Antibiotic prescribing rates in the US ambulatory care setting for patients diagnosed with influenza, 1997-2001

Rapid, Point-of-Care Host-Based Gene Expression Diagnostics Using Giant Magnetoresistive Biosensors

Host-based gene expression analysis is a promising tool for a broad range of clinical applications, including rapid infectious disease diagnostics and real-time disease monitoring. However, the complex instrumentation requirements and slow turnaround-times associated with traditional gene expression analysis methods have hampered their widespread adoption at the point-of-care (POC). To overcome these challenges, we have developed an automated and portable platform that utilizes polymerase chain reaction (PCR) and giant magnetoresistive (GMR) biosensors to perform rapid multiplexed, targeted gene expression analysis at the POC. As proof-of-concept, we utilized our platform to amplify and measure the expression of four genes (HERC5, HERC6, IFI27, and IFIH1) that were previously shown to be upregulated in hosts infected with influenza viruses. The compact instrument conducted highly automated PCR amplification and GMR detection to measure the expression of the four genes in multiplex, then utilized Bluetooth communication to relay results to users on a smartphone application. To validate the platform, we tested 20 cDNA samples from symptomatic patients that had been previously diagnosed as either influenza-positive or influenza-negative using a RT-PCR virology panel. A non-parametric Mann-Whitney test revealed that day 0 (day of symptom onset) gene expression was significantly different between the two groups (p < 0.0001, n = 20). Hence, we preliminarily demonstrated that our platform could accurately discriminate between symptomatic influenza and non-influenza populations based on host gene expression in ∼30 min. This study not only establishes the potential clinical utility of our proposed assay and device for influenza diagnostics but it also paves the way for broadscale and decentralized implementation of host-based gene expression diagnostics at the POC.

Comparative Safety and Attributable Healthcare Expenditures Following Inappropriate Versus Appropriate Outpatient Antibiotic Prescriptions Among Adults With Upper Respiratory Infections

BACKGROUND

Little is known about the clinical and financial consequences of inappropriate antibiotics. We aimed to estimate the comparative risk of adverse drug events and attributable healthcare expenditures associated with inappropriate versus appropriate antibiotic prescriptions for common respiratory infections.

METHODS

We established a cohort of adults aged 18 to 64 years with an outpatient diagnosis of a bacterial (pharyngitis, sinusitis) or viral respiratory infection (influenza, viral upper respiratory infection, nonsuppurative otitis media, bronchitis) from 1 April 2016 to 30 September 2018 using Merative MarketScan Commercial Database. The exposure was an inappropriate versus appropriate oral antibiotic (ie, non-guideline-recommended vs guideline-recommended antibiotic for bacterial infections; any vs no antibiotic for viral infections). Propensity score-weighted Cox proportional hazards models were used to estimate the association between inappropriate antibiotics and adverse drug events. Two-part models were used to calculate 30-day all-cause attributable healthcare expenditures by infection type.

RESULTS

Among 3 294 598 eligible adults, 43% to 56% received inappropriate antibiotics for bacterial and 7% to 66% for viral infections. Inappropriate antibiotics were associated with increased risk of several adverse drug events, including Clostridioides difficile infection and nausea/vomiting/abdominal pain (hazard ratio, 2.90; 95% confidence interval, 1.31-6.41 and hazard ratio, 1.10; 95% confidence interval, 1.03-1.18, respectively, for pharyngitis). Thirty-day attributable healthcare expenditures were higher among adults who received inappropriate antibiotics for bacterial infections ($18-$67) and variable (-$53 to $49) for viral infections.

CONCLUSIONS

Inappropriate antibiotic prescriptions for respiratory infections were associated with increased risks of patient harm and higher healthcare expenditures, justifying a further call to action to implement outpatient antibiotic stewardship programs.

Reducing Antibiotic Use in Ambulatory Care Through Influenza Vaccination

BACKGROUND

Improving appropriate antibiotic use is crucial for combating antibiotic resistance and unnecessary adverse drug reactions. Acute respiratory illness (ARI) commonly causes outpatient visits and accounts for ~41% of antibiotics used in the United States. We examined the influence of influenza vaccination on reducing antibiotic prescriptions among outpatients with ARI.

METHODS

We enrolled outpatients aged ≥6 months with ARI from 50-60 US clinics during 5 winters (2013-2018) and tested for influenza with RT-PCR; results were unavailable for clinical decision making and clinical influenza testing was infrequent. We collected antibiotic prescriptions and diagnosis codes for ARI syndromes. We calculated vaccine effectiveness (VE) by comparing vaccination odds among influenza-positive cases with test-negative controls. We estimated ARI visits and antibiotic prescriptions averted by influenza vaccination using estimates of VE, coverage, and prevalence of antibiotic prescriptions and influenza.

RESULTS

Among 37 487 ARI outpatients, 9659 (26%) were influenza positive. Overall, 36% of ARI and 26% of influenza-positive patients were prescribed antibiotics. The top 3 prevalent ARI syndromes included: viral upper respiratory tract infection (47%), pharyngitis (18%), and allergy or asthma (11%). Among patients testing positive for influenza, 77% did not receive an ICD-CM diagnostic code for influenza. Overall, VE against influenza-associated ARI was 35% (95% CI, 32-39%). Vaccination prevented 5.6% of all ARI syndromes, ranging from 2.8% (sinusitis) to 11% (clinical influenza). Influenza vaccination averted 1 in 25 (3.8%; 95% CI, 3.6-4.1%) antibiotic prescriptions among ARI outpatients during influenza seasons.

CONCLUSIONS

Vaccination and accurate influenza diagnosis may curb unnecessary antibiotic use and reduce the global threat of antibiotic resistance.

The Clinical Utility of Point-of-Care Tests for Influenza in Ambulatory Care: A Systematic Review and Meta-analysis

Background

Point-of-care tests (POCTs) for influenza are diagnostically superior to clinical diagnosis, but their impact on patient outcomes is unclear.

Methods

A systematic review of influenza POCTs versus usual care in ambulatory care settings. Studies were identified by searching six databases and assessed using the Cochrane risk of bias tool. Estimates of risk ratios (RR), standardised mean differences, 95% confidence intervals and I2 were obtained by random effects meta-analyses. We explored heterogeneity with sensitivity analyses and meta-regression.

Results

12,928 citations were screened. Seven randomized studies (n = 4,324) and six non-randomized studies (n = 4,774) were included. Most evidence came from paediatric emergency departments. Risk of bias was moderate in randomized studies and higher in non-randomized studies. In randomized trials, POCTs had no effect on admissions (RR 0.93, 95% CI 0.61–1.42, I2 = 34%), returning for care (RR 1.00 95% CI = 0.77–1.29, I2 = 7%), or antibiotic prescribing (RR 0.97, 95% CI 0.82–1.15, I2 = 70%), but increased prescribing of antivirals (RR 2.65, 95% CI 1.95–3.60; I2 = 0%). Further testing was reduced for full blood counts (FBC) (RR 0.80, 95% CI 0.69–0.92 I2 = 0%), blood cultures (RR 0.82, 95% CI 0.68–0.99; I2 = 0%) and chest radiography (RR 0.81, 95% CI 0.68–0.96; I2 = 32%), but not urinalysis (RR 0.91, 95% CI 0.78–w1.07; I2 = 20%). Time in the emergency department was not changed. Fewer non-randomized studies reported these outcomes, with some findings reversed or attenuated (fewer antibiotic prescriptions and less urinalysis in tested patients).

Conclusions

Point-of-care testing for influenza influences prescribing and testing decisions, particularly for children in emergency departments. Observational evidence shows challenges for real-world implementation.

Antibiotic Use Associated with Confirmed Influenza, Pertussis, and Nontyphoidal Salmonella Infections

Purpose: Antibiotics are not the recommended treatment for uncomplicated influenza or nontyphoidal salmonella infections, whereas they are for current pertussis infection. We investigated adherence to these recommendations in a population of older community-dwelling adults. Methods: Population-based prospective cohort study of Australian adults 45 years of age and older followed by record-linkage to laboratory-confirmed influenza, pertussis, and nontyphoidal salmonella notifications, hospitalization records, and antibiotic dispensing data from January 1, 2009 to December 31, 2015. Proportions of those with infections who were prescribed antibiotics were estimated, and characteristics associated with antibiotic prescribing were examined. Results: There were 1,056 influenza, 151 pertussis, and 334 nontyphoidal salmonella cases in the cohort eligible for analysis. Antibiotics were dispensed in 56.2% (594/1,056) of influenza, 78.8% (119/151) of pertussis, and 39.5% (132/334) of nontyphoidal salmonella cases within the ±10-day window around the infection onset date. The likelihood of antibiotic dispensing did not differ according to most participant characteristics examined, including whether cases had an associated hospitalization, their age, and recorded comorbidities. Macrolides were the predominant class of antibiotics dispensed for pertussis (79%), whereas both beta-lactams (36.3%) and macrolides (35.4%) were used for cases of influenza. There was no dominant antibiotic class dispensed among those with nontyphoidal salmonella. Conclusions: Given concerns regarding increasing antibiotic resistance, the high proportion of adults with influenza and nontyphoidal salmonella cases dispensed antibiotics indicate the need for further strengthening of antimicrobial stewardship by raising education and awareness of guidelines for managing these infections.

Validation of a host response test to distinguish bacterial and viral respiratory infection

BACKGROUND

Distinguishing bacterial and viral respiratory infections is challenging. Novel diagnostics based on differential host gene expression patterns are promising but have not been translated to a clinical platform nor extensively tested. Here, we validate a microarray-derived host response signature and explore performance in microbiology-negative and coinfection cases.

METHODS

Subjects with acute respiratory illness were enrolled in participating emergency departments. Reference standard was an adjudicated diagnosis of bacterial infection, viral infection, both, or neither. An 87-transcript signature for distinguishing bacterial, viral, and noninfectious illness was measured from peripheral blood using RT-PCR. Performance characteristics were evaluated in subjects with confirmed bacterial, viral, or noninfectious illness. Subjects with bacterial-viral coinfection and microbiologically-negative suspected bacterial infection were also evaluated. Performance was compared to procalcitonin.

FINDINGS

151 subjects with microbiologically confirmed, single-etiology illness were tested, yielding AUROCs 0•85-0•89 for bacterial, viral, and noninfectious illness. Accuracy was similar to procalcitonin (88% vs 83%, p = 0•23) for bacterial vs. non-bacterial infection. Whereas procalcitonin cannot distinguish viral from non-infectious illness, the RT-PCR test had 81% accuracy in making this determination. Bacterial-viral coinfection was subdivided. Among 19 subjects with bacterial superinfection, the RT-PCR test identified 95% as bacterial, compared to 68% with procalcitonin (p = 0•13). Among 12 subjects with bacterial infection superimposed on chronic viral infection, the RT-PCR test identified 83% as bacterial, identical to procalcitonin. 39 subjects had suspected bacterial infection; the RT-PCR test identified bacterial infection more frequently than procalcitonin (82% vs 64%, p = 0•02).

INTERPRETATION

The RT-PCR test offered similar diagnostic performance to procalcitonin in some subgroups but offered better discrimination in others such as viral vs. non-infectious illness and bacterial/viral coinfection. Gene expression-based tests could impact decision-making for acute respiratory illness as well as a growing number of other infectious and non-infectious diseases.

Evaluation of a community pharmacy-based influenza and group A streptococcal pharyngitis disease management program using polymerase chain reaction point-of-care testing

OBJECTIVES

The purpose of this study was to demonstrate the feasibility of implementing a Clinical Laboratory Improvement Amendments-waived real-time polymerase chain reaction (PCR) molecular test into a community pharmacy setting as part of a collaborative influenza and group A Streptococcus (GAS) disease management program.

SETTING AND PARTICIPANTS

Two community pharmacy sites in Tennessee.

PRACTICE DESCRIPTION

Patients presenting to the pharmacy with symptoms consistent with influenza or GAS from November 1, 2016, to April 30, 2018.

PRACTICE INNOVATION

Influenza and GAS management programs based on previously developed protocols occurred at 2 community pharmacies in Tennessee. Pharmacies used the Cobas Liat testing system (Roche Diagnostics). Based on test results and under a collaborative practice agreement, pharmacists dispensed prescription medications for patients with a positive test: oseltamivir for influenza and amoxicillin for GAS. Patients with negative tests were treated with over-the-counter (OTC) medications or referred. Patients testing negative for GAS were asked to consent to having a second throat swab sent for culture.

EVALUATION

Number of patients tested, point-of-care test results, and treatment received.

RESULTS

Two hundred and two patients received care at the 2 pharmacies (116 for influenza, 46 for GAS, and 43 for both). Sixty (38%) tested positive for influenza, with 51 receiving an antiviral prescription, and 16 (18%) tested positive and were treated for GAS. No patient testing negative for either or positive for influenza was dispensed an antibiotic. For patients consenting to a follow-up culture, all GAS cultures sent for confirmatory testing were negative.

CONCLUSION

A protocol-driven community pharmacy-based disease management program using real-time PCR testing for influenza and GAS was able to offer appropriate treatment to patients without overuse of antibiotics.

Changes in Gut Microbiota Prior to Influenza A Virus Infection Do Not Affect Immune Responses in Pups or Juvenile Mice

Previous studies demonstrated that oral antibiotic (ABX) treatment prior to and during influenza A virus (IAV) infection of adult mice profoundly altered gut microbiota (GM) and was associated with increased susceptibility and impaired immunity to IAV. We examined the impact of ABX during critical times relevant to the establishment of GM in early life (using perinatal treatment of neonates and direct treatment of juvenile mice) and asked whether cessation of ABX treatment in early life had lasting effects on GM composition and anti-IAV immunity. ABX treatment significantly changed GM composition in juvenile mice and in ABX-treated dams. However, if ABX treatment ceased at the time of infection, neither neonates nor juvenile mice showed enhanced susceptibility to IAV, nor were major differences detected in cellular and humoral adaptive antiviral immunity. Thus, while ABX treatment alters GM diversity in early life, cessation and subsequent re-colonization correlates with effective immunity against IAV.

Cost effectiveness of amoxicillin for lower respiratory tract infections in primary care: an economic evaluation accounting for the cost of antimicrobial resistance

BACKGROUND

Lower respiratory tract infections (LRTIs) are a major disease burden and are often treated with antibiotics. Typically, studies evaluating the use of antibiotics focus on immediate costs of care, and do not account for the wider implications of antimicrobial resistance.

AIM

This study sought to establish whether antibiotics (principally amoxicillin) are cost effective in patients with LRTIs, and to explore the implications of taking into account costs associated with resistance.

DESIGN AND SETTING

Multinational randomised double-blinded trial in 2060 patients with acute cough/LRTIs recruited in 12 European countries.

METHOD

A cost-utility analysis from a health system perspective with a time horizon of 28 days was conducted. The primary outcome measure was the quality-adjusted life year (QALY). Hierarchical modelling was used to estimate incremental cost-effectiveness ratios (ICERs).

RESULTS

Amoxicillin was associated with an ICER of €8216 (£6540) per QALY gained when the cost of resistance was excluded. If the cost of resistance is greater than €11 (£9) per patient, then amoxicillin treatment is no longer cost effective. Including possible estimates of the cost of resistance resulted in ICERs ranging from €14 730 (£11 949) per QALY gained - when only multidrug resistance costs and health care costs are included - to €727 135 (£589 856) per QALY gained when broader societal costs are also included.

CONCLUSION

Economic evaluation of antibiotic prescribing strategies that do not include the cost of resistance may provide misleading results that could be of questionable use to policymakers. However, further work is required to estimate robust costs of resistance.

Antibiotic Use in Cold and Flu Season and Prescribing Quality: A Retrospective Cohort Study

BACKGROUND

Excessive antibiotic use in cold and flu season is costly and contributes to antibiotic resistance. The study objective was to develop an index of excessive antibiotic use in cold and flu season and determine its correlation with other indicators of prescribing quality.

METHODS AND FINDINGS

We included Medicare beneficiaries in the 40% random sample denominator file continuously enrolled in fee-for-service benefits for 2010 or 2011 (7,961,201 person-years) and extracted data on prescription fills for oral antibiotics that treat respiratory pathogens. We collapsed the data to the state level so they could be merged with monthly flu activity data from the Centers for Disease Control and Prevention. Linear regression, adjusted for state-specific mean antibiotic use and demographic characteristics, was used to estimate how antibiotic prescribing responded to state-specific flu activity. Flu-activity associated antibiotic use varied substantially across states-lowest in Vermont and Connecticut, highest in Mississippi and Florida. There was a robust positive correlation between flu-activity associated prescribing and use of medications that often cause adverse events in the elderly (0.755; P<0.001), whereas there was a strong negative correlation with beta-blocker use after a myocardial infarction (-0.413; P=0.003).

CONCLUSIONS

Adjusted flu-activity associated antibiotic use was positively correlated with prescribing high-risk medications to the elderly and negatively correlated with beta-blocker use after myocardial infarction. These findings suggest that excessive antibiotic use reflects low-quality prescribing. They imply that practice and policy solutions should go beyond narrow, antibiotic specific, approaches to encourage evidence-based prescribing for the elderly Medicare population.

Influenza antiviral treatment in spinal cord injury patients, 2007-2010

OBJECTIVE

This study assessed antiviral medication use for treatment of influenza-like illness (ILI) in Veterans with spinal cord injury or disorder (SCI/D) and examined whether antiviral prescribing improved over time.

DESIGN

Retrospective cohort study of Department of Veterans Affairs (VA) facilities.

PARTICIPANTS

Veterans with SCI/D and matched non-SCI/D controls (matched by facility and date of visit/admission) who were diagnosed by a clinician with ILI during the period 1 October 2007 to 31 May 2010.

MAIN OUTCOME MEASURES

Antiviral receipt and appropriateness were examined. Appropriate antiviral prescribing was defined as patients who received an antiviral medication within 2 days of collection of a sample for diagnostic testing or within 2 days of symptom onset.

RESULTS

We identified 101 influenza visits/admissions for veterans with SCI/D and 123 for controls. Antiviral prescribing for Veterans with SCI/D increased from 37.1% in 2007/2008 to 67.6% in 2009/2010 (P = 0.01) and appropriate antiviral prescribing increased from 20.0 to 41.2% (P = 0.05). Predictors of antiviral prescribing included being treated in the 2009/2010 influenza season (vs. 2007/2008) and having a cough. Fever, aches/myalgia, or a positive influenza test was associated with appropriate antiviral treatment. SCI/D was an independent predictor of receiving antiviral treatment (adjusted odds ratio = 1.16, 95% confidence interval 1.04-1.29), but having SCI/D was not associated with receiving appropriate treatment.

CONCLUSIONS

Influenza antiviral prescribing increased over time and in a larger proportion in veterans with SCI/D (vs. controls). This suggests that providers treating patients with SCI/D recognize treatment guidelines and their importance in a high-risk population. Continued efforts are needed to improve appropriate influenza antiviral prescribing.

Socioeconomic impact of seasonal (epidemic) influenza and the role of over-the-counter medicines

The substantial economic impact of influenza on society results primarily from lost work time and reduced productivity of patients and caregivers and increased use of medical resources. Additionally, since the 1980s, aging of the US population has meant rising influenza-related morbidity and mortality. According to the most current published data on this topic, in 2003 the total economic burden of influenza epidemics in the USA across all age groups was US$87.1 billion. As of February 2013, overall vaccine effectiveness for the 2012/2013 season was estimated to be 56 %. The Centers for Disease Control and Prevention's National Center for Immunization and Respiratory Diseases has concluded that more effective vaccines and vaccination strategies are needed. Moderate efficacy of the influenza vaccine, continued questions regarding the value of treatment with antivirals, and a growing self-care movement have led to increased use of over-the-counter (OTC) medicines, which play a vital role in managing symptoms associated with mild to moderate influenza and provide an estimated US$102 billion in annual savings for the US healthcare system. A primary benefit to society of using OTC medicines to manage influenza is decreased use of the healthcare system, thereby mitigating the socioeconomic burden of influenza. Considering the stresses placed on the US healthcare system and the substantial productivity losses resulting from seasonal influenza as well as the growing self-care movement, OTC medicines will play an important role in the course of future influenza epidemics.

The association between influenza treatment and hospitalization-associated outcomes among Korean children with laboratory-confirmed influenza

There are limited data evaluating the relationship between influenza treatment and hospitalization duration. Our purpose assessed the association between different treatments and hospital stay among Korean pediatric influenza patients. Total 770 children ≤ 15 yr-of-age hospitalized with community-acquired laboratory-confirmed influenza at three large urban tertiary care hospitals were identified through a retrospective medical chart review. Demographic, clinical, and cost data were extracted and a multivariable linear regression model was used to assess the associations between influenza treatment types and hospital stay. Overall, there were 81% of the patients hospitalized with laboratory-confirmed influenza who received antibiotic monotherapy whereas only 4% of the patients received oseltamivir monotherapy. The mean treatment-related charges for hospitalizations treated with antibiotics, alone or with oseltamivir, were significantly higher than those treated with oseltamivir-only (P < 0.001). Influenza patients treated with antibiotics-only and antibiotics/oseltamivir combination therapy showed 44.9% and 28.2%, respectively, longer duration of hospitalization compared to those treated with oseltamivir-only. Patients treated with antibiotics, alone or combined with oseltamivir, were associated with longer hospitalization and significantly higher medical charges, compared to patients treated with oseltamivir alone. In Korea, there is a need for more judicious use of antibiotics, appropriate use of influenza rapid testing.

Serum soluble ST2 as diagnostic marker of systemic inflammatory reactive syndrome of bacterial etiology in children

BACKGROUND

Accurate and timely diagnosis of community-acquired bacterial versus viral infections in children with systemic inflammatory response syndrome (SIRS) remains challenging both for clinician and laboratory. In the quest of new biochemical markers to distinguish bacterial from viral infection, we have explored the possible role of the soluble secreted form of ST2 (sST2).

METHODS

This explorative prospective cohort study included children with SIRS who were suspected of having community-acquired infections. Plasma samples for sST2 measurement were obtained from 64 hospitalized children, 41 of whom had SIRS of bacterial etiology and 23 SIRS of viral etiology, and from 20 healthy, age- and sex-matched control children. sST2 measurement was carried out by enzyme-linked immunosorbent assay in parallel with standard measurements of procalcitonin (PCT) and C reactive protein (CRP).

RESULTS

Our findings demonstrate that children with SIRS associated with bacterial infection present significantly increased levels of sST2, when compared with patients with SIRS of viral etiology and healthy children. More important, receiver operating characteristic curve analysis indicated that sST2 has a significant diagnostic performance with respect to early identification of SIRS of bacterial etiology, which was similar to that of PCT and greater than that of CRP. Finally, the combination of sST2 plus PCT and/or CRP, and PCT plus CRP increased their sensitivity and negative predictive value compared with sST2, PCT and CRP alone.

CONCLUSIONS

In conclusion, sST2 level may prove useful in predicting bacterial etiology in children with SIRS.

The effect of rapid diagnostic testing for influenza on the reduction of antibiotic use in paediatric emergency department

AIM

To determine the influence of rapid diagnosis of influenza on antibiotic prescribing to children presenting with influenza-like illness in the emergency department in a inner city hospital in Istanbul, Turkey.

METHODS

Patients aged 3 to 14 years presenting to an urban children's teaching hospital emergency department were screened for fever and cough, coryza, myalgias and/or malaise. After obtaining informed consent, patients were allocated into two groups. Group 1: patients were prescribed antibiotics after only physical examination; or Group 2: patients were prescribed antibiotics after rapid influenza testing. Nasopharyngeal swabs obtained from all patients were immediately tested in a single-blind manner with Influenza A/B Rapid Test(R) for influenza A and B.

RESULTS

A total of 97 patients were enrolled, and 33 (34%) of these tested positive for influenza. Although frequency of positive results for influenza between the groups was similar (36% vs 32%, respectively), patients in Group 2 were less likely to be prescribed antibiotics when compared to those in Group 1 (32% vs 100%, respectively, p < 0.0001).

CONCLUSION

Rapid diagnosis of influenza in the paediatric emergency department may allow a significant reduction in the over-prescription of antibiotics.

Use of antibiotics in children hospitalized with community-acquired, laboratory-confirmed influenza

Many children with influenza are treated with antibiotics. In this report, we describe the rate and indications for antibacterial use in children hospitalized with influenza. A total of 333 of 729 (46%) patients received >2 days of treatment with antibacterial medications, of whom 36% did not have an apparent indication for therapy.

Systematic review of the diagnostic accuracy of C-reactive protein to detect bacterial infection in nonhospitalized infants and children with fever

OBJECTIVE

To determine the accuracy of C-reactive protein (CRP) for diagnosing serious bacterial and bacterial infections in infants and children presenting with fever.

STUDY DESIGN

Systematic review of diagnostic accuracy studies. We included studies comparing the diagnostic accuracy of CRP with microbiologic confirmation of (a) serious bacterial and (b) bacterial infection.

RESULTS

For differentiating between serious bacterial infection and benign or nonbacterial infection (6 studies), the pooled estimate of sensitivity was 0.77 (95% CI, 0.68, 0.83); specificity, 0.79 (95% CI, 0.74, 0.83); positive likelihood ratio, 3.64 (95% CI, 2.99, 4.43); and negative likelihood ratio, 0.29 (95% CI, 0.22, 0.40). In multivariate analysis, CRP is an independent predictor of serious bacterial infection. 3 studies investigating the accuracy of CRP for diagnosing bacterial infection could not be pooled, but all showed a lower sensitivity compared with studies using serious bacterial infection as the reference diagnosis.

CONCLUSIONS

CRP provides moderate and independent information for both ruling in and ruling out serious bacterial infection in children with fever at first presentation. Poor sensitivity means that CRP cannot be used to exclude all bacterial infection.

Rapid diagnosis of influenza infection in older adults: influence on clinical care in a routine clinical setting

BACKGROUND

Laboratory diagnosis of influenza has previously relied on viral isolation in culture. Rapid antigen tests (RATs) are now available but few studies have examined their use in older adults under routine clinical conditions.

OBJECTIVES

To determine the utility of the RAT in older adults presenting to a large medical center and how test results impacted clinical care.

STUDY DESIGN

Retrospective chart review of patients tested for influenza during the 2003--2004 and 2004--2005 influenza seasons. Clinical data were correlated with the results of laboratory testing.

RESULTS

Eighty-four adults tested positive for influenza. Adding the results of the RAT to symptom complexes predictive of influenza significantly enhanced the ability to diagnose influenza in the acute setting. The positive predictive value of fever plus cough increased from 32% to 92% with a positive RAT. The RAT also directed appropriate antiviral therapy. 20/22 (91%) patients with a positive RAT and symptoms < or =48 h received antiviral treatment compared to only 1/12 (8%) patients with a negative RAT and a positive culture.

CONCLUSIONS

Under routine clinical conditions rapid influenza testing enhances the ability to quickly diagnose influenza and can be used to guide early treatment decisions in older adults.

The role of evidence in the decline of antibiotic use for common respiratory infections in primary care

Antibiotic prescribing in primary care for common respiratory infections increased steadily until the mid 1990s, when the trend reversed noticeably. During the subsequent decade, antibiotic prescribing reduced by up to one-third in some countries. Explanations for this reduction have focused on a decline in the incidence and severity of common respiratory infections, and on the resulting decrease in the number of patients seeking consultation. We argue that evidence from primary-care research had a central role in changing the practice of antibiotic prescribing, and discuss the concern that has arisen among some physicians around this issue. Targeted reductions in antibiotic prescribing constitute a balancing act between individual and societal concerns, pitting the expected gains in preserving the usefulness of an antibiotic against any given reduction in use. There may be unintended consequences for decreasing antibiotic use beyond a certain point without adequate supporting evidence. A new approach to antibiotic prescribing requires comprehensive research to answer why change is necessary, and how that change can be safely implemented. Future policies must move beyond a "one size fits all" mindset if public and provider behaviours are expected to become more congruent with the growing research evidence.

The influence of rapid influenza diagnostic testing on antibiotic prescribing patterns in rural Thailand

OBJECTIVES

Rapid influenza diagnostic testing is potentially a useful means to decrease inappropriate prescription of antibiotics. We studied the impact of access to rapid influenza test results on antibiotic prescribing and other patient management practices for outpatients with influenza-like illness (ILI) in a rural province in Eastern Thailand.

METHODS

A medical record review was performed for 300 patients of all ages selected from five outpatient departments using a 1:2 ratio of ILI cases with and without influenza infection identified by the QuickVue rapid test. Chi-square analysis or Fisher's exact test was used to compare patient management practices (antibiotic prescriptions, individual treatments administered, additional tests ordered, and related hospitalization) between rapid test positive and negative patients. Logistic regression was used to evaluate the effect of rapid test results on patient management practices for ILI.

RESULTS

Eighty-two percent of all patients with ILI were prescribed antibiotics. Patients with a positive rapid test were less likely to be prescribed antibiotics than those with a negative result (73% vs. 87%, respectively, p=0.003). The likelihood of antibiotic prescription for influenza positive patients was 0.41 times the likelihood for influenza negative patients (95% CI 0.23-0.74, p=0.003). There was no significant difference in the frequency of other patient management practices between influenza positive and negative patients.

CONCLUSIONS

Thai outpatients with ILI are prescribed antibiotics at a frequency approximately twice that reported in the USA. Having access to a rapid influenza test result was associated with a significant decrease in antibiotic prescription. Improved access to rapid influenza testing and expanded physician education may reduce inappropriate antibiotic use and improve patient care.

Colds and Influenza-Like Illnesses in University Students: Impact on Health, Academic and Work Performance, and Health Care Use

BACKGROUND

Upper respiratory tract illnesses (URIs) are a major cause of morbidity among adults, with substantial direct and indirect costs to society, but their impact among university students has not been well described. We sought to assess the impact of URIs (colds and influenza-like illnesses [ILIs]) on the health, academic and work performance, and health care use of university students.

METHODS

This was a cohort study of college students at the University of Minnesota, Twin Cities campus (Minneapolis-St. Paul), who were recruited during October 2002 and followed up from November 2002 through April 2003. All 42,000 registered students were invited via e-mail to participate. Baseline information was obtained in October 2002. Monthly follow-up information about colds or ILIs was obtained for the period of November 2002 through April 2003. Data were collected by use of Internet-based questionnaires.

RESULTS

Of 4919 volunteers, 3249 completed all follow-up surveys. The mean age was 22.7 years; 68% of the volunteers were female. Ninety-one percent had > or = 1 URI (83% had > or = 1 cold, and 36.7% had > or = 1 ILI). These URIs caused 6023 bed-days, 4263 missed school days, 3175 missed work days, and 45,219 days of illness. Of the cohort, 22.2% had > or = 1 health care visit, and 15.8% used antibiotics to treat a URI; 27.8% did poorly on a test and 46.3% did poorly on a class assignment. ILIs versus colds had a much greater impact on all parameters (e.g., general health level was 55%-60% lower with ILI vs. no URI and 33%-39% lower for colds vs. no URI; P < .001 for each).

CONCLUSION

Colds and ILIs were common and associated with substantial morbidity in university students. Enhanced efforts to prevent and control URIs, especially influenza vaccination, could improve the health and well-being of the 17 million college and university students in this country.