Proportion of hospital stays and costs that involved OR procedures, 2012

Figure 1 presents information on hospital stays and costs with and without OR procedures among nonmaternal and nonneonatal hospitalizations.

Figure 1

Hospital stays and hospital costs with and without operating room procedures, 2012. Source: Agency for Healthcare Research and Quality (AHRQ), Center for Delivery, Organization, and Markets, Healthcare Cost and Utilization Project (HCUP), National Inpatient (more...)

• OR procedures were performed during nearly 30 percent of hospital stays in 2012, and these stays accounted for about half of hospital costs.
  In 2012, there were more than 28 million nonmaternal and nonneonatal hospital stays, which cost more than $342 billion. OR procedures were performed during 28.0 percent of these stays, and stays with OR procedures accounted for nearly half (49.1 percent) of total hospital costs.

OR procedures performed most frequently, 2012

Table 1 presents the all-listed OR procedures that were performed most frequently during hospital stays in 2012.

Table 1

Operating room procedures performed most frequently during hospital stays, 2012.

• The most common OR procedures involved the musculoskeletal system.
  Of the 8 million total nonmaternal and nonneonatal hospital stays with an OR procedure, five of the seven most common procedures involved the musculoskeletal system—these were knee arthroplasty (700,100 stays), laminectomy (removal of part of a spinal vertebra, 468,200 stays), hip replacement (468,000 stays), spinal fusion (450,900 stays), and partial excision bone (338,000 stays). Two other common musculoskeletal procedures were trauma-related (treatment of hip fracture and treatment of other lower extremity fracture).
  Another 4 of the 15 most common OR procedures involved the digestive system: cholecystectomy (removal of the gall bladder, 406,300 stays); colorectal resection (305,900 stays); excision, lysis peritoneal adhesions (305,800 stays); and appendectomy (removal of the appendix, 293,000 stays).
  The remaining stays involved OR procedures related to the cardiovascular system—including the second most common procedure, percutaneous coronary angioplasty (PTCA, 534,600 stays), and coronary artery bypass graft (CABG, 202,900 stays)—and procedures involving female genital organs (hysterectomy and oophorectomy).

OR procedures with the greatest change in occurrence, 2003–2012

Table 2 presents the OR procedures with the greatest change in rate per 100,000 population between 2003 and 2012. The 10 procedures with the greatest increase in rate and the 10 procedures with greatest decrease in rate are presented. Only procedures with a minimum of 50,000 stays in either 2003 or 2012 are reported. Changes in procedure rates may be due to a number of factors, including changes in the prevalence of underlying health conditions treated in ORs and changes in hospital practices, such as a shift in certain procedures to outpatient settings.

Table 2

Operating room procedures with the greatest change in rate, 2003–2012.

• The OR procedure with the greatest increase in rate was gastrectomy.
  Between 2003 and 2012, gastrectomy (partial or total removal of the stomach) had the largest increase in rate of occurrence of any OR procedure, increasing by more than 150 percent over 10 years, from 9.3 to 23.6 stays per 100,000 population (10.9 percent average annual increase).
  Procedures to remove other major organs (kidneys and lungs) also were among those with high increases in rate:
  • Nephrectomy (removal of a kidney) was the procedure with the eighth highest increase in rate (1.8 percent average annual increase).
  • Lobectomy (removal of a lung lobe) was the procedure with the ninth highest increase in rate (1.7 percent average annual increase).
• Five of the six OR procedures with the greatest increase in rate were related to the musculoskeletal system.
  Hospital stays involving knee arthroplasty increased from 421,700 in 2003 to 700,100 in 2012. This procedure underwent the second highest increase in rate, growing by more than 50 percent during the 10-year period, from 145.4 to 223.0 per 100,000 population (4.9 percent average annual increase).
  The OR procedures with third through sixth greatest increase in rate also involved the musculoskeletal system:
  • Arthroplasty, other than the hip or knee (4.5 percent average annual increase)
  • Partial excision bone (3.3 percent average annual increase)
  • Spinal fusion (3.1 percent average annual increase)
  • Partial or total hip replacement (2.9 percent average annual increase)
• OR procedures involving female or male genital organs or the urinary system had the greatest decrease in rate.
  The OR procedure with the greatest decrease in rate was transurethral prostatectomy (TURP), which decreased by 62.6 percent between 2003 and 2012, from 35.8 to 13.4 per 100,000 population (10.4 percent average annual decrease).
  Genitourinary incontinence OR procedures had the second greatest decrease in rate, decreasing by 62.5 percent from 40.0 to 15.0 per 100,000 population (10.3 percent average annual decrease).
  The OR procedures with the third through fifth greatest decrease in rate involved the female genital system:
  • Repair of cystocele and rectocele (9.4 percent average annual decrease)
  • Oophrectomy (removal of an ovary, 8.3 percent average annual decrease)
  • Hysterectomy (removal of the uterus, 7.6 percent average annual decrease)

OR procedures with the highest frequency and greatest change in occurrence by patient characteristics, 2012

Tables 3–5 present the OR procedures with the highest frequency and the greatest change in occurrence by patient age group (Table 3), patient sex (Table 4), and expected primary payer (Table 5). Only procedures with a minimum number of stays in either 2003 or 2012 are reported (see table footnotes for the number of minimum stays required for reporting in the three categories—patient age, sex, and payer).

Table 3

Operating room procedures performed most frequently, 2012, and operating room procedures with the greatest change in rate, 2003–2012, by patient age group.

Table 4

Operating room procedures performed most frequently, 2012, and operating room procedures with the greatest change in rate, 2003–2012, by patient sex.

Table 5

Operating room procedures performed most frequently, 2012, and operating room procedures with the greatest change in frequency, 2003–2012, by payer.

• Spine and joint OR procedures were common among all age groups except infants.
  Spinal fusion was one of the five most common OR procedures performed in every age group except infants younger than 1 year and adults 85 years and older.
  Laminectomy was common among adults aged 18–84 years.
  Knee arthroplasty and hip replacement were in the top five OR procedures for adults aged 45 years and older.
• Brachytherapy performed among adults aged 45–84 years had the greatest change in rate (a decrease) of any OR procedure for any age group between 2003 and 2012.
  Between 2003 and 2012, the rate of hospital stays with brachytherapy (internal radiation therapy) had a 24.4 percent average annual decrease among adults aged 45–64 years and a 27.3 percent average annual decrease among adults aged 65–84 years.
  The OR procedure with the greatest increase in rate was partial or total gastrectomy among adults aged 18–44 years, with an average annual increase of 24.0 percent.
• Musculoskeletal OR procedures were common among both men and women.
  Knee arthroplasty, spinal fusion, and hip replacement were among the top five most frequently performed OR procedures for both men and women.
  Percutaneous coronary angioplasty (PTCA) and laminectomy were among the most frequently performed procedures for men, and hysterectomy and cholecystectomy were among the most frequently performed procedures for women.
• Brachytherapy was the OR procedure with the greatest change in rate among men (decreasing), and gastrectomy was the OR procedure with the greatest change in rate among women (increasing).
  From 2003 to 2012, men experienced a 30.2 percent average annual decrease in the rate of brachytherapy and a 10.3 percent average annual decrease in the rate of transurethral prostatectomy (TURP). During the same time period, women experienced a 14.9 percent average annual increase in the rate of partial or total gastrectomy and a 10.6 percent average annual decrease in the rate of genitourinary incontinence procedures.
• Knee arthroplasty was the most common OR procedure for hospital stays paid by Medicare and by private insurance.
  Among hospitalizations that involved an OR procedure, knee arthroplasty was the OR procedure performed most frequently during hospital stays paid by Medicare (10.8 percent of stays) and by private insurance (9.1 percent). Knee arthroplasty was not among the top five most frequently performed OR procedures for stays paid by Medicaid or for uninsured stays.
• Cholecystectomy was the most common OR procedure for hospital stays paid by Medicaid and for uninsured stays.
  Cholecystectomy was the most frequently performed OR procedure during hospital stays paid by Medicaid (7.4 percent of stays involving an OR procedure) and during uninsured stays (11.2 percent). Cholecystectomy was not among the top five most frequently performed OR procedures for stays paid by Medicare or private insurance.
• Percutaneous coronary angioplasty (PTCA) was among the most common procedures for hospital stays across all payers.
  PTCA was among the five procedures that were performed most frequently during hospital stays that involved an OR procedure for all types of payers: Medicare (7.9 percent of stays), Medicaid (4.6 percent), private insurance (5.6 percent), and uninsured (9.7 percent)
• Brachytherapy was the OR procedure with the greatest change in occurrence among hospital stays paid by Medicare and private insurance.
  The number of hospital stays involving brachytherapy decreased by an average of approximately 25 percent annually among stays paid by Medicare and private insurance.
• OR procedures related to the musculoskeletal system were among those with the greatest change in occurrence for stays paid by Medicaid and for uninsured stays.
  The five OR procedures with the greatest change in occurrence for stays paid by Medicaid involved the musculoskeletal system, including knee arthroplasty (7.3 percent average annual increase), spinal fusion (7.1 percent average annual increase), and partial excision bone (6.9 percent average annual increase).
  Among uninsured hospital stays, the two OR procedures with the greatest change in occurrence also involved the musculoskeletal system: amputation of lower extremity (9.4 percent average annual increase) and partial excision bone (6.9 percent average annual increase).

Procedures, ICD-9-CM, Clinical Classifications Software (CCS), major diagnostic categories (MDCs), and diagnosis-related groups (DRGs)

All-listed procedures include all procedures performed during the hospital stay, whether for definitive treatment or for diagnostic or exploratory purposes.

ICD-9-CM is the International Classification of Diseases, Ninth Revision, Clinical Modification, which assigns numeric codes to procedures. There are approximately 4,000 ICD-9-CM procedure codes.

CCS categorizes ICD-9-CM procedure codes into a manageable number of clinically meaningful categories.⁵ This clinical grouper makes it easier to quickly understand patterns of procedure use. CCS categories identified as Other typically are not reported; these categories include miscellaneous, otherwise unclassifiable procedures that may be difficult to interpret as a group.

MDCs assign ICD-9-CM principal diagnosis codes to one of 25 general diagnosis categories. For this report, maternal and neonatal discharges were excluded from the analysis. Maternal hospital stays were identified using MDC 14 (pregnancy, childbirth, and the puerperium), and neonatal hospital stays were identified using MDC 15 (newborns and other neonates with conditions originating during the perinatal period).

DRGs comprise a patient classification system that categorizes patients into groups that are clinically coherent and homogeneous with respect to resource use. DRGs group patients according to diagnosis, type of treatment (procedure), age, and other relevant criteria. Each hospital stay has one assigned DRG. For this report, major operating room (OR) procedures were defined using procedure classes that categorize each ICD-9-CM procedure code as major therapeutic, major diagnostic, minor therapeutic, or minor diagnostic.⁶ Major OR procedures are considered to be valid OR procedures based on DRGs. This classification scheme relies on physician panels that classify ICD-9-CM procedure codes according to whether the procedure would be performed in a hospital OR in most hospitals. Major OR procedures were identified using all procedure fields (first-listed and secondary) that were available on the discharge record.

Types of hospitals included in the HCUP National (Nationwide) Inpatient Sample

The National (Nationwide) Inpatient Sample is based on data from community hospitals, which are defined as short-term, non-Federal, general, and other hospitals, excluding hospital units of other institutions (e.g., prisons). The NIS includes obstetrics and gynecology, otolaryngology, orthopedic, cancer, pediatric, public, and academic medical hospitals. Excluded are long-term care facilities such as rehabilitation, psychiatric, and alcoholism and chemical dependency hospitals. Beginning in 2012, long-term acute care hospitals are also excluded. However, if a patient received long-term care, rehabilitation, or treatment for psychiatric or chemical dependency conditions in a community hospital, the discharge record for that stay will be included in the NIS.

Costs and charges

Total hospital charges were converted to costs using HCUP Cost-to-Charge Ratios based on hospital accounting reports from the Centers for Medicare & Medicaid Services (CMS).⁷ Costs reflect the actual expenses incurred in the production of hospital services, such as wages, supplies, and utility costs; charges represent the amount a hospital billed for the case. For each hospital, a hospital-wide cost-to-charge ratio is used. Hospital charges reflect the amount the hospital billed for the entire hospital stay and do not include professional (physician) fees.

How HCUP estimates of costs differ from National Health Expenditure Accounts

There are a number of differences between the costs cited in this Statistical Brief and spending as measured in the National Health Expenditure Accounts (NHEA), which are produced annually by the Centers for Medicare & Medicaid Services (CMS).⁸ The largest source of difference comes from the HCUP coverage of inpatient treatment only in contrast to the NHEA inclusion of outpatient costs associated with emergency departments and other hospital-based outpatient clinics and departments as well. The outpatient portion of hospitals' activities has been growing steadily and may exceed half of all hospital revenue in recent years. On the basis of the American Hospital Association Annual Survey, 2012 outpatient gross revenues (or charges) were about 44 percent of total hospital gross revenues.⁹

Smaller sources of differences come from the inclusion in the NHEA of hospitals that are excluded from HCUP. These include Federal hospitals (Department of Defense, Veterans Administration, Indian Health Services, and Department of Justice [prison] hospitals) as well as psychiatric, substance abuse, and long-term care hospitals. A third source of difference lies in the HCUP reliance on billed charges from hospitals to payers, adjusted to provide estimates of costs using hospital-wide cost-to-charge ratios, in contrast to the NHEA measurement of spending or revenue. HCUP costs estimate the amount of money required to produce hospital services, including expenses for wages, salaries, and benefits paid to staff as well as utilities, maintenance, and other similar expenses required to run a hospital. NHEA spending or revenue measures the amount of income received by the hospital for treatment and other services provided, including payments by insurers, patients, or government programs. The difference between revenues and costs include profit for for-profit hospitals or surpluses for nonprofit hospitals.

Unit of analysis

The unit of analysis is the hospital discharge (i.e., the hospital stay), not a person or patient. This means that a person who is admitted to the hospital multiple times in 1 year will be counted each time as a separate discharge from the hospital.

Average annual percentage change

Average annual percentage change is calculated using the following formula:

Payer

Payer is the expected primary payer for the hospital stay. To make coding uniform across all HCUP data sources, payer combines detailed categories into general groups:

• Medicare: includes patients covered by fee-for-service and managed care Medicare
• Medicaid: includes patients covered by fee-for-service and managed care Medicaid
• Private Insurance: includes Blue Cross, commercial carriers, and private health maintenance organizations (HMOs) and preferred provider organizations (PPOs)
• Uninsured: includes an insurance status of self-pay and no charge
• Other: includes Worker's Compensation, TRICARE/CHAMPUS, CHAMPVA, Title V, and other government programs.

Hospital stays billed to the State Children's Health Insurance Program (SCHIP) may be classified as Medicaid, Private Insurance, or Other, depending on the structure of the State program. Because most State data do not identify patients in SCHIP specifically, it is not possible to present this information separately.

When more than one payer is listed for a hospital discharge, the first-listed payer is used.