National Nosocomial Infections Surveillance (NNIS) System Report, data summary from January 1992 through June 2004, issued October 2004

This report is a summary of the data collected and reported by hospitals participating in the National Nosocomial Infections Surveillance (NNIS) System from January 1992 through June 2004 and updates previously published data.1.CDC NNIS System National Nosocomial Infections Surveillance (NNIS) system report, data summary from January 1992 to June 2003, issued August 2003.Am J Infect Control. 2003; 31: 481-498Abstract Full Text Full Text PDF PubMed Scopus (609) Google Scholar, 2.Jarvis W.R. Edwards J.R. Culver D.H. Hughes J.M. Horan T. Emori T.G. et al.Nosocomial infection rates in adult and pediatric intensive care units in the United States.Am J Med. 1991; 91: 185S-191SAbstract Full Text PDF PubMed Scopus (446) Google Scholar, 3.Gaynes R.P. Martone W.J. Culver D.H. Emori T.G. Horan T.C. Banerjee S.N. et al.Comparison rates of nosocomial infections in neonatal intensive care units in the United States.Am J Med. 1991; 91: 192S-196SAbstract Full Text PDF PubMed Scopus (118) Google Scholar, 4.Culver D.H. Horan T.C. Gaynes R.P. Martone W.J. Jarvis W.R. Emori T.G. et al.Surgical wound infection rates by wound class, operative procedure, and patient risk index.Am J Med. 1991; 91: 152S-157SAbstract Full Text PDF PubMed Scopus (1249) Google Scholar The NNIS System was established in 1970 when selected hospitals in the United States routinely began reporting their nosocomial infection surveillance data for aggregation into a national database. Hospitals participating in the NNIS System provide general medical-surgical inpatient services to adults or children requiring acute care. Identity of the nearly 300 hospitals currently participating in the NNIS System is confidential. All NNIS data are collected using standardized protocols, called "surveillance components": adult and pediatric intensive care unit (ICU), high-risk nursery (HRN), and surgical patient.5.Emori T.G. Culver D.H. Horan T.C. Jarvis W.R. White J.W. Olson D.R. et al.National nosocomial infections surveillance (NNIS) system: description of surveillance methodology.Am J Infect Control. 1991; 19: 19-35Abstract Full Text PDF PubMed Scopus (691) Google Scholar, 6.Horan T.C. Gaynes R.P. Surveillance of nosocomial infections.in: Mayhall C.G. Hospital Epidemiology and Infection Control. 3rd ed. Lippincott Williams & Wilkins, Philadelphia2004: 1659-1702Google Scholar, 7.Horan T.C. Emori T.G. Definitions of key terms used in the NNIS system.Am J Infect Control. 1997; 25: 112-116Abstract Full Text PDF PubMed Scopus (192) Google Scholar The components may be used singly or simultaneously, but once selected, they must be used for a minimum of 1 calendar month. All infections are categorized into major and specific infection sites using standard CDC definitions that include laboratory and clinical criteria.6.Horan T.C. Gaynes R.P. Surveillance of nosocomial infections.in: Mayhall C.G. Hospital Epidemiology and Infection Control. 3rd ed. Lippincott Williams & Wilkins, Philadelphia2004: 1659-1702Google Scholar Infection control professionals (ICPs) collect data on all sites of nosocomial infection in patients located in ICUs, as well as ICU-specific denominator data. Site-specific infection rates can be calculated by using as a denominator the number of patients at risk, patient-days, and days of indwelling urinary catheterization, central vascular cannulation (central line), or ventilation. ICPs collect data on all sites of nosocomial infection in patients located in HRN, and HRN-specific denominator data. Site-specific infection rates can be calculated by using as a denominator the number of patients at risk, patient-days, and days of umbilical catheter/central line use or ventilation for each of 4 birth-weight categories (≤1000 gm, 1001–1500 gm, 1501–2500 gm, and ≥2500 gm). ICPs select from the NNIS operative procedure list those procedures they wish to follow up and monitor the patients undergoing those procedures for all infections or surgical site infections (SSI) only. A record on every patient undergoing the selected procedure is generated that includes information on risk factors for SSI such as wound class,8.Mangram A.J. Horan T.C. Pearson M.L. Silver L.C. Jarvis W.R. Guideline for prevention of surgical site infection, 1999.Am J Infect Control. 1999; 27: 97-134Abstract Full Text Full Text PDF PubMed Google Scholar duration of operation, and American Society of Anesthesiology (ASA) score.9.Owens W.D. Felts J.A. Spitznagel Jr., E.L. ASA physical status classification: a study of consistency of ratings.Anesthesiology. 1978; 49: 239-243Crossref PubMed Scopus (1588) Google Scholar Using a composite index for predicting the risk of SSI after operation, ICPs can calculate rates by the number of risk factors present.4.Culver D.H. Horan T.C. Gaynes R.P. Martone W.J. Jarvis W.R. Emori T.G. et al.Surgical wound infection rates by wound class, operative procedure, and patient risk index.Am J Med. 1991; 91: 152S-157SAbstract Full Text PDF PubMed Scopus (1249) Google Scholar The time periods for the data contained in this report vary depending on the table. Each table represents NNIS data from one of the surveillance components. For the ICU and HRN surveillance components where data volume was large after risk stratification, we were able to construct tables comprised of data from fewer and more recent years only (January 2002 through June 2004; Table 1, Table 2, Table 3, Table 4). However for the surgical patient component, we had to use all the data from January 1992 through June 2004, because the numbers of operations in each procedure-risk-stratum was too small to produce stable rates when only more recent years' data were used (Table 5, Table 6, Table 7, Table 8). Similarly, Table 9, Table 10 required use of data reported since January 1998 through June 2004.Table 1Pooled means and percentiles of the distribution of device-associated infection rates, by type of ICU, ICU component, January 2002 through June 2004Urinary catheter-associated UTI rate∗Number of urinary catheter-associated UTIsNumber of urinary catheter-days×1000PercentileType of ICUNo. of unitsUrinary catheter-daysPooled mean10%25%50% (median)75%90%Coronary60170,7594.50.82.64.07.510.2Cardiothoracic48193,4243.00.01.12.43.96.2Medical94448,1615.10.72.54.77.19.5Medical-surgical Major teaching99593,1003.91.32.13.35.27.5 All others108757,5313.30.61.63.15.16.9Neurosurgical2999,0396.71.83.16.07.89.5Pediatric52104,7884.00.01.63.66.18.1Surgical99486,5754.41.42.33.86.58.8Trauma22104,1816.02.13.85.77.39.3Burn1444,3426.7—————Respiratory617,7846.4—————Central line-associated BSI rate†Number of central line-associated BSIsNumber of central line-days×1000PercentileType of ICUNo. of unitsCentral line-daysPooled mean10%25%50% (median)75%90%Coronary60116,5463.51.01.53.27.09.0Cardiothoracic48182,4072.70.00.91.82.74.9Medical94312,4785.00.52.43.96.48.8Medical-surgical Major teaching100430,9794.01.72.63.45.17.6 All others109486,1153.20.81.63.14.36.1Neurosurgical3056,6454.60.00.93.15.810.6Pediatric54161,3146.60.93.05.28.111.2Surgical99358,5784.60.02.03.45.98.7Trauma2270,3727.41.93.35.28.211.9Burn1443,0027.0—————Respiratory612,5934.8—————Ventilator-associated pneumonia rate‡Number of ventilator-associated pneumoniasNumber of ventilator-days×1000PercentileType of ICUNo. of unitsVentilator-daysPooled mean10%25%50% (median)75%90%Coronary5976,1454.40.01.94.06.89.8Cardiothoracic4798,3587.21.22.96.312.615.5Medical92268,5184.90.52.13.76.28.9Medical-surgical Major teaching99320,9165.41.22.64.67.29.9 All others109351,7055.11.72.95.16.78.9Neurosurgical2945,07311.20.02.46.213.516.8Pediatric52133,9952.90.00.92.34.88.1Surgical98253,9009.32.24.78.312.217.9Trauma2263,13715.24.38.011.416.625.3Burn1423,11712.0—————Respiratory618,8384.9—————UTI, Urinary tract infection; BSI, bloodstream infection.∗ Number of urinary catheter-associated UTIsNumber of urinary catheter-days×1000† Number of central line-associated BSIsNumber of central line-days×1000‡ Number of ventilator-associated pneumoniasNumber of ventilator-days×1000 Open table in a new tab Table 2Pooled means and percentiles of the distribution of device utilization ratios, by type of ICU, ICU component, January 2002 through June 2004Urinary catheter utilization∗Number of urinary catheter-daysNumber of patient-daysPercentileType of ICUNo. of unitsPatient-daysPooled mean10%25%50% (median)75%90%Coronary60305,9110.560.260.460.600.700.78Cardiothoracic48230,4870.840.580.760.880.950.96Medical94596,5880.750.580.650.760.830.88Medical-surgical Major teaching99759,4640.780.650.740.820.870.90 All others108979,5500.770.670.730.780.840.87Neurosurgical29116,9310.850.650.760.820.920.95Pediatric53349,2580.300.110.200.300.410.47Surgical99590,2200.820.650.760.860.920.96Trauma22115,0990.910.770.850.930.960.98Burn1476,8770.58—————Respiratory626,5670.67—————Central line utilization†Number of central line-daysNumber of patient-daysPercentileType of ICUNo. of unitsPatient-daysPooled mean10%25%50% (median)75%90%Coronary60305,9110.380.150.220.360.510.60Cardiothoracic48230,4870.790.550.700.830.870.93Medical95596,5880.520.310.370.520.640.75Medical-surgical Major teaching100759,4640.570.360.470.560.660.74 All others109979,5500.500.290.380.490.580.66Neurosurgical30116,9310.480.230.330.500.550.65Pediatric54349,2580.460.200.310.460.570.64Surgical100590,2200.610.340.520.630.720.81Trauma22115,0990.610.400.490.600.710.79Burn1476,8770.56—————Respiratory626,5670.47—————Ventilator utilization‡Number of ventilator-daysNumber of patient-daysPercentileType of ICUNo. of unitsPatient-daysPooled mean10%25%50% (median)75%90%Coronary60305,9110.250.110.140.230.360.41Cardiothoracic48230,4870.430.250.310.400.480.58Medical94596,5880.460.220.320.460.570.67Medical-surgical Major teaching99759,4640.430.230.320.430.550.62 All others109979,5500.370.220.280.350.420.52Neurosurgical29116,9310.390.190.260.340.450.56Pediatric52349,2580.390.170.250.360.490.57Surgical99590,2200.440.190.310.460.530.65Trauma22115,0990.560.390.440.500.670.77Burn1476,8770.31—————Respiratory626,5670.71—————∗ Number of urinary catheter-daysNumber of patient-days† Number of central line-daysNumber of patient-days‡ Number of ventilator-daysNumber of patient-days Open table in a new tab Table 3Pooled means and percentiles of the distribution of device-associated infection rates, by birth-weight category, HRN component, January 2002 through June 2004Umbilical and central line-associated BSI rate∗Number of umbilical and central line-associated BSIsNumber of umbilical and central line-days×1000PercentileBirth-weight categoryNo. of HRNsCentral line-daysPooled mean10%25%50% (median)75%90%≤1000 g104204,4689.11.65.48.511.616.11001–1500 g9895,2545.40.01.84.07.412.21501–2500 g9779,9044.10.00.03.26.58.9>2500 g9497,2023.50.00.01.94.17.4Ventilator-associated pneumonia rate†Number of ventilator-associated pneumoniaNumber of ventilator-days×1000PercentileBirth-weight categoryNo. of HRNsVentilator-daysPooled mean10%25%50% (median)75%90%≤1000 g102204,1173.50.00.02.45.88.51001–1500 g9150,2042.40.00.00.03.28.01501–2500 g8639,9571.90.00.00.01.56.1>2500 g9055,0381.40.00.00.00.93.2BSI, Bloodstream infection.∗ Number of umbilical and central line-associated BSIsNumber of umbilical and central line-days×1000† Number of ventilator-associated pneumoniaNumber of ventilator-days×1000 Open table in a new tab Table 4Pooled means and percentiles of the distribution of device utilization ratios, by birth-weight category, HRN component, January 2002 through June 2004Umbilical and central line utilization ratio∗Number of umbilical and central line-daysNumber of patient-daysPercentileBirth-weight categoryNo. of HRNsPatient-daysPooled mean10%25%50% (median)75%90%≤1000 g105489,1950.420.210.310.430.550.701001–1500 g104319,3160.300.080.160.290.460.581501–2500 g103388,6300.210.050.090.170.310.54>2500 g103335,4300.290.060.120.200.410.54Ventilator utilization ratio†Number of ventilator-daysNumber of patient-daysPercentileBirth-weight categoryNo. of HRNsPatient-daysPooled mean10%25%50% (median)75%90%≤1000 g105489,1950.430.220.320.430.530.631001–1500 g104319,3160.160.050.090.150.200.351501–2500 g103388,6300.100.030.050.070.160.27>2500 g103335,4300.170.040.060.110.210.33∗ Number of umbilical and central line-daysNumber of patient-days† Number of ventilator-daysNumber of patient-days Open table in a new tab Table 5SSI rates∗Per 100 operations., by operative procedure and risk index category, Surgical Patient component, January 1992 through June 2004Operative procedure categoryDuration cut point (h)Risk index categoryNRateRisk index categoryNRateRisk index categoryNRateRisk index categoryNRateCARDCardiac5021470.70149,1351.502,315,2152.21——CBGBCABG-chest and donor site5027181.251380,3403.39282,5355.4332469.76CBGCCABG-chest only401600.00115,2482.192,36,4993.72——OCVSOther cardiovascular20,111,2330.60238281.2831533.92——ORESOther respiratory20,1,2,317282.43——————THORThoracic3014230.42152500.992,31,9842.47——APPYSee Table 7BILILiver/pancreas504823.111,2,317367.37————CHOLSee Table 7COLOSee Table 7GASTSee Table 7OGITOther digestive2014181.90125593.012,31,1085.69——SBSmall bowel3017494.97142187.1122,1448.63336211.60XLAPLaparotomy2064141.71180823.0824,5424.7139877.19NEPHNephrectomy40,1,2,337471.04——————OGUOther genitourinary2013,8310.36178960.852,31,9532.92——PRSTProstatectomy4027320.811,2,323892.05————HNHead and neck706602.2719625.302,340812.50——OENTOther ENT3029090.07113890.722,33072.61——HERHerniorrhaphy2012,6590.81183972.142,32,0334.53——MASTMastectomy3016,2871.74110,7002.202,31,1123.42——CRANCraniotomy4047170.91114,8641.722,34,6662.40——ONSOther nervous system40,1,2,323561.53——————VSHNVentricular shunt2042084.421,2,312,3245.36————CSECCesarean section10154,1412.71146,0814.142,34,8717.53——HYSTAbdominal hysterectomy2049,0241.36124,0642.322,35,0535.17——OOBOther obstetric10,1,2,313630.51——————VHYSVaginal hysterectomy20,1,2,329,8571.31——————AMPLimb amputation20,1,2,310,7323.50——————FUSNSpinal fusion4051,0571.04130,6192.642,38,1226.35——FXOpen reduction of fracture2016,1420.79126,3721.4125,0812.8135234.97HPROHip prosthesis2044,4540.86171,3361.652,318,9412.52——KPROKnee prosthesis2066,3600.88174,0291.282,318,0512.26——LAMLaminectomy2073,8460.88155,5171.352,318,1062.46——OMSOther musculoskeletal3018,8050.63113,5270.942,33,9271.78——OPROOther prosthesis30,1,2,338820.62——————OBLOther hem/lymph system30,1,2,310501.90——————OESOther endocrine system3026070.151,2,320430.78————OEYEOther eye30,1,2,35930.67——————OSKNOther integumentary system20,1,2,395891.29——————SKGRSkin graft3012880.93121551.722,31,5264.19——SPLESplenectomy30,1,2,316092.80——————TPOrgan transplant60,149644.632182413.7135026.00——VSVascular3079010.90170,7171.722,328,4584.34——CBGB, Coronary artery bypass graft with chest and donor site incisions (eg, femoral or radial artery harvested as donor vessel for bypass graft); CBGC, coronary artery bypass graft with chest incision only (eg, use of internal mammary artery for bypass graft); ENT, ear, nose, and throat.∗ Per 100 operations. Open table in a new tab Table 6Percentiles of the distribution of SSI rates,∗Per 100 operations. by operative procedure and risk index category,†Includes only those procedure-risk categories for which at least 20 hospitals have reported at least 20 operations. Surgical Patient component, January 1992 through June 2004PercentileOperative procedure categoryRisk index categoryNo. hospitalsPooled mean rate10%25%50% (median)75%90%CARDCardiac11091.5000.471.21.782.91CARDCardiac2,3882.21001.473.034.67CBGBCABG-chest and donor site0331.25000.492.143.38CBGBCABG-chest and donor site11843.391.562.173.174.366.02CBGBCABG-chest and donor site21745.432.283.645.167.649.86CBGCCABG-chest only11072.19001.513.434.36CBGCCABG-chest only2,3693.7200.992.444.477.02OCVSOther cardiovascular0,1360.600000.671.83OCVSOther cardiovascular2231.280001.12.33THORThoracic0210.4200002.34THORThoracic1370.990001.32.73THORThoracic2,3222.47001.643.546.04APPYAppendectomyM220.670000.741.38APPYAppendectomy0471.31001.132.053.24APPYAppendectomy1582.5501.282.223.295.78APPYAppendectomy2,3394.8501.633.975.9710.15CHOLCholecystectomyM880.450000.531.17CHOLCholecystectomy0920.68000.41.122.38CHOLCholecystectomy1761.78001.323.115.12CHOLCholecystectomy2463.2700.563.234.656.6COLOColonM0993.9801.933.2256.42COLOColon11075.661.913.365.16.978.96COLOColon2848.543.925.489.0911.6217.16COLOColon32811.252.116.6713.3316.2221.67GASTGastric0292.58002.584.225.98GASTGastric1534.690.211.894.216.979.41GASTGastric2,3348.340.853.647.2712.5219.41OGITOther digestive1223.01002.133.376.45SBSmall bowel0274.9702.584.776.088.71SBSmall bowel1377.112.454.345.97.6911.12SBSmall bowel2288.634.635.567.521216.78XLAPLaparotomy0391.71001.292.192.87XLAPLaparotomy1453.0801.142.423.936.7XLAPLaparotomy2354.7101.653.826.6710.17NEPHNephrectomy0,1,2,3281.04000.852.334.98OGUOther genitourinary0330.36000.140.521.3OGUOther genitourinary1290.85000.51.892.36PRSTProstatectomy0310.810000.792.1PRSTProstatectomy1,2,3252.05000.933.694.65HERHerniorrhaphy0510.81000.822.83HERHerniorrhaphy1532.1400.811.923.665.96HERHerniorrhaphy2,3274.53003.825.767.41MASTMastectomy0591.74000.691.613.04MASTMastectomy1532.2000.752.073.86.38CRANCraniotomy0420.910001.873.79CRANCraniotomy1701.72001.042.394.05CRANCraniotomy2,3482.40001.33.455.56ONSOther nervous system0,1,2,3201.530001.752.33VSHNVentricular shunt0304.42002.634.838.17VSHNVentricular shunt1,2,3445.3601.493.456.068.61CSECCesarean section01302.710.421.262.174.326.74CSECCesarean section11174.1401.423.195.538.07CSECCesarean section2,3517.5302.425.3810.3913.62HYSTAbdominal hysterectomy01071.36000.912.183.44HYSTAbdominal hysterectomy11002.3200.71.963.334.65HYSTAbdominal hysterectomy2,3535.1702.064.218.319.93VHYSVaginal hysterectomy0,1,2,3711.3100.280.911.983.92AMPLimb amputation0,1,2,3403.5001.272.865.37.41FUSNSpinal fusion01101.04000.681.382.46FUSNSpinal fusion11142.6400.832.163.54.72FUSNSpinal fusion2,3776.3502.344.787.2710.19FXOpen reduction of fracture0680.79000.31.161.89FXOpen reduction of fracture1761.410011.682.47FXOpen reduction of fracture2462.8101.022.74.456.4HPROHip prosthesis01620.86000.51.212.17HPROHip prosthesis11891.6500.361.412.253.33HPROHip prosthesis2,31532.5200.752.063.75.63KPROKnee prosthesis01620.88000.661.282.29KPROKnee prosthesis11791.2800.291.091.862.86KPROKnee prosthesis2,31522.2600.742.043.575.94LAMLaminectomy01330.88000.591.352.59LAMLaminectomy11371.3500.491.351.893.05LAMLaminectomy2,31102.4601.092.113.525.22OMSOther musculoskeletal0440.63000.340.811.36OMSOther musculoskeletal1450.94000.541.392.32OMSOther musculoskeletal2,3231.7800.351.583.514.31OPROOther prosthesis0,1,2,3290.620000.592.2OESOther endocrine system0200.1500000.27OSKNOther integumentary system0,1,2,3291.2900.441.031.732.55SPLESplenectomy0,1,2,3202.80002.224.416.13TPOrgan transplant0,1204.631.1122.995.149.66VSVascular0700.900001.713.28VSVascular11101.7200.811.542.663.81VSVascular2,31034.341.012.984.796.678.38CBGB, Coronary artery bypass graft with chest and donor site incisions (eg, femoral or radial artery harvested as donor vessel for bypass graft); CBGC, coronary artery bypass graft with chest incision only (eg, use of internal mammary artery for bypass graft).∗ Per 100 operations.† Includes only those procedure-risk categories for which at least 20 hospitals have reported at least 20 operations. Open table in a new tab Table 7SSI rates,∗Per 100 operations. by selected operative procedure and modified risk index category incorporating laparoscope use,†This table uses a modified risk index that incorporates the influence of laparoscope on SSI rates. The influence of scope on SSI rates was different across the 4 procedures: For cholecystectomy and colon operation, when the operation was done laparoscopically, 1 was subtracted from the number of risk factors present (ASA score of 3, 4, or 5; duration of surgery >75th percentile; or contaminated or dirty wound class) in the NNIS risk index. For example, when 2 risk factors were present and the procedure was done laparoscopically, the new modified risk index category is 1 (ie, 2 – 1=1). When no risk factors were present and the procedure was performed with a laparoscope (ie, 0 – 1=−1), we designated this new modified risk category as –1 or "M". For appendectomy and gastric operations, the use of a scope was important only if the patient had no other risk factors. We split patients with no other risk factors into two groups: 0-Yes (laparoscope used) and 0-No (laparoscope not used). Surgical Patient component, January 1992 through June 2004Operative procedure categoryDuration cut point (h)Risk index categoryNRateRisk index categoryNRateRisk index categoryNRateRisk index categoryNRateRisk index categoryNRateCHOL Cholecystectomy2M33,7890.45027,5790.68112,8041.78244603.2734755.68COLO Colon3M,020,6373.98133,5275.66213,7778.543187611.25——APPY Appendectomy10–Yes31460.670–No82201.31111,2222.552,342914.85——GAST Gastric30–Yes7320.680–No35222.58172534.692,333458.34——∗ Per 100 operations.† This table uses a modified risk index that incorporates the influence of laparoscope on SSI rates. The influence of scope on SSI rates was different across the 4 procedures: For cholecystectomy and colon operation, when the operation was done laparoscopically, 1 was subtracted from the number of risk factors present (ASA score of 3, 4, or 5; duration of surgery >75th percentile; or contaminated or dirty wound class) in the NNIS risk index. For example, when 2 risk factors were present and the procedure was done laparoscopically, the new modified risk index category is 1 (ie, 2 – 1 = 1). When no risk factors were present and the procedure was performed with a laparoscope (ie, 0 – 1 = −1), we designated this new modified risk category as –1 or "M". For appendectomy and gastric operations, the use of a scope was important only if the patient had no other risk factors. We split patients with no other risk factors into two groups: 0-Yes (laparoscope used) and 0-No (laparoscope not used). Open table in a new tab Table 8SSI rates∗Per 100 operations. following coronary artery bypass graft (CBGB) operation, by risk index category and specific site, Surgical Patient component, January 1992 through June 2004Risk index category0123Infection siteNo. SSIsRateNo. SSIsRateNo. SSIsRateNo. SSIsRateLeg (Donor Site)200.7454361.4320242.4552.03Superficial incisional150.5542031.1015771.9152.03Deep incisional50.1812330.324470.5400.00Chest140.5174401.9624592.98197.72Superficial incisional70.2627960.749331.1352.03Deep incisional40.1520910.556270.7693.66Organ/space30.1125530.678991.0952.03Total341.2512,8763.3944835.43249.76Denominators for the risk categories are as follows: Category 0 = 2718; Category 1 = 380,340; Category 2 = 82,535; Category 3 = 246.∗ Per 100 operations. Open table in a new tab Table 9Pooled means and percentiles of the distribution of antimicrobial usage rates (defined daily dose∗Defined daily dose (DDD) of antimicrobial agent is calculated by dividing the total grams of the antimicrobial agent used in a hospital area by the number of grams in an average daily dose of the agent given to an adult patient. rates†DDD per 1000 patient-days=DDD of specific agent usedTotal number of patient-days×1000), by non-ICU inpatient areas and various types of ICU, ICARE/AUR, January 1998 through June 2004Non-ICU Inpatient Areas (n = 74)PercentileAntimicrobial agentNo. DDD∗Defined daily dose (DDD) of antimicrobial agent is calculated by dividing the total grams of the antimicrobial agent used in a hospital area by the number of grams in an average daily dose of the agent given to an adult patient.Pooled mean10%25%50% (median)75%90%Penicillin group759,86660.99.216.728.963.896.5Ampicillin group1,899,047152.183.2111.1141.7186.3266.9Antipseudomonal penicillins251,03620.13.18.116.429.042.9Antistaphylococcal penicillins245,77719.72.95.112.524.235.8First-generation cephalosporins982,57378.743.957.476.1106.6125.1Second-generation cephalosporins368,97029.610.316.525.341.554.9Third-generation cephalosporins793,34063.521.932.253.679.592.5Carbapenem group85,7796.90.41.84.79.417.1Aztreonam34,0782.70.10.71.84.36.4Fluoroquinolones1,166,83693.537.957.991.7130.3202.2Trimethoprim/sulfamethoxazole595,24847.75.314.824.539.2106.3Vancomycin (oral)38,2793.10.10.51.42.54.2Vancomycin (parenteral)415,88733.313.117.124.641.065.7Coronary Care Unit (n = 32)PercentileAntimicrobial agentNo. DDD∗Defined daily dose (DDD) of antimicrobial agent is calculated by dividing the total grams of the antimicrobial agent used in a hospital area by the number of grams in an average daily dose of the agent given to an adult patient.Pooled mean10%25%50% (median)75%90%Penicillin group429630.80.00.47.241.7106.4Ampicillin group12,35688.58.644.888.3172.1245.9Antipseudomonal penicillins459932.90.03.320.842.858.6Antistaphylococcal penicillins367926.30.03.612.046.268.2First-generation cephalosporins697850.09.027.736.554.4104.9Second-generation cephalosporins428630.71.57.119.832.542.4Third-generation cephalosporins12,54089.825.132.873.598.0143.5Carbapenem group163511.70.00.26.112.127.4Aztreonam7775.60.00.02.010.814.9Fluoroquinolones12,39088.711.327.358.9112.3214.4Trimethoprim/sulfamethoxazole558540.00.06.016.543.4112.8Vancomycin (oral)5263.80.00.00.01.37.0Vancomycin (parenteral)771355.211.219.836.989.3105.9Cardiothoracic ICU (n = 21)PercentileAntimicrobial agentNo. DDD∗Defined daily dose (DDD) of antimicrobial agent is calculated by dividing the total grams of the antimicrobial agent used in a hospital area by the number of grams in an average daily dose of the agent given to an adult patient.Pooled mean10%25%50% (median)75%90%Penicillin group373638.40.00.04.840.983.0Ampicillin group704472.43.316.658.597.6143.2Antipseudomonal penicillins213922.01.46.316.132.145.4Antistaphylococcal penicillins248325.50.00.06.431.038.6First-generation cephalosporins25,925266.636.5210.3258.7465.4697.9Second-generation cephalosporins899792.52.76.822.773.4470.1Third-generation cephalosporins894191.917.832.261.897.0151.1Carbapenem group166317.10.01.611.818.949.4Aztreonam7407.60.00.51.95.39.2Fluoroquinolones806582.98.623.265.5101.4187.4Trimethoprim/sulfamethoxazole160116.50.00.58.821.843.9Vancomycin (oral)5575.70.00.00.02.510.7Vancomycin (parenteral)12,081124.226.045.697.0156.9210.9Hematology/Oncology/Transplant Wards (n = 17)PercentileAntimicrobial agentNo. DDD∗Defined daily dose (DDD) of antimicrobial agent is calculated by dividing the total grams of the antimicrobial agent used in a hospital area by the number of grams in an average daily dose of the agent given to an adult patient.Pooled mean10%25%50% (median)75%90%Penicillin group341627.6—————Ampicillin group17,578141.8—————Antipseudomonal penicillins3,59929.0—————Antistaphylococcal penicillins197515.9—————First-generation cephalosporins601748.5—————Second-generation cephalosporins290423.4—————Third-generation cephalosporins27,434221.3—————Carbapenem group186315.0—————Aztreonam9357.5—————Fluoroquinolones20,690166.9—————Trimethoprim/sulfamethoxazole400332.3—————Vancomycin (oral)5404.4—————Vancomycin (parenteral)10,17282.1—————Medical ICU (n = 36)PercentileAntimicrobial agentNo. DDD∗Defined daily dose (DDD) of antimicrobial agent is calculated by dividing the total grams of the antimicrobial agent used in a hospital area by the number of grams in an average daily dose of the agent given to an adult patient.Pooled mean10%25%50% (median)75%90%Penicillin group11,59855.10.04.939.163.097.5Ampicillin group46,702222.089.4135.5181.4253.0345.4Antipseudomonal penicillins14,88770.813.130.660.4104.0170.5Antistaphylococcal penicillins936844.50.03.525.143.684.9First-generation cephalosporins745635.410.619.530.739.570.3Second-generation cephalosporins598628.51.27.021.747.967.1Third-generation cephalosporins53,488254.258.288.8140.2199.3317.3Carbapenem group788937.50.08.023.237.298.3Aztreonam19959.50.01.56.111.817.7Fluoroquinolones35,393168.239.382.5134.0184.4307.7Trimethoprim/sulfamethoxazole22,058104.80.021.640.591.7185.3Vancomycin (oral)3661.70.00.00.31.86.7Vancomycin (parenteral)27,921132.742.956.979.0156.4222.1Medical-surgical ICU (n = 61)PercentileAntimicrobial agentNo. DDD∗Defined daily dose (DDD) of antimicrobial agent is calculated by dividing the total grams of the antimicrobial agent used in a hospital area by the number of grams in an average daily dose of the agent given to an adult patient.Pooled mean10%25%50% (median)75%90%Penicillin group21,83746.50.02.313.638.7113.4Ampicillin group94,566201.433.179.1185.0300.8376.9Antipseudomonal penicillins35,47175.518.237.261.795.4115.5Antistaphylococcal penicillins12,07925.71.44.813.829.349.0First-generation cephalosporins48,262102.823.953.576.7126.6209.2Second-generation cephalosporins16,10734.32.66.419.042.591.7Third-generation cephalosporins67,688144.161.280.4116.4163.4200.6Carbapenem group17,72737.83.48.226.847.062.9Aztreonam478510.20.01.96.214.023.9Fluoroquinolones96,695205.955.492.8167.5301.2360.3Trimethoprim/sulfamethoxazole31,44867.00.011.524.268.6203.4Vancomycin (oral)28686.10.00.02.45.99.3Vancomycin (parenteral)40,30385.833.153.266.7122.9143.0Neurosurgical ICU (n = 11)PercentileAntimicrobial agentNo. DDD∗Defined daily dose (DDD) of antimicrobial agent is calculated by dividing the total grams of the antimicrobial agent used in a hospital area by the number of grams in an average daily dose of the agent given to an adult patient.Pooled mean10%25%50% (median)75%90%Penicillin group329455.6—————Ampicillin group6892116.3—————Antipseudomonal penicillins266945.0—————Antistaphylococcal penicillins429672.5—————First-generation cephalosporins6949117.2—————Second-gene