1. Office of Statewide Health Planning and Development Day for Night: Hospital Admissions for Day Surgery Patients in California, 2005 Mary Tran, PhD, MPH Healthcare Outcomes Center OSHPD Brian Paciotti, PhD Healthcare Outcomes Center OSHPD Geeta Mahendra University of California, Davis Dept. of Internal Medicine

2. Office of Statewide Health Planning and Development Slide 2 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Presenter Disclosures (1)The following personal financial relationships with commercial interests relevant to this presentation existed during the past 12 months: Mary Nelson Tran, PhD, MPH “No relationships to disclose”

3. Office of Statewide Health Planning and Development Slide 3 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Background Increasing volume of surgical procedures performed in Ambulatory Surgery Centers (ASCs) since 1980s. –Related to improvements in medical technologies and rising cost of inpatient care. Concerns of providers and public about safety of outpatient procedures. Objectives of this study –Characterize the pattern of post-ASC admissions to the hospital –Identify risk factors for post-ASC admission –Compare mortality rates for hospital vs. ASC surgery patients receiving comparable procedures.

4. Office of Statewide Health Planning and Development Slide 4 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Methods Data Sources: –Inpatient admissions: Patient Discharge Data (PDD), 2005 –ASC patient encounters: Ambulatory Surgery Data (AS), 2005 Submitted by California-licensed ASCs (2005 = 1 st year of data) Free-standing surgery clinics, hospital-associated surgery centers –Death during 2005 California Vital Statistics, Death Statistical Master File, 2005 Linkage: –Linked by Social Security Number, using LinkPlus Analysis (SAS, ver. 9.1): –Logistic regression: Risk of post-ASC hospital admission –Comparing patients of free-standing vs. hospital-associated ASCs Risk of death –Comparing surgical patients of hospitals vs. ASCs Controlling for demographics, severity, payer.

5. Office of Statewide Health Planning and Development Slide 5 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Measures and Definitions Death –Death Certificate date of death 0-30 days after ASC procedure Inpatient Admission –First inpatient admission 0-15 days after ASC service date Diagnoses –ICD-9, principal diagnosis –Coded by Clinical Classifications Software (CCS), AHRQ* Procedures –Inpatients: Principal procedure, ICD-9 procedure code (CCS categories) –ASC Cases: Principal procedure, CPT code (CCS categories) –Selected Procedures: Surgical** and diagnostic procedures*** frequently performed in both ASC and hospital settings Patient Acuity (severity of illness) –Charlson Co-morbidity Index, based on ICD-9 diagnosis codes (range 0-17) *Clinical Classifications Software, Agency for Healthcare Quality and Research (AHRQ). http://www.hcup- us.ahrq.gov/toolssoftware/cc/ccs.jsp. ** A Russo, P Owens, C Steiner, J Josephsen. Ambulatory Surgery in U.S. Hospitals, 2003. HCUP Fact Book No. 9. (Healthcare Cost and Utilization Project). http://ahrq.gov/data/hcup/factbk9. *** Two diagnostic procedures frequently performed in both settings in California. Analyses by author.

6. Office of Statewide Health Planning and Development Slide 6 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Volume of ASC Cases and post-ASC Hospital Admissions Total ASC encounters = 2,552,177 Cases with post-ASC hospital admission within 15 days = 57,678 (2.3%) Of these post-ASC admissions to the hospital: Route of admission –Emergency Department = 40.1% Reported source of admission –Home = 89.8% –Ambulatory Surgery= 2.7% –Other inpatient care= 5.2% –SNF, residential care= 2.1% –Other = 0.2% Time from ASC service to inpatient admission: –0 to 1 Days= 14.2% –2 to 7 Days = 38.1% –8 to 15 Days= 47.6%

7. Office of Statewide Health Planning and Development Slide 7 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Top 10 Hospital Diagnoses for post-ASC Hospital Admissions

8. Office of Statewide Health Planning and Development Slide 8 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Risk factors for post-ASC admission to hospital within 15 days

9. Office of Statewide Health Planning and Development Slide 9 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 For cases with post-ASC admission: ASC procedures with highest 30-day mortality

10. Office of Statewide Health Planning and Development Slide 10 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Volume of Selected Procedures* Performed in ASCs and Hospitals * HCUP Fact Book No. 9: Ambulatory Surgery in U.S. Hospitals, 2003, Surgical procedures commonly performed in both inpatient and outpatient settings; plus additional procedures frequently performed in both settings in California (PTCA, cardiac catheterization), author’s analysis.

11. Office of Statewide Health Planning and Development Slide 11 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Characteristics of Patients Receiving the Selected Procedures

12. Office of Statewide Health Planning and Development Slide 12 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Risk of 30-Day Mortality for Selected Procedures

13. Office of Statewide Health Planning and Development Slide 13 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Limitations Possible bias introduced by exclusion of records with unusable SSNs. Relied on principal diagnosis and principal procedure only. Secondary dx and tx information might be important. The Charlson Co-morbidity Index Total Score might not be sufficient to adjust for differences in patient acuity between hospital inpatients and ASC patients. Only state-licensed ambulatory care facilities submitted data to OSHPD. These results may not reflect admission and mortality risk for procedures performed in other types of outpatient settings. Due to 2007 court decision, free-standing ASCs are not required to be licensed by the State of California. As a result, they are no longer required to submit patient data to OSHPD. As of October 2008, only 25 (19.7%) of the 127 free-standing ASCs have decided to continue reporting patient data to OSHPD.

14. Office of Statewide Health Planning and Development Slide 14 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Summary and Conclusions Post-ASC admission within 15 days: –Most come to the hospital from home and 2 out of 5 enter via the Emergency Department. Half occur a week or more after the ASC service –Likelihood greater if patients have co-morbidities or get care in a hospital-associated facility. Most frequent diagnosis: Complication of [prior] surgical procedure or medical care. Inpatient vs. Outpatient Mortality –Risk of death may be higher for ASC patients for some procedures. –Risk of death is greater for patients who have co-morbidities or pay for care out-of-pocket. Only a small percentage of post-ASC admissions are identified in hospital discharge records.

15. Office of Statewide Health Planning and Development Slide 15 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Acknowledgements Geeta Mahendra: LinkPlus linkages Brian Paciotti, PhD: Linkage, coding for CCS and Charlson Co-morbidity Index, SAS analyses Niya Fong: SAS analyses

16. Office of Statewide Health Planning and Development Slide 16 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Questions and comments

17. Office of Statewide Health Planning and Development Slide 17 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Backup slides

18. Office of Statewide Health Planning and Development Slide 18 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Charlson Co-morbidity Index Components

19. Office of Statewide Health Planning and Development Slide 19 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Days from procedure to inpatient admission, for selected ASC procedures Note: Of all inpatient readmissions within 15 days, 14% occurred in 0-1 days. Of all admissions, 1,551 (2.7%) were coded in PDD as admissions from an ASC.

20. Office of Statewide Health Planning and Development Slide 20 APHA, October 29, 2008 Data sources: PDD, ED/AS, 2005 Days from procedure to inpatient admission, for selected ASC procedures: expanded lower range