Table 2.

Examples showing how units were interpreted and coded into themes for two PROMIS domains

Selected domain	Main theme	Sub theme	Selected unit	Interpretation
Fatigue	Coping with fatigue	Rest	“When I’m at home and I’m tired, I really can’t be bothered with anything, the whole world may be turned upside down for all I care, all I want is to lie down.”	Lying down as a reaction to fatigue.
Fatigue	Effects of fatigue	Downward performance spiral of fatigue: fatigue leads to activity restrictions. Activities trigger breathing difficulties.	“Yes, you get tired more quickly. You’ve also got the feeling that if you want to do something…then you ask yourself right away should I do that or how should I go about it so that I won’t suffer breathing problems.”	Activity limitations due to fatigue, and activities trigger breathing problems.
Fatigue	Determinants of fatigue	Combination of work and medicines lead to fatigue.	“I’m always tired anyway, if I didn’t have to go to work I would be tired all the same, you actually get tired because of the medicines you have to take during the day. One medicine has to widen the blood vessels, the other has to narrow them again …it’s a combination of (the aforementioned).”	Combination of work and medicines lead to severe fatigue.
Ability to participate in social roles and activities	Determinants of ability to participate in social roles and activities	Mobility restrictions	“Because of your shortness of breath you are restricted in your mobility and therefore also in your social roles. A while ago, I was supposed to attend a funeral at XX…that’s a problem.”	Symptoms cause mobility restrictions as a result of which social contacts are not possible which in turn leads to limitation in social roles.
Ability to participate in social roles and activities	Hobby/Leisure time	Limitation in social role at sports club	“I used to be the leader of a football team, and I could run as fast as the boys, but those days are over.”	Quit participation in social role and sports activity
Ability to participate in social roles and activities	Hobby/Leisure time	Limitation during sports activity	“You have to limit it somewhat, don’t you?	Limitation in degree of physical activity during sports activity
			When I go swimming, for instance, I bring two people; well, those two are able to swim very well, when they have reached the other side of the pool for the second time, I have yet to reach the other side for the first time.”