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P17.43 Use of Statistical Control Charts to Improve Reporting of Surveillance of MRSA in Scotland
S94
Abstracts, 6th Int. Conf. of the Hospital Infection Society, 15–18 October 2006, Amsterdam, The Netherlands
Aim: The aim of this enhanced surveillance is to identify risk factors associated with MRSA bacteraemia arising more than 48 hours after admission to hospital. Method: Data is collected on paper forms, based on a structured pro-forma, which are scanned and analysed using a FORMIC data capture system and Microsoft Excel. Results: There were 359 cases of nosocomial MRSA bacteraemia in the two year period April 2004–March 2006. Commonly associated clinical infections included sepsis of unknown origin, lower respiratory tract infection (LRTI), skin and soft tissue infection (SSTI), vascular access device (VAD) site infection and urinary tract infection. Associated positive specimens included MRSA screen, VAD site and tip, sputum and urine. The presence of a VAD, urinary catheter or surgical wound was identified as an additional risk factor. Discussion: Our results support the views of others that VADs, urinary catheters and surgical wounds are associated with nosocomial MRSA bacteraemia, although a proportion of cases had sepsis of unknown origin. However, we have also shown that, in a predominantly DGH setting, LRTI is a common association as is SSTI and superficial MRSA colonisation. Our results suggest that measures to prevent LRTI and SSTI and reduce MRSA colonisation should also be included when prioritising infection control interventions. P17.41 Preliminary Results from the National Mandatory MRSA Bacteraemia Enhanced Surveillance Scheme in England: October 2005–March 2006 A. Pearson1 *, K. Wagner1 , A. Charlett1 , A. Saei1 , M. Fleming2 , J. Giltrow2 , A. Jones1 , M. Painter1 . 1 Health Protection Agency, UK, 2 Department of Health, UK Background: A national voluntary reporting system for Methicillin-resistant S. aureus (MRSA) bacteraemias in England has shown a rise in incidence since 1990. In October 2005 a mandatory MRSA bacteraemia enhanced surveillance scheme was introduced in England. Objective: To examine the first six months of enhanced surveillance data in order to provide an early picture of MRSA bacteraemia patient profiles in acute trust hospitals in England. Methods: All acute trusts in England entered data into a webenabled database for all episodes of MRSA bacteraemia. Patient demographic data, dates of admission and infection, specialty, and the patient location immediately prior to admission to hospital were collected. Data were then extracted centrally for analysis. Results: • 3530 MRSA bacteraemias were recorded from October 2005 to March 2006. • 25% of these were detected within the first two days of admission to hospital. • Of this subset, 68% of patients were admitted into hospital directly from home, 15% from nursing homes and 8% from another hospital. • 70% of these “early” bacteraemias can be linked to a recent (within 1 month) discharge. • Overall, most patients (72%) were admitted into hospital directly from home; only 9% and 8% respectively were admitted from another hospital or a nursing home. Discussion: These results reveal a relatively high proportion of patients whose MRSA bacteraemia was detected within the first two days of admission to hospital. Although most of these patients were recorded as being admitted into hospital directly from home, there is emerging evidence that a significant proportion had recently been discharged from hospital. In depth analysis of the data may enable patterns of patient transfers between hospitals to be identified. The enhanced system has already been expanded to include voluntary data collection
fields such as source of bacteraemia and healthcare interactions prior to the current episode.
P17.42 Staphylococcus aureus Isolated from Inpatients and Outpatients Y. Martin, A. Rezusta, M.J. Revillo, M.J. Hernandez-Navarrete *, J.L. Arribas-Llorente. Miguel Servet Teaching Hospital, Spain Background: MRSA strains harbour the mecA gene, which encodes the low-affinity penicillin-binding protein 2a (PBP2a). The production of PBP2a confers resistance to otherwise inhibitory concentrations of all b-lactam antibiotics. Objective: The aim of this study is to know the incidence of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus (MSSA) considering specimens and patients. On the other hand, we try to know the number of inpatients and outpatients. Methods: We exported from our computered system to Excel all S. aureus isolated between 2003–2005, and then we checked for incidence of specimens and patients with MRSA and MSSA. We considered MRSA all those S. aureus strains that showed resistant according to NCCLS (CLSI) by disk diffusion test. Difference proportions test and lineal trend Mantel–Haenszel test were used. Results: Out of 6342 specimens with S. aureus were isolated in 3558 patients. 2325 specimens (36.7%) were MRSA. Of 3558 patients 930 (26.1%) were MRSA. The distribution per year of patients with MRSA was: 2003 380/1307 (29.1%), 2004 294/1151 (25.5%) and 256/1100 (23.3%). These data include infected, carriers and family members. These proportions were different (p < 0.05) and they showed a decrease trend (p = 0.01). Discussion: The number of patients decreased significantly during the period of study.
P17.43 Use of Statistical Control Charts to Improve Reporting of Surveillance of MRSA in Scotland R. Hill *, G. Allardice, J. Reilly, M. Coyne. Health Protection Scotland, UK Background: MRSA bacteraemia rates in Scotland (by division) have been reported every quarter since January 2001. Tabular methods have similarities to league tables with the obvious pit falls that someone ‘has to be last’ and that ‘first’ is not necessarily good. We recognise the need to use alternative methods that will simultaneously ensure that standards are being met while avoiding such comparative labels. Aim: The aim of this research is to examine the use of alternative methods to enhance the routine reporting of MRSA bacteraemia in Scotland. Methods: Two recent developments in Statistical Process Control (SPC) are examined; Funnel Plots and Cusum Control Charts. Funnel plots meet our needs as they can be used to identify divisions that are not meeting a required standard while avoiding the ranking of the other divisions. We have utilised CUSUM charts to investigate trends within divisions; this method identifies both large changes and smaller sustained drifts in prevalence of MRSA. Results: This paper will develop examples of CUSUM charts and Funnel plots of MRSA bacteraemia rates within acute healthcare divisions in Scotland. Conclusions: SPC methods are a useful tool in monitoring complex healthcare processes, particularly where it is necessary to simultaneously compare institutions and trends over time. They avoid stigmatising institutions unnecessarily while enabling poorly performing institutions to be identified. Other surveillance systems may want to investigate whether these methodologies are appropriate.
Poster Presentations Reference(s) Boyce NW. Potential pitfall of healthcare performance indicators. Medical Journal of Australia 2002; 117 (5): 299– 230. Spiegelhalter DJ. Funnel plots for comparing institutional performance. Statistics in Medicine 2005; 24: 1185–1202. Bird S, Cox D, Farewell VT, Goldstein HG, Holt T, Smith PC. RSS working party on performance monitoring in the public service. Royal Statistics Society, October 2003 P17.44 Laboratory Based Surveillance of Invasive Group A Streptococcal Infections in Edinburgh, 1999–2006 H. Venkatesh1 *, P. Kalima2 . 1 Western General Hospital, Edinburgh, UK, 2 Western General Hospital, UK Objective: To review the incidence of invasive group A streptococcal infections (iGAS) in Edinburgh and to create an awareness among health care professionals regarding the increased incidence of invasive GAS infections in recent years. Methods: This is a retrospective laboratory based review of invasive group A streptococcal isolates from March 1999 to March 2006. Cases were defined as isolation of GAS from a normally sterile site such as blood, cerebrospinal fluid, pleural fluids, joint aspirates and deep specimens. Repeat isolates from the same patient were excluded within a 15 day period. Results: Out of the 5291, 102 (1.9%) were blood culture isolates. The highest incidence was found in the first quarter of 2006. A seasonal variation was noted with a increased incidence in the first two quarters of every year of the study period. Discussion: We retrospectively studied proven GAS bacteremias associated with clinical disease over a six year period. A literature search reporting invasive GAS from other parts of the world includes studies in Europe and the United States. A laboratory based nationwide surveillance of invasive GAS in Netherlands done from 1994–2003 showed the possibility of new serotypes causing severe disease. A surveillance system set up in Italy helped physicians with microbiological analysis of strains and made them aware of the importance of early diagnosis and aggressive management of invasive infection. Conclusions: The increasing incidence of iGAS in Edinburgh remains a potential problem in the health care setting. We are taking several interventional measures to increase the awareness among health care workers and continued surveillance is invaluable. P17.45 Incidence Reduction of Central Venous Catheter Related Infection (CRI) During a 5-Years Surveillance in ICU in Northern France F. L’H´ eriteau1 *, M. Olivier1 , S. Maugat1 , C. Joly1 , G. Beaucaire2 , P. Astagneau1 . 1 C-CLIN Paris Nord, France, 2 CHRU Lille, France Background: Central venous catheter (CVC) related infections (CRI) are among the most common and life threatening nosocomial infections (NI) in intensive care units (ICU). Surveillance systems have already been shown to reduce significantly NI incidence. The regional coordinating center for NI control has implemented a CRI surveillance network in ICU (Reacat) since 1999. This surveillance led to the construction of a standardized incidence ratio (SIR) adjusting CRI incidence for risk factors. Objectives: To evaluate the reduction of CRI incidence in ICU participating in the Reacat network. Methods: All ICU were requested to participate on a voluntary basis. All CVC inserted for more than 48 hours were followed until removal or patient discharge. CRI risk factors were recorded. Standard and microbiological criteria were used to define CRI. A logistic regression model was used to define the
S95 number of expected CRI. SIR was estimated by dividing the number of observed CRI by the number of expected CRI. Results: From 2000 to 2005, 135 ICU participated to surveillance for at least one period. Overall 11,705 CVC in 913 patients accounting for 122,489 CVC-days were included. CRI incidence was 2.8 per 1000 CVC-days. Among ICU, 35 (cohort A), 16 (cohort B), and 10 (cohort C) participated for 3, 4 and 5 consecutive periods, respectively. Cohorts A, B and C included 4350, 2894 and 2445 CVC, respectively. CRI incidence decreased significantly from the first to the last surveillance period in all three cohorts: –60.6%, –58.2% and –77.6% in cohorts A, B and C, respectively. SIR also decreased significantly from the first to the last surveillance period. Conclusion: Our data suggest that surveillance had a significant impact on CRI incidence reduction. Control efforts of CRI based on hygiene practice improvement are needed to complete the surveillance approach. P17.46 Development of a Record Keeping Tool for Infection Prevention & Control Nurses (IPCNs) I. Thompson1 *, C. Clarke2 , C. McGeary2 , E. Smyth2 . 1 The Royal Hospitals Belfast, UK, 2 Bacteriology Department, The Royal Hospitals, Belfast, Northern Ireland, UK Background: IPCNs have a legal and professional responsibility to maintain records on advice and treatments. Record keeping can be time consuming and an added pressure on limited resources. With this system it should be possible to analyse data to inform the Infection Prevention and Control Team (IPCT) in workload analysis, high risk areas and teaching purposes. Aim: To describe the development and benefits of a scannable form to facilitate efficient and accurate record keeping. Methods: Review previous infection prevention and control records. Development of a scannable form to record information with minimal free-text. Form consisted of two A4 printed sides. Completed forms scanned and data captured automatically. Software Formic for Windows version 3. Scanned data exported to SPSS for analysis. Results: From April 2005 to March 2006 there were 986 records generated of which approximately 55% related to MRSA patients that were new to the Trust, 10% with a previous history of MRSA, 15% Clostridium difficile, 12% ESBLs and 8% others. These results will be expanded on in the presentation. Discussion: This method of record keeping has the potential to be an efficient and useful method of record keeping. This information assists the IPCT in the areas listed below and also allows for future planning of resources and targeted surveillance. • Records number of referrals to the IPCN. • Allows comparisons with laboratory records to ensure all patients are captured. • Identifies high risk areas. • Assesses patient placement. • Provides information for Litigation and FOI requests. • Graphical information can be used for teaching purposes and report writing • Easier generation of information pertinent to the Trust. The content and structure of the form has recently been reviewed and we are currently refining the size and content of the form.
Abstracts, 6th Int. Conf. of the Hospital Infection Society, 15–18 October 2006, Amsterdam, The Netherlands
Aim: The aim of this enhanced surveillance is to identify risk factors associated with MRSA bacteraemia arising more than 48 hours after admission to hospital. Method: Data is collected on paper forms, based on a structured pro-forma, which are scanned and analysed using a FORMIC data capture system and Microsoft Excel. Results: There were 359 cases of nosocomial MRSA bacteraemia in the two year period April 2004–March 2006. Commonly associated clinical infections included sepsis of unknown origin, lower respiratory tract infection (LRTI), skin and soft tissue infection (SSTI), vascular access device (VAD) site infection and urinary tract infection. Associated positive specimens included MRSA screen, VAD site and tip, sputum and urine. The presence of a VAD, urinary catheter or surgical wound was identified as an additional risk factor. Discussion: Our results support the views of others that VADs, urinary catheters and surgical wounds are associated with nosocomial MRSA bacteraemia, although a proportion of cases had sepsis of unknown origin. However, we have also shown that, in a predominantly DGH setting, LRTI is a common association as is SSTI and superficial MRSA colonisation. Our results suggest that measures to prevent LRTI and SSTI and reduce MRSA colonisation should also be included when prioritising infection control interventions. P17.41 Preliminary Results from the National Mandatory MRSA Bacteraemia Enhanced Surveillance Scheme in England: October 2005–March 2006 A. Pearson1 *, K. Wagner1 , A. Charlett1 , A. Saei1 , M. Fleming2 , J. Giltrow2 , A. Jones1 , M. Painter1 . 1 Health Protection Agency, UK, 2 Department of Health, UK Background: A national voluntary reporting system for Methicillin-resistant S. aureus (MRSA) bacteraemias in England has shown a rise in incidence since 1990. In October 2005 a mandatory MRSA bacteraemia enhanced surveillance scheme was introduced in England. Objective: To examine the first six months of enhanced surveillance data in order to provide an early picture of MRSA bacteraemia patient profiles in acute trust hospitals in England. Methods: All acute trusts in England entered data into a webenabled database for all episodes of MRSA bacteraemia. Patient demographic data, dates of admission and infection, specialty, and the patient location immediately prior to admission to hospital were collected. Data were then extracted centrally for analysis. Results: • 3530 MRSA bacteraemias were recorded from October 2005 to March 2006. • 25% of these were detected within the first two days of admission to hospital. • Of this subset, 68% of patients were admitted into hospital directly from home, 15% from nursing homes and 8% from another hospital. • 70% of these “early” bacteraemias can be linked to a recent (within 1 month) discharge. • Overall, most patients (72%) were admitted into hospital directly from home; only 9% and 8% respectively were admitted from another hospital or a nursing home. Discussion: These results reveal a relatively high proportion of patients whose MRSA bacteraemia was detected within the first two days of admission to hospital. Although most of these patients were recorded as being admitted into hospital directly from home, there is emerging evidence that a significant proportion had recently been discharged from hospital. In depth analysis of the data may enable patterns of patient transfers between hospitals to be identified. The enhanced system has already been expanded to include voluntary data collection
fields such as source of bacteraemia and healthcare interactions prior to the current episode.
P17.42 Staphylococcus aureus Isolated from Inpatients and Outpatients Y. Martin, A. Rezusta, M.J. Revillo, M.J. Hernandez-Navarrete *, J.L. Arribas-Llorente. Miguel Servet Teaching Hospital, Spain Background: MRSA strains harbour the mecA gene, which encodes the low-affinity penicillin-binding protein 2a (PBP2a). The production of PBP2a confers resistance to otherwise inhibitory concentrations of all b-lactam antibiotics. Objective: The aim of this study is to know the incidence of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus (MSSA) considering specimens and patients. On the other hand, we try to know the number of inpatients and outpatients. Methods: We exported from our computered system to Excel all S. aureus isolated between 2003–2005, and then we checked for incidence of specimens and patients with MRSA and MSSA. We considered MRSA all those S. aureus strains that showed resistant according to NCCLS (CLSI) by disk diffusion test. Difference proportions test and lineal trend Mantel–Haenszel test were used. Results: Out of 6342 specimens with S. aureus were isolated in 3558 patients. 2325 specimens (36.7%) were MRSA. Of 3558 patients 930 (26.1%) were MRSA. The distribution per year of patients with MRSA was: 2003 380/1307 (29.1%), 2004 294/1151 (25.5%) and 256/1100 (23.3%). These data include infected, carriers and family members. These proportions were different (p < 0.05) and they showed a decrease trend (p = 0.01). Discussion: The number of patients decreased significantly during the period of study.
P17.43 Use of Statistical Control Charts to Improve Reporting of Surveillance of MRSA in Scotland R. Hill *, G. Allardice, J. Reilly, M. Coyne. Health Protection Scotland, UK Background: MRSA bacteraemia rates in Scotland (by division) have been reported every quarter since January 2001. Tabular methods have similarities to league tables with the obvious pit falls that someone ‘has to be last’ and that ‘first’ is not necessarily good. We recognise the need to use alternative methods that will simultaneously ensure that standards are being met while avoiding such comparative labels. Aim: The aim of this research is to examine the use of alternative methods to enhance the routine reporting of MRSA bacteraemia in Scotland. Methods: Two recent developments in Statistical Process Control (SPC) are examined; Funnel Plots and Cusum Control Charts. Funnel plots meet our needs as they can be used to identify divisions that are not meeting a required standard while avoiding the ranking of the other divisions. We have utilised CUSUM charts to investigate trends within divisions; this method identifies both large changes and smaller sustained drifts in prevalence of MRSA. Results: This paper will develop examples of CUSUM charts and Funnel plots of MRSA bacteraemia rates within acute healthcare divisions in Scotland. Conclusions: SPC methods are a useful tool in monitoring complex healthcare processes, particularly where it is necessary to simultaneously compare institutions and trends over time. They avoid stigmatising institutions unnecessarily while enabling poorly performing institutions to be identified. Other surveillance systems may want to investigate whether these methodologies are appropriate.
Poster Presentations Reference(s) Boyce NW. Potential pitfall of healthcare performance indicators. Medical Journal of Australia 2002; 117 (5): 299– 230. Spiegelhalter DJ. Funnel plots for comparing institutional performance. Statistics in Medicine 2005; 24: 1185–1202. Bird S, Cox D, Farewell VT, Goldstein HG, Holt T, Smith PC. RSS working party on performance monitoring in the public service. Royal Statistics Society, October 2003 P17.44 Laboratory Based Surveillance of Invasive Group A Streptococcal Infections in Edinburgh, 1999–2006 H. Venkatesh1 *, P. Kalima2 . 1 Western General Hospital, Edinburgh, UK, 2 Western General Hospital, UK Objective: To review the incidence of invasive group A streptococcal infections (iGAS) in Edinburgh and to create an awareness among health care professionals regarding the increased incidence of invasive GAS infections in recent years. Methods: This is a retrospective laboratory based review of invasive group A streptococcal isolates from March 1999 to March 2006. Cases were defined as isolation of GAS from a normally sterile site such as blood, cerebrospinal fluid, pleural fluids, joint aspirates and deep specimens. Repeat isolates from the same patient were excluded within a 15 day period. Results: Out of the 5291, 102 (1.9%) were blood culture isolates. The highest incidence was found in the first quarter of 2006. A seasonal variation was noted with a increased incidence in the first two quarters of every year of the study period. Discussion: We retrospectively studied proven GAS bacteremias associated with clinical disease over a six year period. A literature search reporting invasive GAS from other parts of the world includes studies in Europe and the United States. A laboratory based nationwide surveillance of invasive GAS in Netherlands done from 1994–2003 showed the possibility of new serotypes causing severe disease. A surveillance system set up in Italy helped physicians with microbiological analysis of strains and made them aware of the importance of early diagnosis and aggressive management of invasive infection. Conclusions: The increasing incidence of iGAS in Edinburgh remains a potential problem in the health care setting. We are taking several interventional measures to increase the awareness among health care workers and continued surveillance is invaluable. P17.45 Incidence Reduction of Central Venous Catheter Related Infection (CRI) During a 5-Years Surveillance in ICU in Northern France F. L’H´ eriteau1 *, M. Olivier1 , S. Maugat1 , C. Joly1 , G. Beaucaire2 , P. Astagneau1 . 1 C-CLIN Paris Nord, France, 2 CHRU Lille, France Background: Central venous catheter (CVC) related infections (CRI) are among the most common and life threatening nosocomial infections (NI) in intensive care units (ICU). Surveillance systems have already been shown to reduce significantly NI incidence. The regional coordinating center for NI control has implemented a CRI surveillance network in ICU (Reacat) since 1999. This surveillance led to the construction of a standardized incidence ratio (SIR) adjusting CRI incidence for risk factors. Objectives: To evaluate the reduction of CRI incidence in ICU participating in the Reacat network. Methods: All ICU were requested to participate on a voluntary basis. All CVC inserted for more than 48 hours were followed until removal or patient discharge. CRI risk factors were recorded. Standard and microbiological criteria were used to define CRI. A logistic regression model was used to define the
S95 number of expected CRI. SIR was estimated by dividing the number of observed CRI by the number of expected CRI. Results: From 2000 to 2005, 135 ICU participated to surveillance for at least one period. Overall 11,705 CVC in 913 patients accounting for 122,489 CVC-days were included. CRI incidence was 2.8 per 1000 CVC-days. Among ICU, 35 (cohort A), 16 (cohort B), and 10 (cohort C) participated for 3, 4 and 5 consecutive periods, respectively. Cohorts A, B and C included 4350, 2894 and 2445 CVC, respectively. CRI incidence decreased significantly from the first to the last surveillance period in all three cohorts: –60.6%, –58.2% and –77.6% in cohorts A, B and C, respectively. SIR also decreased significantly from the first to the last surveillance period. Conclusion: Our data suggest that surveillance had a significant impact on CRI incidence reduction. Control efforts of CRI based on hygiene practice improvement are needed to complete the surveillance approach. P17.46 Development of a Record Keeping Tool for Infection Prevention & Control Nurses (IPCNs) I. Thompson1 *, C. Clarke2 , C. McGeary2 , E. Smyth2 . 1 The Royal Hospitals Belfast, UK, 2 Bacteriology Department, The Royal Hospitals, Belfast, Northern Ireland, UK Background: IPCNs have a legal and professional responsibility to maintain records on advice and treatments. Record keeping can be time consuming and an added pressure on limited resources. With this system it should be possible to analyse data to inform the Infection Prevention and Control Team (IPCT) in workload analysis, high risk areas and teaching purposes. Aim: To describe the development and benefits of a scannable form to facilitate efficient and accurate record keeping. Methods: Review previous infection prevention and control records. Development of a scannable form to record information with minimal free-text. Form consisted of two A4 printed sides. Completed forms scanned and data captured automatically. Software Formic for Windows version 3. Scanned data exported to SPSS for analysis. Results: From April 2005 to March 2006 there were 986 records generated of which approximately 55% related to MRSA patients that were new to the Trust, 10% with a previous history of MRSA, 15% Clostridium difficile, 12% ESBLs and 8% others. These results will be expanded on in the presentation. Discussion: This method of record keeping has the potential to be an efficient and useful method of record keeping. This information assists the IPCT in the areas listed below and also allows for future planning of resources and targeted surveillance. • Records number of referrals to the IPCN. • Allows comparisons with laboratory records to ensure all patients are captured. • Identifies high risk areas. • Assesses patient placement. • Provides information for Litigation and FOI requests. • Graphical information can be used for teaching purposes and report writing • Easier generation of information pertinent to the Trust. The content and structure of the form has recently been reviewed and we are currently refining the size and content of the form.