Table 1 The item pool. Items marked 1 and 2 were used in psychometric tests in phase 1 and 2

The condition i.e. asthma

My asthma is mild.

My asthma will never go away.

1

I’ve doubted at times that I really have asthma.

1

My asthma comes and goes.

The treatment

I’m not sure about my inhalation technique.

My asthma inhalator is user friendly.

I don’t know how my asthma medicine works.

My asthma inhalator is difficult to use.

I have different inhalators with asthma medicine and I don’t really know when I should use one or the other.

The health care

I want to participate in deciding on my asthma medication.

I get enough information about my asthma medicine from my nurse/doctor.

I wish I got more information about my asthma medicine.

The individual – beliefs about asthma medication

I avoid unnecessary asthma attacks by taking my medicine.

1, 2

I’m worried about how my asthma medicine will affect my body in the long run.

My asthma medicine prevents me from feeling worse on account of my asthma.

My asthma medicine is a source of security.

1, 2

I worry about the side-effects of asthma medicine.

1

Thanks to my asthma medicine I hardly know I have asthma.

My asthma could get worse in the future if I don’t take my asthma medicine now.

1

I’m tired of taking my asthma medicine.

I’m sceptical about my asthma medicine.

1

I don’t like taking medicine unless I feel I need it.

My asthma medicine makes me feel safe and secure.

I think the advantages of taking asthma medicine outweigh the disadvantages of not taking it.

My asthma medicine makes me feel good and lets me manage my life well.

The individual – personal characteristics

1

I don’t feel I’m participating as far as my asthma medicine is concerned.

I prefer cooperating.

I don't like discipline and routines.

I’m a rather insecure person.

I’m usually suspicious of other people’s intentions.

To remember to take asthma medicine you have to have routines and I’m not really that kind of person. I’m a bit more unstructured.

I often feel worried.

I’m a meticulous person and have routines for my asthma medicine.

The individual – adherence behavior

1, 2

It’s easy to forget asthma medicine.

1, 2

I don’t follow the doctor’s prescription exactly but instead I can feel what I need to take. ²I don’t follow the doctor’s prescription of asthma medicine exactly but instead I can feel how much I need to take.

I really have to struggle to not forget to take my asthma medicine.

Routines are important for helping me remember to take my asthma medicine.

1, 2

I don’t have any real habits for my asthma medicine but instead I take them when I remember to.

I can’t manage if I don’t take more asthma medicine than is prescribed.

1, 2

I don’t use my asthma medicine exactly like my doctor has said.

1, 2

Sometimes I test going without my asthma medicine to see what it’s like.

1, 2

I don’t really follow the instructions for my asthma medicine but instead I can feel what my body needs. If I feel I need more, I take more. If I feel I need less, I take less.

1

I feel I need to take more reliever medicine than is prescribed.

1, 2

I can tell myself how I feel and how much of my asthma medicine I need to take.

1, 2

I’m like a periodical drinker as far as my asthma medicine is concerned.

Even though it would be good if I had a routine for my asthma medicine it’s probably nothing I’m going to do anything about.