Hospital Referral Region DATA BY REGION Dartmouth Atlas of Health Care Region http://www.dartmouthatlas.org/data/region/ 306 healthcare markets Hospital Service Areas (HSAs) http://www.dartmouthatlas.org/data/region/ "Data by Region, the Dartmouth Atlas of Health Care" the Dartmouth Atlas Project http://www.dartmouthatlas.org/data/region/ Dartmouth Atlas of Health Care http://www.dartmouthatlas.org/data/region/ Dartmouth Atlas of Health Care Dartmouth Atlas of Health Care http://www.dartmouthatlas.org/data/region/ http://www.dartmouthatlas.org/data/region/ 306 healthcare markets Hospital Service Areas (HSAs) www.dartmouthatlas.org/data/region/ Dartmouth Atlas of Health Care Hospital Service Areas (HSAs) 306 healthcare markets Dartmouth Atlas of Health Care Dartmouth Atlas of Health Care Dartmouth Atlas of Health Care