Antiviral Treatment among Older Adults Hospitalized with Influenza, 2006-2012

<div><p>Objective</p><p>To describe antiviral use among older, hospitalized adults during six influenza seasons (2006—2012) in Davidson County, Tennessee, USA.</p><p>Methods</p><p>Among adults ≥50 years old hospitalized with symptoms of respiratory illness or non-localizing fever, we collected information on provider-initiated influenza testing and nasal/throat swabs for influenza by RT-PCR in a research laboratory, and calculated the proportion treated with antivirals.</p><p>Results</p><p>We enrolled 1753 adults hospitalized with acute respiratory illness. Only 26% (457/1753) of enrolled patients had provider-initiated influenza testing. Thirty-eight patients had a positive clinical laboratory test, representing 2.2% of total patients and 8.3% of tested patients. Among the 38 subjects with clinical laboratory-confirmed influenza, 26.3% received antivirals compared to only 4.5% of those with negative clinical influenza tests and 0.7% of those not tested (p<0.001). There were 125 (7.1%) patients who tested positive for influenza in the research laboratory. Of those with research laboratory-confirmed influenza, 0.9%, 2.7%, and 2.8% received antivirals (p=.046) during pre-pandemic, pandemic, and post-pandemic influenza seasons, respectively. Both research laboratory-confirmed influenza (adjusted odds ratio [AOR] 3.04 95%CI 1.26-7.35) and clinical laboratory-confirmed influenza (AOR 3.05, 95%CI 1.07-8.71) were independently associated with antiviral treatment. Severity of disease, presence of a high-risk condition, and symptom duration were not associated with antiviral use.</p><p>Conclusions</p><p>In urban Tennessee, antiviral use was low in patients recognized to have influenza by the provider as well as those unrecognized to have influenza. The use of antivirals remained low despite recommendations to treat all hospitalized patients with confirmed or suspected influenza.</p></div

Antiviral treatment among adults ≥50 years of age hospitalized with acute respiratory illness, by season, 2006–2012.

<p>Antiviral treatment among adults ≥50 years of age hospitalized with acute respiratory illness, by season, 2006–2012.</p

Characteristics of Adults 50 years and older Hospitalized with Symptoms of Respiratory Illness or Non-localizing fever during 2006–2012 Influenza Season, by Antiviral Treatment Status.

<p>*defined as transplant, cancer within 5 years, diabetes, no spleen, heart or vascular disease, kidney or liver disease, sickle cell disease, asthma or chronic bronchitis or COPD or other lung disease, memory or thinking problems, HIV/AIDS or other problems with the immune system, genetic or metabolic disorders, neurologic disease, currently on prednisone or other steroids, any chemotherapy in the last 6 months, or any immunosuppressive medications in the last 6 months.</p><p>** Chi-square or Fisher’s exact tests were used where appropriate to compare antiviral treated and untreated groups.</p><p>Characteristics of Adults 50 years and older Hospitalized with Symptoms of Respiratory Illness or Non-localizing fever during 2006–2012 Influenza Season, by Antiviral Treatment Status.</p

Independent factors associated with antiviral treatment among adults, 50 years and older, hospitalized with symptoms of acute respiratory illness or non-localizing fever, and those with research laboratory-confirmed influenza, 2006–2012.

<p>¹ For all patients, the variables included in the model included 1) clinical laboratory influenza testing, 2) research laboratory influenza status, and 3) discharge diagnosis of influenza or pneumonia.</p><p>² For patient with research laboratory-confirmed patients, the variable included clinical laboratory influenza tests status.</p><p>Independent factors associated with antiviral treatment among adults, 50 years and older, hospitalized with symptoms of acute respiratory illness or non-localizing fever, and those with research laboratory-confirmed influenza, 2006–2012.</p

Characteristics of Adults 50 years and older Hospitalized with Symptoms of Respiratory Illness or non-localizing Fever during 2006–2012 Influenza Season.

<p>*defined as transplant, cancer within 5 years, diabetes, no spleen, heart or vascular disease, kidney or liver disease, sickle cell disease, asthma or chronic bronchitis or COPD or other lung disease, memory or thinking problems, HIV/AIDS or other problems with the immune system, genetic or metabolic disorders, neurologic disease, currently on prednisone or other steroids, any chemotherapy in the last 6 months, or any immunosuppressive medications in the last 6 months.</p><p>Characteristics of Adults 50 years and older Hospitalized with Symptoms of Respiratory Illness or non-localizing Fever during 2006–2012 Influenza Season.</p

Clinical diagnostic testing among adults ≥50 years of age hospitalized with acute respiratory illness, by season, 2006–2012.

<p>Clinical diagnostic testing among adults ≥50 years of age hospitalized with acute respiratory illness, by season, 2006–2012.</p

Vaccine effectiveness of at least one dose and 4 or more doses of 7-valent pneumococcal conjugate vaccine (PCV7) against all-serotype invasive pneumococcal disease (IPD) and PCV7-serotype IPD among children 19–35 months of age with vaccine histories using unadjusted screening and case-control methods.

*<p>Includes only cases with vaccine history available.</p>†<p>Unable to calculate because the original case-control study did not collect data on controls after 2004 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041785#pone.0041785-Whitney1" target="_blank">[3]</a>.</p>‡<p>Partially vaccinated individuals (i.e., 1, 2, or 3 PCV7 doses) were excluded from this calculation.</p>¶<p>Unable to calculate vaccine effectiveness estimates for 4-dose schedule using the case-control method due to low numbers of cases.</p><p>°Confidence intervals calculated using Fisher’s exact test.</p><p>′Unable to calculate because of 100% vaccine coverage among case.</p

Estimated vaccine effectiveness using the screening method.

<p>This figure was created using hypothetical data created by the authors, and is adapted from a similar figure in Orenstein, et al. (1985) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041785#pone.0041785-Orenstein1" target="_blank">[4]</a>).</p

Characteristics of statistically significant meningococcal disease clusters.

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0082048#pone-0082048-t001" target="_blank">Table 1</a> for detailed information on the molecular characteristics of each clone.^A See </p><p>^B Case data were aggregated to the level of census tract for these analyses. A radius of 0 km indicates that all cases in that cluster occurred within the same census tract.</p

Case counts of non-singleton meningococcal clones, ranked by decreasing frequency.

<p> ST, sequence type; CC, clonal complex; VR, variable region; CA, California; CO, Colorado; CT, Connecticut; GA, Georgia; MD, Maryland; MN, Minnesota; NY, New York; OR, Oregon; TN, Tennessee.</p