Antibiotic Use In Community Research Articles

Prescriber and dispenser perceptions about antibiotic use in acute uncomplicated childhood diarrhea and upper respiratory tract infection in New Delhi: Qualitative study.

OBJECTIVE:The objective of the study was to explore the prescribing practices, knowledge, and attitudes of primary care doctors and community pharmacists, regarding antibiotic use in acute upper respiratory tract infections (URTI) and diarrhea in children to better understand causes of misuse and identify provider suggestions to change such behavior.MATERIALS AND METHODS:Two focus group discussions (FGDs) each were conducted with primary care government doctors (GDs), private general practitioners (GPs), pediatricians, and community pharmacists in Delhi. Each FGD had 8–12 participants and lasted 2 h. Furthermore, 22 individual face-to-face semi-structured interviews were conducted with providers of varying type and experience at their workplaces. Thematic and summative qualitative content analysis was done.RESULTS:All groups admitted to overusing antibiotics, GPs appearing to use more antibiotics than GDs and pediatricians for URTI and diarrhea in children. Pharmacists copy the prescribing of neighborhood doctors. Antimicrobial resistance (AMR) knowledge was poor for all stakeholders except pediatricians. Causes for prescribing antibiotics were patient pressure, profit motive, lack of follow-up and in addition for GDs, workload, no diagnostic facility, and pressure to use near-expiry medicines. Knowledge was gained through self-experience, copying others, information from pharmaceutical companies, and for some, training, continuous medical education/conferences. All groups blamed other professional groups/quacks for antibiotic overuse. Interventions suggested were sensitizing and empowering prescribers through training of providers and the public about the appropriate antibiotic use and AMR and implementing stricter regulations.CONCLUSIONS:A package of interventions targeting providers and consumers is urgently needed for awareness and change in behavior to reduce inappropriate community antibiotic use.

What Accounts for a Large Increase in Antibiotic Prescribing by Dentists?

Background. While community antibiotic use by physicians has been declining in British Columbia (BC), we launched this study to begin to explain a troubling trend toward increased prescribing by dentists. Methods. All outpatient prescriptions are entered in the BC Pharmanet database. We obtained anonymized, line-listed data on prescriptions from 1996 to 2013, including a variable coding for licensing body of the prescriber. Analyses were conducted in SAS and Excel using Anatomical Therapeutic Classification (ATC) standard codes and defined daily dose values. Rates of prescribing and utilization were normalized to the BC population and expressed in defined daily doses per 1000 persons per day (DID). To evaluate the reasons for trends, a webinar was held through the Canadian Dental Association, inviting correspondence from dentists about the drivers of antibiotic use in practice. Results. From 1996 to 2013, overall community antibiotic use in BC declined from 18.2 to 15.9 DID and physician prescribing for antibiotics declined 18.2% from 17.4 to 14.1 DID. However, dental surgeons increased their rate 62.2% from 0.98 to 1.59 DID and their proportionate contribution of prescriptions from 6.7% to 11.3%. The rate of prescribing increased the most for dental patients aged 60 and over. We had 30 communications from US and Canadian dentists in response to the webinar and the following explanatory themes emerged: unnecessary prescription for periapical abscess and irreversible pulpitis; increase in use of dental implants and associated complications; slow adoption of newer guidelines calling for less perioperative antibiotic coverage for patients with valvular heart disease and prosthetic joints; emphasis on cosmetic practice reducing the surgical skill-set of the average dentist; under-insurance driving antibiotics as a substitute for surgery; aging population; and more dental registrants per capita. Conclusion. The above themes should be further validated in other studies but may already guide priorities in antibiotic stewardship for continuing dental education. Disclosures. F. Marra, Merck Canada Inc: Grant Investigator, Research grant

Urinary Escherichia coli antimicrobial susceptibility profiles and their relationship with community antibiotic use in Tasmania, Australia

This study assessed urinary Escherichia coli antibiotic susceptibility patterns in Tasmania, Australia, and examined their association with community antibiotic use. The susceptibility profiles of all urinary E. coli isolates collected in Tasmania between January 2010 and December 2012 were included. The amount of Pharmaceutical Benefits Scheme (PBS)-subsidised use of amoxicillin, amoxicillin/clavulanic acid (AMC), cefalexin, norfloxacin, ciprofloxacin and trimethoprim was retrieved (at the Tasmanian population level) and the number of defined daily doses per 1000 population per day in Tasmania for these antibiotics was calculated for each month during the study period. Antimicrobial susceptibility data were assessed for changes over time in the 3-year study period. Antimicrobial use and susceptibility data were assessed for seasonal differences and lag in resistance following antibiotic use. Excluding duplicates, 28145 E. coli isolates were included. Resistance levels were low; 35% of isolates were non-susceptible to amoxicillin, 14% were non-susceptible to trimethoprim and <5% were non-susceptible to AMC, cefalexin, gentamicin and norfloxacin. Amoxicillin use increased by 35% during winter/spring compared with summer/autumn, and AMC use increased by 21%. No seasonal variation in quinolone use or resistance was detected. The low levels of antimicrobial resistance identified may relate to Tasmania's isolated geographical location. Significant seasonal variation in amoxicillin and AMC use is likely to be due to increased use of these antibiotics for treatment of respiratory tract infections in winter. Quinolone use is restricted by the PBS in Australia, which is the likely explanation for the low levels of quinolone use and resistance identified.

Antibiotic use varies substantially among adults: a cross-national study from five European Countries in the ARITMO project.

To examine patterns of outpatient and community antibiotic use among adults in five European countries. We used healthcare data of 28.8 million adults from six population-based ARITMO project databases to ascertain information on systemic antibiotic use in Denmark (2000-2008), the Netherlands (1999-2010), Italy (2000-2010), the UK (1996-2009), and Germany (2004-2008). We estimated overall, and age-group and sex specific antibiotic use as defined daily doses (DDD) per 1000 inhabitants per day. We computed annual age- and sex-standardized population prevalence of antibiotic use per 1000 persons-years (p-y) and the mean duration (in days) of antibiotic use. The overall antibiotic use varied from 8.7 DDD per 1000 inhabitants per day in the UK to 18.1 DDD in Denmark, representing a 2.1-fold geographical variation. In all countries, prescribing was relatively high among individuals aged 15-19 years; lower in those aged 20-50 years; and then increased steadily reaching 41.8 DDD per 1000 inhabitants per day in individuals ≥ 85 years in Denmark. After age- and sex-standardization, prevalence of antibiotic use varied threefold from 160.2/1000 p-y in the UK to 421.1/1000 p-y in Italy. The ratio of broad- to narrow-spectrum penicillin, cephalosporin, and macrolide use varied from 0.6 in Denmark to 120.2 in Italy. Women used more antibiotics than men did in all countries. Across countries, the mean duration of antibiotic use varied 1.3 to 21.1-fold for different antibiotics. Antibiotic use is high in women and the elderly. Prescribing patterns vary substantially across European countries, both according to overall consumption, user prevalence, duration, and narrow- versus broad-spectrum antibiotics.

Cost-Effectiveness of Procalcitonin-Guided Antibiotic Use in Community Acquired Pneumonia

Although prior randomized trials have demonstrated that procalcitonin-guided antibiotic therapy effectively reduces antibiotic use in patients with community-acquired pneumonia (CAP), uncertainties remain regarding use of procalcitonin protocols in practice. To estimate the cost-effectiveness of procalcitonin protocols in CAP. Decision analysis using published observational and clinical trial data, with variation of all parameter values in sensitivity analyses. Hypothetical patient cohorts who were hospitalized for CAP. Procalcitonin protocols vs. usual care. Costs and cost per quality adjusted life year gained. When no differences in clinical outcomes were assumed, consistent with clinical trials and observational data, procalcitonin protocols cost $10-$54 more per patient than usual care in CAP patients. Under these assumptions, results were most sensitive to variations in: antibiotic cost, the likelihood that antibiotic therapy was initiated less frequently or over shorter durations, and the likelihood that physicians were nonadherent to procalcitonin protocols. Probabilistic sensitivity analyses, incorporating procalcitonin protocol-related changes in quality of life, found that protocol use was unlikely to be economically reasonable if physician protocol nonadherence was high, as observational study data suggest. However, procalcitonin protocols were favored if they decreased hospital length of stay. Procalcitonin protocol use in hospitalized CAP patients, although promising, lacks physician nonadherence and resource use data in routine care settings, which are needed to evaluate its potential role in patient care.

Seasonality and Temporal Correlation between Community Antibiotic Use and Resistance in the United States

Therapeutic antibiotic use in humans is a significant driver of antibiotic resistance. The seasonal effect of antibiotic use on antibiotic resistance has been poorly quantified because of lack of large-scale, spatially disaggregated time-series data on antibiotic use and resistance. We used time-series analysis (Box-Jenkins) on US antibiotic usage from IMS Health and on antibiotic resistance from The Surveillance Network from 1999-2007 to estimate the effect of aminopenicillin, fluoroquinolone, trimethoprim/sulfamethoxazole, and tetracycline usage on resistance of Escherichia coli to drugs within these classes. We also quantified the effect of fluoroquinolone and macrolide/lincosamide usage on resistance of methicillin-resistant Staphylococcus aureus (MRSA) to ciprofloxacin and clindamycin (which has a similar mode of action to macrolides), respectively. Prevalence of resistant Escherichia coli was significantly correlated with lagged (by 1 month) antibiotic prescriptions for aminopenicillins (0.22, P = .03) and fluoroquinolones (0.24, P = .02), which are highly prescribed, but was uncorrelated to antibiotic classes with lower prescription levels. Fluoroquinolone prescriptions were also significantly correlated with a 1-month lag with the prevalence of ciprofloxacin-resistant MRSA (0.23, P = .03). Large-scale usage of antibiotics can generate seasonal patterns of resistance that fluctuate on a short time scale with changes in antibiotic retail sales, suggesting that use of antibiotics in the winter could have a significant effect on resistance. In addition, the strong correlation between community use of antibiotics and resistance isolated in the hospital indicates that restrictions imposed at the hospital level are unlikely to be effective unless coordinated with campaigns to reduce unnecessary antibiotic use at the community level.

The impact of antibiotic use on the incidence and resistance pattern of extended‐spectrum beta‐lactamase‐producing bacteria in primary and secondary healthcare settings

• The emergence and spread of bacteria producing extended-spectrum beta-lactamases (ESBLs) has important therapeutic and epidemiologic implications. • A key target for the establishment of hospital antibiotic stewardship is reducing the occurrence of additional antibiotic resistance. • Further research is needed to accumulate supporting evidence that reducing antibiotic use will result in a parallel reduction in antibiotic resistance. • Fluoroquinolone restriction reversed ciprofloxacin resistance in primary and secondary healthcare settings. • Fluoroquinolone restriction reduced ESBL-producing bacteria incidence rates in both the primary and secondary healthcare settings. • This study highlights the value of time-series analysis in designing efficient antibiotic stewardship. The objective of the present study was to study the relationship between hospital antibiotic use, community antibiotic use and the incidence of extended-spectrum beta-lactamase (ESBL)-producing bacteria in hospitals, while assessing the impact of a fluoroquinolone restriction policy on ESBL-producing bacteria incidence rates. The study was retrospective and ecological in design. A multivariate autoregressive integrated moving average (ARIMA) model was built to relate antibiotic use to ESB-producing bacteria incidence rates and resistance patterns over a 5 year period (January 2005-December 2009). Analysis showed that the hospital incidence of ESBLs had a positive relationship with the use of fluoroquinolones in the hospital (coefficient = 0.174, P= 0.02), amoxicillin-clavulanic acid in the community (coefficient = 1.03, P= 0.03) and mean co-morbidity scores for hospitalized patients (coefficient = 2.15, P= 0.03) with various time lags. The fluoroquinolone restriction policy was implemented successfully with the mean use of fluoroquinolones (mainly ciprofloxacin) being reduced from 133 to 17 defined daily doses (DDDs)/1000 bed days (P < 0.001) and from 0.65 to 0.54 DDDs/1000 inhabitants/day (P= 0.0007), in both the hospital and its surrounding community, respectively. This was associated with an improved ciprofloxacin susceptibility in both settings [ciprofloxacin susceptibility being improved from 16% to 28% in the community (P < 0.001)] and with a statistically significant reduction in ESBL-producing bacteria incidence rates. This study supports the value of restricting the use of certain antimicrobial classes to control ESBL, and demonstrates the feasibility of reversing resistance patterns post successful antibiotic restriction. The study also highlights the potential value of the time-series analysis in designing efficient antibiotic stewardship.

Association of community antibiotic consumption with clinically active trachoma in rural Ethiopia

Community antibiotic utilization and its relationship with trachoma has been poorly characterized in areas with endemic trachoma. A survey of all drug-dispensing facilities in an area of rural Ethiopia was conducted. Antibiotic use was calculated using both retrospective and prospective methodology, and expressed as defined daily doses (DDDs). Overall antibiotic consumption estimates ranged from 2.91 to 3.07 DDDs per 1000 person days. Macrolide antibiotics accounted for 0.01 to 0.02 DDDs per 1000 person days. Each additional DDD of antibiotic use per 1000 person days was associated with a 15.0% (95% CI -19.7 to -10.3) decrease in the prevalence of clinically active trachoma among children under 10 years of age after adjusting for age, gender, altitude and the distance to nearest town. Increased background community antibiotic use may therefore be an aspect of socioeconomic development that can partially explain why trachoma prevalence has decreased in some areas in the absence of a trachoma program. The low volume of macrolide consumption in this area suggests that selection for nasopharyngeal pneumococcal macrolide resistance after mass azithromycin treatments likely has little clinical significance.

Trends in antibiotic use among outpatients in New Delhi, India.

BackgroundThe overall volume of antibiotic consumption in the community is one of the foremost causes of antimicrobial resistance. There is much ad-hoc information about the inappropriate consumption of antibiotics, over-the-counter availability, and inadequate dosage but there is very little actual evidence of community practices.MethodsThis study surveyed antibiotic use in the community (December 2007-November 2008) using the established methodology of patient exit interviews at three types of facilities: 20 private retail pharmacies, 10 public sector facilities, and 20 private clinics to obtain a complete picture of community antibiotic use over a year. The Anatomical Therapeutic Chemical (ATC) classification and the Defined Daily Dose (DDD) measurement units were assigned to the data. Antibiotic use was measured as DDD/1000 patients visiting the facility and also as percent of patients receiving an antibiotic.ResultsDuring the data collection period, 17995, 9205, and 5922 patients visiting private retail pharmacies, public facilities and private clinics, respectively, were included in our study. 39% of the patients attending private retail pharmacies and public facilities and 43% of patients visiting private clinics were prescribed at least one antibiotic. Consumption patterns of antibiotics were similar at private retail pharmacies and private clinics where fluoroquinolones, cephalosporins, and extended spectrum penicillins were the three most commonly prescribed groups of antibiotics. At public facilities, there was a more even use of all the major antibiotic groups including penicillins, fluoroquinolones, macrolides, cephalosporins, tetracyclines, and cotrimoxazole. Newer members from each class of antibiotics were prescribed. Not much seasonal variation was seen although slightly higher consumption of some antibiotics in winter and slightly higher consumption of fluoroquinolones during the rainy season were observed.ConclusionsA very high consumption of antibiotics was observed in both public and private sector outpatients. There was a high use of broad spectrum and newer antibiotics in the community. Suitable and sustainable interventions should be implemented to promote rational use of antibiotics that will help in decreasing the menace of antibiotic resistance.

Outpatient antibiotic use in the four administrations of the UK: cross-sectional and longitudinal analysis

We compared community antibiotic use in the four administrations of the UK with that in other European countries. A cross-sectional analysis of 24 European countries and UK administrations in 2005 with longitudinal analysis of data from Belgium and UK from 1997 was performed. Antibiotic use was measured as defined daily doses per 1000 inhabitants per day (DID) or as prescriptions or packages per 1000 inhabitants per day (PID) with aggregate data from patients who received antibiotics in the primary care or outpatient setting. In 2005, there were marked differences in antibiotic prescriptions between the four UK administrations, for example, in descending order of DIDs, Northern Ireland and England ranked 8th and 24th, respectively, out of the 28 countries. DIDs for Northern Ireland were 37% greater than that for England. Longitudinal analysis showed that differences were present before devolution in 1999. Increase in the age of exemption from prescription charges in Wales in 2002 was not associated with significant change in use in comparison with the other UK countries. There were discrepancies between changes in DID and changes in PID, particularly in Belgium. This suggests that some changes in DID were due to changes in dosing or duration of the treatment rather than in the number of people treated and shows the importance of using both measures. The European Surveillance of Antimicrobial Consumption project has for the first time made data about antibiotic use in the four UK administrations publicly available. This reveals important practice variations that should stimulate research to explain differences and assess their consequences.

Overview of Antibiotic Use and Resistance: Setting the Stage for Tigecycline

Since the introduction of antibiotics 6 decades ago, clinicians have taken comfort in the relative safety and exceptional efficacy of these drugs. Patients initially looked on antibiotics as “wonder drugs,” primarily because of their life-saving benefits in treating serious wounds, postsurgical infections, pneumonia, meningitis, endocarditis, and sepsis, as well as their dramatic effect on sexually transmitted infections and infections of the urinary tract. Antibiotics are available for use in the community with oral formulations, as well as in the hospital with parenteral preparations. Over the past several decades, antibiotics have been used enthusiastically by physicians, and patients have learned to expect them for the treatment of many ailments, even those that are known not to be caused by bacteria. It is widely believed that more than half of the community use of antibiotics is for the treatment of respiratory infections in children, well more than half of which are caused by viruses. Antibiotics have been used for decades in the treatment of acne vulgaris and many other common skin conditions and have been used adjunctive to surgical drainage for a large number of deeper cutaneous and fascial abscesses and carbuncles. That antibiotics are frequently prescribed in response to patient requests for these miracle drugs to treat trivial or nonbacterial infections and that most physicians are very comfortable prescribing these agents by telephone for presumed but not proven bacterial infections are understatements. Initially, sulfonamides and penicillins dominated the field, but cephalosporins and penicillinase-resistant semisynthetic penicillins soon followed. Macrolides and tetracyclines were also introduced relatively early during the history of antibiotics as broad-spectrum agents for a variety of indications. The development of macrolides included the introduction of clarithromycin and the azalide azithromycin, both of which had improved tolerability and activity. Tetracyclines were

The role of the polymerase chain reaction in the diagnosis of bacterial meningitis in Vietnam.

Bacterial meningitis remains an important cause of morbidity and mortality in Vietnam. Diagnosis is hampered by the ready availability of antibiotics in the community, leading to late presentation, masked clinical signs, and poor organism detection during the microscopical examination and culture of cerebrospinal fluid (CSF). In order to improve organism detection at the Hospital for Tropical Diseases in Ho Chi Minh City, a diagnostic PCR-based protocol was developed. This protocol was followed in the investigation of CSF samples from 36 patients with clinical signs of bacterial meningitis. Each sample was first tested in a semi-nested PCR using primers for the 16sRNA gene common to all bacteria. The products of this reaction were then amplified using a 16sru8 primer and primers specific for Neisseria meningitidis, Haemophilus influenzae or Streptococcus spp. The samples found positive for Streptococcus were further investigated in a nested PCR using primers specific for the pneumolysin gene of S. pneumoniae. The sensitivity of detection was increased from 36% with culture to 44% with PCR. Although the sample size was small, the results indicate that PCR would be a feasible and useful adjunct in the diagnosis of bacterial meningitis, particularly in areas where community antibiotic use is common.

Minimum antibiotic stewardship measures

An ESCMID study group on antibiotic policies (ESGAP) was formed in 1998. Several subgroups have been formed to develop key strategy in various aspects of antibiotic stewardship. Sub group III was formed to lead on antibiotic stewardship in European hospitals. This article is a final version of guidelines that have been developed by the group through internet discussion. A provisional version has been posted on the ESGAP section of ESCMID’s website. Some important aspects of community antibiotic use have also been included.

Minimum antibiotic stewardship measures

An ESCMID study group on antibiotic policies (ESGAP) was formed in 1998. Several subgroups have been formed to develop key strategy in various aspects of antibiotic stewardship. Sub group III was formed to lead on antibiotic stewardship in European hospitals. This article is a final version of guidelines that have been developed by the group through internet discussion. A provisional version has been posted on the ESGAP section of ESCMID's website. Some important aspects of community antibiotic use have also been included.

Principles of appropriate antibiotic use for treatment of acute respiratory tract infections in adults: Background, specific aims, and methods

The need to decrease excess antibiotic use in ambulatory practice has been fueled by the epidemic increase in antibiotic-resistant Streptococcus pneumoniae . The majority of antibiotics prescribed to adults in ambulatory practice in the United States are for acute sinusitis, acute pharyngitis, acute bronchitis, and nonspecific upper respiratory tract infections (including the common cold). For each of these conditions—especially colds, nonspecific upper respiratory tract infections, and acute bronchitis (for which routine antibiotic treatment is not recommended)—a large proportion of the antibiotics prescribed are unlikely to provide clinical benefit to patients. Because decreasing community use of antibiotics is an important strategy for combating the increase in community-acquired antibiotic-resistant infections, the Centers for Disease Control and Prevention convened a panel of physicians representing the disciplines of internal medicine, family medicine, emergency medicine, and infectious diseases to develop a series of “Principles of Appropriate Antibiotic Use for Treatment of Acute Respiratory Tract Infections in Adults.” These principles provide evidence-based recommendations for evaluation and treatment of adults with acute respiratory illnesses. This paper describes the background and specific aims of and methods used to develop these principles. The goal of the principles is to provide clinicians with practical strategies for limiting antibiotic use to the patients who are most likely to benefit from it. These principles should be used in conjunction with effective patient educational campaigns and enhancements to the health care delivery system that facilitate nonantibiotic treatment of the conditions in question.[Gonzales R, Bartlett JG, Besser RE, Cooper RJ, Hickner JM, Hoffman JR, Sande MA. Principles of appropriate antibiotic use for treatment of acute respiratory tract infections in adults: background, specific aims, and methods. Ann Emerg Med. June 2001;37:690-697.]

Principles of appropriate antibiotic use for treatment of acute respiratory tract infections in adults: background, specific aims, and methods.

The need to decrease excess antibiotic use in ambulatory practice has been fueled by the epidemic increase in antibiotic-resistant Streptococcus pneumoniae. The majority of antibiotics prescribed to adults in ambulatory practice in the United States are for acute sinusitis, acute pharyngitis, acute bronchitis, and nonspecific upper respiratory tract infections (including the common cold). For each of these conditions-especially colds, nonspecific upper respiratory tract infections, and acute bronchitis (for which routine antibiotic treatment is not recommended)-a large proportion of the antibiotics prescribed are unlikely to provide clinical benefit to patients. Because decreasing community use of antibiotics is an important strategy for combating the increase in community-acquired antibiotic-resistant infections, the Centers for Disease Control and Prevention convened a panel of physicians representing the disciplines of internal medicine, family medicine, emergency medicine, and infectious diseases to develop a series of "Principles of Appropriate Antibiotic Use for Treatment of Acute Respiratory Tract Infections in Adults." These principles provide evidence-based recommendations for evaluation and treatment of adults with acute respiratory illnesses.This paper describes the background and specific aims of and methods used to develop these principles. The goal of the principles is to provide clinicians with practical strategies for limiting antibiotic use to the patients who are most likely to benefit from it. These principles should be used in conjunction with effective patient educational campaigns and enhancements to the health care delivery system that facilitate nonantibiotic treatment of the conditions in question.

National and Local Antibiotic Policies in Central and Eastern Europe

To assess the antibiotic policies of Central European countries, we performed an overview of antibiotic stewardship, prescription habits and antibiotic prescription regulatory procedures. Since most Central European countries have had centralized health care and drug policies, the situation 10 years after decentralization is surprising. Only 3 of 10 Central European countries have some regulation of prescription of antibiotics, only 4 restrict some antibiotics, only 5 have hospital and only 3 national antibiotic policies. In all but 3 countries physicians can prescribe quinolones and/or 3rd generation oral cephalosporins as first-line antibiotics. Information on local and national antibiotic policies in Central and Eastern European countries is given including prescription guidelines for antibiotic use in community and hospital.

The Influence of Case Mix, Site Selection, and Methods Biases on Costs of Hospitalization For Acute Exacerbations of Chronic Obstructive Airways Disease and Lower Respiratory Tract Infections

Objective To compare costs of hospitalization for lower respiratory tract infection (LRTI) in patients who received antibiotics before admission to those who did not, and in patients with and without underlying chronic obstructive airways disease (COAD) or diabetes mellitus. Methods All hospitalizations in a population of 366,849 residents in Tayside Scotland from 1993 to 1994 were analyzed. Three groups of patients were identified by primary discharge diagnosis in 1993/94 and previous admissions from 1980 to 1992: 1) acute exacerbation of COAD; 2) LRTI plus a secondary diagnosis of COAD or previous admission with COAD; 3) LRTI but no secondary COAD or previous admission with COAD. Setting specific costs were applied (e.g., general medicine, intensive care, geriatrics). Dispensed antibiotic prescribing in the 28 days before admission was identified from all community pharmacies. Nonparametric statistical tests were used. Results Patients with COAD were more likely to have received antibiotics before admission: COAD ( n = 893) 49%; COAD + LRTI ( n = 316) 43%; LRTI only ( n = 822) 33%. Patients who received antibiotics before admission had lower hospital costs than patients who did not. Mean total costs per admission: COAD £1604 versus £1625 ( p = .5); COAD + LRTI £2281 versus £2297 ( p = .5); LRTI only £2365 versus £3233; ( p = .009). Increasing age and diabetes mellitus were associated with higher hospital costs in all three groups. Conclusion Economic models of the value of preventing hospital admissions for COAD or LRTI will be subject to case mix bias unless they adjust for age, community antibiotic use, and comorbidity.

The independent evolution of resistance to ciprofloxacin, rifampicin, and fusidic acid in methicillin-resistant Staphylococcus aureus in Australian teaching hospitals (1990-1995). Australian Group for Antimicrobial Resistance (AGAR).

Methicillin-resistant Staphylococcus aureus (MRSA) is endemic in teaching hospitals in eastern Australian states, with prevalence rates averaging 25-30% of all S. aureus. Between 1990 and 1995, 1467 non-duplicate MRSA isolates from clinically infected sites were tested in Sydney, Melbourne, and Brisbane as part of a national survey of staphylococcal susceptibility. We reviewed the differing evolution of resistance to ciprofloxacin, rifampicin, and fusidic acid. Despite similarities in community and hospital antibiotic use and MRSA prevalence rates, trends in resistance to the oral antibiotics in these cities have progressed independently of each other. In the 1995 survey in individual hospitals in Melbourne, 16-24% of strains were ciprofloxacin-resistant, compared with 80-100% in Sydney and 30-44% in Brisbane. There was great diversity of phage type patterns for ciprofloxacin-resistant strains, suggesting heterogeneous development of resistance. Rifampicin resistance was more closely associated with distinct dominant epidemic phage types, common to institutions in the same city, but without spread to the other cites. Between 1990 and 1995, these comprised 30-60% of all MRSA in Brisbane, compared with 5-10% in Melbourne and < 25% in Sydney. Fusidic acid resistance was uncommon and sporadic (< 5%), and was distributed equally between methicillin-resistant and methicillin-susceptible strains. Resistance to the oral agents in MRSA is due to a complex mix of antibiotic selection pressures and cross-infection with local and epidemic strains in closely related institutions. Each of these mechanisms can predominate, dependent on local factors and the antibiotics used.

PIC10 The Influence of Case Mix Bias On Costs of Hospitalisation for Lower Respiratory Tract Infection

OBJECTIVE: To compare costs of hospitalisation for lower respiratory tract infection (LRTI) in patients who received antibiotics before admission versus those who did not and in patients with and without underlying chronic obstructive airways disease (COAD). METHODS: All hospitalisations were analysed in a population of 350,000 resident in Tayside during 1993–94. Three groups of patients were identified by primary discharge diagnosis in 1993–94 and previous admissions from 1980 to 1992: (1) acute exacerbation of COAD, (2) LRTI plus a secondary diagnosis of COAD or previous admission with COAD, and (3) LRTI but no secondary COAD or previous admission with COAD. Setting-specific costs were applied (e.g., general medicine, intensive care, geriatrics). Dispensed antibiotic prescribing in the 28 days before admission was identified from all community pharmacies. Non-parametric statistical tests were used. RESULTS: Patients with COAD were more likely to have received antibiotics before admission: COAD (n = 893) 49%; COAD+LRTI (n = 316) 43%; LRTI only (n = 822) 33%. Odds ratio for COAD vs LRTI only 1.90 (95% CI 1.56 to 2.31); COAD+LRTI vs LRTI only 1.50 (95% CI 1.15 to 1.96). Patients who received antibiotics before admission had lower hospital costs than patients who did not. Median total costs per admission: COAD £1050 vs £1164 (p = 0.5); COAD+LRTI £1067 vs £1354 (p = 0.5); LRTI only £1220 vs £1500; (p = 0.009). Adjusted for community antibiotic prescribing, the hospital costs of patients with LRTI were significantly higher than those of patients with COAD (p = 0.001) but not those of patients with COAD+LRTI (p = 0.096). CONCLUSION: Economic models of the potential impact of different community antibiotics on hospital LRTI costs will be subject to case mix bias unless they adjust for community antibiotic use and co-morbidity with COAD.