Preventable hospital stays

Rate of hospital stays for ambulatory-care sensitive conditions per 100,000 Medicare enrollees.

The 2021 County Health Rankings used data from 2018 for this measure.

Reason for Ranking

Hospitalization for ambulatory-care sensitive conditions, diagnoses usually treatable in outpatient settings, suggests that the quality of care provided in the outpatient setting was less than ideal. This measure may also represent a tendency to overuse emergency rooms and urgent care as a main source of care. Preventable Hospital Stays could be classified as both a quality and access measure, as some literature describes hospitalization rates for ambulatory care-sensitive conditions primarily as a proxy for access to primary health care.[1]

Key Measure Methods

Preventable Hospital Stays is a Rate

Preventable Hospital Stays measures the number of hospital stays for ambulatory-care sensitive conditions per 100,000 Medicare enrollees. Rates measure the number of events (i.e., deaths, births, etc.) in a given time period (generally one or more years) divided by the average number of people at risk during that period. Rates help us compare health data across counties with different population sizes.

Preventable Hospital Stays is Age-Adjusted

Age is a non-modifiable risk factor, and as age increases, poor health outcomes are more likely. We report an age-adjusted rate in order to fairly compare counties with differing age structures.

The Method for Calculating Preventable Hospital Stays Changed

In the 2019 County Health Rankings, the source for this measure switched from Dartmouth Atlas of Health Care to Mapping Medicare Disparities. The rate also switched from per 1,000 to 100,000 Medicare enrollees. The definition of hospitalizations also changed. Previously, hospitalizations for the following conditions were included: Convulsions, Chronic Obstructive Pulmonary Disease, Bacterial Pneumonia, Asthma, Congestive Heart Failure, Hypertension, Angina, Cellulitis, Diabetes, Gastroenteritis, Kidney/Urinary Infection, and Dehydration. See the numerator definition below for current hospitalizations included.

Measure Limitations

A limitation of this measure is that it uses Medicare claims data, which limits the population evaluated to mostly individuals age 65 and older. This measure, therefore, may potentially miss trends and disparities among younger age groups.


The numerator is the number of discharges for Medicare beneficiaries ages 18 years or older continuously enrolled in Medicare fee-for-service Part A and hospitalized for any of the following reasons: diabetes with short or long-term complications, uncontrolled diabetes without complications, diabetes with lower-extremity amputation, chronic obstructive pulmonary disease, asthma, hypertension, heart failure, dehydration, bacterial pneumonia, or urinary tract infection.


The denominator is the Medicare beneficiaries ages 18 years or older continuously enrolled in Medicare fee-for-service Part A.

Can This Measure Be Used to Track Progress

This measure can be used to track progress with some caveats. The trend graph data presented on County Health Rankings county snapshots for 2020 can be used to help understand change over time. Data in snapshots from before 2019 should not be used due to measure changes.

Data Source

Years of Data Used


Mapping Medicare Disparities Tool

The Centers for Medicare & Medicaid Services Office of Minority Health's Mapping Medicare Disparities (MMD) Tool contains health outcome measures for all states and counties for disease prevalence, costs, hospitalization for 55 specific chronic conditions, emergency department utilization, readmissions rates, mortality, preventable hospitalizations, and preventive services.

Digging Deeper
Age 1
Gender 1
Race 1
Education 0
Income 0
Subcounty Area 0

Prevention Quality Indicator data by age groups, sex, and race can be obtained from the Mapping Medicare Disparities tool.


[1] Brumley R, Enguidanos S, Jamison P, et al. Increased satisfaction with care and lower costs: Results of a randomized trial of in-home palliative care. J Am Geriatr Soc. 2007;55:993-1000.

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When it comes to developing and implementing solutions to problems that affect communities, evidence matters. The strategies below give some ideas of ways communities can harness evidence to make a difference locally. You can learn more about these and other strategies in What Works for Health, which summarizes and rates evidence for policies, programs, and systems changes.

Implement multi-component efforts that include coordination of health services by multidisciplinary teams of health care professionals, patient self-management, and patient education
Provide continuous, comprehensive, whole person primary care that uses a coordinated team of medical providers across the health care system

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