.	230	2.18 (1.56)	0.55	0.64

“N valid” indicates number of valid values per item. Those shaded in gray have extremely high difficulty indices (P_i ≥ 0.80) and low discriminatory power (r_it ≤ 0.30). Values in bold indicate mean domain difficulty.

Abbreviations: HRQoL, health-related quality of life; SD, standard deviation; VAD, ventricular assist device.