Potentially Preventable Hospitalizations

In this report, we identify current disease burden and disparities in Allegheny County hospitalizations for ambulatory-care sensitive conditions and describe changes in hospitalization rates from 2016-2021.

Ambulatory-care sensitive conditions (ACSCs) are diseases or conditions that are sensitive to quality and timely outpatient care.  ¹   Some examples of ACSCs include hypertension (high blood pressure), diabetes and asthma. Given adequate primary care, hospitalizations for these conditions are considered potentially preventable.

High rates of preventable hospitalizations may indicate barriers to accessing outpatient care, which provide a useful metric for measuring overall access to care within a community.  ¹   Surveillance of potentially preventable hospitalizations in Allegheny County is important for identifying populations and geographic areas that may have issues with access to outpatient or primary care. Understanding these disparities can inform the development of interventions.

*Italicized words are defined in the Definitions and Abbreviations section.

The  Pennsylvania Health Care Containment Council  (PHC4) provides annual inpatient hospitalization data to Allegheny County. The PHC4 data contains information for every hospital discharge, including diagnosis codes for the conditions related to the hospitalization. In this analysis, the PHC4 data was filtered for hospitalizations among Allegheny County residents from 2016-2021.

From the PHC4 data, potentially preventable hospitalizations were identified using   Prevention Quality Indicators   created by the   Agency for Healthcare Research and Quality.  

These indicators use ICD-10 codes to identify hospital admissions specifically for ACSCs. Using Prevention Quality Indicator codes provides a standardized way of obtaining estimates of preventable hospitalizations.

The PQIs are widely used to identify ACSC hospitalizations.  ^3-5   Most indicators are assessed among adults 18 and older, except for COPD, asthma, and the pediatric indicators.

In this report, we describe the following for each indicator:

• Demographic Characteristics
• Age-Adjusted Hospitalization Rates
  • Age-adjusted rates were calculated by year and by quarter. Though hospitalization rates are shown by year for each indicator, trend analyses were performed using quarterly hospitalization rates. More information on using quarterly hospitalization rates for trend analyses can be found in the Technical Notes section. Statistically significant trends indicate that the hospitalization rate is increasing (upward trend) or decreasing (downward trend) over time and are noted where applicable.
  • Allegheny County rates are shown for all indicators, with subgroup analyses by race and sex, when possible.
• 2021 Map of Hospitalization Rates by Patient ZIP Code
  • PHC4 data provides location data for each patient at the ZIP code level, so hospitalization rates were mapped by patient ZIP code.
  • ZIP codes with fewer than 10 hospitalizations were censored to protect patient privacy, and because estimates produced are unreliable

In Pennsylvania, hospitalization rates for potentially preventable hospitalizations have decreased during the pandemic. The 2019 PA ACSC hospitalization rate was 151 per 10,000 residents, and in 2021 was 124 per 10,000 residents 18 and older.  ^4,5 

Nationally, hospitalization rates have decreased during the COVID-19 pandemic. Non-COVID-19 hospital admissions decreased by 42.8 percent by April 2020, compared to February 2020.  ²   This trend was also seen in potentially preventable hospitalizations, where analyses of hospital systems across the United States observed a decreased risk for ACSC hospitalization during the pandemic period.  ³  

Racial disparities exist in ACSC hospitalizations. Black patients hospitalized for ACSCs are, on average, two years younger with a higher number chronic diseases than White patients. Hospitalizations examined from 2011-2015 observed significantly higher rates among Black patients compared to White patients.  ⁶  

When examining trends over time, preventable hospitalization rates significantly decreased among White adults during the pandemic, but not among Black adults.  ⁷   In Allegheny County, the disparity in ACSC hospitalizations between White and Black adults increased from 2016-2021. In 2016, the hospitalization rate for ACSCs among Black adults was 2.9 times higher than White adults, and in 2021 was 3.4 times higher than White adults.

Overall ACSC hospitalizations represent hospitalization among adults 18 and older for all conditions included in this analysis.

From 2016-2021, there were 798,463 adult hospitalizations in Allegheny County. Of those, 69,413 (8.7%) were potentially preventable.

The median age at hospitalization for preventable hospitalizations was 70 years, and 52 percent of those hospitalized were female. These hospitalizations cost over $4.1 billion in total hospital charges.

On average, Black adults are hospitalized for ACSCs at a younger age than White adults. ⁶ 

From 2016-2021 in Allegheny County, the median age at hospitalization for an ACSC among Black males was 11 years younger than White males. For Black females, the median age at hospitalization for an ACSC was 14 years younger than the median age at hospitalization for White females.

From 2016-2021, there were 16,392 adult and 529 pediatric diabetes-related hospitalizations in Allegheny County.

Adults diabetes hospitalizations were analyzed for all residents 18 and older, and pediatric diabetes hospitalizations were analyzed for children ages 0 to 17.

Pediatric Diabetes Hospitalizations

Pediatric diabetes hospitalizations were defined as any short-term diabetes complication hospitalization among children ages 0-17.

In 2021, there was a low number of pediatric diabetes hospitalizations. To protect patient privacy and prevent the calculation of unreliable rates, the Health Department did not create a 2021 map of hospitalization rates for pediatric diabetes.

The PQIs outline a diabetes composite indicator for adults, which includes all diabetes-related hospitalizations; short-term diabetes complications, long-term diabetes complications, uncontrolled diabetes and lower-extremity amputation with diabetes.

Each diabetes-related indicator is shown individually with their respective 2021 map of age-adjusted hospitalization rates by ZIP code, in addition to the composite indicator.

Short-term diabetes complication hospitalizations include ketoacidosis, hyperosmolarity or coma.  Ketoacidosis  occurs when someone does not have enough insulin in their body and needs to convert fat into energy instead of sugar from the blood. ⁸  This process causes a buildup of acid in the body.  Hyperosmolarity  occurs when concentrations of glucose or salt in the blood are too high. ⁹ 

From 2016-2021, there were 4,546 short-term diabetes complication hospitalizations in Allegheny County.

Over time, high blood sugar can damage blood vessels and nerves and cause long-term complications. ¹⁰  Hospitalizations for long-term diabetes complications include  renal ,  eye ,  neurological ,  circulatory  or  other complications .

From 2016-2021, there were 7,981 long-term diabetes complication hospitalizations in Allegheny County.

Uncontrolled diabetes hospitalizations include admissions for uncontrolled diabetes without mention of short or long-term complications of diabetes.

From 2016-2021, there were 2,928 uncontrolled diabetes hospitalizations. In 2021, there was a low number of uncontrolled diabetes hospitalizations. To protect patient privacy and prevent the calculation of unreliable rates, the ACHD did not create a 2021 map of hospitalization rates for this indicator.

Figure 8. Age-adjusted rates for uncontrolled diabetes hospitalizations per 10,0000 adults by race and sex, Allegheny County, 2016-2021

Allegheny County hospitalization rates for uncontrolled diabetes significantly decreased from 2016-2021. Uncontrolled diabetes hospitalization rates significantly decreased for all groups from 2016-2018. In 2021, the rate of uncontrolled diabetes hospitalizations among Black adults was 5.1 times higher than White adults.

 Nerve damage and reduced blood flow  from high blood sugars can lead to feet sores that do not heal properly. In severe cases, this may require amputation to contain the infection. ¹¹  Lower-extremity amputations include hospitalizations for procedures with an amputation of a lower-extremity (excluding toes) with a principal diagnosis of diabetes.

From 2016-2021, there were 937 lower-extremity amputations with diabetes hospitalizations in Allegheny County. In 2021, there was a low number of lower-extremity amputation hospitalizations. To protect patient privacy and prevent the calculation of unreliable rates, the Health Department did not create a 2021 map of hospitalization rates.

Figure 9. Age-adjusted rates for lower-extremity amputation with diabetes hospitalizations per 10,000 Adults by race, Allegheny County, 2016-2021

Due to low hospitalization counts, trend analysis was performed for the overall Allegheny County hospitalization rate only. Hospitalization rates for lower-extremity amputations with diabetes decreased from 2016-2021. In 2021, the rate of lower-extremity amputation hospitalizations among Black adults was 4.5 times higher than White adults.

Pediatric asthma hospitalizations were evaluated among children ages 0-17. From 2016-2021, there were 1,121 pediatric asthma hospitalizations. In 2021, there was a low number of pediatric asthma hospitalizations. To protect patient privacy and prevent the calculation of unreliable rates, the ACHD did not create a 2021 map of hospitalization rates for pediatric asthma.

 Asthma  hospitalizations were analyzed among younger adults ages 18-39. From 2016-2021, there were 716 asthma hospitalizations among adults 18-39. Due to a low number of hospitalizations in 2021 for each ZIP code, the ACHD was unable to create a 2021 map of hospitalization rates for this indicator.

This indicator includes hospitalizations among adults ages 40 and older for  chronic obstructive pulmonary disease  (COPD) or  asthma . COPD is a group of conditions causing airflow blockage and breathing problems. The disease is typically seen in smokers and adults over 40 years old, regardless of tobacco history. ¹²  From 2016-2021, there were 16,718 hospitalizations for COPD or asthma among adults 40 and older.

Hospitalizations with a principal diagnosis of  heart failure  were included in this indicator. Heart failure occurs when the heart is unable to pump enough blood to the body, and is typically caused by other health conditions that damage the heart, such as heart disease or high blood pressure. ¹³ 

From 2016-2021, there were 32,932 hospitalizations for congestive heart failure in Allegheny County.

This indicator includes hospitalizations for  hypertension  (high blood pressure). Over time, high blood pressure can cause damage to the heart and other health conditions. ¹⁴ 

From 2016-2021, there were 2,655 hospitalizations for hypertension.

The Allegheny County Health Department's  Chronic Disease Prevention Program  works to prevent and manage chronic disease in Allegheny County residents through education, outreach and partnering with community organizations.

Potentially preventable hospitalizations can be indicative of access to health care within a community. Increasing access to outpatient or primary care can help prevent these hospitalizations. The ACHD's  Guide to Health Care Services for Underinsured or Uninsured  provides locations of Federally Qualified Health Centers and other clinics that provide free, or reduced cost, medical care.

The ACHD's  Live Well Allegheny  initiative provides local resources to help residents address overall wellness through healthy eating, physical activity and quality of life. Live Well Allegheny has several strategic initiatives, like the  Safe and Healthy Communities  initiative, which partners with local organizations to address access to healthy foods, safe physical activity, and more.

The  Office of Family and Child Health  provides smoking cessation support for people who are pregnant or have small children in their home. Certified tobacco treatment specialists work with individuals or in group sessions to help take steps to quit smoking.

 Allegheny Quits for Life , a campaign sponsored by Live Well Allegheny and Adagio Health, provides the region with smoking cessation support and resources. The week-long campaign occurs in November and offers events and communications to promote efforts to help residents quit smoking. Adagio Health also offers  online nicotine cessation classes .

PA Quitline: 1-800-QUIT-NOW. The PA Quitline is a free phone counseling service for smoking cessation and can help connect those looking to quit smoking with free medication.

The Asthma Task Force was created by the Allegheny County Health Department in 2018 to collaborate with providers and community partners to use an evidence-based approach to lower asthma emergency department visits and hospitalizations and impact asthma policy. Their  Allegheny County Asthma Resources  flyer provides links and information for local asthma clinics and programs to address smoking cessation and environmental asthma triggers in the home.

The  Racial and Ethnic Approaches to Community Health  (REACH) program partners with national and local organizations to address disparities in African-American communities. This program seeks to promote health equity and prevent chronic diseases in communities in the East End, Hill District, Mon Valley, Wilkinsburg and the North Side through increasing access to healthy foods and physical activity and transportation.

The hospitalization rates in this analysis were calculated as  age-adjusted rates.  Because older adults are more likely to develop a chronic disease than younger adults, we would expect older adults to be hospitalized at a higher rate than younger adults. Age-adjustment allows us to compare rates by adjusting for the bias different age distributions can cause. The age-adjusted rates in this analysis were calculated using the direct standardization method. The direct standardization method involves calculating an age-specific rate, which divides the number of hospitalizations in specific age groups by the total population in that specific age group. That rate is then weighted with a standard population, the U.S. 2000 Standard population, for each age group.

Age-adjusted rates in any group with fewer than 10 hospitalizations were censored, or not included in this analysis. Rates calculated with 10-20 counts should be interpreted with caution as low counts can sometimes lead to unreliable rates. Figures with rates calculated with low counts were marked with an (*), with the rates that should be interpreted with caution specified for the figure.

 Mann Kendall Trend tests  were used to determine significant changes in hospitalization rates over time. When data is collected over a period of time, this test can be used to determine if the data significantly increased or decreased over that time period. Mann Kendall trend tests produce more reliable estimates with additional data, so age-adjusted rates were calculated quarterly, when possible, to provide additional data points. Trend tests with significant results were detailed in the description for each figure.

The PQI inclusion and exclusion criteria were followed for all indicators, except for pediatric asthma and diabetes. These indicators outlined different age criteria, however, we included all pediatric ages for these hospitalizations (0-17 years old) to effectively compare hospitalization rates. This analysis also included duplicate observations, as the same person could have been hospitalized for an ACSC multiple times throughout the selected time period. In addition, while all individuals with available race data were included in the calculation for overall county rates; there were too few hospitalizations among races/ethnicities other than Black, non-Hispanic or White, non-Hispanic to be included in the subgroup analyses.

• ACSC: ambulatory-care sensitive condition, diseases or conditions that are affected by or sensitive to timely and quality outpatient care
• AHRQ:  Agency for Healthcare Research and Quality , Department of Health and Human Services agency that creates prevention quality indicators
• ICD-10-CM: ICD-10-CM refers to the 10th revision of clinical modifications of the International Classification of Disease codes provided by the World Health Organization. ICD-10 codes are used to identify specific conditions or diseases in medical records.
• PHC4:  Pennsylvania Healthcare Cost Containment Council , data source for annual inpatient hospitalizations in Pennsylvania
• Potentially preventable hospitalizations: inpatient hospitalizations for diseases/conditions that may have been prevented with timely and quality outpatient care
•  Principal diagnosis : condition determined to be responsible for the hospital admission
• PQI:  Prevention Quality Indicator , set of indicators provided by the AHRQ to assess access to outpatient care by identifying inpatient hospital admissions for potentially preventable hospitalizations. Each indicator is defined with ICD-10-CM inclusion and exclusion codes to use when identifying hospitalizations.

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