How should anaesthetic skills best be deployed for quality, safety and efficiency of care? A reply.

We thank Coldwell and Craig for their editorial [1] addressing the important issue of skill matching and anaesthetic complexity. It is reassuring to know that colleagues in both anaesthesia and surgery are aware of the problems facing the health service in this respect and that agile approaches and new tools such as the OxAnCo score can form part of the solution. Indeed this is not UK-specific; we have already corresponded with researchers and clinicians from Spain and India looking to validate the system in their populations. The OxAnCo score is also being piloted as part of a popular anaesthetic logbook app (https://anaesthetics.app), demonstrating its potential in the training environment. Our effort to unbundle complexity and risk does not ignore the relationship between the two. Indeed, as the editorial notes, one risk tool (ASA physical status) is actually contained within OxAnCo, as are several other factors shown to have a strong link to anaesthetic and surgical risk. However, there are some clear examples in which risk and complexity diverge, for example, an upset 2-year-old child presenting for a foreign body removal from the ear. Vascular access is relatively difficult and perhaps the parents do not share a common language with the anaesthetist. This patient is not high risk by any measure and their clinical outcome will be excellent, but this is still a case of some complexity, requiring an anaesthetist of suitable seniority and experience. Conversely, a patient with diabetes, hypertension and asthma taking more than three medications and presenting for a knee arthroscopy may score above baseline for risk, but does not for complexity, and the gut feeling of the jobbing anaesthetist cited in the editorial would likely agree that this patient probably does not require a senior consultant for their anaesthetic. It must be noted that this same gut feeling performs poorly as a predictor of risk [2]. Objectivity is always preferred, and our belief is that the same is true of complexity. We do not deny that finding an accurate objective vantage point can be difficult; tools and scores should be developed over time and OxAnCo may be adapted to include other markers of health, as suggested in the editorial. Similarly, it may branch into subspecialist scores or be validated in specific surgical groups (such as O- and V-POSSUM [3, 4]). However, the scoring system performs as intended when used in, for example, cardiac anaesthesia (as discussed in the editorial), and delivers a high-complexity result. This reflects the almost exclusively consultant-delivered service in this anaesthetic subspecialty. This evolution of the scoring system will also occur in its interpretation. Local centres will understand their own workforce in terms of experience, particularly for those in groups that are not mapped to the UK training curriculum (speciality or SAS doctors, anaesthesia associates). We deliberately do not explain how OxAnCo should be used in this respect; hospitals and departments will need to set their own complexity cut-offs for each group, or even make them bespoke for each doctor in order to meet professional development and training needs. This goes hand-in-hand with avoiding the ‘unintended consequences’ highlighted in the editorial. Proper use of the score allows appropriate supervision arrangements. The training list does not disappear overnight, nor does the role of the supervising consultant. Logbooks of complexity will surely reveal a weighting towards lower scores early in a career, with increasing scores as experience builds. This happens now but will be more efficient and objective. In our challenged system, the idea of ‘relaxing’ cases feels anachronistic. It is no accident that the lowest OxAnCo score is 15; there is no such thing as a zero-complexity anaesthetic, regardless of experience. The issue of burnout is not one that was created by, or can be solved by, a complexity scoring system. Staffing shortages are a reality, as is the growth of new anaesthetic staffing groups. Grappling with these problems in the context of a growing surgical backlog requires novel approaches, one of which we have described. The score does not replace the need for good departmental well-being and proper systems-level workforce planning, such that burnout is avoided. Systems-level thinking is similarly important in structuring operating lists. If patients are inappropriately allocated, or lists wrongly booked, planned or located, this is a user error or a pathway failure, not an intrinsic problem of the OxAnCo score. As highlighted earlier, centres will rapidly build local experience in how to manage complexity stratification and skill mix. Using the score properly does not exclude clinical oversight in list planning. Surgeons and anaesthetists are encouraged to engage with managerial processes and should feel empowered to adjust sessions in response to historic and live complexity data. Without overlooking the challenges of implementation noted by Coldwell and Craig, we hope OxAnCo is useful for clinicians and patients, and is a step towards having the right staff in the right place at the right time.