Skip Navigation U.S. Department of Health and Human Services www.hhs.gov
Agency for Healthcare Research Quality www.ahrq.gov
Archive print banner

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: https://info.ahrq.gov. Let us know the nature of the problem, the Web address of what you want, and your contact information.

Please go to www.ahrq.gov for current information.

Part I: Overview

How Did Ambulatory and Inpatient Surgeries Compare?

The American Hospital Association (AHA) defines "community hospitals" as non-Federal, short-term (or acute care) general and specialty hospitals whose facilities and services are available to the public, including children's, orthopedic, and rehabilitation hospitals, as well as non-Federal academic medical centers. Approximately 85 percent of all hospitals registered in the United States are community hospitals.5

The following table compares the characteristics of community hospitals in which both ambulatory and inpatient surgeries were performed.

Table 1. Characteristics of Community Hospitals

Characteristics of Community Hospitals Ambulatory Surgeries (SASD) Inpatient Surgeries (SID)
Total visits/stays for surgeries 3,919,100 3,655,000
Visits/stays per 100,000 population3 4,100 3,800
Total number of surgeries 4,932,700 5,095,100
Average number of surgeries per visit/stay 1.5 1.5
Total (aggregate) charge $18.3 billion $103.4 billion
Mean charge per visit/staya $5,600 $28,300
Percentage of visits/stays by type of hospital:b
   Large hospitals 59.8 67.1
   Metropolitan hospitals 81.4 86.6
   Teaching hospitals 42.3 53.7
   Non-Federal government hospitals 12.6 11.9
   Private not-for-profit hospitals 78.5 80.6
   Private for-profit hospitals 8.9 7.5

a Mean charges are for hospital-based ambulatory and inpatient surgical visits and stays. Inpatient surgical stays are typically more expensive because of longer lengths of stay and the use of multiple procedures.
b Hospital characteristics related to bed size, location, and teaching status are not mutually exclusive.

  • In 2003, nearly 52 percent of all surgical visits and stays occurred in outpatient settings; figures ranged from 42 to 66 percent in the 17 selected States.
  • Adjusted for State population levels,3 approximately 4,100 ambulatory surgical visits per 100,000 individuals occurred. This rate ranged from 2,800 per 100,000 individuals in New Jersey to 5,600 per 100,000 individuals in Vermont.
  • For all States in 2003, the mean number of inpatient surgical stays per 100,000 individuals was nearly 3,800, ranging from 2,900 in Vermont to 4,500 in Missouri and Tennessee.

Select for Figure 1 (13 KB), Distribution of Surgical Visits and Stays by State.

Return to Contents

Who Obtained Ambulatory Surgeries?

  • Although the population of males and females was nearly equal in the 17 selected States,6 approximately 59 percent of ambulatory surgical visits occurred among females.
  • While more females than males obtained surgeries in both settings, females were disproportionately more likely to have an ambulatory surgical visit than males.

Select for Figure 2 (6 KB), Percent of Surgical Visits and Stays by Gender.

  • The mean age for both ambulatory surgical visits and inpatient surgical stays was about 46 years (data not shown).
  • Patients ages 18 to 44 comprised about 33 percent of ambulatory surgical visits—more visits than for any other age group. This group was followed closely by individuals ages 45 to 64 (30.1 percent). In comparison, inpatient surgical stays occurred most often among patients 65 and older.
  • Patients ages 65 and above comprised about 12 percent of the total population of the 17 selected States,7 but they accounted for 24 percent of all ambulatory surgical visits. Conversely, only 13 percent of ambulatory surgical visits occurred among patients ages 0 to 17, even though they constituted 25 percent of the total 17-State population.

Select for Figure 3 (7 KB), Percentage of Surgical Visits and Stays by Age Group.

Return to Contents

What Were the Most Common Ambulatory Surgeries?

  • Lens and cataract procedures accounted for nearly 9 percent of ambulatory surgeries and were performed primarily on patients 65 and older.
  • Three of the 10 most common ambulatory surgeries were related to the musculoskeletal system: other therapeutic procedures on the muscles and tendons (5.0 percent), other operating room (O.R.) therapeutic procedures on the joints (3.4 percent), and excision of the semilunar cartilage of the knee (3.2 percent).
  • Two of the 10 most common ambulatory surgeries were primarily performed on children: tonsillectomy and/or adenoidectomy (3.8 percent) and myringotomy, or ear tube surgery (3.0 percent).
  • Hernia repair and cholecystectomy each accounted for 3 percent of ambulatory surgeries.

Table 2. Top 10 All-Listed Procedures

Top 10 All-Listed Procedures Total Number of Ambulatory Surgeries
(in thousands)
Percentage of Ambulatory Surgeries Total Number of Inpatient Surgeries
(in thousands)
Percent Ambulatory
Lens and cataract procedures 431 8.7 2 99.6
Other therapeutic procedures on muscles and tendons* 246 5.0 72 77.5
Tonsillectomy and/or adenoidectomy 186 3.8 10 94.9
Other O.R. therapeutic procedures on joints* 166 3.4 38 81.6
Excision of semilunar cartilage of knee 159 3.2 4 97.5
Inguinal and femoral hernia repair 153 3.1 19 89.1
Cholecystectomy and common duct exploration 152 3.1 143 51.5
Lumpectomy, quadrantectomy of breast 151 3.1 8 94.7
Myringotomy (ear tube surgery) 149 3.0 4 97.7
Diagnostic dilatation and curettage (D&C) 142 2.9 10 93.2

* Go to footnotes in Appendix table for definitions of other procedures.

  • Lumpectomies and diagnostic D&C—two surgeries primarily or exclusively performed on women—were two of the most common surgical procedures performed in the ambulatory setting (3.1 percent and 2.9 percent, respectively).
  • In 2003, about 90 percent of ambulatory surgeries were performed for therapeutic reasons; nearly 10 percent of ambulatory surgeries were performed for diagnostic reasons (data not shown).
  • By body system, more ambulatory surgeries involved the treatment and/or diagnosis of disorders of the musculoskeletal system (25.5 percent) than any other system. In comparison, more inpatient surgeries were performed to treat and/or diagnose disorders of the musculoskeletal system or the digestive system (18.3 percent each) (data not shown).
  • Surgeries performed on the musculoskeletal system, eye, integumentary system, ear, and nose, mouth, and pharynx were disproportionately performed in an outpatient setting; surgeries related to the eye, ear, and nose, mouth, and pharynx were 90 to 98 percent outpatient.
  • Surgeries performed to treat and/or diagnose disorders of the digestive, nervous, cardiovascular, male genital, heme and lymphatic, respiratory, and endocrine systems, as well as obstetrical surgeries, were primarily inpatient.
  • Surgeries involving the treatment and/or diagnosis of the female genital and urinary systems were equally performed as ambulatory and inpatient procedures.

Select for Figure 4 (15 KB), Ambulatory vs. Inpatient Surgeries by Body System.

Return to Contents

How Did Ambulatory Surgeries Vary by Gender and Age?

Gender

  • Lens and cataract procedures were the most common ambulatory procedure performed on both males (7.9 percent) and females (9.3 percent).
  • Three of the top 10 surgeries among females related to female-specific procedures—lumpectomy (5.1 percent), diagnostic D&C (4.9 percent), and other excision of the cervix and uterus (4.4 percent).
  • Transurethral excision, drainage, or removal of a urinary obstruction—a male-specific procedure—was among the top 10 ambulatory surgeries performed on males and accounted for nearly 3 percent of ambulatory surgeries performed on this population.
  • Hernia repair (6.7 percent), excision of the semilunar cartilage of the knee (4.3 percent), myringotomy (4.3 percent), other O.R. therapeutic procedures on nose, mouth, and pharynx (3.3 percent), and arthroscopy (2.6 percent) were among the top 10 surgeries for males but not for females.
  • Cholecystectomy (4.1 percent), decompression of the peripheral nerve (2.8 percent), and other O.R. therapeutic procedures on the skin and breast (2.5 percent) were top 10 surgeries performed on females but not for males.

Table 3. Top 10 All-Listed Procedures, by Gender

Top 10 All-Listed Procedures, by Gender Males Females
Number of Ambulatory Surgeries, in Thousands
(percentage of surgical visits with this procedure)
Lens and cataract procedures 161 (7.9) 270 (9.3)
Inguinal and femoral hernia repair 136 (6.7)  
Other therapeutic procedures on muscles and tendonsa 120 (5.9) 127 (4.4)
Tonsillectomy and/or adenoidectomy 90 (4.5) 96 (3.3)
Excision of semilunar cartilage of knee 87 (4.3)  
Myringotomy (ear tube surgery) 87 (4.3)  
Other O.R. therapeutic procedures on joints* 84 (4.2) 82 (2.8)
Other O.R. therapeutic procedures on nose, mouth, and pharynx* 67 (3.3)  
Arthroscopy 53 (2.6)  
Transurethral excision, drainage, or removal of a urinary obstruction 50 (2.5)  
Lumpectomy, quadrantectomy of breast   147 (5.1)
Diagnostic dilatation and curettage (D&C)   142 (4.9)
Other excision of cervix and uterus*   128 (4.4)
Cholecystectomy and common duct exploration   119 (4.1)
Decompression of the peripheral nerve   82 (2.8)
Other O.R. therapeutic procedures on skin and breast*   73 (2.5)

* Go to footnotes in Appendix table for definitions of other procedures.

Age

  • Three procedures were common to all age groups: inguinal and femoral hernia repair, other therapeutic procedures on the muscles and tendons, and other operating room therapeutic procedures on joints.
  • Removal of the tonsils and/or adenoids and myringotomy were the most common ambulatory surgeries performed on children ages 0 to 17. These procedures accounted for 24 percent and 23 percent, respectively, of ambulatory surgeries performed on children.
  • Surgeries performed exclusively or primarily on women—other excision of cervix and uterus, diagnostic D&C, and lumpectomy—accounted for 3 of the 10 most common ambulatory surgeries performed on patients ages 18 to 44.
  • Among patients 45 to 64 years of age, 4 of the 10 most commonly performed ambulatory surgeries related to the musculoskeletal system: other therapeutic procedures on the muscles and tendons (7.0 percent), excision of the semilunar cartilage of the knee (5.0 percent), other O.R. procedures on the joints (4.7 percent), and partial bone excision (2.8 percent).
  • Approximately 1 out of 3 ambulatory surgeries performed on patients 65 and older involved cataract and lens procedures.

Select for Table 4, Top 10 All-Listed Procedures, by Age Group.

Return to Contents

Which Ambulatory Surgeries Were Associated With the Highest Charges?

Hospital charges are the amount the hospital bills for the entire visit or stay and do not include most professional (physician) fees. Charges represent what the hospital billed for the case, rather than the amount actually reimbursed. Note that charges reflect the total hospital charge for an encounter (i.e., visit or stay), not the charge for a particular surgery. In addition, the most expensive ambulatory surgeries are not very common. Collectively, the 10 surgeries associated with the most expensive ambulatory surgical visits represented less than 4 percent of all outpatient surgeries.

  • In 2003, the average hospital charge for an ambulatory surgical visit was $5,600, compared with $28,300 for an inpatient surgical stay.ii
  • Five of the top 10 surgeries associated with the most expensive ambulatory surgical visits involved the treatment and diagnosis of the cardiovascular system: percutaneous coronary angioplasty (PTCA), insertion of a cardiac pacemaker or defibrillator, other O.R. heart procedures, endovascular repair of aneurysm, and other O.R. procedures on vessels other than head and neck.
  • Two of the 10 most expensive ambulatory surgeries were related to the treatment of musculoskeletal system disorders: spinal fusion and laminectomy.
  • Open prostatectomy—a surgery performed only on men—was the fifth most expensive ambulatory surgery.

ii Inpatient surgical stays are typically more expensive than ambulatory surgery visits because of longer lengths of stay and the use of multiple procedures.


Select for Figure 5 (13 KB), Procedures Associated With the Most Expensive Ambulatory Surgical Visits.

Return to Contents

Who Was Billed For Ambulatory Surgical Visits?

Select for Figure 6 (7 KB), Percentage of Surgical Visits and Stays Billed to Each Payer.

Payer data reflect the expected payer for an ambulatory surgical visit. It is important to note that in the outpatient hospital setting, payers are not billed for specific procedures; rather, they are billed for a patient's full surgical visit. 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."

  • Government insurance programs, primarily Medicare and Medicaid, were billed for about one-third of ambulatory surgical visits. In contrast, nearly half of inpatient surgical stays were billed to Medicare and Medicaid.
  • About 12 percent of ambulatory surgical visits and 17 percent of inpatient surgical stays were billed to Medicaid.
  • Private insurance was billed for approximately 55 percent of ambulatory surgical visits and nearly 46 percent of inpatient surgical stays.
  • Uninsured patients accounted for 3 to 4 percent of ambulatory and inpatient surgical visits and stays.

Medicare

  • In 2003, about 14.6 million individuals in the 17 selected States—representing 13 percent of the population in these States—were covered by Medicare.4
  • Medicare was billed for nearly 24 percent of all ambulatory surgical visits.
  • Approximately 3 out of 4 outpatient surgeries related to lens and cataract procedures were billed to Medicare; these procedures constituted the most common ambulatory surgeries performed on patients with Medicare (28.7 percent).
  • Among ambulatory surgeries billed to Medicare, 4 of the top 10 procedures were for the treatment and/or diagnosis of the musculoskeletal system: other therapeutic procedures on muscles and tendons (4.1 percent), excision of the semilunar cartilage of the knee (2.1 percent), other O.R. therapeutic procedures on joints (1.9 percent), and partial bone excisions (1.4 percent).
  • Transurethral excision, drainage, or removal of urinary obstruction was a top 10 ambulatory surgery billed to Medicare but was not in the top 10 for other payer groups. Medicare was billed for 40 percent of all ambulatory surgeries related to this procedure.

Table 5. Top 10 All-Listed Procedures, Medicare

Top 10 All-Listed Procedures, Medicare Number of Ambulatory Surgeries, in Thousands
(percentage of surgical visits with this procedure)
Medicare's Share of Ambulatory Surgeries With This Procedure
(percentage)
Lens and cataract procedures 324 (28.7) 75.2
Other therapeutic procedures on muscles and tendonsa 46 (4.1) 18.7
Inguinal and femoral hernia repair 35 (3.1) 22.9
Lumpectomy, quadrantectomy of breast 34 (3.0) 22.7
Transurethral excision, drainage, or removal of a urinary obstruction 31 (2.8) 40.4
Decompression of the peripheral nerve 29 (2.6) 23.6
Cholecystectomy and common duct exploration 24 (2.1) 15.9
Excision of semilunar cartilage of knee 23 (2.1) 14.7
Other O.R. therapeutic procedures on jointsa 22 (1.9) 13.0
Partial excision of the bone 16 (1.4) 17.3

a Go to footnotes in Appendix table for definitions of other procedures.

Medicaid

  • About 12.7 million individuals in the 17 selected States, representing 12 percent of the population in these states, were covered by Medicaid in 2003.4
  • Approximately 12 percent of ambulatory surgical visits were billed to Medicaid.
  • Two of the most common ambulatory surgery procedures billed to Medicaid were primarily performed on children: removal of the tonsils and adenoids and myringotomy. Medicaid was billed for approximately 23 percent of outpatient tonsillectomies and/or adenoidectomies and for 27 percent of outpatient myringotomies.
  • Other excision of the cervix and uterus (3.0 percent), diagnostic D&C (2.5 percent), and lumpectomy (2.2 percent) were 3 of the most common ambulatory surgeries billed to Medicaid.

Table 6. Top 10 All-Listed Procedures, Medicaid

Top 10 All-Listed Procedures, Medicaid Number of Ambulatory Surgeries, in Thousands
(percentage of surgical visits with this procedure)
Medicaid's Share of Ambulatory Surgeries With This Procedure
(percentage)
Tonsillectomy and/or adenoidectomy 42 (9.4) 22.5
Myringotomy (ear tube surgery) 41 (9.2) 27.2
Other therapeutic procedures on muscles and tendonsa 15 (3.5) 6.3
Cholecystectomy and common duct exploration 15 (3.3) 9.6
Other excision of cervix and uterusa 13 (3.0) 10.4
Lens and cataract procedures 12 (2.7) 2.8
Inguinal and femoral hernia repair 11 (2.5) 7.3
Diagnostic dilatation and curettage (D&C) 11 (2.5) 7.8
Other O.R. therapeutic procedures on nose, mouth, and pharynxa 10 (2.3) 7.9
Lumpectomy, quadrantectomy of breast 10 (2.2) 6.3

a Go to footnotes in Appendix table for definitions of other procedures.

Private Insurance

  • In 2003, about 78.3 million individuals in the 17 selected States, representing 71 percent of the population in these States, were covered by private insurers.4
  • Private insurers were billed for approximately 55 percent of all ambulatory surgical visits.
  • Three of the top 10 ambulatory surgery procedures billed to private insurers were for the treatment and diagnosis of musculoskeletal disorders: other therapeutic procedures on muscles and tendons (5.1 percent), other O.R. therapeutic procedures on the joints (3.8 percent), and excision of the semilunar cartilage of the knee (3.8 percent). Private insurers were billed for more than half of all ambulatory surgeries related to these procedures.
  • Private insurers were billed for 71 percent of ambulatory surgeries involving the removal of the tonsils and adenoids and 66 percent of myringotomies.
  • Approximately 3 out of 4 ambulatory surgeries involving diagnostic dilatation and curettage (D&C) and other excision of the cervix and uterus were billed to private insurers.
  • Nearly 2 out of 3 lumpectomies were billed to private insurers. In addition, private insurers were billed for two-thirds of all cholecystectomies (surgical removal of the gallbladder.)

Table 7. Top 10 All-Listed Procedures, Private Insurance

Top 10 All-Listed Procedures, Private Insurance Number of Ambulatory Surgeries,
in Thousands
(percentage of surgical visits
with this procedure)
Private Insurer's Share
of Ambulatory Surgeries
With This Procedure
(percentage)
Other therapeutic procedures on muscles and tendonsa 145 (5.1) 59.1
Tonsillectomy and/or adenoidectomy 132 (4.6) 71.2
Other O.R. therapeutic procedures on jointsa 108 (3.8) 65.5
Diagnostic dilatation and curettage (D&C) 107 (3.8) 75.9
Excision of semilunar cartilage of knee 107 (3.8) 67.6
Cholecystectomy and common duct exploration 101 (3.5) 66.5
Other excision of cervix and uterusa 99 (3.5) 77.2
Myringotomy (ear tube surgery) 98 (3.4) 65.8
Lumpectomy, quadrantectomy of breast 97 (3.4) 64.2
Other O.R. therapeutic procedures on nose, mouth, and pharynxa 93 (3.2) 73.4

a Go to footnotes in Appendix table for definitions of other procedures.

Uninsured

  • About 14.9 million individuals in the 17 selected States, representing 14 percent of the population in these States, were uninsured in 2003.4
  • Just over 3 percent of ambulatory surgical visits occurred among uninsured patients.
  • Other O.R. therapeutic procedures on the skin and breast were the most common ambulatory surgeries performed on the uninsured (11.3 percent). Approximately 1 in 6 of these procedures was performed on an uninsured patient.
  • Except for lens and cataract procedures, 9 of the top 10 most common ambulatory surgeries performed on uninsured patients were also the most common procedures performed on patients ages 18 to 44 years.

Table 8. Top 10 All-Listed Procedures, Uninsured

Top 10 All-Listed Procedures, Uninsured Number of Ambulatory Surgeries,
in Thousands
(percentage of surgical visits
with this procedure)
Share of Ambulatory Surgeries
That Are Uninsured
With This Procedure
(percentage)
Other O.R. therapeutic procedures on skin and breasta 17 (11.3) 16.7
Other therapeutic procedures on muscles and tendonsa 8 (4.9) 3.1
Cholecystectomy and common duct exploration 6 (3.6) 3.7
Inguinal and femoral hernia repair 5 (3.4) 3.4
Lumpectomy, quadrantectomy of breast 5 (3.2) 3.3
Lens and cataract procedures 5 (3.2) 1.1
Other excision of cervix and uterusa 4 (2.8) 3.3
Other O.R. therapeutic procedures on nose, mouth, and pharynxa 3 (2.3) 2.8
Diagnostic dilatation and curettage (D&C) 3 (2.2) 2.4
Other O.R. therapeutic procedures on jointsa 3 (1.7) 1.6

a Go to footnotes in Appendix table for definitions of other procedures.

Return to Contents
Proceed to Next Section

 

The information on this page is archived and provided for reference purposes only.

 

AHRQ Advancing Excellence in Health Care