This manuscript presents the distance between each US county and the nearest clinical trial site that were utilized in guideline changing studies evaluating pharmacologic treatment for glycemic control.

The results is, very few (<5%) US clinical trial sites for guideline changing studies of pharmacologic approaches to glycemic treatment were in rural areas.

The conclusion is, efforts are likely needed to increase the generalizability of diabetes clinical trials.

Results:The author shows only graphically the distance between each US county and the nearest clinical trial site in the figure.I would suggest that the author add a summary table of the distance between each US county and the nearest clinical trial site.

Conclusions:The author describes very few (<5%) US clinical trial sites for guideline changing studies of pharmacologic approaches to glycemic treatment were in rural areas.The author should also discuss the ratio of the populations in the rural and urban areas.

Conclusions:The author classified sites into rural and urban areas.

To increase or assess the generalizability, it would be useful to perform subgroup analyses of the clinical trial data by the classification (i.e. rural vs urban area) and compare them.I would suggest that the author cite related papers or give discussion to make that sort of recommendations.

Thank you for your polite response. The manuscript has been revised and is convincing.