Comments on abstract, title, references

The abstract is well composed with all information within. The title is maybe could be in singular as the system delay should be considered as unique as per definition. All the references are relevant, update and sufficient for the article.

Comments on introduction/background

the • It is clear what is already known. • The research question should point out the system delay as unique whether is it calculated as the time for the call till the patient came to the hospital or from the time the team had contact with patient. • The question should be made as the one system delay and not as two delays without not prior definition of what is taking in the account.

Comments on methodology

The process of subject selection in clear. The variables are not well defined, because there is not clear what time is measuring as the start of system delay: weather it is the time from the receive of the phone call, the time from the ambulance crew arrives at the scene or the time the patient indicates the start of the symptoms. The study methods are valid and reliable. There is enough details to replicate with well defined components of the system and patient delays.

Comments on data and results

The tables could be presented as box plots as interquartile ranges. The table 5 and 6 could be presented in a form that better present the contents, as they are with two columns. The text adds to the results and is not repetitive. It is clear to me the statistical significance of the results of the parameters measured. As the future direction actions are presented and have goal to meet it is the practical relevance in decreasing the time delay on the onset of the revascularisation in patients with acute myocardial infarction.

Comments on discussion and conclusions

The results are discussed from the multiple angles in Poland context and are not overinterpreted. The conclusions answers the question that are in the aims of the study. There are numerous study that compare the relevant results in other countries regards the system setup to minimize the time delay in commencing in time of the treatment for acute myocardial infarction thus shortening patient and system delay.
The limitations of the study are presented and there are the proposed measures for the future improvements of the system delays.