Impact of Prompt Influenza Antiviral Treatment on Extended Care Needs After Influenza Hospitalization Among Community-Dwelling Older Adults

Clinical Infectious Diseases, Nov 2015

Background. Patients hospitalized with influenza may require extended care on discharge. We aimed to explore predictors for extended care needs and the potential mitigating effect of antiviral treatment among community-dwelling adults aged ≥65 years hospitalized with influenza. Methods. We used laboratory-confirmed influenza hospitalizations from 3 influenza seasons. Extended care was defined as new placement in a skilled nursing home/long-term/rehabilitation facility on hospital discharge. We focused on those treated with antiviral agents to explore the effect of early treatment on extended care and hospital length of stay using logistic regression and competing risk survival analysis, accounting for time from illness onset to hospitalization. Treatment was categorized as early (≤4 days) or late (>4 days) in reference to date of illness onset. Results. Among 6593 community-dwelling adults aged ≥65 years hospitalized for influenza, 18% required extended care at discharge. The need for care increased with age and neurologic disorders, intensive care unit admission, and pneumonia were predictors of care needs. Early treatment reduced the odds of extended care after hospital discharge for those hospitalized ≤2 or >2 days from illness onset (adjusted odds ratio, 0.38 [95% confidence interval {CI}, .17–.85] and 0.75 [.56–.97], respectively). Early treatment was also independently associated with reduction in length of stay for those hospitalized ≤2 days from illness onset (adjusted hazard ratio, 1.81; 95% CI, 1.43–2.30) or >2 days (1.30; 1.20–1.40). Conclusions. Prompt antiviral treatment decreases the impact of influenza on older adults through shorten hospitalization and reduced extended care needs.

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Impact of Prompt Influenza Antiviral Treatment on Extended Care Needs After Influenza Hospitalization Among Community-Dwelling Older Adults

CID Impact of Prompt Influenza Antiviral Treatment on Extended Care Needs After Influenza Hospitalization Among Community-Dwelling Older Adults Sandra S. Chaves () 0 13 Alejandro Pérez 0 13 Lisa Miller 0 12 Nancy M. Bennett 0 10 Ananda Bandyopadhyay 0 18 Monica M. Farley 0 16 17 Brian Fowler 0 15 Emily B. Hancock 0 20 Pam Daily Kirley 0 19 Ruth Lynfield 0 14 Patricia Ryan 0 8 Craig Morin 0 14 William Schaffner 0 9 Ruta Sharangpani 0 6 Mary Lou Lindegren 0 9 Leslie Tengelsen 0 7 Ann Thomas 0 4 Mary B. Hill 0 5 Kristy K. Bradley 0 2 Oluwakemi Oni 0 3 James Meek 0 1 Shelley Zansky 0 11 Marc-Alain Widdowson 0 13 Lyn Finelli 0 13 0 Received 11 March 2015; accepted 11 August 2015; electronically published 2 September 2015. A-32 , Atlanta, GA 30333 1 Connecticut Emerging Infections Program, Yale School of Public Health , New Haven 2 Oklahoma State Department of Health , Oklahoma City 3 Iowa Department of Public Health , Des Moines 4 Oregon Public Health Division , Portland 5 Salt Lake County Health Department , Utah 6 Michigan Department of Community Health , Lansing 7 Idaho Department of Health and Welfare , Boise 8 Maryland Department of Health and Mental Hygiene , Baltimore 9 Vanderbilt University School of Medicine , Nashville, Tennessee 10 Department of Medicine, University of Rochester School of Medicine and Dentistry , New York 11 Emerging Infections Program, New York State Department of Health , Albany 12 Colorado Department of Public Health and Environment , Denver 13 Influenza Division, Centers for Disease Control and Prevention , Atlanta Georgia 14 Minnesota Department of Health , St Paul 15 Ohio Department of Health , Columbus 16 Atlanta Veterans Affairs Medical Center , Georgia 17 Department of Medicine, Emory University School of Medicine , Atlanta 18 Rhode Island Department of Health , Providence 19 California Emerging Infections Program , Oakland 20 New Mexico Department of Health , Santa Fe Background. Patients hospitalized with influenza may require extended care on discharge. We aimed to explore predictors for extended care needs and the potential mitigating effect of antiviral treatment among communitydwelling adults aged ≥65 years hospitalized with influenza. Methods. We used laboratory-confirmed influenza hospitalizations from 3 influenza seasons. Extended care was defined as new placement in a skilled nursing home/long-term/rehabilitation facility on hospital discharge. We focused on those treated with antiviral agents to explore the effect of early treatment on extended care and hospital length of stay using logistic regression and competing risk survival analysis, accounting for time from illness onset to hospitalization. Treatment was categorized as early (≤4 days) or late (>4 days) in reference to date of illness onset. Results. Among 6593 community-dwelling adults aged ≥65 years hospitalized for influenza, 18% required extended care at discharge. The need for care increased with age and neurologic disorders, intensive care unit admission, and pneumonia were predictors of care needs. Early treatment reduced the odds of extended care after hospital discharge for those hospitalized ≤2 or >2 days from illness onset (adjusted odds ratio, 0.38 [95% confidence interval {CI}, .17-.85] and 0.75 [.56-.97], respectively). Early treatment was also independently associated with reduction in length of stay for those hospitalized ≤2 days from illness onset (adjusted hazard ratio, 1.81; 95% CI, 1.43-2.30) or >2 days (1.30; 1.201.40). Conclusions. Prompt antiviral treatment decreases the impact of influenza on older adults through shorten hospitalization and reduced extended care needs. influenza; influenza hospitalizations; elderly; extended care; influenza antiviral treatment - Annual influenza epidemics lead to substantially increased morbidity and mortality rates, principally among the elderly in the United States [1, 2]. In most seasons, about 60% of influenza-related hospitalizations occur in adults aged ≥65 years [1]. Many of those affected are frail and residents of long-term care facilities and are therefore at high risk of further functional decline [3, 4]. However, functional decline caused by influenza-associated hospitalization among older adults living independently in the community has not been well documented. Serious illness or injury leading to hospitalization or restricted activity has been shown to precipitate disability in older adults, even among those not considered physically frail [4, 5]. Disability is often measured by the loss of independence in performing essential activities of daily living (ADLs), such as bathing, dressing, and walking. Disability is associated with increased risk of mortality and may result in nursing home placement or a greater use of formal or informal home care services. Influenza vaccine in older adults has low to moderate effectiveness [6, 7], and antiviral treatment may be an important adjunct in preventing severe influenza-related complications. Currently, antiviral treatment is recommended for those hospitalized with confirmed or suspected influenza or at high risk for complications [8]. Some studies have shown that prompt treatment with influenza antiviral agents can reduce the duration of illness and prevent influenza-related complications, including death, among hospitalized patients [9–12]. However, data on the benefit of antiviral agents among older adults hospitalized with influenza are limited. We explored the effect of influenza-associated hospitalization and the potential mitigating impact of early treatment with influenza antiviral agents on hospital length of stay and disability, as measured by extended care needs at discharge, among community-dwelling adults aged ≥65 years. Study Setting and Population We used data from the Influenza Hospitalization Surveillance Network (FluSurv-NET), collected during the 2010–2011, 2011–2012, and 2012–2013 influenza seasons from 1 October through 30 April. FluSurv-NET conducts population-based hospitalization surveillance for influenza in approximately 80 selected counties located in California, Colorado, Connecticut, Georgia, Idaho, Iowa, Maryland, Michigan, Minnesota, New York, Oklahoma, Ohio, Oregon, Rhode Island, Tennessee, and Utah. Cases were prospectively identified based on review of hospital laboratory, infection control, and admission or discharge logs. Information on demographic characteristics, medical history, underlying conditions, clinical course, and treatment was collected for each case through review of medical charts, using a standardized questionnaire as described elsewhere [13]. Data on influenza vaccination status were verified using a vaccination registry or the patient’s primary care provider. Influenza virus infection was laboratory-confirmed by real time-reverse-transcription polymerase chain reaction, viral culture, direct or indirect fluorescent antibody staining, or rapid antigen test; influenza testing was ordered at the discretion of attending clinicians. We analyzed data on community-dwelling adults aged ≥65 years admitted to the hospital with communityacquired influenza (ie, hospitalized ≤3 days from a positive influenza test). Human Subjects Review This data collection was determined by the Centers for Disease Control and Prevention’s (CDC’s) human subject expert to be for routine public health surveillance purposes, and thus was not subject to CDC institutional review board approval for human research protections. Participating sites submitted the study to their state and local institutional review boards for review as needed. Definitions Underlying conditions were organized in categories. We studied immunosuppressive conditions, neurologic disorders, cardiovascular diseases, chronic lung diseases, metabolic disorders, blood disorders, renal disease, and liver disease. The category of immunosuppressive condition included immunoglobulin deficiency, cancer, human immunodeficiency virus/AIDS, and treatment with oral or injectable steroids for a ≥2 weeks before admission. The category of neurologic disorders included paralysis, muscular dystrophies, myasthenia gravis, multiple sclerosis, dementia, and cognitive dysfunction. Cardiovascular diseases included conditions such as coronary heart disease, cardiac valve disorders, congestive heart failure, and pulmonary hypertension (isolated hypertension excluded). Chronic lung diseases included chronic obstructive pulmonary disease and interstitial lung disease. Metabolic disorders included diabetes mellitus, thyroid dysfunction, and adrenal insufficiency. Blood disorders included thalassemia, thrombocytopenia, and polycythemia vera. A patient could be reported with ≥1 comorbidity category. Body mass index (BMI) was used to classify patients within weight categories as underweight (BMI, <18.5), normal weight (18.5 to <25), overweight (25 to <30), obese (30 to <40), or morbidly obese (≥40). Pneumonia at admission was defined by the presence of air space density/opacity, consolidation, lobar infiltrate, or pleural effusion in a chest radiograph obtained during the first 24 hours of hospital admission, combined with a discharge diagnosis of pneumonia. We categorized timing of antiviral treatment as early (given ≤4 days after illness onset) or late (given >4 days after illness onset), based on the finding that antiviral treatment may not affect course of illness if given >4–5 days after illness onset [12, 14, 15]. Extended care was defined as new placement in a skilled nursing home/long-term care facility or rehabilitation facility at hospital discharge. Patients transferred to other hospitals during hospitalization were excluded from the analysis. Statistical Analysis Demographic and clinical characteristics were described according to extended care needs at hospital discharge. The association between categorical variables was assessed using χ2 test (or Fisher exact test when appropriate), and Kruskal–Wallis tests were used for continuous variables. We used logistic regression to explore risk factors for and the impact of antiviral treatment on extended care needs on discharge. Variables known as potential confounders and/or associated with extended care in the univariate analysis (P < .1) were included in the multivariable models; variables that changed the odds ratio for outcomes of interest by ≥10% when removed were retained in the model. We also used competing risk survival analysis model based on Fine and Gray [16] to assess whether patients treated early with antivirals had an increased probability of being discharged from hospital sooner than those treated late (>4 days from illness onset), using death as a competing event and adjusting for potential confounders. Kaplan–Meier cumulative incidence curves were derived. For both the logistic regression and competing risk survival models, we decided to show the models separately for those hospitalized early in the course of illness (≤2 days from illness onset) versus late (>2 days), because of collinearity between time from illness onset to treatment and time from illness onset to hospitalization. We also limited these analysis to patients treated with antiviral agents. We were concerned about potential treatment indication bias, because treated patients were different from untreated ones. Treated patients (n = 5741) were older than untreated patients (n = 1229), more frequently white, more likely to be vaccinated against influenza, more often admitted to the intensive care unit (ICU), and had a longer hospitalization. Furthermore, those not treated with antiviral agents had a longer interval between onset of illness and hospital admission than those treated (median [interquartile range], 3 [2–5] vs 2 [1–4] days; P < .001). Data analysis was performed using SAS (version 9.3; SAS Institute) and R (version 3.0.2) software. Characteristics by Extended Care Needs at Hospital Discharge During the 2010–2011, 2011–2012, and 2012–2013 influenza seasons, 9059 influenza-associated hospitalizations were reported among adults aged ≥65 years. To look at extended care needed on discharge, we excluded 2215 cases who were living in institutions (not community dwellers) before hospitalization, 192 who died during hospitalization, 30 who were transferred to other hospitals, and 29 whose disposition at hospital discharge was unknown. Of the remaining 6593 communitydwelling adults aged ≥65 years with laboratory-confirmed influenza, 1184 (18%) patients required new placement at a skilled nursing/long-term care, or rehabilitation facility on hospital discharge. In our univariate analysis, extended care among those previously living in the community was associated with increasing age: 10% (230) among those aged 65–74 years, 16% (407) among those aged 75–84 years, and 30% (547) among those aged ≥85 years (P < .001) (Table 1). Extended care was also associated with white non-Hispanic race, presence of underlying chronic medical conditions, low BMI, and receipt of influenza vaccination and antiviral treatment. The prevalence of specified chronic medical conditions was fairly evenly distributed among those who did and those who did not require extended care, with the exception of the presence of cardiovascular disease (61% vs 54%; P < .001), and neurologic disorders (18% vs 9%; P < .001), both associated with the need for extended care. Most influenza hospitalizations were associated with influenza A virus infections, reflecting the dominant influenza virus type in circulation during the surveillance period. However, patients with influenza A virus infection required extended care slightly more often than those with influenza B (18% vs 16%; P = .04). In >50% of influenza A cases, the viral subtype was unavailable. The proportion of patients discharged to extended care varied significantly by surveillance site and ranged from 12% to 27%. Patients who required extended care at discharge were more likely to have experienced influenza-related complications than those discharged to home. The frequency of communityacquired pneumonia (35% vs 26%), encephalitis (4% vs 1%), ICU admission (25% vs 10%), mechanical ventilation (11% vs 2%), and hospitalization >5 days (72% vs 29%) were all significantly higher among those requiring extended care than among those patients discharged to home (Table 2). Treatment with Influenza Antiviral Drugs Among all 5741 patients with history of antiviral treatment (including 142 who died), we excluded 290 that had no date of treatment, and 149 who started treatment >2 days before hospital admission. Among the remaining 5302 treated patients, 76% received antivirals early in the course of illness (Figure 1). The time from illness onset to hospital admission was a median (interquartile range) of 1 (1–2) day for those treated early and 4 (3–7) days for those treated late (P < .01; Kruskal–Wallis test). Risk Factors and Effect of Antiviral Treatment on Extended Care (Logistic Regression Analysis) Among 3110 treated patients admitted ≤2 days after illness onset, our logistic regression model included age group, race/ethnicity, cardiovascular disease, neurologic disorder, timing of antiviral treatment (early vs late), ICU admission, BMI categories, receipt of influenza vaccination for the season, influenza virus type, influenza season, and study site. Community-acquired pneumonia General Characteristics Age, y 65–74 y 2278 (35) 2048 (90) 75–84 y 2477 (38) 2070 (84) 85 y and over 1838 (28) 1291 (70) Sex Male 3107 (47) 2548 (82) Female 3486 (53) 2861 (82) Race/ethnicity White non-Hispanic 4619 (70) 3720 (80) Black non-Hispanic 741 (11) 640 (86) Other 1125 (17) 959 (85) Weight category Underweight 266 (4) 196 (74) Normal 1932 (29) 1510 (78) Overweight 2013 (31) 1666 (83) Obese 1413 (21) 1212 (86) Morbidly obese 337 (5) 292 (87) ≥1 Chronic medical condition Yes No Blood disorder Yes No Cardiovascular disease Yes 3712 (56) 2991 (80) No 2881 (44) 2418 (84) Chronic lung disease Yes 2103 (32) 1733 (82) No 4490 (68) 3676 (82) Chronic metabolic disorder Yes 2940 (45) 2403 (82) No 3653 (55) 3006 (82) Immunosuppressive condition Yes No Liver disease Yes No Neurologic disorder Yes 697 (11) 482 (70) No 5896 (89) 4927 (84) 5910 (90) 4829 (82) 1081 (18) 683 (10) 580 (85) 103 (15) 110 (2) 82 (78) 24 (22) 6483 (98) 5323 (82) 1160 (18) 749 (11) 626 (84) 120 (16) 5844 (89) 4780 (82) 1064 (18) 64 (1) 52 (81) 12 (19) 6529 (99) 5357 (82) 1172 (18) Table 1. Characteristics of Patients Hospitalized With Patients, No. (%) Extended Extended Care Not Care Total Needed Needed P (N = 6593)a (n = 5409) (n = 1184) Valueb a The 6593 total includes only those alive at discharge and with outcome information (251 missing observations include 192 deaths). The percentages in this column are column percentages; those in the other columns are row percentages. b P values determined with χ2 test. c Statistically significant differences (P < .05). was used as a measure of severity at admission. We did not add mechanical ventilation or length of hospital stay to the model; these variables were highly correlated with being admitted to Table 1 continued. General Characteristics Renal disease Yes No Patients, No. (%) Extended Extended Care Not Care Total Needed Needed P (N = 6593)a (n = 5409) (n = 1184) Valueb 1414 (21) 5179 (79) 5356 (81) 1229 (19) 3819 (62) 2327 (38) 1142 (81) 4267 (82) 4364 (81) 1038 (85) 3120 (82) 1960 (84) 5708 (87) 4661 (82) 1047 (18) 846 (13) 716 (85) 130 (15) 3557 (54) 3038 (46) 2873 (81) 2536 (84) Table 2. Complications Among Patients Hospitalized With Complication Encephalitis Stroke Total Patients, No. (%)a Extended Care Not Needed (n = 5409) Extended Care Needed (n = 1184) 1424 (26) 64 (1) Abbreviations: ARDS, acute respiratory distress syndrome; ICU, intensive care unit. a All percentages are row percentages. For all variables, difference in percentages were statistically significant in terms of extended care needs after hospital discharge (P < .001; χ2 test). the ICU. Other complications listed had small numbers of observations. We had a total of 3110 patients, we excluded missing values and used a total of 2238 (72%) observations; 424 (19%) of these patients required extended care on discharge. Compared with patients treated late (>4 days after illness onset), those treated early (≤4 days) were less than half as likely to require extended care (adjusted odds ratio [aOR], 0.38; 95% confidence interval [CI], .17–.85; P = .02) (Figure 2, Supplementary Table 1). The aOR for extended care needs was 4.60 (95% CI, 3.30–6.40) for patients aged ≥85 years and 2.12 (1.53–2.93) for those aged 75–84 years, when compared with patients aged 65–74 years (Figure 2). Patients with neurologic disorders (aOR, 2.05; 95% CI, 1.50–2.80), and those admitted to the ICU during the course of hospitalization (3.27; 2.41–4.42) were more likely to require extended care on discharge. Patients with pneumonia at admission were also more likely to require extended care (aOR 1.52; 95% CI, 1.18–1.95). The odds of requiring extended care were significantly associated with study site, being higher in Connecticut, Maryland, and Minnesota compared with Rhode Island (Supplementary Table 1). Among 2436 treated patients admitted >2 days after illness onset, our logistic regression model included the same covariates as described in the model above. After exclusions of missing values, we used a total of 1976 (81%) observations; 328 (16%) patients required extended care after discharge. The model showed similar independent risk factors for extended care needs (older age, presence of neuromuscular disorder, and ICU admission), all with comparable magnitudes of association (Figure 2; Supplementary Table 1). Early treatment still provided protection from extended care needs (aOR, 0.75; 95% CI, .56 –.97; P = .03) Effect of Antiviral Treatment on Length of Hospital Stay (Competing Risk Survival Analysis) Patients treated early were more likely to be discharged earlier than those who had antiviral treatment initiated later in the course of illness (ie, >4 days after illness onset). This was true for patients hospitalized soon after illness onset (≤2 days), with an adjusted hazard ratio of 1.8 (95% CI, 1.43–2.30; P <.01), and for those hospitalized >2 days after illness onset (adjusted hazard ratio, 1.30; 95% CI, 1.20–1.40; P <.01). Both models were adjusted for age categories, presence of underlying chronic medical conditions, pneumonia diagnosed at admission and influenza season. The cumulative incidence function for hospital discharge by timing of treatment for those hospitalized ≤2 or >2 days after illness onset can be seen in Figure 3A and 3B respectively; in both, death was considered a competing risk. DISCUSSION In our analysis, 18% of community-dwelling adults aged ≥65 years required extended care after influenza-associated hospitalization. Extended care needs increased with age, with almost 1 in every 3 adults aged ≥85 years requiring new placement in skilled nursing homes or rehabilitation facilities after influenza hospitalization. Older age, the presence of neurologic disorders, ICU admission, and pneumonia at admission were all independent risk factors for extended care needs. Early treatment with antiviral agents significantly reduced the odds of requiring extended care at discharge compared with later treatment, and it reduced the length of hospitalization. To our knowledge, our study is the first to look at the benefit of antiviral treatment on preventing the need for extended care after influenza hospitalization in older adults living in the community. This benefit could be explained by the reduced length of stay among patients treated early in the course of illness, because lengthy restriction to bed can precipitate disability [4, 5]. A few studies have shown the benefit in duration and severity of illness of starting antiviral treatment even after 48 hours of illness onset [10, 12–15, 17]. Lee et al [12] showed that oseltamivir treatment started within 4 days of illness onset among hospitalized, severely ill patients with influenza was associated with viral clearance and improved survival; these patients have prolonged viral replication, thus widening the window of opportunity to initiate antiviral treatment [12, 14, 15, 17, 18]. Time from illness onset to hospitalization could be associated with disease severity, but in our study we documented the benefit of early antiviral treatment (≤4 days after illness onset) among those hospitalized early in the course of illness and those hospitalized late (>2 days after onset). Nonetheless, many older adults with respiratory infection delay seeking care, missing the opportunity for early therapeutic interventions that could halt life-threatening outcomes, principally among those suffering from comorbid conditions. To our knowledge, only 1 other study has attempted to quantify the effect of influenza in those ≥65 years based on specialized care needed after influenza-associated hospitalization. Falsey et al [19] described influenza-associated hospitalization among 210 patients aged ≥65 years during 1989–1992 and found that among those who were living independently at home before admission and who survived hospitalization, 10% required extended care at discharge. This rate is somewhat lower than what we found in our analysis and may be partially explained by changes in hospital policy toward discharging patients early to acute care facilities. Increased care needs after influenza hospitalization may result from worsening of existing disabilities or development of new ones. The presence of a neurologic disorder was also associated with extended care needs. Complications such as pneumonia are more likely among patients with muscle weakness and may lead to more medical monitoring and treatment requirements. We also found that admission to the ICU during hospitalization increased the odds of extended care needs by approximately 3-fold. Jeitziner et al [20] reported that among older adults surviving ICU admission, a decline in physical functional status (measured by ADLs) was observed, and patients were likely to require assistance in perform such tasks as using public transportation, shopping, and doing laundry. Moreover, ICU survivors have documented worsening cognitive functions which could also explain the need for extended care at hospital discharge [21]. Our study has a number of limitations. Treatment day and influenza testing were not randomly allocated, and unmeasured differences in patient’s characteristics that correlate with testing and treatment day could contribute to observed effect. Nonetheless, we had participation of >250 surveillance hospitals from 13 states across the United States, which probably dilutes any bias effect on differences in testing and treatment; we also controlled for site effects on our multivariate models. We did not directly measure ADLs in our study population, but it is likely that the need for extended care observed after hospitalization was due in part to impairment of functional status affecting the patient’s ability to live independently. Information regarding the functional status of the patients living at home before the influenza hospitalization was not collected, but the fact that they were living at home in the community suggests a degree of independence and well-being. Assessment of changes in functional status and level of care needs after influenza hospitalization should be considered in future research. A substantial proportion of older adults hospitalized with influenza require extended care after discharge. Antiviral treatment for all hospitalized patients with suspected or confirmed influenza is recommended [8], and is particularly important among older adults. These patients should be oriented to seek care early in the course of their illness to fully benefit from therapeutic interventions. Our study suggests that antiviral treatment initiated ≤4 days after illness onset could lessen the overall impact of influenza and should be emphasized during influenza seasons as an important adjunct to influenza vaccination efforts. Supplementary Data Supplementary materials are available at Clinical Infectious Diseases online (http://cid.oxfordjournals.org). Supplementary materials consist of data provided by the author that are published to benefit the reader. The posted materials are not copyedited. The contents of all supplementary data are the sole responsibility of the authors. Questions or messages regarding errors should be addressed to the author. Acknowledgments. We are very grateful to Paul Gargiullo, PhD, Carmem Sofia Arriola, DVM, PhD, and Melissa Rolfes, PhD, for statistical support and contributions with the graphs as well as for Carmen Sofia Arriola, DVM, PhD who assisted with the competing risk models. We also thank the following for their assistance with the Influenza Hospitalization Surveillance Network (FluSurv-NET) surveillance: Kathy Angeles, Lisa Butler, Sarah Khanlian, and Robert Mansmann, New Mexico Emerging Infections Program, University of New Mexico; Lauri Smithee and Christie McDonaldHamm, Oklahoma State Department of Health; Kimberly Yousey-Hindes and Karman H. Tam, Connecticut Emerging Infections Program, Yale School of Public Health, New Haven; Kyle Openo and Olivia Almendares, Georgia Emerging Infections Program, Atlanta; Nancy Spina, Gary Hollick, and Maria Gaitán, Emerging Infections Program, New York State Department of Health, Albany; Krista Lung and Shannon Page, Ohio Department of Health, Columbus; Karen Leib and Katie Dyer, Vanderbilt University School of Medicine, Nashville, Tennessee; Susan Brooks and Erin Garcia, California Emerging Infections Program, Oakland; Chris Hahn and Leslie Tengelsen, Idaho Department of Health and Welfare, Boise; Deborah Aragon and Steve Burnite, Colorado Department of Public Health and Environment, Denver; Dave Boxrud, Susan Fuller, Sara Vetter, and Team Flu, Minnesota Department of Health, St Paul; and Diane S. Brady, Rhode Island Department of Health, Providence. Disclaimer. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention (CDC). Financial support. FluSurv-NET is a collaboration of state health departments, academic institutions, and local partners and is funded by the CDC. This publication was also supported in part by the CDC (cooperative agreements CDC-RFA-CK12-1202 and 5U38HM000414). Potential conflicts of interest. All authors: No potential conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed. 1. Zhou H , Thompson WW , Viboud CG , et al. Hospitalizations associated with influenza and respiratory syncytial virus in the United States , 1993 - 2008 . Clin Infect Dis 2012 ; 54 : 1427 - 36 . 2. Centers for Disease Control and Prevention (CDC). 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Sandra S. Chaves, Alejandro Pérez, Lisa Miller, Nancy M. Bennett, Ananda Bandyopadhyay, Monica M. Farley, Brian Fowler, Emily B. Hancock, Pam Daily Kirley, Ruth Lynfield, Patricia Ryan, Craig Morin, William Schaffner, Ruta Sharangpani, Mary Lou Lindegren, Leslie Tengelsen, Ann Thomas, Mary B. Hill, Kristy K. Bradley, Oluwakemi Oni, James Meek, Shelley Zansky, Marc-Alain Widdowson, Lyn Finelli. Impact of Prompt Influenza Antiviral Treatment on Extended Care Needs After Influenza Hospitalization Among Community-Dwelling Older Adults, Clinical Infectious Diseases, 2015, 1807-1814, DOI: 10.1093/cid/civ733