More Than Half of All Hospital Procedures Are Done Outpatient

AHRQ News and Numbers
More Than Half of All Hospital Procedures Are Done Outpatient

Nearly 58 percent of the surgeries performed in hospitals were done as outpatient procedures, according to the latest News and Numbers from the Agency for Healthcare Research and Quality (AHRQ).

In outpatient surgery, also called ambulatory or same-day surgery, patients normally require hospital care for less than 24 hours. These operations are increasingly being used because advances in surgical technology and anesthesia enable surgeons to perform many operations formerly limited to inpatient care.

The Federal agency's analysis of data available from 28 States found that in 2007:
Charges for outpatient procedures were 7 times lower than for inpatient ones. The average hospital charge for an outpatient procedure was $6,100 in 2007, compared with $39,900 for an inpatient procedure.

Hospital outpatient surgery charges totaled $55.6 billion compared with $259 billion for inpatient surgeries.

Colonoscopies and resulting biopsies were the most frequently performed outpatient procedure (18 percent of all ambulatory procedures), followed by upper gastrointestinal endoscopies and related biopsies (11 percent), lens and cataract procedures (5.5 percent), and diagnostic cardiac catheterization (4 percent).
This AHRQ News and Numbers is based on data in Hospital-Based Ambulatory Surgery, 2007. The report uses statistics from 28 States that provide data to the Healthcare Cost and Utilization Project State Ambulatory Surgery Databases and their corresponding State Inpatient Databases. These databases provide information on hospital-based ambulatory and inpatient surgeries performed in short-term, acute care hospitals

Hospital-Based Ambulatory Surgery, 2007

Allison Russo, M.P.H., Anne Elixhauser, Ph.D., Claudia Steiner, M.P.H., M.D., and Lauren Wier, M.P.H



Introduction

Ambulatory surgery (AS), or outpatient surgery, is a planned surgical episode where the patient requires hospital care for less than 24 hours. Outpatient procedures account for a growing proportion of surgeries performed in U.S. hospitals because AS increasingly substitutes for inpatient surgery for many procedures.1 Nationally, 63 percent of all surgeries in 2005 did not require an overnight hospital stay and were considered outpatient, compared with 51 percent in 1990 and only 16 percent in 1980.2,3

Two major factors explain this overall growth in ambulatory surgeries. First, advances in surgical technology and anesthesia have made surgery easier on patients and increased the demand for outpatient procedures. Second, in an effort to reduce rising health care costs, health care payment policies have encouraged AS. For example, the Medicare program adopted an outpatient prospective payment system authorizing payment for surgical services in a variety of settings, such as a physician’s office, a hospital outpatient department, or an ambulatory surgical center. A comparison of AS data to inpatient surgery data is essential for understanding utilization patterns and costs for specific surgical procedures.

This Statistical Brief presents data from the Healthcare Cost and Utilization Project (HCUP) State Ambulatory Surgery Databases (SASD) and State Inpatient Databases (SID). These databases provide information on hospital-based ambulatory and inpatient surgeries performed in short-term, acute-care hospitals in the 28 states that provided AS data to HCUP in 2007. These 28 states encompass about two-thirds of the U.S. population. These statistics exclude procedures performed in freestanding AS centers because these centers are not included in many State AS data sources.

This report compares the utilization of ambulatory surgery procedures in hospitals to inpatient procedures in 28 states that provide data sources for both hospital-based ambulatory and inpatient surgery. The analysis is limited to major invasive procedures requiring anesthesia services or sedation, but excludes procedures that are performed infrequently in ambulatory surgery settings, procedures that are adjunct to the principal procedure, dental procedures, obstetrical procedures, and procedures that are done predominantly in outpatient settings outside of hospitals.4 This report provides information about the distribution of inpatient versus outpatient surgical procedures by body system, as well as the most common surgical procedures performed in an outpatient setting. In addition, ambulatory and inpatient volume, procedure rates, and hospital charge information are compared for each procedure. Unless otherwise noted, estimates are based on all-listed procedures. All differences between estimates provided in the text are statistically significant at the 0.05 level or better. Highlights
In the 28 states evaluated, nearly 58 percent of surgical encounters in hospitals were performed on outpatients.


There were nearly 5,600 ambulatory surgery (AS) visits per 100,000 population compared with almost 4,100 inpatient surgical visits per 100,000.


The mean charge for AS was lower than for inpatient surgery—$6,100 versus $39,900. The aggregate charge across the 28 states for AS was about one-fifth of total inpatient charges—$55.6 billion versus $259 billion.


Procedures related to the digestive system accounted for 40 percent of all AS.


Procedures done on the eye, ear, and nose/mouth/pharynx were predominantly outpatient. Roughly two-thirds of surgical procedures on the skin, digestive system, and urinary system were outpatient.


Colonoscopy and biopsy was the most commonly performed AS procedure in 2007, followed by upper GI endoscopy, lens and cataract procedures, diagnostic cardiac catheterization, and debridement of wound.


Major procedures that were performed less frequently on an outpatient basis, but with significant numbers include PTCA, appendectomy, open prostatectomy, oophorectomy, hysterectomy, hip fracture/ dislocation repair, lower extremity amputation, and spinal fusion.


Findings


Characteristics of ambulatory surgery procedures performed in community hospitals
Based on data from the 28 states examined for this report, nearly 10.8 million ambulatory surgery (AS) visits took place in 2007, totaling $55.6 billion in aggregate charges (table 1). These visits resulted in over 12.4 million procedures (1.2 procedures per AS visit). This compares to 7.9 million inpatient stays that involved 11.0 million surgical procedures (1.4 procedures per hospital stay). Overall, 57.7 percent of procedures performed in hospitals were ambulatory in nature. In 2007, this translated to approximately 5,600 hospital-based AS visits per 100,000 population, compared with 4,100 inpatient procedure stays per 100,000 population.

The mean charge for hospital-based AS procedures was considerably lower than the charge for inpatient hospital stays that included procedures—$6,100 versus $39,900. Aggregate charges across the 28 states were about one-fifth of the national bill for inpatient—$55.6 billion versus $259 billion. Most hospital-based AS procedures were performed in large, metropolitan, private not-for-profit hospitals. However, compared with inpatient procedures, AS was more likely to be performed in smaller hospitals, outside metropolitan areas, and in non-teaching settings.

Ambulatory versus inpatient surgeries, by body system
Figure 1 shows that nearly all hospital-based procedures related to the eye (99.3 percent), ear (96.3 percent), and nose/mouth/pharynx (93.8 percent) were outpatient. About two-thirds of all hospital-based procedures on the skin (70.4 percent), digestive system (66.8 percent), and urinary system (61.7 percent) were also outpatient. Roughly half of all hospital-based procedures involving the musculoskeletal (54.0 percent), nervous (47.9 percent), female genital (47.5 percent), and endocrine systems (46.0 percent), were outpatient.

In contrast, respiratory, cardiovascular, male genital, and hemic/lymphatic procedures were primarily inpatient. About one in three surgical procedures on the respiratory (31.2 percent) and cardiovascular (29.4 percent) systems were performed in an outpatient setting, while less than 10 percent of all procedures on male genital organs and the hemic/lymphatic system were outpatient.

The most common ambulatory surgeries performed in community hospitals
Table 2 lists the 25 most common AS procedures performed in community hospitals. Colonoscopy and biopsy was the most common AS procedure and comprised nearly 18.1 percent of all procedures performed in an outpatient setting. Upper GI endoscopy and biopsy accounted for 10.8 percent of all outpatient procedures. Other digestive system procedures commonly performed in the outpatient setting included: cholecystectomy, or gall bladder surgery (2.5 percent of all AS); hernia repair (inguinal and femoral–2.1 percent; other hernias–1.4 percent); and esophageal dilatation (1.3 percent). In fact, more ambulatory surgeries involved the digestive system (40.0 percent) than any other body system (data not shown).

Though procedures on the cardiovascular system accounted for a small number of AS overall, diagnostic cardiac catheterization alone comprised 3.8 percent of all outpatient procedures in the hospitals in these 28 states. Four of the 25 most common ambulatory procedures were related to the musculoskeletal system: excision of semilunar cartilage of knee (2.5 percent of all AS), partial bone excision (1.5 percent), arthroplasty other than hip or knee (1.4 percent), and other fracture and dislocation procedure (1.2 percent). Two commonly performed outpatient procedures on the skin were wound debridement (2.6 percent) and incision and drainage of the skin and subcutaneous tissue (1.4 percent).

Lens and cataract procedures, most often performed on elderly patients, accounted for 5.5 percent of all AS in the hospitals in these 28 states.5 Four of the 25 most common outpatient procedures were primarily or exclusively performed on women: other excision of cervix and uterus (2.1 percent of all AS), breast biopsy (1.9 percent), lumpectomy/quadrantectomy of the breast (1.9 percent), and diagnostic dilatation and curettage (D&C) (1.5 percent). Tonsillectomy and/or adenoidectomy and myringotomy (ear tube surgery)—two procedures primarily performed on children—were two of the most common surgical procedures performed in the ambulatory setting (2.5 percent and 1.9 percent of all procedures, respectively).

Three procedures involving the urinary tract were also among the top 25 AS procedures performed in hospitals—endoscopy/biopsy (1.6 percent of all AS), transurethral procedures for urinary obstruction (1.5 percent), and ureteral catheterization (1.3 percent). Finally, decompression of peripheral nerves (e.g., carpal tunnel release) comprised 1.5 percent of all AS, while bronchoscopy made up 1.1 percent of all AS.

Table 2 also provides information on the total number of procedures, rates, and the percentage of each procedure performed on an outpatient basis. For many procedures, it is clear that very few are done in an inpatient setting. For example, lens and cataract procedures, excision of semilunar cartilage of the knee, tonsillectomy, breast biopsy, lumpectomy, myringotomy, D&C, and decompression of peripheral nerve have rates lower than 10 inpatient procedures per 100,000 population, while rates for their outpatient counterparts are 12–50 times higher (over 300 times higher for lens procedures).

An inventory of ambulatory surgical procedures performed in community hospitals
The appendix provides a comprehensive listing of all major procedures, by body system, performed in an outpatient setting in community hospitals.6 Overall, the highest numbers of ambulatory surgical procedures were performed on the digestive and musculoskeletal systems. The endocrine system accounted for the fewest outpatient procedures.

The appendix also provides details on procedures less commonly performed in AS settings that were not covered in table 2. For example, although laminectomy (Clinical Classifications Software (CCS) 3) is not a predominantly outpatient procedure, 22.1 percent were performed in an ambulatory setting (42.7 AS procedures per 100,000 population versus 150.8 inpatient (IP) procedures per 100,000 population). Other major procedures that are not predominantly AS but with significant numbers of ambulatory cases include:


PTCA (CCS 45): 17.7 AS procedures vs. 242.4 IP procedures per 100,000 population
Appendectomy (CCS 80): 26.8 AS procedures vs. 118.9 IP procedures per 100,000 population
Open prostatectomy (CCS 114): 3.0 AS procedures vs. 28.1 IP procedures per 100,000 population
Oophorectomy (CCS 119): 31.9 AS procedures vs. 121.4 IP procedures per 100,000 population
Hysterectomy (CCS 124): 26.7 AS procedures vs. 166.6 IP procedures per 100,000 population
Hip fracture/dislocation repair (CCS 146): 8.1 AS procedures vs. 98.0 IP procedures per 100,000 population
Lower extremity amputation (CCS 157): 8.1 AS procedures vs. 38.2 IP procedures per 100,000 population
Spinal fusion (CCS 158): 14.8 AS procedures vs. 124.0 IP procedures per 100,000 population

Mean charges for outpatient procedures were always lower than for inpatient. However, the difference in inpatient and outpatient charges for operations on the male genital organs was minimal when compared to other surgeries. The highest mean charges per visit were found among outpatient procedures performed on the cardiovascular system.

abrir aquí para acceder al documento AHRQ completo (extenso):
http://www.hcup-us.ahrq.gov/reports/statbriefs/sb86.jsp



For More Information

For more information about HCUP, visit http://www.hcup-us.ahrq.gov.

For additional HCUP statistics, visit HCUPnet, our interactive query system, at www.hcup-us.ahrq.gov.

For information on other hospitalizations in the U.S., download HCUP Facts and Figures: Statistics on Hospital-Based Care in the United States in 2007, located at http://www.hcup-us.ahrq.gov/reports.jsp.

For a detailed description of HCUP, more information on the design of the SID, SASD, and methods to calculate estimates, please refer to the following publications:

Steiner, C., Elixhauser, A., Schnaier, J. The Healthcare Cost and Utilization Project: An Overview. Effective Clinical Practice 5(3):143–51, 2002.

Introduction to the HCUP State Inpatient Databases. Online. July 17, 2009. U.S. Agency for Healthcare Research and Quality. http://www.hcup-us.ahrq.gov/db/state/siddist/Introduction_to_SID.pdf.

Introduction to the HCUP State Ambulatory Surgery Databases. Online. July 17, 2009. U.S. Agency for Healthcare Research and Quality. http://www.hcup-us.ahrq.gov/db/state/sasddist/Introduction_to_SASD.pdf.

Russo, C.A., Owens, P., Steiner, C., Josephsen J. Ambulatory Surgery in U.S. Hospitals, 2003. HCUP Fact Book No. 9. Online. January 2007. U.S. Agency for Healthcare Research and Quality. http://www.ahrq.gov/data/hcup/factbk9/factbk9.pdf.

Suggested Citation
Russo, C.A. (Thomson Reuters), Elixhauser, A. (AHRQ), Steiner, C. (AHRQ), and Wier, L. (Thomson Reuters). Hospital-Based Ambulatory Surgery, 2007. HCUP Statistical Brief #86. February 2010. Agency for Healthcare Research and Quality, Rockville, MD. http://www.hcup-us.ahrq.gov/reports/statbriefs/sb86.pdf.