Top Outpatient Procedures at Hospitals vs Surgery Centers

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*Updated July 2019

The continual shift from inpatient to outpatient procedures is one of the most common ways hospitals and care facilities reduce healthcare spending. This is especially cost-effective when patients seek outpatient care at a clinic or ambulatory surgery center (ASC) rather than a traditional hospital. Because services are often limited at ASCs and outpatient clinics, these facilities are able to charge less than hospitals, whose charges must cover operating costs of a wide breadth of services and staff. 

Major influencing factors in the shift to outpatient facilities and services include advances in surgical technology, improved outcomes via regulatory changes, edits to the Centers for Medicare and Medicaid Services (CMS) outpatient-only procedure list, and others.

Below, we've compiled list of the top 10 outpatient medical procedures at U.S. hospitals and ASCs for comparison.

Top 10 Hospital Outpatient Procedures by Volume

Rank HCPS/CPT Code Description Number of Procedures
1. 36415 Routine venipuncture 106,427,264  
2. 85025 Complete blood count w/ differential white blood cell count 96,067,285  
3. 80053 Comprehensive metabolic panel 86,269,324  
4. 97110 Therapeutic exercises 45,689,684  
5. J2704 Injection of propofol, 10 mg 37,477,960  
6. 80048 Metabolic panel total ca 36,755,844  
7. 81001 Urinalysis auto w/scope 33,770,814  
8. 93005 Electrocardiogram tracing 30,862,698  
9. 84443 Assay thyroid stimulating hormone 28,927,631  
10. 80061 Lipid panel 27,840,770  

Fig 1 Data from Definitive Healthcare based on 2018 Medicare and all-payor procedure estimates. YTD Medicare data is from the 2018 Medicare Quarterly SAF. Does not include visits to emergency departments or clinics.

Of the top 10 outpatient medical procedures at hospitals, seven are diagnostic tests and one is a precursor to anesthesia. The only two treatments present are "therapeutic exercises" and "assay thyroid stimulating hormone." Unlike at ASCs, patients often visit primary care physicians or urgent care clinics at hospitals for diagnoses rather than procedures and treatments. Patients are tested and receive diagnoses at hospitals before selecting where to undergo a procedure or other treatment.

Top 10 ASC Outpatient Procedures

Rank HCPS Code Description Number of Procedures
1. 66984 Cataract surg w/ intraocular implant, 1 stage 1,252,835  
2. J0585 Injection, onabotulinumtoxinA (Botox) 759,997  
3. 43239 Esophagogastroduodenoscopy (Egd) biopsy single/multiple 539,772  
4. 45380 Colonoscopy and biopsy 464,136  
5. 45385 Colonoscopy w/lesion removal 397,339  
6. 64483 Epidural steroid injection in lumbar spine w/ imaging guidance 319,592  
7. 66821 After cataract laser surgery 283,574  
8. 64493 Injection into lumbar/sacral spine w/ image guidance 220,472  
9. 62323 Lumbar interlaminar epidural steroid injection 195,648  
10. G0105 Colorectal screening; high risk individual   137,697  

Fig 2 Data from Definitive Healthcare based on 2017 Medicare procedure estimates. Does not include visits to emergency departments or clinics. 

Cataract surgeries are by far the most common ASC procedure with over 1.2 million claims in 2017, with botox injections taking the next highest slot. There are no reports of "routine venipunctures" or other diagnostic panels at ASCs, which notably make up the majority of hospital outpatient procedures. The ability of ASCs to focus solely on treatments rather than diagnostics means these facilities are likely able to charge patients less than hospitals for the same procedures, as ASCs have fewer lab fees or other related costs to cover.

Learn More

Looking for more information on outpatient procedures? Definitive Healthcare's medical procedure and diagnosis data can help you:

  • Examine all outpatient (and inpatient) procedures and diagnoses, broken down by ICD-9, ICD-10, CPT/HCPCS, or DRG code
  • Look up the total number of payments for specific procedures and diagnoses
  • Find readmission rates for diagnoses by DRG code as well as the average length of stay in days for patients readmitted for specific conditions







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