Rates of emergency department visits due to pneumonia in the United States, July 2006-June 2009

OBJECTIVES

Pneumonia hospitalization rates are frequently reported as a measure of pneumonia disease burden in the United States. However, a detailed understanding of pneumonia burden in all health care settings, including the emergency department (ED), is essential for measuring the full effect of this disease on the population and planning and evaluating interventions to reduce pneumonia-related morbidity. The aim of this study was to quantify pneumonia-attributable ED visits in the United States among children and adults during the 3-year period July 2006 through June 2009.

METHODS

Rates of pneumonia ED visits were calculated using the Nationwide Emergency Department Sample (NEDS), the largest source of U.S. ED data. Pneumonia ED visits were identified using International Classification of Diseases (ICD) codes within NEDS. A pneumonia ED visit was defined by a primary (first-listed) pneumonia discharge diagnosis or a secondary pneumonia diagnosis with an accompanying primary diagnosis of respiratory failure, shock, septicemia, a sign or symptom consistent with pneumonia, another acute respiratory infection, or an acute exacerbation of a chronic pulmonary disease. Population-based annual rates of pneumonia ED visits stratified by age group and geographic region from July 2006 through June 2009 were calculated. The percentages of pneumonia ED visits resulting in treat-and-release outpatient ED visits were also calculated within each age stratum.

RESULTS

During the study period, 6,917,025 ED visits for pneumonia were identified, representing 2.2% of all U.S. ED visits. During the 3 study years, defined as July through June of 2006-2007, 2007-2008, and 2008-2009, pneumonia ED visit rates per 1,000 person-years were 7.4 (95% confidence interval [CI] = 7.0 to 7.8), 7.8 (95% CI = 7.3 to 8.2), and 7.6 (95% CI = 7.1 to 8.0), respectively. Annual rates were stable over the 3 years within each age group and geographic region. Overall, 39.3% of pneumonia ED visits, including 74.5% of pediatric and 28.1% of adult visits, were managed as treat-and-release outpatient visits.

CONCLUSIONS

Pneumonia accounts for 2.2% of ED visits in the United States and results in approximately seven to eight ED visits per 1000 persons per year. A substantial proportion of pneumonia cases diagnosed in the ED are managed in treat-and-release ED outpatient visits, highlighting that enumeration of ED visit rates provides important complementary information to hospitalization rates for the assessment of pneumonia burden.

Respiratory syncytial virus-associated hospitalizations among children less than 24 months of age

BACKGROUND

Respiratory syncytial virus (RSV) infection is a leading cause of hospitalization among infants. However, estimates of the RSV hospitalization burden have varied, and precision has been limited by the use of age strata grouped in blocks of 6 to ≥ 12 months.

METHODS

We analyzed data from a 5-year, prospective, population-based surveillance for young children who were hospitalized with laboratory-confirmed (reverse-transcriptase polymerase chain reaction) RSV acute respiratory illness (ARI) during October through March 2000-2005. The total population at risk was stratified by month of age by birth certificate information to yield hospitalization rates.

RESULTS

There were 559 (26%) RSV-infected children among the 2149 enrolled children hospitalized with ARI (85% of all eligible children with ARI). The average RSV hospitalization rate was 5.2 per 1000 children <24 months old. The highest age-specific rate was in infants 1 month old (25.9 per 1000 children). Infants ≤ 2 months of age, who comprised 44% of RSV-hospitalized children, had a hospitalization rate of 17.9 per 1000 children. Most children (79%) were previously healthy. Very preterm infants (<30 weeks' gestation) accounted for only 3% of RSV cases but had RSV hospitalization rates 3 times that of term infants.

CONCLUSIONS

Young infants, especially those who were 1 month old, were at greatest risk of RSV hospitalization. Four-fifths of RSV-hospitalized infants were previously healthy. To substantially reduce the burden of RSV hospitalizations, effective general preventive strategies will be required for all young infants, not just those with risk factors.

U.S. hospitalizations for pneumonia after a decade of pneumococcal vaccination

BACKGROUND

The introduction of 7-valent pneumococcal conjugate vaccine (PCV7) into the U.S. childhood immunization schedule in 2000 has substantially reduced the incidence of vaccine-serotype invasive pneumococcal disease in young children and in unvaccinated older children and adults. By 2004, hospitalizations associated with pneumonia from any cause had also declined markedly among young children. Because of concerns about increases in disease caused by nonvaccine serotypes, we wanted to determine whether the reduction in pneumonia-related hospitalizations among young children had been sustained through 2009 and whether such hospitalizations in older age groups had also declined.

METHODS

We estimated annual rates of hospitalization for pneumonia from any cause using the Nationwide Inpatient Sample database. The reason for hospitalization was classified as pneumonia if pneumonia was the first listed diagnosis or if it was listed after a first diagnosis of sepsis, meningitis, or empyema. Average annual rates of pneumonia-related hospitalizations from 1997 through 1999 (before the introduction of PCV7) and from 2007 through 2009 (well after its introduction) were used to estimate annual declines in hospitalizations due to pneumonia.

RESULTS

The annual rate of hospitalization for pneumonia among children younger than 2 years of age declined by 551.1 per 100,000 children (95% confidence interval [CI], 445.1 to 657.1), which translates to 47,000 fewer hospitalizations annually than expected on the basis of the rates before PCV7 was introduced. The rate for adults 85 years of age or older declined by 1300.8 per 100,000 (95% CI, 984.0 to 1617.6), which translates to 73,000 fewer hospitalizations annually. For the three age groups of 18 to 39 years, 65 to 74 years, and 75 to 84 years, the annual rate of hospitalization for pneumonia declined by 8.4 per 100,000 (95% CI, 0.6 to 16.2), 85.3 per 100,000 (95% CI, 7.0 to 163.6), and 359.8 per 100,000 (95% CI, 199.6 to 520.0), respectively. Overall, we estimated an age-adjusted annual reduction of 54.8 per 100,000 (95% CI, 41.0 to 68.5), or 168,000 fewer hospitalizations for pneumonia annually.

CONCLUSIONS

Declines in hospitalizations for childhood pneumonia were sustained during the decade after the introduction of PCV7. Substantial reductions in hospitalizations for pneumonia among adults were also observed. (Funded by the Centers for Disease Control and Prevention.).

Brief report: incidence of selected opportunistic infections among children with juvenile idiopathic arthritis

OBJECTIVE

To compare incidence rates of selected opportunistic infections among children with and children without juvenile idiopathic arthritis (JIA).

METHODS

Using U.S. national Medicaid administrative claims data from 2000 through 2005, we identified a cohort of children with JIA based on physician diagnosis codes and dispensed medications. We also identified a non-JIA comparator cohort of children diagnosed as having attention deficit hyperactivity disorder (ADHD). We defined 15 types of opportunistic infection using physician diagnosis or hospital discharge codes; criteria for 7 of these types also included evidence of treatment with specific antimicrobial agents. We calculated infection incidence rates. The rates in the ADHD comparator cohort were standardized to the age, sex, and race distribution of the JIA cohort. We calculated incidence rate ratios (IRRs) with 95% confidence intervals (95% CIs) to compare infection rates.

RESULTS

The JIA cohort included 8,503 children with 13,990 person-years of followup. The ADHD comparator cohort included 360,362 children with 477,050 person-years of followup. When all opportunistic infections were considered together as a single outcome, there were 42 infections in the JIA cohort (incidence rate 300 per 100,000 person-years; IRR 2.4 [95% CI 1.7-3.3] versus ADHD). The most common opportunistic infections among children with JIA were 3 cases of Coccidioides (incidence rate 21 per 100,000 person-years; IRR 101 [95% CI 8.1-5,319] versus ADHD), 5 cases of Salmonella (incidence rate 35 per 100,000 person-years; IRR 3.8 [95% CI 1.2-9.5]), and 32 cases of herpes zoster (incidence rate 225 per 100,000 person-years; IRR 2.1 [95% CI 1.4-3.0]).

CONCLUSION

Opportunistic infections are rare among children with JIA. Nevertheless, children with JIA had a higher rate of opportunistic infections, including an increased rate of Coccidioides, Salmonella, and herpes zoster compared to children with ADHD.

Cohort profile: The study of respiratory pathogens in Andean children

We investigated respiratory pathogens in a prospective cohort study of young children living in the Peruvian Andes. In the study we assessed viral respiratory infections among young children, and explored interactions of viruses with common respiratory bacteria, especially Streptococcus pneumoniae. Through weekly household visits, data were collected on the signs and symptoms of acute respiratory illness (ARI), nasal samples were collected to test for viruses during episodes of ARI, and nasopharyngeal samples were collected on a monthly basis to monitor bacterial colonisation. We also collected data on vaccination coverage, patterns of social mixing, geographic information, and environmental and socio-demographic variables. Understanding the interaction of respiratory viruses with bacteria and its impact on the burden and severity of ARIs in rural areas of developing countries is critical to designing strategies for preventing such infections.

Panel 6: Vaccines

OBJECTIVE

To update progress on the effectiveness of vaccine for prevention of acute otitis media (AOM) and identification of promising candidate antigens against Streptococcus pneumoniae, nontypeable Haemophilus influenzae, and Moraxella catarrhalis.

REVIEW METHODS

Literature searches were performed in OvidSP and PubMed restricted to articles published between June 2007 and September 2011. Search terms included otitis media, vaccines, vaccine antigens, and each of the otitis pathogens and candidate antigens identified in the ninth conference report.

CONCLUSIONS

The current report provides further evidence for the effectiveness of pneumococcal conjugate vaccines (PCVs) in the prevention of otitis media. Observational studies demonstrate a greater decline in AOM episodes than reported in clinical efficacy trials. Unmet challenges include extending protection to additional serotypes and additional pathogens, the need to prevent early episodes, the development of correlates of protection for protein antigens, and the need to define where an otitis media vaccine strategy fits with priorities for child health.

IMPLICATIONS FOR PRACTICE

Acute otitis media continues to be a burden on children and families, especially those who suffer from frequent recurrences. The 7-valent PCV (PCV7) has reduced the burden of disease as well as shifted the pneumococcal serotypes and the distribution of otopathogens currently reported in children with AOM. Antibiotic resistance remains an ongoing challenge. Multiple candidate antigens have demonstrated the necessary requirements of conservation, surface exposure, immunogenicity, and protection in animal models. Further research on the role of each antigen in pathogenesis, in the development of correlates of protection in animal models, and in new adjuvants to elicit responses in the youngest infants is likely to be productive and permit more antigens to move into human clinical trials.

Association between the initiation of anti-tumor necrosis factor therapy and the risk of herpes zoster

IMPORTANCE

Herpes zoster reactivation disproportionately affects patients with rheumatoid arthritis (RA). It is unclear whether anti-tumor necrosis factor (anti-TNF) therapy elevates herpes zoster risk.

OBJECTIVES

To ascertain whether initiation of anti-TNF therapy compared with nonbiologic comparators is associated with increased herpes zoster risk.

DESIGN, SETTING, AND PATIENTS

We identified new users of anti-TNF therapy among cohorts of patients with RA, inflammatory bowel disease, and psoriasis, psoriatic arthritis, or ankylosing spondylitis from 1998 through 2007 within a large US multi-institutional collaboration combining data from Kaiser Permanente Northern California, Pharmaceutical Assistance Contract for the Elderly, Tennessee Medicaid, and national Medicaid/Medicare programs. We compared herpes zoster incidence between new anti-TNF users (n=33,324) and patients initiating nonbiologic disease-modifying antirheumatic drugs (DMARDs) (n=25,742) within each inflammatory disease cohort (last participant follow-up December 31, 2007). Within these cohorts, we used Cox regression models to compare propensity score-adjusted herpes zoster incidence between new anti-TNF and nonbiologic DMARD users while controlling for baseline corticosteroid use.

MAIN OUTCOME MEASURES

Incidence of herpes zoster cases occurring after initiation of new anti-TNF or nonbiologic DMARD therapy.

RESULTS

Among 33,324 new users of anti-TNF therapy, we identified 310 herpes zoster cases. Crude incidence rates among anti-TNF users were 12.1 per 1000 patient-years (95% CI, 10.7-13.6) for RA, 11.3 per 1000 patient-years (95% CI, 7.7-16.7) for inflammatory bowel disease, and 4.4 per 1000 patient-years (95% CI, 2.8-7.0) for psoriasis, psoriatic arthritis, or ankylosing spondylitis. Baseline use of corticosteroids of 10 mg/d or greater among all disease indications was associated with elevated risk (adjusted hazard ratio [HR], 2.13 [95% CI, 1.64-2.75]) compared with no baseline use. For patients with RA, adjusted incidence rates were similar between anti-TNF and nonbiologic DMARD initiators (adjusted HR, 1.00 [95% CI, 0.77-1.29]) and comparable between all 3 anti-TNF therapies studied. Across all disease indications, the adjusted HR was 1.09 (95% CI, 0.88-1.36).

CONCLUSION AND RELEVANCE

Among patients with RA and other inflammatory diseases, those who initiated anti-TNF therapies were not at higher risk of herpes zoster compared with patients who initiated nonbiologic treatment regimens.

Emergency department visits for influenza A(H1N1)pdm09, Davidson County, Tennessee, USA

To determine the number of emergency department visits attributable to influenza A(H1N1)pdm09 in Davidson County, Tennessee, USA, we used active, population-based surveillance and laboratory-confirmed influenza data. We estimated ≈10 visits per 1,000 residents during the pandemic period. This estimate should help emergency departments prepare for future pandemics.

Use of a disease risk score to compare serious infections associated with anti-tumor necrosis factor therapy among high- versus lower-risk rheumatoid arthritis patients

OBJECTIVE

To evaluate whether rates of serious infection with anti-tumor necrosis factor (anti-TNF) therapy in rheumatoid arthritis (RA) patients differ in magnitude by specific drugs and patient characteristics.

METHODS

Among new nonbiologic disease-modifying antirheumatic drug users enrolled in Medicare and Medicaid or a large US commercial health plan, we created and validated a person-specific infection risk score based on age, demographics, insurance type, glucocorticoid dose, and comorbidities to identify patients at high risk for hospitalized infections. We then applied this risk score to new users of infliximab, etanercept, and adalimumab and compared the observed 1-year rates of infection to one another and to the predicted infection risk score estimated in the absence of anti-TNF exposure.

RESULTS

Among 11,657 RA patients initiating anti-TNF therapy, the observed 1-year rate of infection was 14.2 infections per 100 person-years in older patients (age ≥65 years) and 4.8 in younger patients (age <65 years). There was a relatively constant rate difference of ~1-4 infections per 100 person-years associated with anti-TNF therapy across the range of the infection risk score. Infliximab had a significantly greater adjusted rate of infection compared to etanercept and adalimumab in both high- and lower-risk RA patients.

CONCLUSION

The rate of serious infections for anti-TNF agents was incrementally increased by a fixed absolute difference irrespective of age, comorbidities, and other factors that contributed to infections. Older patients and those with high comorbidity burdens should be reassured that the magnitude of their incremental risk with anti-TNF agents is not greater than for lower-risk patients.

Reducing blood culture contamination in the emergency department: an interrupted time series quality improvement study

OBJECTIVES

Blood culture contamination is a common problem in the emergency department (ED) that leads to unnecessary patient morbidity and health care costs. The study objective was to develop and evaluate the effectiveness of a quality improvement (QI) intervention for reducing blood culture contamination in an ED.

METHODS

The authors developed a QI intervention to reduce blood culture contamination in the ED and then evaluated its effectiveness in a prospective interrupted times series study. The QI intervention involved changing the technique of blood culture specimen collection from the traditional clean procedure to a new sterile procedure, with standardized use of sterile gloves and a new materials kit containing a 2% chlorhexidine skin antisepsis device, a sterile fenestrated drape, a sterile needle, and a procedural checklist. The intervention was implemented in a university-affiliated ED and its effect on blood culture contamination evaluated by comparing the biweekly percentages of blood cultures contaminated during a 48-week baseline period (clean technique) and 48-week intervention period (sterile technique), using segmented regression analysis with adjustment for secular trends and first-order autocorrelation. The goal was to achieve and maintain a contamination rate below 3%.

RESULTS

During the baseline period, 321 of 7,389 (4.3%) cultures were contaminated, compared to 111 of 6,590 (1.7%) during the intervention period (p < 0.001). In the segmented regression model, the intervention was associated with an immediate 2.9% (95% confidence interval [CI] = 2.2% to 3.2%) absolute reduction in contamination. The contamination rate was maintained below 3% during each biweekly interval throughout the intervention period.

CONCLUSIONS

A QI assessment of ED blood culture contamination led to development of a targeted intervention to convert the process of blood culture collection from a clean to a fully sterile procedure. Implementation of this intervention led to an immediate and sustained reduction of contamination in an ED with a high baseline contamination rate.

Rates of hospitalized bacterial infection associated with juvenile idiopathic arthritis and its treatment

OBJECTIVE

To compare the incidence of hospitalized bacterial infections among children with and children without juvenile idiopathic arthritis (JIA) and to examine the effects of selected medications.

METHODS

Using national Medicaid data from 2000 through 2005, we identified a cohort of children with JIA and a comparator cohort of children with attention deficit hyperactivity disorder (ADHD). Exposures to methotrexate (MTX), TNF inhibitors, and oral glucocorticoids (GCs) were determined using pharmacy claims. Patients hospitalized with bacterial infections were identified using coded discharge diagnoses. We calculated adjusted hazard ratios (HR(adj) ) to compare infection incidence rates while adjusting for relevant covariates.

RESULTS

We identified 8,479 JIA patients with 13,003 person-years of followup; 36% took MTX and 16% took TNF inhibitors. Compared with ADHD patients, JIA patients who were not currently taking MTX or TNF inhibitors had an increased rate of infection (HR(adj) 2.0 [95% confidence interval (95% CI) 1.5, 2.5]). Among JIA patients not receiving TNF inhibitor therapy, MTX users had a similar rate of infection as those not currently taking MTX (HR(adj) 1.2 [95% CI 0.9, 1.7]). TNF inhibitor use (irrespective of MTX) resulted in a similar rate of infection as use of MTX without a TNF inhibitor (HR(adj) 1.2 [95% CI 0.8, 1.8]). Use of high-dose GCs (≥10 mg/day of prednisone or equivalent) increased the rate of infection as compared with no GC use, after adjustment for MTX and TNF inhibitor use (HR(adj) 3.1 [95% CI 2.0, 4.7]).

CONCLUSION

Children with JIA had an increased rate of infection compared to children with ADHD. Among children with JIA, the rate of infection was not increased with MTX or TNF inhibitor use, but was significantly increased with high-dose GC use.

Comparative effectiveness of sulfonylurea and metformin monotherapy on cardiovascular events in type 2 diabetes mellitus: a cohort study

BACKGROUND

The effects of sulfonylureas and metformin on outcomes of cardiovascular disease (CVD) in type 2 diabetes are not well-characterized.

OBJECTIVE

To compare the effects of sulfonylureas and metformin on CVD outcomes (acute myocardial infarction and stroke) or death.

DESIGN

Retrospective cohort study.

SETTING

National Veterans Health Administration databases linked to Medicare files.

PATIENTS

Veterans who initiated metformin or sulfonylurea therapy for diabetes. Patients with chronic kidney disease or serious medical illness were excluded.

MEASUREMENTS

Composite outcome of hospitalization for acute myocardial infarction or stroke, or death, adjusted for baseline demographic characteristics; medications; cholesterol, hemoglobin A1c, and serum creatinine levels; blood pressure; body mass index; health care utilization; and comorbid conditions.

RESULTS

Among 253 690 patients initiating treatment (98 665 with sulfonylurea therapy and 155 025 with metformin therapy), crude rates of the composite outcome were 18.2 per 1000 person-years in sulfonylurea users and 10.4 per 1000 person-years in metformin users (adjusted incidence rate difference, 2.2 [95% CI, 1.4 to 3.0] more CVD events with sulfonylureas per 1000 person-years; adjusted hazard ratio [aHR], 1.21 [CI, 1.13 to 1.30]). Results were consistent for both glyburide (aHR, 1.26 [CI, 1.16 to 1.37]) and glipizide (aHR, 1.15 [CI, 1.06 to 1.26]) in subgroups by CVD history, age, body mass index, and albuminuria; in a propensity score-matched cohort analysis; and in sensitivity analyses.

LIMITATION

Most of the veterans in the study population were white men; data on women and minority groups were limited but reflective of the Veterans Health Administration population.

CONCLUSION

Use of sulfonylureas compared with metformin for initial treatment of diabetes was associated with an increased hazard of CVD events or death.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality and the U.S. Department of Health and Human Services.

Influence of hospital guidelines on management of children hospitalized with pneumonia

BACKGROUND AND OBJECTIVE

Clinical practice guidelines (CPGs) assist clinicians in making appropriate diagnostic and treatment decisions based on available evidence. The objective of this study was to describe the availability and content of institutional community-acquired pneumonia (CAP) CPGs, and to evaluate the association between institutional CPGs and care utilization, antibiotic administration, and outcomes among children hospitalized with CAP.

METHODS

This multicenter retrospective cohort study included children aged 1 to 18 years hospitalized with CAP from July 1, 2009, to June 30, 2011. CPGs from each institution were reviewed to abstract information regarding diagnostic testing and antimicrobial selection. We compared overall and specific utilization patterns, antimicrobial use, and hospital length of stay (LOS) for children with CAP between hospitals with and without CPGs.

RESULTS

Thirteen (31.7%) of 41 hospitals had an institutional CPG for nonsevere CAP. There was marked heterogeneity among CPGs. Among the 19,710 children hospitalized with CAP, cost of care, hospital LOS, and 14-day readmission rate were not associated with the presence of a CPG. CPGs did not influence ordering patterns for most diagnostic tests, including blood culture and chest radiographs. Penicillin or aminopenicillins were prescribed to 46.3% of children at institutions where a CPG recommended the use of these antibiotics as first-line agents compared with 23.9% of children at institutions without a CPG (odds ratio = 2.7; 95% confidence interval = 1.4-5.5).

CONCLUSIONS

The availability of a CAP CPG had minimal impact on resource utilization and was not associated with cost or hospital LOS. Institutional CPGs, however, did influence patterns of antimicrobial use.

Reweighted Mahalanobis distance matching for cluster-randomized trials with missing data

PURPOSE

This paper introduces an improved tool for designing matched-pairs randomized trials. The tool allows the incorporation of clinical and other knowledge regarding the relative importance of variables used in matching and allows for multiple types of missing data. The method is illustrated in the context of a cluster-randomized trial. A Web application and an R package are introduced to implement the method and incorporate recent advances in the area.

METHODS

Reweighted Mahalanobis distance (RMD) matching incorporates user-specified weights and imputed values for missing data. Weight may be assigned to missingness indicators to match on missingness patterns. Three examples are presented, using real data from a cohort of 90 Veterans Health Administration sites that had at least 100 incident metformin users in 2007. Matching is utilized to balance seven factors aggregated at the site level. Covariate balance is assessed for 10,000 randomizations under each strategy: simple randomization, matched randomization using the Mahalanobis distance, and matched randomization using the RMD.

RESULTS

The RMD matching achieved better balance than simple randomization or MD randomization. In the first example, simple and MD randomization resulted in a 10% chance of seeing an absolute mean difference of greater than 26% in the percent of nonwhite patients per site; the RMD dramatically reduced that to 6%. The RMD achieved significant improvement over simple randomization even with as much as 20% of the data missing.

CONCLUSIONS

Reweighted Mahalanobis distance matching provides an easy-to-use tool that incorporates user knowledge and missing data.

Diagnostic performance of the BinaxNow Influenza A&B rapid antigen test in ED patients

OBJECTIVE

The objective of this study is to evaluate the diagnostic performance of the BinaxNow Influenza A&B rapid antigen test (RAT) in emergency department (ED) patients.

METHODS

We prospectively enrolled a systematic sample of ED patients older than 6 months with acute respiratory symptoms or nonlocalizing fever during 3 consecutive influenza seasons (2008-2011). Nasal and throat swabs collected by research personnel were tested for influenza by real-time reverse transcription-polymerase chain reaction (RT-PCR). Clinicians independently ordered RATs during clinical care; these specimens were collected by clinical staff and tested for influenza using the BinaxNow RAT. Patients with both a research RT-PCR and clinical RAT were included in the study. Rapid antigen test diagnostic performance was evaluated using RT-PCR as a criterion standard, with preplanned, stratified analysis for subject age, duration of symptoms, influenza subtype, and polymerase chain reaction cycle threshold, which provides a semiquantitative estimate of viral load.

RESULTS

Of 561 subjects enrolled, 131 (23.4%) had a positive RT-PCR, and 37 (6.6%) had a positive RAT. Overall, RAT performance included sensitivity of 24.4% (95% confidence interval [CI], 17.5%-32.9%), specificity of 98.8% (95% CI, 97.1%-99.6%), positive predictive value of 86.5% (95% CI, 70.4%-94.9%), negative predictive value of 81.1% (95% CI, 77.4%-84.3%). Rapid antigen test sensitivities were low for all categories of subject age, symptom duration, influenza subtype, and cycle threshold.

CONCLUSION

The BinaxNow RAT demonstrated high specificity and poor sensitivity in ED patients selected by treating clinicians for influenza testing. A negative RAT is a poor predictor for the absence of influenza in the ED and should not be used as a criterion to withhold antiviral medications.

Incidence and risk factors for progressive multifocal leukoencephalopathy among patients with selected rheumatic diseases

OBJECTIVE

To ascertain the incidence of progressive multifocal leukoencephalopathy (PML) in patients with selected rheumatic diseases, to describe the characteristics of PML cases occurring in this setting, and to evaluate the extent to which such cases occurred in the context of biologic therapies such as rituximab or tumor necrosis factor antagonists.

METHODS

We conducted a large population-based study to describe the incidence and risk factors for PML among patients with rheumatoid arthritis, psoriatic arthritis, psoriasis, juvenile idiopathic arthritis, inflammatory bowel disease, and ankylosing spondylitis using national inpatient and outpatient administrative data from the entire Center for Medicare and Medicaid Services from 2000-2009. Suspected PML cases were identified using hospital discharge diagnosis codes. Risk factors for PML were evaluated using outpatient data ≥6 months prior to PML diagnosis.

RESULTS

Among 2,030,578 patients with autoimmune diseases of interest, a total of 53 PML cases were identified (2.6 per 100,000 patients). Most PML cases had human immunodeficiency virus (HIV) and/or cancer. Nine PML cases had evidence for biologic use prior to PML hospitalization, of which 3 had neither HIV nor malignancy and were exposed to biologics within 12 (rituximab) or 6 months (all other biologics) prior to PML diagnosis. PML occurred at an estimated incidence of 0.2 per 100,000 patients with autoimmune diseases who did not have HIV or malignancy.

CONCLUSION

PML occurs at a very low incidence among patients with rheumatic diseases but can occur even in the absence of HIV or malignancy.

Estimating age-specific influenza-related hospitalization rates during the pandemic (H1N1) 2009 in Davidson Co, TN

BACKGROUND

In April 2009, a pandemic caused by a novel influenza strain, the A(H1N1)pdm09 virus, started. Few age-specific estimates of hospitalizations associated with the first year of circulation of the pandemic virus are available.

OBJECTIVES

To estimate age-specific hospitalization rates associated with laboratory-confirmed A(H1N1)pdm09 virus in Davidson County, TN, from May 2009 to March 2010.

PATIENTS/METHODS

Two separate strategies were applied: capture-recapture and surveillance-sampling methods. For the capture-recapture estimates, we linked data collected via two independent prospective population-based surveillance systems: The Influenza Vaccine Effectiveness Network (Flu-VE) tested consenting county patients hospitalized with respiratory symptoms at selected hospitals using real-time reverse transcriptase polymerase chain reaction (rRT-PCR); the Emerging Infections Program identified county patients with positive influenza tests in all area hospitals. For the surveillance-sampling estimates, we applied the age-specific proportions of influenza-positive patients (from Flu-VE) to the number of acute respiratory illness hospitalizations obtained from the Tennessee Hospital Discharge Data system.

RESULTS

With capture-recapture, we estimated 0·89 (95% CI, 0·72-1·49), 0·62 (0·42-1·11), 1·78 (0·99-3·63), and 0·76 (0·50-1·76) hospitalizations per 1000 residents aged < 5, 5-17, 18-49, and ≥ 50 years, respectively. Surveillance-sampling estimated rates were 0·78 (0·46-1·22), 0·32 (0·14-0·69), 0·99 (0·64-1·52), and 1·43 (0·80-2·48) hospitalizations per 1000 residents aged <5, 5-17, 18-49, and ≥ 50 years, respectively. In all age-groups combined, we estimated approximately 1 influenza-related hospitalization per 1000 residents.

CONCLUSIONS

Two independent methods provided consistent results on the burden of pandemic virus in Davidson County and suggested that the overall incidence of A(H1N1)pdm09-associated hospitalization was 1 per 1000 county residents.

Accuracy of pharmacy and coded-diagnosis information in identifying tuberculosis in patients with rheumatoid arthritis

PURPOSE

Previous studies suggest that disease-modifying anti-rheumatic drugs (DMARDs) increase tuberculosis (TB) risk. The accuracy of pharmacy and coded-diagnosis information to identify persons with TB is unclear.

METHODS

Within a cohort of rheumatoid arthritis (RA) patients (2000-2005) enrolled in Tennessee Medicaid, we identified those with potential TB using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD9-CM) diagnosis codes and/or pharmacy claims. Using the Tennessee TB registry as the gold standard for identification of TB, we estimated the sensitivity, specificity, predictive values, and the respective 95% confidence intervals for each TB case-ascertainment strategy.

RESULTS

Ten of 18,094 RA patients had confirmed TB during 61,461 person-years of follow-up (16.3 per 100,000 person-years). The sensitivity and positive predictive value (PPV) and respective 95% confidence intervals were low for confirmed TB based on ICD9-CM codes alone (60.0% (26.2-87.8) and 1.3% (0.5-2.9)), pharmacy data alone (20% (2.5-55.6) and 4.1% (0.5-14.3)), and both (20% (2.5-55.6) and 25.0% (3.2-65.1)).

CONCLUSIONS

Algorithms that use administrative data alone to identify TB have a poor PPV that results in a high false positive rate of TB detection.

Comparative effectiveness of incident oral antidiabetic drugs on kidney function

Diabetes is a major cause of chronic kidney disease, and oral antidiabetic drugs are the mainstay of therapy for most patients with Type 2 diabetes. Here we evaluated their role on renal outcomes by using a national Veterans Administration database to assemble a retrospective cohort of 93,577 diabetic patients who filled an incident oral antidiabetic drug prescription for metformin, sulfonylurea, or rosiglitazone, and had an estimated glomerular filtration rate (eGFR) of 60 ml/min or better. The primary composite outcome was a persistent decline in eGFR from baseline of 25% or more (eGFR event) or a diagnosis of end-stage renal disease (ESRD). The secondary outcome was an eGFR event, ESRD, or death. Sensitivity analyses included using a more stringent definition of the eGFR event requiring an eGFR <60 ml/min per 1.73 m(2) in addition to the 25% or more decline; controlling for baseline proteinuria thereby restricting data to 15,065 patients; and not requiring persistent treatment with the initial oral antidiabetic drug. Compared to patients using metformin, sulfonylurea users had an increased risk for both the primary and the secondary outcome, each with an adjusted hazard ratio of 1.20. Results of sensitivity analyses were consistent with the main findings. The risk associated with rosiglitazone was similar to metformin for both outcomes. Thus, compared to metformin, oral antidiabetic drug treatment with sulfonylureas increased the risk of a decline in eGFR, ESRD, or death.

Initiation of sulfonylureas versus metformin is associated with higher blood pressure at one year

PURPOSE

To determine if incident oral antidiabetic drug (OAD) use was associated with 12-month systolic blood pressure (BP) and if this was mediated through body mass index (BMI) changes.

METHODS

A retrospective cohort of veterans with hypertension who initiated metformin (n = 2057) or sulfonylurea (n = 1494) between 1 January 2000 and 31 December 2007 in the Veterans Administration Mid-South Network was assembled. Patients were included if they had complete covariates, including 12-month BP and BMI, and persisted on therapy for 12 months. Linear regression was conducted to investigate the effect of OADs on 12-month systolic BP adjusting for demographics, glycated hemoglobin, creatinine, BMI, health care utilization, and comorbidities, including cardiovascular disease (CVD). A second analysis examined if these effects were mediated by BMI change. The secondary outcome was the proportion of patients who had a controlled BP (≤ 140/90 mmHg) at 12 months adjusted for baseline BP and covariates.

RESULTS

Patients were white (82%) males (97%) with median age of 64 years (interquartile range [IQR] 57, 72), and 27% had history of CVD. Sulfonylurea users had a 1.33 mmHg (0.16, 2.50, p = 0.03) higher 12-month systolic BP than metformin users. The median change in BMI from OAD initiation to 12 months was -0.76 (IQR -1.78, 0.07) and 0.21 (IQR -0.57, 1.03) among metformin and sulfonylurea users, respectively. In a model adjusting for BMI change, the difference in 12-month systolic BP between sulfonylurea and metformin users became insignificant (0.23 (-1.00, 1.45), p = 0.72), while one BMI unit change was associated with an increase in 12-month systolic BP of 1.07 mmHg (0.74, 1.40, p < 0.0001). At 12 months, 68.3% of metformin patients had controlled BP versus 64.2% of sulfonylurea patients (p = 0.01).

CONCLUSIONS

Compared with metformin, sulfonylurea initiation was associated with increased systolic BP at 12 months, which appears to be mediated by the differential effects of these drugs on BMI.

Comparative safety of infliximab and etanercept on the risk of serious infections: does the association vary by patient characteristics?

PURPOSE

Infliximab, a chimeric monoclonal anti-TNFα antibody, has been found to increase the risk of serious infections compared with the TNF receptor fusion protein etanercept in some studies. It is unclear whether the risk varies by patient characteristics. We conducted a study to address this question.

METHODS

We identified members of Kaiser Permanente Northern California who initiated infliximab (n = 793) or etanercept (n = 2692) in 1997-2007. Using a Cox model, we estimated the propensity-score-adjusted hazard ratio (HR) and 95% confidence interval (CI) of serious infections requiring hospitalization or opportunistic infections comparing infliximab initiators to etanercept initiators. We tested whether the adjusted HR differed by age, sex, race/ethnicity, body mass index, and smoking status.

RESULTS

The crude incidence rate of serious infections per 100 person-years was 5.4 (95%CI: 3.8, 7.5) in patients <65 years and 16.0 (95%CI: 10.4, 23.4) in patients ≥ 65 years during the first 3 months following treatment initiation. Compared with etanercept, the adjusted HR during this period was elevated for infliximab in patients <65 years (HR: 3.01; 95%CI: 1.49, 6.07), but not in those ≥ 65 years (HR 0.94; 95%CI: 0.41, 2.13). Findings did not suggest that the HR varied by the other patient characteristics examined.

CONCLUSIONS

An increased risk of serious infections associated with infliximab relative to etanercept did not appear to be modified by patients' sex, race/ethnicity, body mass index, or smoking status. There was an indication that the increased risk might be limited to patients <65 years. Additional studies are warranted to verify or refute this finding.

Factors associated with the non-completion of conventional anti-tuberculosis treatment in Peru

BACKGROUND

The non-adherence to tuberculosis treatment is associated with increased infection, antibiotic resistance, increased costs and death. Our objective was to identify factors associated with lack of completion of conventional treatment for tuberculosis in Peru.

PATIENTS AND METHODS

An unmatched case-control study in patients diagnosed with tuberculosis from 2004-2005 who completed treatment until September 2006. The cases were defined as patients who discontinued treatment for ≥30 consecutive days, while the controls were defined as those who completed treatment without interruption. The factors were identified by logistic regression, calculating odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

We studied 265 cases and 605 controls. The non-adherence to treatment in our study was associated with the male sex (OR=1.62; CI: 1.07-2.44), having felt discomfort during treatment (OR=1.76; CI: 1.19-2.62), a prior history of non-compliance (OR=7.95; CI: 4.76-13.27) and illegal drug use (OR=3.74; CI: 1.25-11.14). Also, if we consider the interaction of previous non-adherence history and poverty, the risk of non-completion increases (OR=11.24; CI: 4-31.62). Conversely, having been properly informed about the disease (OR=0.25; CI: 0.07-0.94) and being able to access health-care services within office hours (8 am-8 pm) (OR=0.52; CI: 0.31-0.87) were associated with better adherence.

CONCLUSIONS

The non-compliance with anti-tuberculosis treatment was associated with non-modifiable factors (male sex, previous non-compliance) and with others whose control would improve compliance (malaise during treatment, illegal drug use and poverty). Likewise, providing access to the health-care system and improving the information given about tuberculosis should be priorities.

Initiation of tumor necrosis factor-α antagonists and the risk of hospitalization for infection in patients with autoimmune diseases

CONTEXT

Although tumor necrosis factor (TNF)-α antagonists are increasingly used in place of nonbiologic comparator medications, their safety profile remains incomplete.

OBJECTIVES

To determine whether initiation of TNF-α antagonists compared with nonbiologic comparators is associated with an increased risk of serious infections requiring hospitalization.

DESIGN, SETTING, AND PATIENTS

Within a US multi-institutional collaboration, we assembled retrospective cohorts (1998-2007) of patients with rheumatoid arthritis (RA), inflammatory bowel disease (IBD), and psoriasis, psoriatic arthritis, or ankylosing spondylitis (psoriasis and spondyloarthropathies) combining data from Kaiser Permanente Northern California, New Jersey and Pennsylvania Pharmaceutical Assistance programs, Tennessee Medicaid, and national Medicaid/Medicare. TNF-α antagonists and nonbiologic regimens were compared in disease-specific propensity score (PS)-matched cohorts using Cox regression models with nonbiologics as the reference. Baseline glucocorticoid use was evaluated as a separate covariate.

MAIN OUTCOME MEASURE

Infections requiring hospitalization (serious infections) during the first 12 months after initiation of TNF-α antagonists or nonbiologic regimens.

RESULTS

Study cohorts included 10,484 RA, 2323 IBD, and 3215 psoriasis and spondyloarthropathies matched pairs using TNF-α antagonists and comparator medications. Overall, we identified 1172 serious infections, most of which (53%) were pneumonia and skin and soft tissue infections. Among patients with RA, serious infection hospitalization rates were 8.16 (TNF-α antagonists) and 7.78 (comparator regimens) per 100 person-years (adjusted hazard ratio [aHR], 1.05 [95% CI, 0.91-1.21]). Among patients with IBD, rates were 10.91 (TNF-α antagonists) and 9.60 (comparator) per 100 person-years (aHR, 1.10 [95% CI, 0.83-1.46]). Among patients with psoriasis and spondyloarthropathies, rates were 5.41 (TNF-α antagonists) and 5.37 (comparator) per 100 person-years (aHR, 1.05 [95% CI, 0.76-1.45]). Among patients with RA, infliximab was associated with a significant increase in serious infections compared with etanercept (aHR, 1.26 [95% CI, 1.07-1.47]) and adalimumab (aHR, 1.23 [95% CI, 1.02-1.48]). Baseline glucocorticoid use was associated with a dose-dependent increase in infections.

CONCLUSION

Among patients with autoimmune diseases, compared with treatment with nonbiologic regimens, initiation of TNF-α antagonists was not associated with an increased risk of hospitalizations for serious infections.