Payers of Care

Who Was Billed for Hospital Care?

Payer data reflect the expected payer for a hospital stay. It is important to note that in the inpatient hospital setting, payers are not billed for specific procedures; rather, they are billed for a patient's full hospital stay, often based on the diagnosis related group (DRG). The DRG assignment reflects the expected consumption of hospital resources based on characteristics of each stay, such as diagnoses, procedures, age of patient, and presence of complications or comorbidities.

Payer information is presented in the following general payer categories:

• Medicare—Fee-for-service and managed care Medicare patients.
• Medicaid—Fee-for-service and managed care Medicaid patients.
• Private insurance—Blue Cross, commercial carriers, private health maintenance organizations (HMOs), and preferred provider organizations (PPOs).
• Uninsured—Insurance status of "self-pay" and "no charge."
• Other—Workers' Compensation, Civilian Health and Medical Program of the Uniformed Services (CHAMPUS), Civilian Health and Medical Program of the Department of Veterans Affairs (CHAMPVA), Title V, and other government programs.

Together, Medicare and Medicaid are billed for more than half (58 percent) of all hospitalizations. Private insurers are billed for 35 percent while uninsured hospitalizations account for about 5 percent of hospital stays. The remaining 3 percent of hospitalizations are billed to other insurers or the expected payer cannot be determined.

Medicare

• Medicare continues to be billed for 34 percent of all hospitalizations, with a mean charge of $24,900.
• About 40 million individuals, or 14 percent of the U.S. population, were covered by Medicare in 2003.²
• Eight of the 10 procedures most commonly billed to Medicare remained the same from 1997 to 2003. Two new additions included procedures related to cardiac pacemaker and arthroplasty of the knee. These replaced CT scan of the head and physical therapy as top 10 procedures.
• Of hospitalizations billed to Medicare, 4 of the top 10 procedures involved the cardiovascular system. Medicare was billed for one-half to three-fourths of all hospital stays involving these cardiovascular procedures: diagnostic cardiac catheterizations, PTCA, echocardiogram, and procedures related to cardiac pacemaker or cardioverter/defibrillator.
• The percentage of hospital stays involving dialysis billed to Medicare remained about the same (65 percent in 1997 and 63 percent in 2003). These high figures are indicative of the fact that patients with end-stage renal disease are covered by Medicare, regardless of the patient's age.
• In 2003, blood transfusions surpassed diagnostic cardiac catheterizations as the most common procedures performed during stays billed to Medicare.

Table 7. Top 10 Procedures Billed to Medicare, 2003

All-Listed Procedures, 2003	Total Number of Discharges In This Procedure Category (in thousands)	Medicare's Share of All Hospital Stays For This Procedure (percentage)
All Medicare discharges	13,136	34.4
1. Blood transfusion	1,107	56.0
2. Diagnostic cardiac catheterization, coronary, arteriography	854	49.8
3. Upper gastrointestinal endoscopy, biopsy	670	53.9
4. Respiratory intubation and mechanical ventilation	494	43.8
5. Hemodialysis	416	62.9
6. Percutaneous coronary angioplasty (PTCA)	400	50.0
7. Colonoscopy and biopsy	362	56.9
8. Diagnostic ultrasound of heart (echocardiogram)	353	53.5
9. Insertion, revision, replacement, removal of cardiac pacemaker or cardioverter/defibrillator	264	73.6
10. Arthroplasty knee	249	57.5

Note: "All-listed procedures" refers to all procedures performed during a hospital stay; patients often receive more than 1 procedure. Miscellaneous minor diagnostic and therapeutic procedures are excluded.

Medicaid

• Medicaid was billed for 23 percent of all hospitalizations in 2003—slightly more than in 1997, when Medicaid was billed for 20 percent. The mean charge for Medicaid hospital stays was $16,700.
• About 36 million individuals were covered by Medicaid in 2003; this figure represents 12 percent of the U.S. population.²
• Nine of the top 10 procedures billed to Medicaid did not change since 1997. The only exception was hearing examinations, which replaced episiotomies as a top 10 procedure in 2003.
• Six pregnancy- and childbirth-related procedures appeared among the top 10 procedures billed to Medicaid in 2003: medical procedures to assist delivery, C-section, repair of current obstetric laceration, circumcision, fetal monitoring, and artificial rupture of membranes to assist delivery. This list is similar to 1997, with the exception of episiotomy dropping out of the top 10. A seventh procedure—vaccinations—was also predominantly performed on newborns. After these pregnancy- and childbirth-related procedures (including vaccinations) were excluded, blood transfusion was the most common procedure billed to Medicaid.
• When pregnancy- and childbirth-related procedures were excluded, 3 additional diagnostic procedures entered the top 10 procedures billed to Medicaid: upper GI endoscopy, diagnostic cardiac catheterization, and diagnostic spinal tap (data not shown).

Table 8. Top 10 Procedures Billed to Medicaid, 2003

All-Listed Procedures, 2003	Total Number of Discharges In This Procedure Category (in thousands)	Medicaid's Share of All Hospital Stays For This Procedure (percentage)
All Medicaid discharges	8,954	23.4
1. Medical induction, manually assisted delivery, and other procedures to assist delivery	855	43.9
2. Cesarean section	457	39.0
3. Repair of current obstetric laceration	455	36.1
4. Prophylactic vaccinations and inoculations	400	46.6
5. Circumcision	371	31.0
6. Fetal monitoring	361	39.5
7. Blood transfusion	344	17.4
8. Artificial rupture of membranes to assist delivery	321	39.8
9. Respiratory intubation and mechanical ventilation	269	23.9
10. Hearing examinations	203	46.9

Note: "All-listed procedures" refers to all procedures performed during a hospital stay; patients often receive more than 1 procedure. Miscellaneous minor diagnostic and therapeutic procedures are excluded.

Private Insurance

• Private insurance was billed for 35 percent of all hospitalizations, which is comparable to the 1997 figure of 37 percent. The mean charge for privately insured hospital stays was $16,900.
• Nearly 200 million individuals, or 69 percent of the U.S. population, were covered by private insurers in 2003.²
• Eight of the 10 procedures most commonly billed to private insurers remained the same from 1997 to 2003. In 2003, blood transfusions and vaccinations replaced episiotomies and oophorectomies as top 10 procedures billed to commercial insurers.
• Of hospitalizations billed to private insurers, 6 of the top 10 procedures were for pregnancy- and childbirth-related procedures: procedures to assist delivery, circumcision, repair of current obstetric laceration, C-section, fetal monitoring, and artificial rupture of membranes to assist delivery. A seventh procedure—vaccinations—was also performed mainly on newborns. These are the same pregnancy- and childbirth-related procedures that were commonly billed to Medicaid.
• Similar to 1997, nearly three-fourths of hysterectomies were billed to private insurers.
• Private insurers continued to be billed for just over one-third of hospital stays in which diagnostic catheterizations were performed.
• After pregnancy- and childbirth-related procedures were excluded, oophorectomy became a top 10 procedure in 2003, with about 330,000 procedures billed to private insurers (data not shown).

Table 9. Top 10 Procedures Billed to Private Insurers, 2003

All-Listed Procedures, 2003	Total Number of Discharges In This Procedure Category (in thousands)	Private Insurer's Share of All Hospital Stays For This Procedure (percentage)
All discharges for private insurers	13,264	34.7
1. Medical induction, manually assisted delivery, and other procedures to assist delivery	972	49.9
2. Circumcision	746	62.4
3. Repair of current obstetric laceration	733	58.1
4. Cesarean section	652	55.7
5. Diagnostic cardiac catheterization, coronary arteriography	583	33.9
6. Fetal monitoring	502	55.1
7. Hysterectomy, abdominal and vaginal	447	73.5
8. Artificial rupture of membranes to assist delivery	440	54.5
9. Blood transfusion	419	21.2
10. Prophylactic vaccinations and inoculations	399	46.6

Note: "All-listed procedures" refers to all procedures performed during a hospital stay; patients often receive more than 1 procedure. Miscellaneous minor diagnostic and therapeutic procedures are excluded.

Uninsured

• Uninsured hospitalizations continued to account for approximately 5 percent of all hospitalizations, with a mean charge of $16,800.
• About 45 million individuals, or 16 percent of the U.S. population, were uninsured in 2003.²
• Eight of the most commonly performed procedures in uninsured hospitalizations remained the same from 1997 to 2003. In 2003, blood transfusions and appendectomies replaced fetal monitoring and CT scans of the head in the top 10.
• Three of the top 10 procedures being performed in uninsured hospitalizations were related to pregnancy and childbirth: procedures to assist delivery, circumcision, and repair of current obstetric laceration.
• As in 1997, more than 20 percent of hospital stays that involved procedures for alcohol and drug rehabilitation/detoxification were not covered by insurance. It is not possible to determine if this is because insurance does not cover these conditions or because these conditions occur more frequently among uninsured patients.

Table 10. Top 10 Procedures That Were Uninsured, 2003

All-Listed Procedures, 2003	Number of Discharges (in thousands)	All Hospital Stays That Are Uninsured (percentage)
All discharges for the uninsured	1,725	4.5
	Total number of discharges in this procedure category (in thousands)	All hospital stays involving this procedure that are uninsured (percentage)
1. Alcohol and drug rehabilitation/detoxification	66	21.5
2. Medical induction, manually assisted delivery, and other procedures to assist delivery	65	3.4
3. Diagnostic cardiac catheterization, coronary arteriography	64	3.8
4. Blood transfusion	60	3.0
5. Respiratory intubation and mechanical ventilation	52	4.6
6. Upper gastrointestinal endoscopy, biopsy	50	4.0
7. Circumcision	41	3.4
8. Repair of current obstetric laceration	38	3.0
9. Appendectomy	36	9.4
10. Prophylactic vaccinations and inoculations	36	4.2

Note: "All-listed procedures" refers to all procedures performed during a hospital stay; patients often receive more than 1 procedure. Miscellaneous minor diagnostic and therapeutic procedures are excluded.

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In-Hospital Mortality

Which Procedures Were Associated With the Highest In-Hospital Mortality?

In-hospital mortality refers to death during the hospital stay. This section examines procedures that were performed most often in those hospital stays that resulted in death.

It is important to note that in-hospital deaths are not necessarily caused by these procedures but may simply indicate severe underlying disease. In fact, many of these procedures are not inherently risky procedures, but may be associated with hospital stays that result in high mortality linked to other causes. For example, patients may be admitted to the hospital for end-of-life care, and mortality is expected to be high.

• The procedures involved in hospital stays that resulted in death remained largely unchanged since 1997. As in 1997, hospital stays involving conversion of cardiac rhythm, which indicates an unsuccessful attempt at resuscitation, most commonly ended in death. In 2003, 39 percent of hospital stays in which conversion of cardiac rhythm was performed resulted in death.
• The second most common procedure associated with high inhospital mortality continued to be respiratory intubation and mechanical ventilation, with an in-hospital mortality rate of 29 percent. This procedure is performed in hospitalizations involving respiratory failure, myocardial infarction, stroke, pneumonia, and septicemia.
• Hospital stays that included procedures indicating the presence of organ failure and critical illness continued to have high in-hospital mortality rates. These included Swan-Ganz catheterization, tracheostomy, ileostomy and other enterostomy, and enteral and parenteral nutrition.

Table 11. Top 10 Procedures Associated With Highest In-Hospital Mortality, 2003

All-Listed Procedures, 2003	In-Hospital Mortality (percent)
1. Conversion of cardiac rhythm	39.3
2. Respiratory intubation and mechanical ventilation	28.5
3. Swan-Ganz catheterization	27.8
4. Tracheostomy, temporary and permanent	20.6
5. Injection or ligation of esophageal varices	16.2
6. Ileostomy and other enterostomy	14.1
7. Enteral and parenteral nutrition	14.0
8. Exploratory laparotomy	13.2
9. Arterial blood gases	12.1
10. Diagnostic bronchoscopy and biopsy of bronchus	11.5

Note: "All-listed procedures" refers to all procedures performed during a hospital stay; patients often receive more than 1 procedure.

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Patient Safety Indicators

How Did Selected Procedure-Based Patient Safety Quality Indicators Change from 1997 to 2003?

AHRQ has developed an array of health care decisionmaking and research tools that can be used by program managers, researchers, and others at the Federal, State and local levels. One of these tools is the AHRQ Quality Indicators (QIs) which use hospital administrative data to highlight potential quality concerns, identify areas that need further study and investigation, and track changes over time.

The AHRQ QIs are comprised of the Inpatient Quality Indicators, Prevention Quality Indicators, and Patient Safety Indicators. This section presents selected findings from the Patient Safety Indicators that relate to procedures performed in U.S. hospitals.

Patient Safety Indictors identify hospital stays during which a potentially avoidable patient safety event occurred. Below are comparisons of how U.S. hospitals performed in 2003 relative to 1997 on four procedure-based Patient Safety Indicators.

• Complications of anesthesia remained stable at 8 complications per 10,000 surgical discharges.
• Postoperative respiratory failure increased dramatically from 2.3 to 4.6 cases per 1,000 elective-surgery discharges, a 100-percent increase.
• Postoperative sepsis increased from 8.5 to 12.5 cases per 1,000 elective-surgery discharges of longer than 3 days, a 46-percent increase.
• Birth trauma decreased from 16.1 to 6.5 injuries to neonates per 1,000 live births, a 60-percent decrease.

More information about the AHRQ QIs is available at http://www.qualityindicators.ahrq.gov. Detailed data on quality of care in the U.S. is available on HCUPnet (http://hcupnet.ahrq.gov/).

Select for Figure 13 (5 KB), Complications of Anesthesia.

Select for Figure 14 (5 KB), Postoperative Respiratory Failure.

Select for Figure 15 (5 KB), Postoperative Sepsis.

Select for Figure 16 (5 KB), Birth Trauma—Injury to Neonate.

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Source of Data for This Report

The results presented in this report are drawn from the Healthcare Cost and Utilization Project (HCUP), a Federal-State-Industry partnership to build a multi-State health care data system. This partnership is sponsored by the Agency for Healthcare Research and Quality (AHRQ) and is managed by staff in AHRQ's Center for Delivery, Organization, and Markets (CDOM). HCUP is based on data collected by individual State Partner organizations (including State departments of health, hospital associations, and private agencies), which provide the data to AHRQ. HCUP would not be possible without statewide data collection projects and their partnership with AHRQ.

For the year 2003, 38 State Partner organizations contributed their data to AHRQ, where all files are validated and converted into a uniform format. The uniform HCUP databases enable comparative studies of health care services and the use and cost of hospital care, including:

• Effects of market forces on hospitals and the care they provide.
• Variations in medical practice.
• Effectiveness of medical technology and treatments.
• Use of services by special populations.

HCUP includes short-term, non-Federal, community hospitals as defined by the American Hospital Association (AHA). This definition includes general hospitals and specialty facilities, such as pediatric, obstetrics-gynecology, short-term rehabilitation, and oncology hospitals. Long-term care and psychiatric hospitals are excluded, as are substance abuse treatment facilities.

HCUP includes several sets of inpatient databases for health services research. This report is based on the 2003 Nationwide Inpatient Sample (NIS) data, which includes data from 37 of our participating Partners that supplied 2003 data to the project. The NIS is the largest all-payer inpatient care database that is publicly available in the U.S. The database contains data for nearly 8 million hospital stays from roughly 1,000 hospitals sampled to approximate a 20-percent stratified sample of U.S. community hospitals. The data are weighted to obtain estimates representing the total number of inpatient hospital discharges in the United States; in the year 2003, this figure is approximately 38 million.

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Methods

This report is based on data from the HCUP Nationwide Inpatient Sample database. The NIS data are weighted to obtain estimates representing the total number of inpatient hospital discharges in the United States; in 2003, this figure totaled 38,220,659. The 2003 NIS is based on a sampling frame of 37 States compared with 22 States in the 1997 NIS. A brief discussion of selected methodological issues pertaining to this Fact Book follows.

Procedures and Clinical Classification Software (CCS)

Procedures and diagnoses are recorded within the NIS using the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM).While ICD-9-CM codes may be used to provide descriptive statistics, the granular nature of ICD-9-CM reporting is difficult to summarize. Thus, for this report, the AHRQ-developed Clinical Classifications Software is applied to hospital records to aggregate ICD-9-CM procedure codes into a limited number of clinically meaningful categories for most tables. More detailed information on CCS can be downloaded from the HCUP User Support Web site at: http://www.hcup-us.ahrq.gov/toolssoftware/ccs/ccs.jsp.

Procedure Classes

The Procedure Classes tool provides an easy way to categorize ICD-9-CM procedure codes into one of four broad categories: minor diagnostic, minor therapeutic, major diagnostic, and major therapeutic. This tool was created to facilitate health services research on hospital procedures using administrative data. All ICD-9-CM procedure codes are assigned to one of the following categories:

1. Minor diagnostic—Non-operating room procedures that are diagnostic (e.g., 87.03 CT scan of head).
2. Minor therapeutic—Non-operating room procedures that are therapeutic (e.g., 02.41 Irrigate ventricular shunt).
3. Major diagnostic—All procedures considered valid operating room procedures by the DRG grouper and that are performed for diagnostic reasons (e.g., 01.14 Open brain biopsy).
4. Major therapeutic—All procedures considered valid operating room procedures by the DRG grouper and that are performed for therapeutic reasons (e.g., 39.24 Aorta-renal bypass).

More detailed information on the Procedure Classes tool can be obtained from the HCUP User Support Web site at: http://www.hcup-us.ahrq.gov/toolssoftware/procedure/procedure.jsp.

Unit of Analysis

For this report, the unit of analysis is the inpatient stay rather than the patient or the procedure. For example, a patient admitted 4 times to the hospital is included 4 times in the NIS data. Thus, the same individual can account for more than 1 hospital stay. Also, frequencies and rankings of procedures are based on all-listed procedures codes on a discharge record—and are not limited to the principal procedure code. Each HCUP NIS record can contain up to 15 procedure codes. This Fact Book provides information on all procedures performed during the stay. The unit of analysis remains the discharge: if a particular CCS procedure code occurs multiple times during the same discharge, it is still counted only once.

Definition of Payer

Payer is the expected payer for the hospital stay. It is important to note that charges billed to payers reflect the entire hospital stay, not a charge for a specific procedure. To make coding uniform across all HCUP data sources, the payer variable combines detailed categories into more general groups:

• Medicare includes fee-for-service and managed care Medicare patients.
• Medicaid includes fee-for-service and managed care Medicaid patients.
• Private insurance includes Blue Cross, commercial carriers, and private HMOs and PPOs.
• Uninsured includes an insurance status of "self-pay" and "no charge."
• Other includes Workers' Compensation, CHAMPUS, CHAMPVA, Title V, and other government programs.

Up to two payers can be coded for a hospital stay in HCUP data. When this occurs, the following hierarchy is used:

• If either payer is listed as Medicaid—payer is "Medicaid."
• For non-Medicaid stays, if either payer is listed as Medicare—payer is "Medicare."
• For stays that are neither Medicaid nor Medicare, if either payer is listed as private insurance—payer is "private insurance."
• For stays that are not Medicaid, Medicare, or private insurance, if either payer is some other third party payer—payer is "other."
• For stays that have no third-party payer and the payer is listed as "self-pay" or "no charge"—payer is "uninsured."
• If no insurance information is available—payer is missing.

Charges

Data indicating "hospital charges" are the amount the hospital billed for the entire hospital stay—not for a specific procedure. These charges do not necessarily reflect reimbursements or costs and do not include professional (physician) fees. Typically, charges are higher than actual costs.

High-Volume Providers

High-Volume Providers Research indicates that hospitals that perform more than a specific number of certain procedures have fewer in-hospital deaths for those particular procedures than lower volume hospitals. This "threshold number" varies with the type of procedure. The volume thresholds used in this Fact Book are adapted from Dudley, et al.¹:

Procedure	Threshold number of procedures
Abdominal aortic aneurysm	32
Carotid endarterectomy	101
Lower extremity arterial bypass	20
Coronary artery bypass graft	500
Percutaneous coronary angioplasty	400
Heart transplantation	9
Pediatric heart surgery	100
Pancreatic cancer surgery	7
Esophageal cancer surgery	7
Cerebral aneurysm surgery	30

New Weights for 1997 NIS Data

In 1998, the NIS sample design was changed:

• Rehabilitation hospitals were excluded from the NIS hospital universe and sample.
• AHA hospital unit discharges were used instead of total facility discharges, which include nursing home unit discharges.

In order to facilitate analysis of trends using multiple years of NIS data, alternate weights for NIS discharge and hospital data for the 1988-1997 HCUP NIS were developed. These alternative weights were calculated in the same way as the weights for the 1998 and later years of the NIS. These new weights were applied to the 1997 data presented in this report. The NIS Trends Report includes details regarding the alternate weights and other recommendations for trends analysis: http://www.hcup-us.ahrq.gov/reports/TrendReport2005_1.pdf (PDF Help). The new weights are available at: http://www.hcup-us.ahrq.gov/db/nation/nis/trendwghts.jsp.

Comparisons of 1997 and 2003 Hospital Procedures

Because this Fact Book updates an earlier report that described hospital procedures in 1997, this document provides many comparative statistics that reflect how hospital care has evolved from 1997 to 2003. Only statistically significant differences (p-value ≤ .05) are presented.

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References

¹ Dudley RA, Johansen KL, Brand R, Rennie DJ, Milstein A. Selective referral to high-volume hospitals: estimating potentially avoidable deaths. JAMA 2000 Mar 1;283(9):1159-66.

² DeNavas-Walt C, Proctor BD, Mills RJ. Income, poverty, and health insurance coverage in the United States: 2003. Current population reports P60-226. Washington, DC: U.S. Census Bureau; August 2004. http://www.census.gov/prod/2004pubs/p60-226.pdf. (Accessed March 24, 2009).

³ American Hospital Association. Fast facts on U.S. hospitals from AHA hospital statistics.

⁴ U.S. Census Bureau, Population Division. National intercensal estimates (1990-2000). http://www.census.gov/popest/archives/EST90INTERCENSAL/US-EST90INT-datasets.html. (Accessed March 24, 2009).

⁵ U.S. Census Bureau, Population Division. National population estimates—Characteristics: Annual estimates of the population by sex and selected age groups for the United States: April 1, 2000 to July 1, 2003. http://www.census.gov/popest/national/asrh/NC-EST2003-as.html. (Accessed March 24, 2009).

⁶ U.S. Department of Labor. Bureau of Labor Statistics. Producer price indexes. http://www.bls.gov/ppi/home.htm. (Accessed March 24, 2009).

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For More Information

More information regarding HCUP data is available at http://www.ahrq.gov/data/hcup, as well as on the HCUP User Support Web site at http://www.hcup-us.ahrq.gov.

Additional descriptive statistics can be viewed through HCUPnet (http://hcupnet.ahrq.gov/), a Web-based tool providing easy access to information on hospital stays.

NIS data are available for the following data years:

• 2003 data (available June 2005).
• 2002 data.
• 2001 data.
• 2000 data.
• 1999 data (PB 2002-500020).
• 1998 data (PB 2001-500092).
• 1997 data, Release 6 (PB 2000-500006).
• 1996 data, Release 5 (PB 99-500480).
• 1995 data, Release 4 (PB 98-500440).
• 1994 data, Release 3 (PB 97-500433).
• 1993 data, Release 2 (PB 96-501325).
• 1988-1992 data, Release 1 (PB 95-503710).

NIS data can be purchased for research through the HCUP Central Distributor sponsored by AHRQ: telephone: (866) 556-4287 (toll-free), fax: 866-792-5313, or e-mail: HCUPDistributor@ahrq.gov.

Price of the data is $322 for Release 1; $160 per year for 1993 to 1999; and $200 per year for 2000 to 2003. All prices may be higher for customers outside the U.S., Canada, and Mexico.

AHRQ is always looking for ways in which AHRQ-funded research, products, and tools have influenced clinical practice, improved policies, affected patient outcomes, and changed people's lives. Impact case studies describe AHRQ research findings in action. These case studies have been used in testimony, budget documents, and speeches. If you are aware of any impact your research has had on health care policy, clinical practice, or patient outcomes, please let us know by using the contact information below.

Healthcare Cost and Utilization Project (HCUP)
Center for Delivery, Organization, and Markets
Agency for Healthcare Research and Quality
Phone: 866-290-HCUP (4287)
E-mail: hcup@ahrq.gov

Acknowledgments

Thanks to the following individuals for their collaboration in producing this Fact Book: David Ross (Thomson Medstat) and Julie Nisbet (Thomson Medstat) for statistical programming, Megan Mulligan (Thomson Medstat) for administrative support, Gail Eisen (Thomson Medstat) and DonnaRae Castillo (AHRQ) for editorial guidance, and The Madison Design Group (MDG) for design and layout assistance.

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