Skin and soft tissue infections and current antimicrobial prescribing practices in Australian aged care residents.

To determine the burden of skin and soft tissue infections (SSTI), the nature of antimicrobial prescribing and factors contributing to inappropriate prescribing for SSTIs in Australian aged care facilities, SSTI and antimicrobial prescribing data were collected via a standardised national survey. The proportion of residents prescribed ⩾1 antimicrobial for presumed SSTI and the proportion whose infections met McGeer et al. surveillance definitions were determined. Antimicrobial choice was compared to national prescribing guidelines and prescription duration analysed using a negative binomial mixed-effects regression model. Of 12 319 surveyed residents, 452 (3.7%) were prescribed an antimicrobial for a SSTI and 29% of these residents had confirmed infection. Topical clotrimazole was most frequently prescribed, often for unspecified indications. Where an indication was documented, antimicrobial choice was generally aligned with recommendations. Duration of prescribing (in days) was associated with use of an agent for prophylaxis (rate ratio (RR) 1.63, 95% confidence interval (CI) 1.08-2.52), PRN orders (RR 2.10, 95% CI 1.42-3.11) and prescription of a topical agent (RR 1.47, 95% CI 1.08-2.02), while documentation of a review or stop date was associated with reduced duration of prescribing (RR 0.33, 95% CI 0.25-0.43). Antimicrobial prescribing for SSTI is frequent in aged care facilities in Australia. Methods to enhance appropriate prescribing, including clinician documentation, are required.

What are the similarities and differences in antimicrobial prescribing between Australian public and private hospitals?

BACKGROUND: Identifying themes associated with inappropriate prescribing in Australian public and private hospitals will help target future antimicrobial stewardship initiatives. AIMS: To describe current antimicrobial prescribing practices, identify similarities and differences between hospital sectors and provide target areas for improvement specific to each hospital sector. METHODS: All hospitals included in the study were part of the 2014 national antimicrobial prescribing survey and conducted one of the following: a whole hospital point prevalence survey, serial point prevalence surveys or a sample of randomly selected patients. Data on the types of antibiotics used, their indications for use and the quality of prescription based on compliance with national and local prescribing guidelines were collected. RESULTS: Two hundred and two hospitals (166 public and 36 private) comprising 10 882 patients and 15 967 antimicrobial prescriptions were included. Public hospitals had higher proportions of prescriptions for treatment (81.5% vs 48.4%) and medical prophylaxis (8.8% and 4.6%), whilst private hospitals had significantly higher surgical prophylaxis use (9.6% vs 46.9%) (P < 0.001). In public hospitals, the main reasons for non-compliance of treatment prescriptions were spectrum being too broad (30.5%) while in private it was incorrect dosing. Prolonged duration was the main reason for non-compliance among surgical prophylaxis prescriptions in both types of hospitals. CONCLUSIONS: Australian hospitals need to target specific areas to improve antimicrobial use. Specifically, unnecessary broad-spectrum therapy should be a priority area in public hospitals, whilst emphasis on curtailing antimicrobial overuse in surgical prophylaxis needs to be urgently addressed across in the private hospital sector.

Managing a nosocomial outbreak of carbapenem-resistant Klebsiella pneumoniae: an early Australian hospital experience.

BACKGROUND: Carbapenems are traditionally reserved as the last line of defence for treatment of serious infections with multiresistant Gram-negative bacilli. Reports of Klebsiella pneumoniae carbapenemase (KPC)-producing organisms have been emerging globally, but rare in Australasia to date. We describe an outbreak of KPC-2 producing K. pneumoniae at an Australian hospital. METHODS: After initial detection in October 2012, a retrospective review of patients with meropenem-resistant K. pneumoniae to June 2012, and ongoing prospective surveillance, was undertaken. Included patients were admitted to the hospital after June 2012 and had meropenem-resistant K. pneumoniae isolated from any site. Available isolates underwent detection of the KPC-2 gene by polymerase chain reaction and molecular typing was performed to determine genetic relatedness between isolates. Point-prevalence screening was performed on selected wards to detect asymptomatic carriage. Infection control procedures were implemented to contain the outbreak. RESULTS: Ten cases were identified in the initial cluster. Eight were localised to a single inpatient ward. Point-prevalence screening revealed one extra case. After temporary containment, re-emergence of KPC-producing isolates was observed post October 2013 with 18 further cases identified. Four K. pneumoniae isolates in the 2012 cluster and 16 from the 2013-2014 cluster were referred for further testing. All carried the KPC-2 beta-lactamase gene. The 2012 isolates were genetically similar to the 2014 isolates. CONCLUSION: KPC-2 mediated resistance is an emerging threat in Australia. The re-emergence of KPC despite initial containment emphasises the need for constant vigilance in the microbiology laboratory and ongoing maintenance of infection control and antimicrobial stewardship activity.

Sticking to minimum standards: implementing antibiotic stewardship in intensive care.

BACKGROUND: In Australia, antimicrobial stewardship programmes are a compulsory component of hospital accreditation. Good documentation around anti-microbial prescribing aids communication and can improve prescribing practice in environments with multiple decision makers. AIM: This study aims to develop and implement an intervention to improve antimicrobial prescribing practice in a 24-bed intensive care unit in a tertiary referral adult hospital. METHODS: We conducted a four-phase (observation, reflection, implementation, evaluation) prospective collaborative before-after quality improvement study. Baseline audits and surveys of antimicrobial prescribing practices identified barriers to and enablers of good prescribing practice. A customised intervention was then implemented over 6 weeks and included a yellow medication record sticker, quarterly education sessions and intensive care unit-specific empiric antimicrobial prescribing guidelines. Post-implementation, the effects were monitored by serial antimicrobial prescribing audits for 1 year. The primary outcomes were clear documentation of the start date, the planned stop date or review date and the indication for an antibiotic. These were all considered the 'minimum standards' for an antimicrobial prescription on the medication record. RESULTS: Documentation of minimum standards specifically addressed by the sticker improved (start date (72% to 90%, P < 0.001), stop date (16% to 63%, P < 0.001), antimicrobial indication documented on medication chart (58% to 83%, P < 0.01)). Overall, adherence to all three minimum standards (start date, stop date and indication) improved from 41/306 (13%) to 306/492 (63%) (P < 0.001). One-year post-implementation, the yellow sticker had become embedded into daily practice. CONCLUSION: A systematic approach to quality improvement combined with the implementation of a tailored, multi-faceted intervention can improve antimicrobial prescribing practices.

Using periodic point-prevalence surveys to assess appropriateness of antimicrobial prescribing in Australian private hospitals.

BACKGROUND AND AIMS: Appropriateness of antimicrobial use is a measure of key importance in evaluating safety and quality of prescribing but has been difficult to define and assess on a wide scale. Published work is limited and has generally focused on tertiary public hospitals, whereas the private sector provides a significant proportion of care in many countries. Information on prescribing in the private hospital context is needed to identify where intervention might be required. An antimicrobial prescribing survey tool was utilised to assess the appropriateness of antimicrobial prescribing among large private hospitals in Australia. METHODS: 'Appropriateness' of antimicrobial therapy was evaluated by a team consisting of an infectious diseases physician and specialist infectious diseases pharmacist based on clear criteria. RESULTS: Thirteen hospital-wide point-prevalence surveys were conducted. Three thousand, four hundred and seventy-two inpatient medication charts were reviewed to identify 1125 (32.4%) inpatients on 1444 antimicrobials. An indication was documented in 911 (63.1%) of surveyed prescriptions, and overall, 757 (52.4%) of antimicrobials were assessed as appropriate. Antimicrobials prescribed for treatment had a higher proportion of appropriateness when compared with antimicrobials prescribed for surgical prophylaxis (80.4% vs 40.6%). The main reason for a treatment prescription to be considered inappropriate was incorrect selection, while prolonged duration (>24 h) was the main reason for inappropriate surgical prophylaxis prescriptions. CONCLUSIONS: This study provides important data on antimicrobial prescribing patterns in Australian private hospitals. Results can be used to target areas for improvement, with documentation of indication and surgical antibiotic prophylaxis requiring initial attention.

Outcome of debridement and retention in prosthetic joint infections by methicillin-resistant staphylococci, with special reference to rifampin and fusidic acid combination therapy.

The management of prosthetic joint infections remains a clinical challenge, particularly infections due to methicillin-resistant staphylococci. Previously, this infection was considered a contraindication to debridement and retention strategies. This retrospective cohort study examined the treatment and outcomes of patients with arthroplasty infection by methicillin-resistant staphylococci managed by debridement and retention in conjunction with rifampin-fusidic acid combination therapy. Over an 11-year period, there were 43 patients with infection by methicillin-resistant staphylococci managed with debridement and retention. This consisted of close-interval repeated arthrotomies with pulsatile lavage. Rifampin was combined with fusidic acid for the majority of patients (88%). Patients were monitored for a median of 33.5 months (interquartile range, 20 to 54 months). Overall, 9 patients experienced treatment failure, with 12- and 24-month estimates of infection-free survival of 86% (95% confidence interval [CI], 71 to 93%) and 77% (95% CI, 60 to 87%), respectively. The following factors were associated with treatment failure: methicillin-resistant Staphylococcus aureus (MRSA) arthroplasty infection, a single surgical debridement or ≥4 debridements, and the receipt of less than 90 days of antibiotic therapy. Patients with infection by methicillin-resistant coagulase-negative staphylococci (MR-CNS) were less likely to fail treatment. The overall treatment success rate reported in this study is comparable to those of other treatment modalities for prosthetic joint infections by methicillin-resistant staphylococci. Therefore, the debridement and retention of the prosthesis and rifampin-based antibiotic therapy are a valid treatment option for carefully selected patients.

Use of pristinamycin for infections by gram-positive bacteria: clinical experience at an Australian hospital.

Thirty-six patients were treated with pristinamycin for 46 different microbiological isolates between April 2007 and July 2009. Pathogens included 9 methicillin-resistant Staphylococcus aureus isolates, 13 methicillin-resistant coagulase negative staphylococci, and 9 vancomycin-resistant enterococci. Sites of infections included 12 osteomyelitis cases, 10 prosthetic joints, 4 other prostheses, and 1 epidural abscess. Five patients ceased treatment due to side effects. Ten patients were cured of their infections, and 21 patients had infections successfully suppressed.

Improved susceptibility of Gram-negative bacteria in an intensive care unit following implementation of a computerized antibiotic decision support system.

OBJECTIVES: Emergence of multiresistant Gram-negative organisms in intensive care units (ICUs) throughout the world is a concerning problem. Therefore we undertook a study to follow the resistance patterns of the most common clinically isolated Gram-negative organisms within our ICU following an antibiotic stewardship intervention to evaluate whether a reduction in broad-spectrum antibiotics improves local antibiotic resistance patterns. METHODS: This prospective study was conducted over a 7 year period within an ICU at a tertiary teaching hospital in Melbourne, Australia. All clinically isolated Gram-negative organisms were identified and extracted from the hospital pathology system. Three monthly antibiograms were created. The pre-interventional period occurred between January 2000 and June 2002 (10 quarters) and the post-interventional period was defined from July 2002 to December 2006 (18 quarters). Segmented linear regression was used to analyse for a difference in the rates of change in susceptibility. RESULTS: A total of 2838 Gram-negative organisms were isolated from clinical sites from ICU patients during the study period. There was significant improvement in susceptibility of Pseudomonas to imipenem 18.3%/year [95% confidence interval (CI): 4.9-31.6; P = 0.009] and gentamicin 11.6%/year (95% CI: 1.8-21.5; P = 0.02) compared with the pre-intervention trend. Significant changes in the rates of gentamicin and ciprofloxacin susceptibility were also observed in the inducible Enterobacteriaceae group although these were less clinically significant. CONCLUSIONS: This study demonstrates improved antibiotic susceptibility of ICU Gram-negative isolates including Pseudomonas following an intervention aimed at reducing broad-spectrum antibiotics.

Qualitative study of the factors impacting antimicrobial stewardship programme delivery in regional and remote hospitals.

BACKGROUND: Many regional and remote ('regional') hospitals are without the specialist services that support antimicrobial stewardship (AMS) programmes in hospitals in major cities. This can impact their ability to implement AMS activities. AIM: To identify factors that impact on the delivery of AMS programmes in regional hospitals. METHODS: Healthcare clinicians who have primary AMS responsibilities or provide AMS support to a health service or across health services with an Australian Statistical Geography Standard Remoteness classification of inner regional, outer regional, remote or very remote were recruited purposively and via snowballing. A series of focus groups and interviews were held, and the discussions were audiotaped and transcribed verbatim. The transcripts were coded by two researchers, and thematic analysis was undertaken using a framework method. FINDINGS: Four focus groups and one interview were conducted (22 participants). Six main themes that impacted on AMS programme delivery were identified: culture of independence and self-reliance by local clinicians, personal relationships, geographical location of the hospital influencing antimicrobial choice, local context, inability to meaningfully benchmark performance, and lack of resources. Possible strategies to support the delivery of AMS programmes in regional hospitals proposed by participants were categorized into two main themes: those that may be best developed or managed centrally, and those that should be a local responsibility. CONCLUSION: AMS programme delivery in regional hospitals is influenced by factors that are not present in hospitals in major cities. These findings provide a strong basis for the development of strategies to support regional hospitals to implement sustainable AMS programmes.

Chlorhexidine-alcohol versus iodine-alcohol for surgical site skin preparation in an elective arthroplasty (ACAISA) study: a cluster randomized controlled trial.

OBJECTIVES: Surgical site skin preparation is an effective method to prevent wound complications. The optimal agent has not been established, and guidelines contain conflicting recommendations. METHODS: The aim of alcoholic chlorhexidine or alcoholic iodine skin antisepsis (ACAISA) was to assess the efficacy of surgical site skin preparation with 0.5% chlorhexidine gluconate (w/v) in 70% ethanol (v/v) to 1% iodine (w/v) in 70% ethanol (v/v). This was a cluster randomized, controlled, single-centre, assessor-blinded, superiority trial in patients undergoing elective hip or knee arthroplasty. Each surgeon had a set operating day and the unit of randomization was the day of surgery. The primary outcome was superficial wound complication, defined as a composite endpoint of superficial incisional surgical site infection and/or clinically significant wound ooze in the 30 days following arthroplasty. The secondary outcome was any surgical site infection, including prosthetic joint infection. Outcome ascertainment was undertaken by an independent verification panel. The primary analysis was intention-to-treat, performed at the individual level. Taking into account the clustering effect, analysis of primary and secondary outcomes was undertaken at the level of the surgeon. RESULTS: A total of 780 participants were included; 390 participants were allocated chlorhexidine-alcohol and 390 participants were allocated iodine-alcohol. There was no difference in superficial wound complications: 19 (4.9%) versus 15 (3.8%) respectively (OR 1.28; 95%CI 0.62, 2.63; p 0.50). There was an increased odds of surgical site infection in the chlorhexidine-alcohol group compared to iodine-alcohol: 12 (3.1%) versus four (1.0%) respectively (OR 3.06; 95%CI 1.26, 7.46; p 0.014). The odds of prosthetic joint infection were also increased in the chlorhexidine-alcohol arm compared with iodine-alcohol: seven (1.8%) versus two (0.5%) respectively (OR 3.55; 95%CI 1.20, 10.44; p 0.022). CONCLUSIONS: No difference was observed in the primary outcome of superficial wound complications when chlorhexidine-alcohol and iodine-alcohol were compared. However, on a secondary analysis, iodine-alcohol had greater efficacy than chlorhexidine-alcohol for preventing surgical site infection. CLINICAL TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12614000177651.

Electronic antibiotic stewardship--reduced consumption of broad-spectrum antibiotics using a computerized antimicrobial approval system in a hospital setting.

OBJECTIVES: Antibiotic stewardship is important, but the ideal strategy for providing stewardship in a hospital setting is unknown. A practical, sustainable and transferable strategy is needed. This study evaluates the impact of a novel computerized antimicrobial approval system on antibiotic-prescribing behaviour in a hospital. Effects on drug consumption, antibiotic resistance patterns of local bacteria and patient outcomes were monitored. METHODS: The study was conducted at a tertiary referral teaching hospital in Melbourne, Australia. The system was deployed in January 2005 and guided the use of 28 restricted antimicrobials. Data were collected over 7 years: 5 years before and 2 years after deployment. Uptake of the system was evaluated using an in-built audit trail. Drug utilization was prospectively monitored using pharmacy data (as defined daily doses per 1000 bed-days) and analysed via time-series analysis with segmental linear regression. Antibiograms of local bacteria were prospectively evaluated. In-hospital mortality and length of stay for patients with Gram-negative bacteraemia were also reported. RESULTS: Between 250 and 300 approvals were registered per month during 2006. The gradients in the use of third- and fourth-generation cephalosporins (+0.52, -0.05, -0.39; P < 0.01), glycopeptides (+0.27, -0.53; P = 0.09), carbapenems (+0.12, -0.24; P = 0.21), aminoglycosides (+0.15, -0.27; P < 0.01) and quinolones (+0.76, +0.11; P = 0.08) all fell after deployment, while extended-spectrum penicillin use increased. Trends in increased susceptibility of Staphylococcus aureus to methicillin and improved susceptibility of Pseudomonas spp. to many antibiotics were observed. No increase in adverse outcomes for patients with Gram-negative bacteraemia was observed. CONCLUSIONS: The system was successfully adopted and significant changes in antimicrobial usage were demonstrated.

Empiric antibiotic prescribing for patients with community-acquired pneumonia: where can we improve?

BACKGROUND: Community acquired pneumonia is one of the most common infections for which antibiotics are prescribed in Australia. METHODS: We audited empiric antibiotic prescribing for 392 adults with community-acquired pneumonia. RESULTS: Only 61.9% of patients received empiric antibiotic coverage for both typical and atypical pathogens. Of those who required intensive care unit management, 34.6% did not receive antibiotic cover for atypical pneumonia pathogens within the first 24 h. Approximately 21.9% of patients reporting antibiotic allergies were given antibiotics to which they had a documented allergy. CONCLUSION: Efforts to improve prescribing practices could be focused towards identifying patients with severe illness early and improving recognition of documented allergies.

Treatment of staphylococcal prosthetic joint infections with debridement, prosthesis retention and oral rifampicin and fusidic acid.

There is growing evidence of the efficacy of treating early staphylococcal infections of prosthetic joints with surgical debridement and prosthesis retention, combined with oral antibiotic regimens that include rifampicin in combination with a fluoroquinolone. With rising rates of fluoroquinolone-resistant staphylococci, evidence concerning the efficacy of alternative combinations of antibiotics is required. Twenty patients with staphylococcal prosthetic joint infections who had been treated with surgical debridement and prosthesis retention, and a combination of rifampicin and fusidic acid were analysed. The mean duration of symptoms before initial debridement was 16 (range 2-75) days. The median time of follow-up was 32 (range 6-76) months. Treatment failure occurred in two patients. The cumulative risk of treatment failure after 1 year was 11.76% (95% CI 3.08-39.40%). Two patients had their treatment changed because of nausea. Ten of 11 patients with infections involving methicillin-resistant Staphylococcus aureus had successful outcomes. Debridement without prosthesis removal, in combination with rifampicin and fusidic acid treatment, was effective and should be considered for patients with early staphylococcal prosthetic joint infections, including those with infections involving fluoroquinolone-resistant organisms.

Risk factors for KPC-producing Enterobacteriaceae acquisition and infection in a healthcare setting with possible local transmission: a case-control study.

BACKGROUND: Reports of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-Kp) in Australia were previously uncommon, with cases imported sporadically by travellers from higher prevalence countries. AIM: The study institution reported the first outbreak of KPC-Kp in Australia. The aim of this study was to identify risk factors for KPC-Kp colonization and infection using a matched case-control study. METHODS: The study included all hospitalized patients with KPC-Kp colonization or infection from January 2012 to September 2015. FINDINGS: Thirty-four cases of KPC-producing Enterobacteriaceae (including 31 KPC-Kp cases) were matched with 136 controls. Variables associated with KPC-Kp acquisition included: length of hospital stay >28 days in the past 12 months, prior vancomycin-resistant enterococci (VRE) colonization, central venous catheter (CVC), gastrointestinal disease and invasive procedures. Exposure to broad-spectrum antibiotics was also found to be a significant risk factor. In the multi-variate analysis, three factors independently associated with KPC-Kp acquisition were length of hospital stay >28 days in the past 12 months [odds ratio (OR) 23.6, 95% confidence interval (CI) 4.9-113.3], presence of a CVC (OR 15.4, 95% CI 2.7-86.9), and prior VRE colonization (OR 6.0, 95% CI 1.6-23.2). Very few patients had a history of overseas travel. CONCLUSION: This study demonstrates that patients with prolonged hospital exposure are more likely to acquire KPC-Kp in the setting of a local outbreak, and suggests that risk factors for KPC-Kp acquisition may be shared with those for VRE colonization. Local screening strategies targeting overseas travellers would likely miss many cases. The results of this study will help to inform screening policies for carbapenemase-producing Enterobacteriaceae.

Direct hospital cost determinants following hip and knee arthroplasty.

OBJECTIVE: Total joint arthroplasty (TJA) places a significant economic burden on health care resources. This cohort study examines the costs associated with arthroplasty in 827 patients undergoing hip and knee TJA from January 2011 to June 2012 at a single center in Melbourne, Australia. METHODS: Data included total inpatient, outpatient, and readmissions costs in the 30 days following TJA. Factors associated with cost were modeled using negative binomial regression and extrapolated to the Australian population. RESULTS: The base cost (i.e., the cost for a patient with no modifying factors) over the first 30 days following TJA was $13,060 Australian (AU) (interquartile range $12,126-14,067 AU). The median length of stay was 4 days (range 2-33 days) and 35 patients (4%) were readmitted in the first 30 days following index TJA, the majority of whom had a surgical site infection (SSI) (74%). The following factors were independently associated with increased costs: SSI, preoperative warfarin therapy, American Society of Anesthesiologists score of 3 or 4, hip TJA, increasing operation time, increasing postoperative blood transfusion requirements, other nosocomial infections, postoperative venous thromboembolism (VTE), pressure ulcers, postoperative confusion, and acute urinary retention. Based on data from the present study, the cost of TJA in Australia is estimated to exceed $1 billion AU per year. Preventable postoperative complications were major cost drivers: SSI and VTE added a further $97 million AU and $66 million AU, respectively, to arthroplasty costs in the first 30 days following surgery. CONCLUSION: This unique study has identified important factors influencing TJA costs and providing guidance for future research and resource allocation.

Alcoholic Chlorhexidine or Alcoholic Iodine Skin Antisepsis (ACAISA): protocol for cluster randomised controlled trial of surgical skin preparation for the prevention of superficial wound complications in prosthetic hip and knee replacement surgery.

INTRODUCTION: Wound complications following arthroplasty are associated with significant impact on the patient and healthcare system. Skin cleansing prior to surgical incision is a simple and effective method to prevent wound complications however, the question of which agent is superior for surgical skin antisepsis is unresolved. METHODS AND ANALYSIS: This cluster randomised controlled trial aims to compare the incidence of superficial wound complications in patients undergoing elective prosthetic hip or knee replacement surgery receiving surgical skin antisepsis with either: 0.5% chlorhexidine gluconate (CHG) in 70% alcohol or 10% povidone in 70% alcohol. The trial will be conducted at an Australian tertiary, university affiliated hospital over a 3-year period involving 750 participants. Participants will be drawn from the surgical waiting list. Consent for this study will be 'opt-out' consent. On a given day, all eligible participants will have skin preparation either with 0.5% chlorhexidine in 70% alcohol or 10% povidone iodine in 70% alcohol. The primary outcome is superficial wound complications (comprised of superficial incisional surgical site infections (SSI) and/or prolonged wound ooze) in the first 30 days following prosthetic joint replacement surgery. Secondary outcomes will include the incidence of wound complications according to the joint replaced, assessment of the causative agents of SSI and cost-effectiveness analysis. The primary analysis is an intention-to-treat analysis including all participants who undergo randomisation and will be performed at the individual level taking into account the clustering effect. ETHICS AND DISSEMINATION: The study design and protocol was reviewed and approved by the St Vincent's Hospital Human Research Ethics Committee (HREC-A 016/14 10/3/2014). Study findings will be disseminated in the printed media, and learned forums. A written lay summary will be available to study participants on request. TRIAL REGISTRATION NUMBER: The trial has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12614000177651.

Cost analysis of debridement and retention for management of prosthetic joint infection.

Prosthetic joint infection remains one of the most devastating complications of arthroplasty. Debridement and retention of the prosthesis is an attractive management option in carefully selected patients. Despite this, there are no data investigating the cost of this management modality for prosthetic joint infections. The aim of this case-control study was to calculate the cost associated with debridement and retention for management of prosthetic joint infection compared with primary joint replacement surgery without prosthetic joint infection. From 1 January 2008 to 30 June 2010, there were 21 prosthetic joint infections matched to 42 control patients. Controls were matched to cases according to the arthroplasty site, age and sex. Cases had a greater number of unplanned readmissions (100% vs. 7.1%; p <0.001), more additional surgery (3.3 vs. 0.07; p <0.001) and longer total bed days (31.6 vs. 7.9 days; p <0.001). In addition they had more inpatient, outpatient and emergency department visits (p <0.001, respectively). For patients with prosthetic joint infection the total cost, including index operation and costs of management of the prosthetic joint infection, was 3.1 times the cost of primary arthoplasty; the mean cost for cases was Australian dollars (AUD) $69,414 (±29,869) compared with $22,085 (±8147) (p <0.001). The demand for arthroplasty continues to grow and with that, the number of prosthetic joint infections will also increase, placing significant burden on the health system. Our study adds significantly to the growing body of evidence highlighting the substantial costs associated with prosthetic joint infection.

Factors influencing the cost of prosthetic joint infection treatment.

BACKGROUND: Prosthetic joint infection (PJI) is associated with significant costs to the healthcare system. Current literature examines the cost of specific treatment modalities without assessing other cost drivers for PJI. AIMS: To examine the overall cost of the treatment of PJI and to identify factors associated with management costs. METHODS: The costs of treatment of prosthetic joint infections were examined in 139 patients across 10 hospitals over a 3-year period (January 2006 to December 2008). Cost calculations included hospitalization costs, surgical costs, hospital-in-the-home costs and antibiotic therapy costs. Negative binomial regression analysis was performed to model factors associated with total cost. FINDINGS: The median cost of treating prosthetic joint infection per patient was Australian $34,800 (interquartile range: 20,305, 56,929). The following factors were associated with increased treatment costs: septic revision arthroplasty (67% increase in treatment cost; P = 0.02), hypotension at presentation (70% increase; P = 0.03), polymicrobial infections (41% increase; P = 0.009), surgical treatment with one-stage exchange (100% increase; P = 0.002) or resection arthroplasty (48% increase; P = 0.001) were independently associated with increased treatment costs. Culture-negative prosthetic joint infections were associated with decreased costs (29% decrease in treatment cost; P = 0.047). Treatment failure was associated with 156% increase in treatment costs. CONCLUSIONS: This study identifies clinically important factors influencing treatment costs that may be of relevance to policy-makers, particularly in the setting of hospital reimbursement and guiding future research into cost-effective preventive strategies.

Early onset prosthetic hip and knee joint infection: treatment and outcomes in Victoria, Australia.

BACKGROUND: Prosthetic joint infection (PJI) remains a devastating complication of arthroplasty. There are no internationally endorsed consensus management guidelines and treatment approaches differ widely. AIM: The aim of this multicentre study was to examine treatment approaches and predictors of treatment failure in patients with early PJI managed in hospitals in Victoria, Australia. METHODS: This cohort study was conducted across 10 hospitals over a three-year period (January 2006 to December 2008) and involved 147 patients who presented with early PJI. FINDINGS: Most patients (76%) were managed with debridement and retention of the prosthesis. Patients were followed for a median 20 months (interquartile range: 7-36). Overall 43 patients experienced treatment failure with a 12-month infection-free survival estimate of 76% [95% confidence interval (CI): 68-83%]. The following factors were associated with treatment failure: septic revision arthroplasty (hazard ratio: 7.5; 95% CI: 2.4-23.1; P < 0.0001), hypotension at presentation (4.9; 1.5-15.7; P = 0.007), one-stage exchange (3.1; 1.0-9.2; P = 0.048), total duration of antibiotic therapy <90 days: specifically <30 days (18.5; 5.4-63.1; P < 0.001), 30-60 days (8.0; 2.6-23.9; P < 0.001) and 60-90 days (7.3; 2.2-24.4; P = 0.001), respectively. Effective empiric antibiotic therapy was associated with a decreased risk of treatment failure (0.20; 0.09-0.47; P < 0.001). CONCLUSIONS: The management approach in Australia differs from that used elsewhere in the world. We have identified a number of clinically relevant risk factors for treatment failure that may impact on treatment recommendations.

Risk factors for prosthetic hip and knee infections according to arthroplasty site.

Prosthetic joint infection is a devastating complication of arthroplasty. Previous epidemiological studies have assessed factors associated with arthroplasty infections but have not assessed the impact of comorbidity on infection at different arthroplasty locations. We used a case-control design to investigate risk factors for prosthetic joint infection with reference to the anatomical site. During an eight-year period at a single hospital, 63 patients developed a prosthetic joint infection (36 hips, 27 knees). Cases of prosthetic hip or knee joint infection were matched 1:2 to controls. The results suggest that factors associated with arthroplasty infections differ with anatomical location. Following knee arthroplasty, wound discharge was associated with an increased risk of prosthetic joint infection whereas the presence of a drain tube reduced the risk. By contrast, increased body mass index, increased drain tube loss and superficial incisional surgical site infections (SSIs) were associated with prosthetic hip infection. When analysed as a combined cohort, systemic steroid use, increased SSI drain tube losses, wound discharge, and superficial incisional SSIs were predictors of infection.