To determine the cities with the worst hospital care, 24/7 Wall St. created an index of data from the Centers for Medicare and Medicaid Services (CMS) and other sources. The CMS produces statistics on numerous health measures for more than 4,000 Medicare-certified hospitals in the country. We grouped hospitals by metropolitan areas and aggregated the hospital data to the MSA level.
The index measures three sets of indicators: 30-day mortality rates, 30-day readmission rates, and preventable hospitalizations. Mortality and readmission rates each make up 42.1% of the index, and the rate of preventable hospitalizations makes up the remaining 15.8%.
We calculated a weighted average of 30-day mortality rates for heart attacks, chronic obstructive pulmonary disease (COPD), coronary artery bypass grafting (CABG), heart failure, pneumonia, and stroke patients to find the average percentage of people who died within 30 days of being admitted to a hospital. The mortality measures are adjusted for differences in risk variables such as age, comorbidities, and patient frailty. CMS estimates the data for 30-day mortality by each condition per hospital from Medicare patients.
The readmission measures are estimates of unplanned readmission to an acute care hospital in the 30 days after discharge from a hospitalization for Medicare beneficiaries 65 or older. Patients may have an unplanned readmission for any reason.
Lastly, we used the share of hospitalizations for conditions that could have been treated at outpatient or ambulatory care facilities — often referred to as the preventable hospitalization rate. This measure counts hospitalizations for conditions such as asthma, dehydration, or hypertension per 1,000 patients. This data came from the 2017 County Health Rankings report, an annual analysis produced by the Robert Wood Johnson Foundation.