Frequently Asked Questions

What's new this year on the Lown Index?

For 2021 we have several updates to the Index making the ranking more comprehensive and accurate.

Social Responsibility

  • Our overall ranking is now called “Social Responsibility.”
  • This year, hospitals’ Social Responsibility scores are calculated based on their grades in each category, rather than their raw scores. This means that hospitals ranked at the very top will have A grades in each category (see below for more details).
  • This year, each hospital receives a grade and a ranking for each component. (Components are Inclusivity, Community Benefit, Pay Equity, Avoiding Overuse, Cost Efficiency, Clinical Outcomes, Patient Safety, and Patient Satisfaction.)
  • This year, the Tier 2 and Tier 3 grades and Tier 4 stars are based on underlying hospital performance rather than relative performance (how other hospitals did). Previously, hospitals only received 5 stars or A grades if they scored in the top percentile of all hospitals. This year, if many hospitals all perform well on a certain metric, they could all receive 5 stars or A grades.
  • About 350 more hospitals are included in this year’s rankings compared to last year, for a total of 3,709 hospitals.


  • A new component of Cost Efficiency has been added to the Value category. Due to this addition, the Value category is weighed slightly higher than last year in the overall Social Responsibility ranking.
  • Adjustments have been made to the Avoiding Overuse algorithm to improve accuracy (see JAMA paper for details), including updating our definitions to use ICD-10 codes.


  • The category previously called “Civic Leadership” is now “Equity.” The components of this category are unchanged.
  • In the Community Benefit component, the metric previously called “Charity care and other community benefits” has been separated into the two metrics “Charity care” and “Community investment.” This change was implemented to make it easier to compare hospitals on these metrics separately.
  • In the Inclusivity component, instead of using the center of the hospital's zip code, we now use the hospital's address as the center of the hospital's community area radius. Also, for the community area zip code weighting, we now use a hospital-specific rate rather than a constant rate across all hospitals (see MedRxiv paper for details).


  • For this year, our clinical outcomes measures include a new adjustment for hospitals having disproportionately sicker or healthier patients by including patient risk mix within the model. This means that the proportion of high-risk patients at a hospital is taken into account when looking at clinical outcomes.
  • Our clinical outcomes measures include a new adjustment for hospitals having disproportionately sicker or healthier patients by including patient risk mix within the model. This means that the proportion of high-risk patients at a hospital is taken into account when looking at clinical outcomes.
  • Our clinical outcomes measures include an adjustment for hospital case mix, based on the proportion of cases that fall within certain Diagnosis Related Groups (DRG) such as cardiac or orthopedic cases.
  • For clinical outcomes, we added a patient-level indicator for end-stage renal disease to the algorithm, to better adjust for patient risk.
  • In 2020, the clinical outcomes component included a metric for 1-year mortality. We have removed this metric in 2021.

What is the Lown Hospitals Index?

The Lown Institute Hospitals Index is the first ranking of hospital social responsibility, by evaluating hospital performance on health outcomes, value, and equity.

A lot of hospital rankings exist already. Why do we need another one?

Most hospital rankings focus solely on patient outcomes, but hospitals do more than just provide medical services. Hospitals make decisions every day that impact the health and well-being of their community, such as how they invest in community health initiatives, who they welcome into the hospital, and how much they pay their workers. The Lown Institute Hospitals Index is the first ranking to take these factors into account, in a holistic measure of social responsibility. Read more about why we took this project on

Who is the Lown Index for?

The Lown Index shows how well hospitals serve communities, as well as individual patients. We think this is something that everyone should be interested in, especially policymakers, hospital administrators, community health advocates, and other actors seeking to enact health system change in their communities or institutions.

How are the stars and grades calculated?

For each detail (eg. racial inclusivity, charity care), hospitals receive between 1-5 stars and a ranking. The stars reflect the actual result of hospital performance on a metric, not just their performance relative to other hospitals; many hospitals may get 5 stars on a metric if they all have similar (and good) results. 

The respective detail scores are weighted to create grades and rankings for each component (eg. inclusivity, community benefit). Each hospital gets a grade rating: A (highest) to D (lowest). Hospitals within the top range of scores (approximately the top 25%) get an A, the next 40% get a B, the next 20% get a C, and the last 15% get a D. These component grades are then weighted to create grades for each category (equity, value, and outcomes).

Finally, an overall Social Responsibility grade is assigned based on the weighted grades from value (30% weight), equity (30%) and outcomes (40%).

Why did my hospital not receive a composite grade?

Some very small hospitals did not have enough patient stays to reliably calculate their outcomes, cost-efficiency, or avoiding overuse scores (698 hospitals). These hospitals were were not given a composite score, but were still graded on the components for which data were available.

Why is my hospital missing from the Index?

The following types of hospitals are excluded from the Index:

  • Hospitals outside the 50 US states and Washington, DC
  • Hospitals that are not included in Medicare fee-for-service data (such as children’s hospitals and Kaiser Permanente hospitals)
  • Federally-run hospitals (such as VA Hospitals)
  • Specialty hospitals (such as orthopedic hospitals). We defined specialty hospitals with more than 45% of their cases in orthopedics, cardiac care, or surgeries. 
  • Hospitals that were closed in 2020. We determined closed hospitals through a check of Hospital Compare, a website run by CMS.

See the methodology paper for more details.

My hospital is part of a system but doesn't appear in the system list. Why is that?

Some hospitals were excluded from our rankings (see above). Only hospitals that were ranked are included in our system rankings. In addition, systems membership is based on 2018 American Hospitals Association records and may not reflect current membership.

Understand the Rankings

The Lown Index rolls up scores from 42 detailed metrics, 8 components, and 3 categories to create an overall composite score.

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