Table 2 Summary of the factors influencing prescribing by thematic categories

1. Characteristics of the intervention

Scientific evidence of effect

"There's been so much data on the … biologics, their effectiveness … and even side-effect profiles and above all perhaps the absence of serious side effects have meant that they have come earlier and earlier in the treatment arsenal." (P24, CC2)

Cost of the drug

"The striking fact about the biological drugs when they arrived was that they were very expensive. So this led to far more expensive treatment than before." (P10, CC3)

2. Characteristics of the individual prescribers

Knowledge and beliefs about biologics

"How much you know about the drug, how much experience you have with it…If you have something that's gone wrong, you think it might be the same for the next patient…experiences and habit largely affect prescribing." (P6, CC3)

Personal attributes

"Some physicians are also very conservative, they use what they've learned … and don't want to test something else." (P24, CC2)

3. The patient

Patient characteristics

"The patient influences the decision the most, it all starts there…Because then I can always justify my decision if somebody questions it and says that I prescribed something very expensive, I can always say `we chose this based on the patient' and then I can't get any criticism for it. The patient is the factor with the most influence." (P3, CC4)

Patient as an actor in decision- making

"But then of course there's also some pressure from the patients. They're very well informed. And if you decide not to prescribe biologics you'll presumably have to motivate that decision." (P26, CC2)

4. Inner setting—the department

Structure of the department

"Another reason (for the varying prescription decisions) is that the number of rheumatologists varies substantially across the country, and if you're not a specialist in rheumatology you probably don't feel very accustomed to using that type of drug." (P23, R2)

Networks and communication

"When we want to start biological medication in a new patient, we have a group discussion and the decision is made in the group… to get a common practice for the patients we treat. The choice of treatment is still made by the individual physician so it's more about the decision that it's okay to start with a biological drug for this patient." (P12, CC1)

Leadership engagement

"One thing that influenced prescribing was that I was the medical chief [at the rheumatology department] and I sat down and prioritized the extra resources needed for the drugs at our department." (P23, CC2)

Available resources

"We have the pharmaceutical budget, we have had a … well, a limited budget, simply. And these treatments are expensive of course and it's hard to stick to the budget." (P11, CC3)

Culture

"When discussing a patient that I want to put on biologics, my colleagues usually question whether I've tried this and that first… My opinion is that it's more restrictive that way." (P15, CC1)

5. Outer setting

Cost responsibility

"… I think that the budget still plays a role there… the stricter the budget you have at the department, the more careful you are with the money. I think there are other departments with higher prescription levels that do not really … carry their own drug costs in the same way we do and of course that facilitates their prescribing more." (P5, CC4)

Political and administrative influence

"Sometimes you're lucky and this is an area that is highly prioritized by the county council and then you're more willing to start treatments, but in other regions it has been quite the opposite and starting treatments has been banned, yes, there has simply been a total stop." (P20, CC5)

External policies

"When the new guidelines came there was a clear increase in funding for the drugs in the region… then we also had the new guidelines from the SRF and they could of course also be used as an argument that there were many more [patients] that should have biological drugs so then we need to have more money." (P18, CC5)

External peer pressure

"And that was actually what made it possible to increase our previous low level of prescription. When the Open Comparisons came they made it a bit freer to prescribe the drugs." (P10, CC3)

Participation in clinical trials

"The studies facilitated understanding of the new drugs, because when you test the new drugs in clinical trials, you're always in the forefront of development, so we were familiar with the new drugs before they were even available. And I think that has facilitated their use." (P21, CC5)

Influence from the pharmaceutical industry

"If companies are very active in marketing at one department, then that can have an impact. Or if there are some personal ties between [physicians and reps] and they think they are nice or something. Then you can get a higher prescription level." (P7, CC3)