A benchmark is a standard which something is measured against. This will generally be the "norm" for the majority. For example, Core Measures are JCAHO's version of Benchmarking. Core Measures are performance measurement initiatives that aim to drive hospitals to perform at or above their competitors. These can include things like the length of time it took to give a cardiac patient aspirin upon intake. Do you feel that benchmarking is an ethical way of rating healthcare organizations?
I would argue that benchmarking is an ethical way of rating health care organizations. It is ethical so long as the benchmarks are legitimate benchmarks. If meeting or exceeding the benchmarks will truly mean that the patient is more likely to have gotten quality care, then there is no reason to think that benchmarking would be unethical.
In your question, you say that the Joint Commission uses the length of time before a cardiac patient is given aspirin as a benchmark for the quality of care. This seems to me to be an ethical benchmark. If the patient is given aspirin sooner than the benchmark, it surely would not harm the patient. So long as all cardiac patients ought to have aspirin, this is a good benchmark.
However, if the benchmark is not beneficial to the patient, it is not an ethical way to rate health care organizations. Let us say that cardiac patients ought to be evaluated and that the decision to give aspirin can only be made after the evaluation. In that case, we would not want to use a benchmark to encourage hospitals to simply give aspirin right away even though that might not be indicated. We do not want to have benchmarks that are used solely because they are easily measured.
Benchmarks are ethical as long as the things measured are truly positive outcomes for a patient. We must now use benchmarks to encourage providers to do things that are not necessarily in the best interests of the patient.