Terri Conner,PhD Nybeck Analytics Partnership for Patients

1. USE OF MEDICARE DIAGNOSIS AND PROCEDURE CODES TO IMPROVEDETECTION OF SURGICAL SITE INFECTIONS Terri Conner,PhD Nybeck Analytics Partnership for Patients 14th May 2012

2. Why focus on surgical quality? • ~30 million major operations each year in the U.S. • Despite advances in surgical and anesthesia techniques, improvements in perioperative care, variations in outcomes for patients having surgery are well known. • Lack of an adequate surveillance system for proper reporting of SSIs, as majority of these cases occur after hospital discharge.

3. Consequences of Surgical Complications • CDC estimates that nearly 300,000 surgical site infections (SSIs), which are potentially preventable occur annually in US hospitals, leading to several billion dollars in direct medical costs [1]. • Khuri and colleagues demonstrated that, independent of preoperative patient risk, the occurrence of a 30-day complication reduced median patient survival by 69% [2].

4. Why use standardized methods of data collection? 4 Surveillance reports based on using this method have been shown to be more effective in identifying SSIs compared with the traditional methods used by hospital infection prevention programs [3]. Inconsistent and incomplete identification of SSIs due to varying degrees of effort and resources, which in turn impact healthcare outcomes.

5. Standardized methods 5 • These demonstrations of increased detection include the use of Medicare claims data to identify SSI following coronary artery bypass graft (CABG) surgery. • Coded diagnoses and procedures from these claims are used as primary tools for identifying SSIs after procedures like knee arthroplasty, hip arthroplasty and vascular surgery.

6. Methods for Using Medicare Diagnosis and Procedure Codes • Review of Calderwood publication: Infection Control and Hospital Epidemiology 2012;33(1):40-49 • Communities of Practice website www.healthcarecommunities.org • Conference Binder

7. Study Description 7 • Type of study: Retrospective cohort studies • Setting: 4 hospitals in Oklahoma • Eligibility criteria: non-health maintenance organization (HMO) Medicare recipients > 65 yrs who underwent 1 of the SCIP-targeted hip procedures between a determined one year period. • Exclusion criteria: • HMO (Medicare Advantage) participant. • Patients who had a prior SCIP procedure. • Patients who had diagnosis or procedure codes suggestive of infection at the surgical site on or before the days of the surgery.

8. Methodology:Inclusion and exclusion criteria Lists of procedure-specific SSI indicator codes were developed to identify possible SSIs following each procedure. To increase sensitivity, these lists were expanded to include all codes that were suggestive of the presence of an SSI. Due to low discriminatory values, ICD codes for cellulitis (ICD-9 682.x) were removed. ICD Ninth Revision (ICD-9), Current Procedural Terminology (CPT) diagnosis and procedure codes submitted under Medicare Parts A and B physician claims from inpatient and outpatient facilities were included.

9. Methodology:Indicators’ eligibility period 9 • Vascular SSI indicators: 60 days period following a vascular procedure • Knee and hips SSI indicators: 365 days period following knees and hips arthroplasty • These periods are based on CDC’s recommendations for SSI surveillance. Longer periods are warranted in diagnostic cases of deep incisional and organ/space SSI

10. Methodology: All participating hospitals were sent a list of Medicare patients who had both undergone a study procedure at their hospital and had been flagged by a procedure-specific indicator code. Staff at these hospitals then compared the patient list with their own patients who were captured by the procedure specific SSI indicator code.

11. Methodology: Complete medical records for both cases (traditional or claims-based surveillance) were reviewed by an experienced researcher using CDC/NHSN criteria to confirm the presence of an SSI.

12. Methodology: Gold standard for detection were all confirmed SSIs as identified by either of the two methods. Codes that did not identify confirmed SSIs nor were related to SSIs were removed in the pilot study by reviewing performance of each codes.

13. Conclusions Use of claims-based surveillance improves detection mostly because the traditional method relies on unproven screening strategies. Diagnosis and procedure codes provide an efficient, labor-saving, and improved method for primary SSI surveillance. Using this methodology for surveillance would improve SSI detection and allow for more standardized comparisons of hospitals on a national level.

14. REFERENCES Scott RD II. The Direct Medical Costs of Healthcare-Associated Infections in U.S. Hospitals and the Benefits of Prevention. Atlanta: Centers for Disease Control and Prevention, 2009. http://www.cdc.gov/ncidod/dhqp/pdf/Scott_CostPaper.pdf Khuri SF, et al. Ann Surg 2005;242:326-41 Miner AL, Sands KE, Yokoe DS, et al. Enhanced identification of postoperative infections among outpatients. Emerg Infect Dis 2004;10:1931–1937.

15. Thank you!