The National Institute of Health and Care Excellence (NICE) in England makes recommendations on medicines and treatments based on how well they work and their cost. Most recommendations are positive, but some are 'optimised', meaning they have restrictions. A study looked at optimised recommendations from 2015 to 2019 and found that in 65% of cases, NICE recommended the treatment for less than half of eligible patients. This means that even though the treatment might work well, not everyone who could benefit from it is allowed to use it. More detailed reporting could give a clearer picture of how many patients can access treatments recommended by NICE.