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A real-time surgical site infections surveillance mode to monitor surgery classification−specific, hospital-wide surgical site infections in a Chinese tertiary hospital
American Journal of Infection Control 45 (2017) 430-2
Contents lists available at ScienceDirect
American Journal of Infection Control
American Journal of Infection Control
j o u r n a l h o m e p a g e : w w w. a j i c j o u r n a l . o r g
Brief Report
A real-time surgical site infections surveillance mode to monitor surgery classification−specific, hospital-wide surgical site infections in a Chinese tertiary hospital Mingmei Du MD a,1, Meng Li MD b,1, Kexin Liu MB c,1, Jijiang Suo MB a, Yubin Xing MB a, Bowei Liu MB a, Rui Huo MC d, Chunping Chen MC d, Yunxi Liu PhD a,* a
Department of Infection Management and Disease Control, Chinese PLA General Hospital, Beijing, China Department of Hematology, Chinese PLA General Hospital, Beijing, China Department of Medical Record Management, Chinese PLA General Hospital, Beijing, China d Xinglin Information Technology Company, Hangzhou, Zhejiang Province, China b c
Key Words: Surgical site infections Hospital-wide surveillance Surveillance system
We introduced a real-time surgical site infections surveillance mode (SSISM) to monitor hospital-wide surgical site infections (SSIs) based on the ICD-9-CM Volume 3 operational codes and the ICD-10 disease codes. Compared with the gold standard, the SSISM confirmed 71.9% (82/114) of SSIs from 3,048 operations with a 60-fold time-savings. The SSISM could obtain the SSI rates for each type of surgery or disease among hospital-wide inpatients in a tertiary hospital with 3,800 beds. © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).
BACKGROUND
METHODS
Computer systems for surgical site infection (SSI) surveillance have been used by infection control practitioners (ICPs) to effectively monitor SSIs, such as the use of Medicare diagnostic tests to detect arthroplasty SSIs or applying laboratory data to monitor orthopedic and traumatology SSIs.1,2 Our goal is to expand SSI surveillance to monitor hospitalwide surgeries. In a prior study, 3 we reported the successful development of a real-time nosocomial infection screening system for efficient screening of all nosocomial infections, including SSIs during current admission. We therefore developed a new surgical site infections surveillance mode (SSISM) in which readmission and postdischarge SSIs were added. In addition, we used the ICD-9CM Volume 3 and the ICD-10 to classify surgery and disease type, respectively.
This study was carried out in a tertiary hospital in Beijing, China, with 3,800 beds (approximately 270 surgical operations each day). All 3,048 inpatients in this study consented to take part. To upgrade the real-time nosocomial infection screening system, we combined outpatient records and readmission information to identify patients at high risk of SSI during postdischarge or readmission. Another upgrade was the inclusion of the ICD-9-CM Volume 3 surgical codes and the ICD10 disease codes. The SSI results are referred to as SSISM.
* Address correspondence to Yunxi Liu, Department of Infection Management and Disease Control, Chinese PLA General Hospital, 28 Fuxing Rd, Haidian District, Beijing, China 100853. E-mail address: [email protected] (Y. Liu). Funding/support: Supported by the China Special Grant for the Prevention and Control of Infectious Diseases (grant nos. 2013ZX10004805-003 and 2013ZX10004217-002). Conflicts of interest: None to report. 1Equal contributors.
SSIs computer algorithms For inpatients, SSI screening strategies, including common strategies for all surgeries and additional strategies for certain surgeries, were shown in a prior study.3 The screening strategies took into consideration temperature, positive microbiologic examinations, and new antibiotic administration after surgery. Readmission surveillance for SSIs was performed in discharged patients readmitted within 30 days (without prosthetic material) or 1 year (with prosthetic material) after surgery to the same surgical department. In these cases, the criteria of fever, positive microbiologic examination, or antibiotic administration within 48 hours after readmission were applied to exclude expectant readmission. For postdischarge patients, the SSI screening criteria included antibiotic administration or the diagnostic protocol of flare, fever,
0196-6553/© 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. This is an open access article under the CC BY-NCND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). http://dx.doi.org/10.1016/j.ajic.2016.12.002
M. Du et al. / American Journal of Infection Control 45 (2017) 430-2
431
types of operations. SSIs in the manual survey were identified by ICPs, based on their twice-weekly observation of inpatients until their discharge. Postdischarge surveillance was carried out by the ICPs in telephone interviews. The total amount of time spent by ICPs on the manual survey was approximately 600 hours. The 12 minutes per operation consisted of two 4-minute observations of inpatients, 2 minutes for input of surgical data, and 2 minutes for telephone interview. RESULTS Daily SSIs alert and confirmation Among the 10-15 daily SSI alerts, there were 2-4 confirmed SSIs. One ICP would spend approximately 0.5 h/d dealing with these alerts. After the ICP linked the SSI to the exact operation, all the information about this SSI would be entered into the relevant statistical analysis. SSISM versus manual survey results The SSISM issued 212 SSI alerts among the 3,048 operations, 82 of which were subsequently confirmed SSIs. Approximately 10 hours were needed for 1 ICP to deal with the 212 alerts using the SSISM (3 minutes per alert). This translated into a 60-fold time-savings compared with the manual survey (600 hours). The SSISM confirmed 71.9% (82/114) of all 114 SSIs, with a range of 44.4%-100.0% for 12 types of surgery. Table 1 provides a comparison of the SSIs identified by the SSISM and by the manual survey. The SSIs were classified into 3 types according to the time of their occurrence. Of the 82 out of 114 SSIs identified by SSISM versus manually, 62 of 66 (94.0%) were detected during current admission, 14 of 15 (93.3%) were detected during readmission, and 6 of 33 (18.2%) were detected during postdischarge. Also, the SSIs were classified according to their anatomic location: 8 of 23 (34.8%) were superficial incisional SSIs, 15 of 26 (57.7%) were deep incisional SSIs, and 59 of 65 (90.8%) were organ-space SSIs. Among the 32 SSIs recognized by the manual survey but not by the SSISM, there were 15 superficial incisional SSIs, 11 deep incisional SSIs, and 6 organspace SSIs. DISCUSSION Fig 1. Flowchart of SSI alerts and confirmation. Bold text indicates upgrades to the surgical site infections surveillance mode. AOS, anesthesia operation system; HIS, hospital information system; ICP, infection control practitioner; LIS, laboratory information system; PACS, picture achieving and communication system; RT-NISS, realtime nosocomial infection screening system; SSI, surgical site infection. *The SSI warning alerts can be transmitted to the ICP and the attending surgeons simultaneously. All SSI confirmations or exclusions, as assessed by the surgeon, are transmitted to the ICP.
or pain during changing of a dressing in an outpatient within 30 days or 1 year after corresponding surgery. SSIs daily alerts and confirmation Each day at 2 AM, the SSISM provided about 10-15 SSI alerts, including 6-10 alerts during current admission, 0-3 alerts during readmission, and 0-2 alerts during postdischarge. A flowchart of SSI alerts and their confirmation is shown in Figure 1. Comparison between SSISM and manual survey A manual survey used as the gold standard was compared with the SSISM findings concerning the 3,048 patients undergoing 12
Compared with the manual survey, good results were achieved with the SSISM, except for postdischarge surveillance. The sensitivity during current admission or readmission was >90% (94.0% and 93.3%, respectively). Other studies reported a sensitivity of 97.8% or >90% for the surveillance of 1 type surgery.4,5 The SSISM resulted in a 60-fold time-savings compared with the manual survey. The efficiency of the SSISM thus allowed the ICP to monitor hospitalwide surgeries. Another advantage of the SSISM was the SSI rates based on ICD9-CM Volume 3 and ICD-10 codes, thus informing ICPs about the types of operations or diseases with the highest risk of SSI. Our results showed the distinct SSI rates of different diseases with the same ICD-9-CM Volume 3 code, such as for operational code 01.5, in which the rates associated with neurogliocytoma (ICD-10: C71) and meningioma (ICD-10: D32) were 12.6% and 2.8%, respectively. The drawback of common postdischarge surveillance based on patient questionnaires, or telephone patient interviews, is that it is time consuming.6 As Petherick et al reported,7 only 4.1% (n = 6/ 146) of hospitals performed postdischarge surveillance for all surgeries. Problems with postdischarge surveillance were also encountered in this study, in which the sensitivity was 18.2% (6/33). This was probably because postdischarge patients typically choose
432
M. Du et al. / American Journal of Infection Control 45 (2017) 430-2
Table 1 SSI rate as determined using SSISM versus gold standard (manual survey) for 12 types of surgery
Procedure
ICD-9-CM Volume 3
ICD-10
Total performed (n)
Anterior cruciate ligament prosthesis Ventriculoperitoneal shunt Neuro gliocytoma resection* Meningeal resection* Knee joint replacement Radical surgery for lung cancer Coronary bypass operation Radical surgery for esophageal carcinoma Radical surgery for colon carcinoma Radical surgery for rectal carcinoma Radical surgery for breast cancer Radical surgery for thyroid cancer Total
81.4 02.2, 02.3 01.5 01.5 81.5 32.2, 32.3, 32.4, 32.5 36.1 42.4, 42.5 45.5, 45.7, 45.8 48.3, 48.5, 48.6 85.2, 85.3, 85.4 06.2, 06.3, 06.4 —
M23, S83 G91 C71 D32 M06, M17 C34 I20, I21 C15, C16 C18 C20 C50 C73 —
98 49 238 212 263 323 157 214 246 266 266 716 3,048
Gold standard
SSISM surveillance
SSI confirmed (n)
SSI rate (%)
Alerts (n)
SSI confirmed (n)
SSI rate (%)
SSISM/gold standard (%)
2 4 32 7 4 4 6 11 9 20 6 9 114
2.0 8.2 13.5 3.3 1.5 1.2 3.8 5.1 3.7 7.5 2.3 1.3 3.7
3 7 57 15 13 15 14 22 16 34 9 7 212
2 4 30 6 3 3 4 7 5 11 3 4 82
2.0 8.2 12.6 2.8 1.1 0.9 2.6 3.3 2.0 4.1 1.1 0.6 2.7
100.0 100.0 93.8 85.7 75.0 75.0 66.7 63.6 55.6† 55.0† 50.0‡ 44.4‡ 71.9
SSI, surgical site infection; SSISM, surgical site infections surveillance mode. *Same ICD-9-CM Volume 3 code but different ICD-10 code. †In 2 types of colorectal surgery, mild incisional SSIs occurred postdischarge and were dealt with at a community clinic rather than by a readmission to the hospital. Thus, most of these patients were lost to SSISM documentation because the information could not be obtained from the clinic. ‡ Patients undergoing these operations are normally discharged 2-3 days postoperatively; thus, most SSIs developed postdischarge. Most of these SSIs were mild incisional SSIs that did not require readmission.
a community clinic or other hospital to deal with their SSIs; therefore, SSISM-based surveillance could not collect these patients’ information. The problem of post-discharge surveillance will be overcome when the Chinese national medical information system covering all hospitals and clinics is setup. To date, >500 hospitals in China have already adopted our system, and it usually costs approximately ¥200,000 within 1-2 months of implementing.
2.
3.
4.
Acknowledgments
5.
We thank Professor Na Jia, who has read the manuscript carefully and given valuable advice.
6.
References 7. 1. Calderwood MS, Ma A, Khan YM, Olsen MA, Bratzler DW, Yokoe DS, et al. Use of medicare diagnosis and procedure codes to improve detection of surgical site
infections following hip arthroplasty, knee arthroplasty, and vascular surgery. Infect Control Hosp Epidemiol 2012;33:40-9. Mabit C, Marcheix PS, Mounier M, Dijoux P, Pestourie N, Bonnevialle P, et al. Impact of a surgical site infection (SSI) surveillance program in orthopedics and traumatology. Orthop Traumatol Surg Res 2012;98:690-5. Du M, Xing Y, Suo J, Liu B, Jia N, Huo R, et al. Real-time automatic hospital-wide surveillance of nosocomial infections and outbreaks in a large Chinese tertiary hospital. BMC Med Inform Decis Mak 2014;14:9. Inacio MC, Paxton EW, Chen Y, Harris J, Eck E, Barnes S, et al. Leveraging electronic medical records for surveillance of surgical site infection in a total joint replacement population. Infect Control Hosp Epidemiol 2011;32:351-9. Calderwood MS, Kleinman K, Murphy MV, Platt R, Huang SS. Improving public reporting and data validation for complex surgical site infections after coronary artery bypass graft surgery and hip arthroplasty. Open Forum Infect Dis 2014;1:ofu106. Gaynes RP, Culver DH, Horan TC, Edwards JR, Richards C, Tolson JS. Surgical site infection (SSI) rates in the United States, 1992-1998: the national nosocomial infections surveillance system basic SSI risk index. Clin Infect Dis 2001; 33(Suppl):S69-77. Petherick ES, Dalton JE, Moore PJ, Cullum N. Methods for identifying surgical wound infection after discharge from hospital: a systematic review. BMC Infect Dis 2006;6:170.
Contents lists available at ScienceDirect
American Journal of Infection Control
American Journal of Infection Control
j o u r n a l h o m e p a g e : w w w. a j i c j o u r n a l . o r g
Brief Report
A real-time surgical site infections surveillance mode to monitor surgery classification−specific, hospital-wide surgical site infections in a Chinese tertiary hospital Mingmei Du MD a,1, Meng Li MD b,1, Kexin Liu MB c,1, Jijiang Suo MB a, Yubin Xing MB a, Bowei Liu MB a, Rui Huo MC d, Chunping Chen MC d, Yunxi Liu PhD a,* a
Department of Infection Management and Disease Control, Chinese PLA General Hospital, Beijing, China Department of Hematology, Chinese PLA General Hospital, Beijing, China Department of Medical Record Management, Chinese PLA General Hospital, Beijing, China d Xinglin Information Technology Company, Hangzhou, Zhejiang Province, China b c
Key Words: Surgical site infections Hospital-wide surveillance Surveillance system
We introduced a real-time surgical site infections surveillance mode (SSISM) to monitor hospital-wide surgical site infections (SSIs) based on the ICD-9-CM Volume 3 operational codes and the ICD-10 disease codes. Compared with the gold standard, the SSISM confirmed 71.9% (82/114) of SSIs from 3,048 operations with a 60-fold time-savings. The SSISM could obtain the SSI rates for each type of surgery or disease among hospital-wide inpatients in a tertiary hospital with 3,800 beds. © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).
BACKGROUND
METHODS
Computer systems for surgical site infection (SSI) surveillance have been used by infection control practitioners (ICPs) to effectively monitor SSIs, such as the use of Medicare diagnostic tests to detect arthroplasty SSIs or applying laboratory data to monitor orthopedic and traumatology SSIs.1,2 Our goal is to expand SSI surveillance to monitor hospitalwide surgeries. In a prior study, 3 we reported the successful development of a real-time nosocomial infection screening system for efficient screening of all nosocomial infections, including SSIs during current admission. We therefore developed a new surgical site infections surveillance mode (SSISM) in which readmission and postdischarge SSIs were added. In addition, we used the ICD-9CM Volume 3 and the ICD-10 to classify surgery and disease type, respectively.
This study was carried out in a tertiary hospital in Beijing, China, with 3,800 beds (approximately 270 surgical operations each day). All 3,048 inpatients in this study consented to take part. To upgrade the real-time nosocomial infection screening system, we combined outpatient records and readmission information to identify patients at high risk of SSI during postdischarge or readmission. Another upgrade was the inclusion of the ICD-9-CM Volume 3 surgical codes and the ICD10 disease codes. The SSI results are referred to as SSISM.
* Address correspondence to Yunxi Liu, Department of Infection Management and Disease Control, Chinese PLA General Hospital, 28 Fuxing Rd, Haidian District, Beijing, China 100853. E-mail address: [email protected] (Y. Liu). Funding/support: Supported by the China Special Grant for the Prevention and Control of Infectious Diseases (grant nos. 2013ZX10004805-003 and 2013ZX10004217-002). Conflicts of interest: None to report. 1Equal contributors.
SSIs computer algorithms For inpatients, SSI screening strategies, including common strategies for all surgeries and additional strategies for certain surgeries, were shown in a prior study.3 The screening strategies took into consideration temperature, positive microbiologic examinations, and new antibiotic administration after surgery. Readmission surveillance for SSIs was performed in discharged patients readmitted within 30 days (without prosthetic material) or 1 year (with prosthetic material) after surgery to the same surgical department. In these cases, the criteria of fever, positive microbiologic examination, or antibiotic administration within 48 hours after readmission were applied to exclude expectant readmission. For postdischarge patients, the SSI screening criteria included antibiotic administration or the diagnostic protocol of flare, fever,
0196-6553/© 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. This is an open access article under the CC BY-NCND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). http://dx.doi.org/10.1016/j.ajic.2016.12.002
M. Du et al. / American Journal of Infection Control 45 (2017) 430-2
431
types of operations. SSIs in the manual survey were identified by ICPs, based on their twice-weekly observation of inpatients until their discharge. Postdischarge surveillance was carried out by the ICPs in telephone interviews. The total amount of time spent by ICPs on the manual survey was approximately 600 hours. The 12 minutes per operation consisted of two 4-minute observations of inpatients, 2 minutes for input of surgical data, and 2 minutes for telephone interview. RESULTS Daily SSIs alert and confirmation Among the 10-15 daily SSI alerts, there were 2-4 confirmed SSIs. One ICP would spend approximately 0.5 h/d dealing with these alerts. After the ICP linked the SSI to the exact operation, all the information about this SSI would be entered into the relevant statistical analysis. SSISM versus manual survey results The SSISM issued 212 SSI alerts among the 3,048 operations, 82 of which were subsequently confirmed SSIs. Approximately 10 hours were needed for 1 ICP to deal with the 212 alerts using the SSISM (3 minutes per alert). This translated into a 60-fold time-savings compared with the manual survey (600 hours). The SSISM confirmed 71.9% (82/114) of all 114 SSIs, with a range of 44.4%-100.0% for 12 types of surgery. Table 1 provides a comparison of the SSIs identified by the SSISM and by the manual survey. The SSIs were classified into 3 types according to the time of their occurrence. Of the 82 out of 114 SSIs identified by SSISM versus manually, 62 of 66 (94.0%) were detected during current admission, 14 of 15 (93.3%) were detected during readmission, and 6 of 33 (18.2%) were detected during postdischarge. Also, the SSIs were classified according to their anatomic location: 8 of 23 (34.8%) were superficial incisional SSIs, 15 of 26 (57.7%) were deep incisional SSIs, and 59 of 65 (90.8%) were organ-space SSIs. Among the 32 SSIs recognized by the manual survey but not by the SSISM, there were 15 superficial incisional SSIs, 11 deep incisional SSIs, and 6 organspace SSIs. DISCUSSION Fig 1. Flowchart of SSI alerts and confirmation. Bold text indicates upgrades to the surgical site infections surveillance mode. AOS, anesthesia operation system; HIS, hospital information system; ICP, infection control practitioner; LIS, laboratory information system; PACS, picture achieving and communication system; RT-NISS, realtime nosocomial infection screening system; SSI, surgical site infection. *The SSI warning alerts can be transmitted to the ICP and the attending surgeons simultaneously. All SSI confirmations or exclusions, as assessed by the surgeon, are transmitted to the ICP.
or pain during changing of a dressing in an outpatient within 30 days or 1 year after corresponding surgery. SSIs daily alerts and confirmation Each day at 2 AM, the SSISM provided about 10-15 SSI alerts, including 6-10 alerts during current admission, 0-3 alerts during readmission, and 0-2 alerts during postdischarge. A flowchart of SSI alerts and their confirmation is shown in Figure 1. Comparison between SSISM and manual survey A manual survey used as the gold standard was compared with the SSISM findings concerning the 3,048 patients undergoing 12
Compared with the manual survey, good results were achieved with the SSISM, except for postdischarge surveillance. The sensitivity during current admission or readmission was >90% (94.0% and 93.3%, respectively). Other studies reported a sensitivity of 97.8% or >90% for the surveillance of 1 type surgery.4,5 The SSISM resulted in a 60-fold time-savings compared with the manual survey. The efficiency of the SSISM thus allowed the ICP to monitor hospitalwide surgeries. Another advantage of the SSISM was the SSI rates based on ICD9-CM Volume 3 and ICD-10 codes, thus informing ICPs about the types of operations or diseases with the highest risk of SSI. Our results showed the distinct SSI rates of different diseases with the same ICD-9-CM Volume 3 code, such as for operational code 01.5, in which the rates associated with neurogliocytoma (ICD-10: C71) and meningioma (ICD-10: D32) were 12.6% and 2.8%, respectively. The drawback of common postdischarge surveillance based on patient questionnaires, or telephone patient interviews, is that it is time consuming.6 As Petherick et al reported,7 only 4.1% (n = 6/ 146) of hospitals performed postdischarge surveillance for all surgeries. Problems with postdischarge surveillance were also encountered in this study, in which the sensitivity was 18.2% (6/33). This was probably because postdischarge patients typically choose
432
M. Du et al. / American Journal of Infection Control 45 (2017) 430-2
Table 1 SSI rate as determined using SSISM versus gold standard (manual survey) for 12 types of surgery
Procedure
ICD-9-CM Volume 3
ICD-10
Total performed (n)
Anterior cruciate ligament prosthesis Ventriculoperitoneal shunt Neuro gliocytoma resection* Meningeal resection* Knee joint replacement Radical surgery for lung cancer Coronary bypass operation Radical surgery for esophageal carcinoma Radical surgery for colon carcinoma Radical surgery for rectal carcinoma Radical surgery for breast cancer Radical surgery for thyroid cancer Total
81.4 02.2, 02.3 01.5 01.5 81.5 32.2, 32.3, 32.4, 32.5 36.1 42.4, 42.5 45.5, 45.7, 45.8 48.3, 48.5, 48.6 85.2, 85.3, 85.4 06.2, 06.3, 06.4 —
M23, S83 G91 C71 D32 M06, M17 C34 I20, I21 C15, C16 C18 C20 C50 C73 —
98 49 238 212 263 323 157 214 246 266 266 716 3,048
Gold standard
SSISM surveillance
SSI confirmed (n)
SSI rate (%)
Alerts (n)
SSI confirmed (n)
SSI rate (%)
SSISM/gold standard (%)
2 4 32 7 4 4 6 11 9 20 6 9 114
2.0 8.2 13.5 3.3 1.5 1.2 3.8 5.1 3.7 7.5 2.3 1.3 3.7
3 7 57 15 13 15 14 22 16 34 9 7 212
2 4 30 6 3 3 4 7 5 11 3 4 82
2.0 8.2 12.6 2.8 1.1 0.9 2.6 3.3 2.0 4.1 1.1 0.6 2.7
100.0 100.0 93.8 85.7 75.0 75.0 66.7 63.6 55.6† 55.0† 50.0‡ 44.4‡ 71.9
SSI, surgical site infection; SSISM, surgical site infections surveillance mode. *Same ICD-9-CM Volume 3 code but different ICD-10 code. †In 2 types of colorectal surgery, mild incisional SSIs occurred postdischarge and were dealt with at a community clinic rather than by a readmission to the hospital. Thus, most of these patients were lost to SSISM documentation because the information could not be obtained from the clinic. ‡ Patients undergoing these operations are normally discharged 2-3 days postoperatively; thus, most SSIs developed postdischarge. Most of these SSIs were mild incisional SSIs that did not require readmission.
a community clinic or other hospital to deal with their SSIs; therefore, SSISM-based surveillance could not collect these patients’ information. The problem of post-discharge surveillance will be overcome when the Chinese national medical information system covering all hospitals and clinics is setup. To date, >500 hospitals in China have already adopted our system, and it usually costs approximately ¥200,000 within 1-2 months of implementing.
2.
3.
4.
Acknowledgments
5.
We thank Professor Na Jia, who has read the manuscript carefully and given valuable advice.
6.
References 7. 1. Calderwood MS, Ma A, Khan YM, Olsen MA, Bratzler DW, Yokoe DS, et al. Use of medicare diagnosis and procedure codes to improve detection of surgical site
infections following hip arthroplasty, knee arthroplasty, and vascular surgery. Infect Control Hosp Epidemiol 2012;33:40-9. Mabit C, Marcheix PS, Mounier M, Dijoux P, Pestourie N, Bonnevialle P, et al. Impact of a surgical site infection (SSI) surveillance program in orthopedics and traumatology. Orthop Traumatol Surg Res 2012;98:690-5. Du M, Xing Y, Suo J, Liu B, Jia N, Huo R, et al. Real-time automatic hospital-wide surveillance of nosocomial infections and outbreaks in a large Chinese tertiary hospital. BMC Med Inform Decis Mak 2014;14:9. Inacio MC, Paxton EW, Chen Y, Harris J, Eck E, Barnes S, et al. Leveraging electronic medical records for surveillance of surgical site infection in a total joint replacement population. Infect Control Hosp Epidemiol 2011;32:351-9. Calderwood MS, Kleinman K, Murphy MV, Platt R, Huang SS. Improving public reporting and data validation for complex surgical site infections after coronary artery bypass graft surgery and hip arthroplasty. Open Forum Infect Dis 2014;1:ofu106. Gaynes RP, Culver DH, Horan TC, Edwards JR, Richards C, Tolson JS. Surgical site infection (SSI) rates in the United States, 1992-1998: the national nosocomial infections surveillance system basic SSI risk index. Clin Infect Dis 2001; 33(Suppl):S69-77. Petherick ES, Dalton JE, Moore PJ, Cullum N. Methods for identifying surgical wound infection after discharge from hospital: a systematic review. BMC Infect Dis 2006;6:170.