English hospitals and their efforts to adhere to the 18-week referral to treatment standard, a long-term data analysis has uncovered a fascinating phenomenon: the ‘threshold effect.’ This effect significantly influences their commitment to meeting this pivotal target.
Introduced in 2012, the 18-week referral to treatment standard in England mandated that a minimum of 92% of patients requiring hospital treatment should not wait beyond 18 weeks. But how this target affects hospitals close to meeting it, as opposed to those who have already achieved it or are far from doing so, remains a question mark.
To unravel, researchers embarked on a comprehensive retrospective analysis. They meticulously scrutinized publicly available monthly data on treatment waiting times for all 144 non-specialist acute NHS hospital trusts in England, covering the period from January 2016 to September 2021.
In healthcare, “treatment” encompasses various facets, from hospital admissions and surgeries to the commencement of medication courses and the fitting of medical devices. Researchers explain that a threshold effect manifests as a noticeable spike in data, referred to as a discontinuity, which typically appears around the target threshold.
The research findings shed light on the evolving landscape of NHS hospital trusts in meeting the 18-week target. Over time, the proportion of trusts meeting the target declined progressively, dropping from 92% in 2015-16 to 64% in 2021-22.
Interestingly, the percentage of trusts where patients waited less than 18 weeks exhibited a gradual decline following the removal of financial sanctions for breaching the standard in 2016-17. This decline accelerated during the early stages of the COVID-19 pandemic in 2020-21 before gradually rebounding.
Even more intriguingly, the data consistently revealed strong evidence of a threshold effect until 2019-20 despite the decreasing number of hospital trusts meeting the target.
The hallmark of this effect was a substantial spike in the number of trusts precisely meeting the 92% target threshold for the 18-week standard, followed by a sharp drop-off after reaching the target. It suggests that some trusts might be treating the minimum number of patients waiting less than 18 weeks to comply with the standard.
Remarkably, the threshold effect only dissipated in the financial years 2020-21 and 2021-22, when the COVID-19 pandemic made it nearly impossible for most hospitals to meet the target.
Researchers speculate that hospitals near the 18-week target may be inclined to make a final push to attain it, while those considerably far from reaching it might not see the effort as worthwhile.
While the study wasn’t explicitly designed to delve into the behavioral triggers and motivations behind the threshold effect, the researchers assert that their findings suggest that hospital trusts might prioritize patients based on the target rather than clinical need.
Performance targets are a common feature in the NHS, but the researchers caution against their indiscriminate use. They suggest that policymakers should exercise caution in target implementation. If targets are employed, they should be scrutinized regularly for threshold effects. Furthermore, targets must be meticulously designed to mitigate the emergence of such effects.
In an associated editorial, Nigel Edwards, Chief Executive of the Nuffield Trust, a health think tank in London, acknowledges the effectiveness of targets in fostering public accountability. However, he underscores the unintended consequences that often arise.
Edwards advocates for a more sustainable approach to target attainment, emphasizing the need to redesign processes and allocate resources efficiently to ensure targets are met as a natural outcome of a well-structured system.
In cases where resources are insufficient, such as when demand outstrips capacity or the organization cannot conduct a comprehensive review of processes, less favorable approaches may be adopted.
Historically, the NHS has leaned towards input targets rather than outcomes, prioritizing numerical achievements over a deeper understanding of the underlying issues. This approach often excluded the input of those responsible for delivery.
The use of targets in the English NHS, highlighted by the study and numerous other researchers, underscores the need for a more comprehensive, nuanced approach to healthcare improvement.
Targets alone are insufficient; effective improvement systems require managerial judgment and a clear understanding of how the healthcare system operates, how staff and managers behave, and what motivates them. This multifaceted approach can help avoid the pitfalls of gaming the system and missing the broader healthcare objectives.