There is a lack of direct evidence of the downstream resource impact of using Kurin Lock. By reducing the blood culture contamination rate, the number of false positives should also be reduced. This is expected to have an impact on a patient's length of stay and antibiotic use. The clinical experts advised that there is uncertainty in the length of stay for people who have a blood culture taken and that many factors influence this. The length of stay data used in the economic model was from Skoglund 2019, based in the US. The key parameters were that a person with a true-negative blood culture result would have a hospital stay of 5 days, and a person with a false-positive result would have a hospital stay of 7 days. The clinical experts advised that there is uncertainty in the length of stay for people who have a blood culture taken, and that many factors influence this. One clinical expert explained that other test results and clinical information are routinely used to help decide if a blood culture result is contaminated. So, in their opinion only a small proportion of people with a false-positive blood culture result would have additional treatment and a longer hospital stay. In Alahmadi (2010) a retrospective case-control study design was used in which false-positive blood culture cases were matched with comparator cases. But the EAG and clinical experts noted that contaminated blood cultures were not all matched to comparator cases from the settings. The committee agreed that it is reasonable to assume that people in intensive care may be expected to have longer stays and higher daily stay costs compared with other settings, so the cost savings per contaminated blood culture may be overestimated. The committee agreed with the EAG's view that the Alahmadi (2010) study, which estimated longer hospital stays associated with false positives compared with Skoglund 2019, was not generalisable to a wider NHS setting because of the high proportion of people (42%) in intensive care. The committee agreed that the 2‑day difference from Skoglund (2019) may not represent NHS clinical practice, and that further evidence of the resource impact in the NHS should be generated.