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Comparing surgical site infection (SSI) rates using the NNIS SSI risk index and the standardized infection ratio
AJIC
102
Abstracts
April
COMPARING SURGICAL SlTE INFECTION (SSI) RATES USING THE NNIS SSI RISK INDFIX AND THE STANDARDIZED -ON RATIO. D. Culver, PhD, T. Horan, MPH, CIC; R. Gayma, MD. Caters for Disease control, Atlanta, GA.
categories into four risk categories (0.1,2,3) depndiru on the m&a of ihcse risk factors pledat. Mom than 236,ow operative pmcutmw Md 6ooo SSI have been wportedmCDCfromlO5NNIShospitalrdmingl986-1993. Theaggm#edNNISdam havebecnuscd(oestimPte~SSlriskbyproccd\newi(hincsfhcp(cgory. Wbmno difference in rates existed beiwecn adjaceot cab?goriu for a procedure, the data were ~&cd. For examvIe. the mta cholwstectomv (CHOL) with 2 or 3 risk factors wem &mbii bccaweeth& wm-e not sigkicmly hi&m-it &e table). Such aggmgated NNIS SSI rates can be used as standards for comparison. Further, they can be wed to calculate the xi&-adiusted exoectcd 03) number of SSI for P sutcific SUIPCOII.soccialtv. or hospital. M&ly the &mbu bi operaions performed *by the c&p&& g&p (e.g., wrge~n) times the NNIS SSI rate and sum OQer all the promduna performed by the wmparimn group in each risk category. The mtio of actual number of observed (0) SSI 10 the expected (E) number is called the Sm Infection Ratio (SIR). For aisle. for CHOL, the SIR for Dr. X can be obtained from the data in the sample table CHOL Risk CWorY
obs. I SSI (0)
xopm by Dr. x
NNIS Rate
Enp. # SSI 0
0
3
30
0.01
0.3
1
2
20
0.02
0.04
2,3
1
10
0.04
0.4
Totnl
6
60
___-
1.1
SIR = ;
= 6
- 5.45 (2 = 2.8,~ = 0X03)
The SIR is a simple, risk-adjusted meawe whom valw.3 mm be compared to the NNIS standad (1.0) or to other surgeons. hospitals, or axurn time using, for example, P Z-M.
FAILUlU3 l-0 CONTROL VANCOMYCIN RESISTANT ENTZROCOCCUS FABCRlM IN AN ACUTE CARE SEITING. A. Go&, IUNJSd, R.R. Muda, MD. VAMC, Pittsburgh, PA. vancomycin-ruirtmt w (VREF) w bltmduced into OUT blstitutioll in June, 1993 when a colon&d patit was aaasfmled to the intamivc care unit (KU) for liver banapbmt tvllurtion. After idmtliflcatkm of the orgaoism, we attemputocultmltbeapmadofVREFtithligid measmuaodhospimlwi& cduatlm. NprtimtshoumdbttheICUbsdweeklyrrctnlcultumadone,ifawlmdmd patieatwulnthcwitwithbttJmpwmk. colocliudlinfentdpatlmuwacplawdin aingltmmmlcubii. Emplo~wuemquimdtowargowosaodglovuifincca~ withtheDatlmtorhirimm -t. Hmldwaahing WPI enfond and special signs w&e posted. A h~aphhide
btwwn
eduwtiomd campat@ ti
v@musly
initiotob.
6/93 and 11193.39 of 224 (17%) oatiats wme found to be colonized
admimion, with a &an of 29.5 days. 10% (4139) wme coloni?ed prior to ad&ion. 86% M/351 of nosncomial VRElF wem colon&d ale housed in ICU. Colonimtion of ppticnta in ICU occur&i+129 days pfter admission. Tim m+an was 23.1 days. None diedsaammlltofVREF. Educ&mat~tiudcddaurrmm~,nmrlettas, mdhulleth:fmmtJmI,4mcbdroffiw. Tbmewmrdmpfmml0ca.wJmoothtoooe cerlftermeinitiPLedrePtionrlthrurt;however,theineideDcemm~totheinitiol me of lo/month Md then leveled off to 4 cases monthly. Extensive eoviNmmaml wlmm mrveilbvlw fomld 110En-. We coo&k that aggrcmive implemmwion of body substance isolation sod employee education were ineffective in catrolling VREF. Novel approacha to control am ncukd.
1994
INCIDENCE OF PGSTOPERATIVE INFECTIONS IN PATIENTS UNDERGOING CAESARLW SXXlONS. J.F. Eoglish, RN, MSN; L.W. Mushall, MD, E.L. Horton, MD, G.L. Lipkin, BA, MBA. Columbia Hospital for Women, Wash@@& DC. llda wP( P lttmqcdve study of 263 paienta who ha Cacaian Sections (CS) at Colmnbm Hospital for Womm (CIiW) during the months of February and Oc@b~ 1991 compared with hvo previous CHW smdies of padents in 1983 and 1977, ptuvidiog &taspmmhlgthn?odecadm. Hypo(bah: Use of antibiotics for prophytaxis reduce incidence of postoperative id&ion in pDtients undcr%oing CS. objtcttves: Asses v/he&x the use of antibiotics reduced incideocc of postopaatlvc infections and determine whetha patient outcomes (nosommial attack rates) improved over time. S&t&z 148 adult/l00 infant bed acute care women’s hospital. MttItodoIow: RcmsIKctive SbldY. CHW wmputer mainhunt tiles were marched using ICC9 cod4 14.1 to identify CS performed either as primary or secondary pmxdum in Fdnwy and Cktobu 1991. Infections at all sitm WQC invmt@ted. In 1991 study tbme wme 4/151(3%) posmpemtive infections following CS in pptienu receiving antibiotic prophylaxis compared to lo/l12 (9%) for patienb who did not receive antibiotic Drmhvtis (Chi-souan = 3.86. II< .05). In 1983 study there WE 5/60 (8%) postop&~e’infecti&s foilowing CS in’patieob mceiving &biotic pmphylaxis corn&red-to 631186 (34%) for patients who- did not receive antibiotic omohvlaxis rchi-muan = 13.54. o<.ool). In 1977 shadv there wem 2121 (10%) po&pm& infe&ons follow&‘C!S in ‘patients receivi~ aotibiotic proph&is compmd to 58/171 (34%) for patients who did not receive antibiotic prophylaxis (Chisquare = 4.11, p< .05). Ovemll attack mta were 14/263 (5%) in 1991 study, 681246 (28%) in 1983 sh!dy, and 601192 (31%) in 1977 s’udy. Conchslon~: Antibiotic prophylaxis significantly reduced infection rates in all of the studies. Quality improvement was documemed via pMopmative attack rata decreasi~ in shxlies over three decals.
THE EFFRCT OF SODIUM H YPOCHLORI’IE DISINFECTION OF THE [email protected] ON NOSOCOhUAL ACQUISlTION OF B DEEJCU&. L. Ken, MT, CIC,* I. Iohoson. MD. Uoivmsity of Pittsburgh medical Ccntera, Pitub&, PA. Backgmulla: Anincrcascinthe~of~difhcile-associwd ~wpsnotcdonaaurgicploncolopyunitinSeptembpMd~of199lin patients who mctived paioperative, pmphywic clhdmnycin. Initial bltmvatioll measm?dtointcnuptpnontopcrmnhsnrmirdonoftheorgmduniQcludedunivarpl Pmcaulimb (with the additimt of Emmic PmcmJtioor for known plxitive patients), ambnicmbla.l smp for handwmhblg (gluconatc), and eduption Of staff. ThopemacUrrspFmcdrnbeincMetiveindecrrPsingin~~Ofthedi~, prompdnig an effort to elimirmte environmental bmsmisslon of (he orgmdsm. After the unit was disinfected with a dilution of sodium hypocblorite (1000 ppm), incidence &cmascd. &cause it is believed that tbe decrrapc was doe to the effectiof sodhm hypochlnite in removing Cloetridiumdifhdlc from the awironmcnt, it baa been used aa tht disinfccant for routine cleaning of the unit since Ianuary of 1992 (replacing quptcmary ammali@. Metbodsz To evaluate the effect of tbe change in disinfectant on nosocomial zquisition of clontridiumQiffidlc, results of cytotoxin asmys wem reviewed rctmDpectively over P four year period. The toxin positivity rate during hvo years of q~nmmoninusegewwmm~tothe~duringhuoycen,ofsodium hypochlorite “sage. Incidence mtes of infected pvit”b per 100 patient discharges were also compared for the sameperiod. Rsultr: Tlleto*nposltivityntcdtcmamd significantly from 33% when the qutmmry ammonia was used to 13.6% @< .Ol) PRer the change was made to sodium hypocblorite. ‘Ihe incidcoce rate duxased hum 2.2 to 1.4 (p< .20). Coodwbn: We conclude that the use of P dilution of sodium hypochlotite for mutim disinfectica is effective in pmvrntig mwinmmental tmnsmission of w s ztig tbc risk of nowcomial acquisition of the organism. Infection to prevmt pemn to person Uansmission must also continue to be
Stlt.5.d.
102
Abstracts
April
COMPARING SURGICAL SlTE INFECTION (SSI) RATES USING THE NNIS SSI RISK INDFIX AND THE STANDARDIZED -ON RATIO. D. Culver, PhD, T. Horan, MPH, CIC; R. Gayma, MD. Caters for Disease control, Atlanta, GA.
categories into four risk categories (0.1,2,3) depndiru on the m&a of ihcse risk factors pledat. Mom than 236,ow operative pmcutmw Md 6ooo SSI have been wportedmCDCfromlO5NNIShospitalrdmingl986-1993. Theaggm#edNNISdam havebecnuscd(oestimPte~SSlriskbyproccd\newi(hincsfhcp(cgory. Wbmno difference in rates existed beiwecn adjaceot cab?goriu for a procedure, the data were ~&cd. For examvIe. the mta cholwstectomv (CHOL) with 2 or 3 risk factors wem &mbii bccaweeth& wm-e not sigkicmly hi&m-it &e table). Such aggmgated NNIS SSI rates can be used as standards for comparison. Further, they can be wed to calculate the xi&-adiusted exoectcd 03) number of SSI for P sutcific SUIPCOII.soccialtv. or hospital. M&ly the &mbu bi operaions performed *by the c&p&& g&p (e.g., wrge~n) times the NNIS SSI rate and sum OQer all the promduna performed by the wmparimn group in each risk category. The mtio of actual number of observed (0) SSI 10 the expected (E) number is called the Sm Infection Ratio (SIR). For aisle. for CHOL, the SIR for Dr. X can be obtained from the data in the sample table CHOL Risk CWorY
obs. I SSI (0)
xopm by Dr. x
NNIS Rate
Enp. # SSI 0
0
3
30
0.01
0.3
1
2
20
0.02
0.04
2,3
1
10
0.04
0.4
Totnl
6
60
___-
1.1
SIR = ;
= 6
- 5.45 (2 = 2.8,~ = 0X03)
The SIR is a simple, risk-adjusted meawe whom valw.3 mm be compared to the NNIS standad (1.0) or to other surgeons. hospitals, or axurn time using, for example, P Z-M.
FAILUlU3 l-0 CONTROL VANCOMYCIN RESISTANT ENTZROCOCCUS FABCRlM IN AN ACUTE CARE SEITING. A. Go&, IUNJSd, R.R. Muda, MD. VAMC, Pittsburgh, PA. vancomycin-ruirtmt w (VREF) w bltmduced into OUT blstitutioll in June, 1993 when a colon&d patit was aaasfmled to the intamivc care unit (KU) for liver banapbmt tvllurtion. After idmtliflcatkm of the orgaoism, we attemputocultmltbeapmadofVREFtithligid measmuaodhospimlwi& cduatlm. NprtimtshoumdbttheICUbsdweeklyrrctnlcultumadone,ifawlmdmd patieatwulnthcwitwithbttJmpwmk. colocliudlinfentdpatlmuwacplawdin aingltmmmlcubii. Emplo~wuemquimdtowargowosaodglovuifincca~ withtheDatlmtorhirimm -t. Hmldwaahing WPI enfond and special signs w&e posted. A h~aphhide
btwwn
eduwtiomd campat@ ti
v@musly
initiotob.
6/93 and 11193.39 of 224 (17%) oatiats wme found to be colonized
admimion, with a &an of 29.5 days. 10% (4139) wme coloni?ed prior to ad&ion. 86% M/351 of nosncomial VRElF wem colon&d ale housed in ICU. Colonimtion of ppticnta in ICU occur&i+129 days pfter admission. Tim m+an was 23.1 days. None diedsaammlltofVREF. Educ&mat~tiudcddaurrmm~,nmrlettas, mdhulleth:fmmtJmI,4mcbdroffiw. Tbmewmrdmpfmml0ca.wJmoothtoooe cerlftermeinitiPLedrePtionrlthrurt;however,theineideDcemm~totheinitiol me of lo/month Md then leveled off to 4 cases monthly. Extensive eoviNmmaml wlmm mrveilbvlw fomld 110En-. We coo&k that aggrcmive implemmwion of body substance isolation sod employee education were ineffective in catrolling VREF. Novel approacha to control am ncukd.
1994
INCIDENCE OF PGSTOPERATIVE INFECTIONS IN PATIENTS UNDERGOING CAESARLW SXXlONS. J.F. Eoglish, RN, MSN; L.W. Mushall, MD, E.L. Horton, MD, G.L. Lipkin, BA, MBA. Columbia Hospital for Women, Wash@@& DC. llda wP( P lttmqcdve study of 263 paienta who ha Cacaian Sections (CS) at Colmnbm Hospital for Womm (CIiW) during the months of February and Oc@b~ 1991 compared with hvo previous CHW smdies of padents in 1983 and 1977, ptuvidiog &taspmmhlgthn?odecadm. Hypo(bah: Use of antibiotics for prophytaxis reduce incidence of postoperative id&ion in pDtients undcr%oing CS. objtcttves: Asses v/he&x the use of antibiotics reduced incideocc of postopaatlvc infections and determine whetha patient outcomes (nosommial attack rates) improved over time. S&t&z 148 adult/l00 infant bed acute care women’s hospital. MttItodoIow: RcmsIKctive SbldY. CHW wmputer mainhunt tiles were marched using ICC9 cod4 14.1 to identify CS performed either as primary or secondary pmxdum in Fdnwy and Cktobu 1991. Infections at all sitm WQC invmt@ted. In 1991 study tbme wme 4/151(3%) posmpemtive infections following CS in pptienu receiving antibiotic prophylaxis compared to lo/l12 (9%) for patienb who did not receive antibiotic Drmhvtis (Chi-souan = 3.86. II< .05). In 1983 study there WE 5/60 (8%) postop&~e’infecti&s foilowing CS in’patieob mceiving &biotic pmphylaxis corn&red-to 631186 (34%) for patients who- did not receive antibiotic omohvlaxis rchi-muan = 13.54. o<.ool). In 1977 shadv there wem 2121 (10%) po&pm& infe&ons follow&‘C!S in ‘patients receivi~ aotibiotic proph&is compmd to 58/171 (34%) for patients who did not receive antibiotic prophylaxis (Chisquare = 4.11, p< .05). Ovemll attack mta were 14/263 (5%) in 1991 study, 681246 (28%) in 1983 sh!dy, and 601192 (31%) in 1977 s’udy. Conchslon~: Antibiotic prophylaxis significantly reduced infection rates in all of the studies. Quality improvement was documemed via pMopmative attack rata decreasi~ in shxlies over three decals.
THE EFFRCT OF SODIUM H YPOCHLORI’IE DISINFECTION OF THE [email protected] ON NOSOCOhUAL ACQUISlTION OF B DEEJCU&. L. Ken, MT, CIC,* I. Iohoson. MD. Uoivmsity of Pittsburgh medical Ccntera, Pitub&, PA. Backgmulla: Anincrcascinthe~of~difhcile-associwd ~wpsnotcdonaaurgicploncolopyunitinSeptembpMd~of199lin patients who mctived paioperative, pmphywic clhdmnycin. Initial bltmvatioll measm?dtointcnuptpnontopcrmnhsnrmirdonoftheorgmduniQcludedunivarpl Pmcaulimb (with the additimt of Emmic PmcmJtioor for known plxitive patients), ambnicmbla.l smp for handwmhblg (gluconatc), and eduption Of staff. ThopemacUrrspFmcdrnbeincMetiveindecrrPsingin~~Ofthedi~, prompdnig an effort to elimirmte environmental bmsmisslon of (he orgmdsm. After the unit was disinfected with a dilution of sodium hypocblorite (1000 ppm), incidence &cmascd. &cause it is believed that tbe decrrapc was doe to the effectiof sodhm hypochlnite in removing Cloetridiumdifhdlc from the awironmcnt, it baa been used aa tht disinfccant for routine cleaning of the unit since Ianuary of 1992 (replacing quptcmary ammali@. Metbodsz To evaluate the effect of tbe change in disinfectant on nosocomial zquisition of clontridiumQiffidlc, results of cytotoxin asmys wem reviewed rctmDpectively over P four year period. The toxin positivity rate during hvo years of q~nmmoninusegewwmm~tothe~duringhuoycen,ofsodium hypochlorite “sage. Incidence mtes of infected pvit”b per 100 patient discharges were also compared for the sameperiod. Rsultr: Tlleto*nposltivityntcdtcmamd significantly from 33% when the qutmmry ammonia was used to 13.6% @< .Ol) PRer the change was made to sodium hypocblorite. ‘Ihe incidcoce rate duxased hum 2.2 to 1.4 (p< .20). Coodwbn: We conclude that the use of P dilution of sodium hypochlotite for mutim disinfectica is effective in pmvrntig mwinmmental tmnsmission of w s ztig tbc risk of nowcomial acquisition of the organism. Infection to prevmt pemn to person Uansmission must also continue to be
Stlt.5.d.