Table 3 Sustainability threats encountered across the cases and their impact on CFS sustainability constructs

1. Workforce stability: caused issues in handover and continuity as staff moved on and new staff were brought in.

Demonstrating effectiveness: unstable workforce compromised the ability of initiative rationale, learning, and measures to be communicated adequately and consistently.

“You have turnover of junior doctors every six weeks…so, again, just when you've got them comfortable and happy to use it then they change into another. So it's always going to be a challenge.” (I21_QI manager)

Training and capacity building: Staff turnover required extra training as well as continual engagement and establishment of working relationships with recruits and partners.

“You need to think about new training awareness…that’s a constant challenge actually because your staff group is always changing.” (I2_Clinical lead)

Organisational readiness and capacity: Staff turnover compromised initiative delivery and organisational memory as staff left.

“I can point to at least five people if not more within the original project team, that have got promoted during that time….you’ve taken away a lot of that ‘know how’ that was generated.” (I6_QI manager)

2. Improvement timelines: limited improvement project funding and timelines

Evidence base for the initiative: limited timeframes compromised the ability to perform meaningful evaluation of the improvement work during and at the end of the initiative.

“We’ve had some good things happening with the project…but I think it’s the frustration that things haven’t come on as well or as fast maybe, as we would have thought.” (I3_Service User)

“A lot of people feel that even with them working quite hard there is still not the evidence they want to see. There’s still not the patient impact that they want to see.” (Allery_12 month review transcripts)

Belief in the initiative: limited QI timelines compromised the capacity to demonstrate impact to staff and funders by hindering the generation of the evidence base needed to sustain the initiative.

“Outcome measures (A&E attendances) look positive, but reliability and (project) attribution are unclear. Process measures (management plan, skin prick testing etc.) look promising, but need to be looked at in more detail.” (LTST Questionnaire response_Allergy _February 2016)

3. Competing organisational priorities: difficulty operating within organisational limitations and shifting strategies as well as remaining relevant to organisational leaders.

Resources: Shifting strategies compromised the initiatives’ ability to garner support and buy-in as well as the capacity to gain access to necessary resources to continue the initiatives.

“Projects have clearly got over it by committed people within the organisation just going, hell, we’re going to do it, and doing it….you’ve done it regardless of the fact that actually the funding and administration support has not been offered.” (Allergy_18 month review transcript)

Integration with existing programs and policies: organisational limitations compromised ability of teams to embed changes within existing programs, processes, and policies.

“In a big organisation like this there’s every chance that someone else will decide there’s some other way of doing things and then all of a sudden this all goes out the window…and things change so much in the NHS (National Health Service) that good things just get wiped out sometimes.” (I1_Clinical lead)

Opposition: competing priorities compromised staff motivation as well as local and organisational support.

“There seems to be minimal organisational support within the project; sometimes I felt that we (core team) have been working against a whole organisation to improve children's health outcomes.” ( LTST Questionnaire response_Allergy_February 2016)

4. Capacity for improvement: difficulty to conduct improvement work without having dedicated time and therefore relying on core individuals.

Team functioning: limited staff capacity compromised the fair distribution of workload and responsibilities.

“In the short term you’re delivering the improvements in the project, but in the longer term you’re going to have a detrimental effect on the sustainability of the project…if it’s somebody’s job to do it now, then what happens when they’re not there or what happens when they leave.” (I6, QI manager)

Job requirements: improvement work increased workload and responsibilities for staff with no additional resources.

“We definitely will need admin support…I can do that now…because I’m only covering two specific areas...I don’t think they realised how much admin support would be needed.” (I19_Nurse)

Ownership: Lack of ownership as projects are seen as personal projects rather than organisational priorities, compromising the organisational ownership of the initiative.

“The project seems to belong to somebody rather than to the organisation and I think that's been the biggest factor that I’ve seen in sustainability, is the lack of organisational ownership of projects, they think it belongs to an individual consultant or nurse or even a team of people, not the organisation.” (I6_QI manager)

5. Stakeholder support: difficulty to garner and maintain support and stakeholder engagement in the initiatives.

Intervention adaptation and receptivity: Lack of stakeholder engagement compromised the ability to understand the experience of staff and patients and how to tailor improvements to their preferences and needs.

“If what we’re doing is clunky and alienating and unmanageable for patients, then they won’t go along with it either, so I think having them, gave us a bit of a check and a balance with that to make sure that we were doing something that was likely to be acceptable to patients and service users.” (I2_Clinical lead)

Staff involvement and community participation: Lack of support from stakeholders resulted in missed opportunities for raising awareness, championing, and influencing decision-making.

“True involvement, engagement of patients, I would say that this is a weakness of the project and…it’s very hard to know whether that would have created some pressure with the hospital management or the trust management, but it may have been a positive influence on the involvement of GPs.” (I20_QI manager).