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Clinical Trial
. 2018 Mar 22;13(3):e0194180.
doi: 10.1371/journal.pone.0194180. eCollection 2018.

Performance of the inFLUenza Patient-Reported Outcome (FLU-PRO) diary in patients with influenza-like illness (ILI)

John H Powers 3rd  1 , Elizabeth D Bacci  2 , Nancy K Leidy  3 , Jiat-Ling Poon  3 , Sonja Stringer  3 , Matthew J Memoli  4 , Alison Han  4 , Mary P Fairchok  5   6   7 , Christian Coles  6   7 , Jackie Owens  6   7 , Wei-Ju Chen  6   7 , John C Arnold  8 , Patrick J Danaher  9 , Tahaniyat Lalani  7   10 , Timothy H Burgess  6   11 , Eugene V Millar  6   7 , Michelande Ridore  12 , Andrés Hernández  13 , Patricia Rodríguez-Zulueta  14 , Hilda Ortega-Gallegos  15 , Arturo Galindo-Fraga  15 , Guillermo M Ruiz-Palacios  15 , Sarah Pett  16   17   18   19   20 , William Fischer  17   21 , Daniel Gillor  17   22 , Laura Moreno Macias  17   23 , Anna DuVal  24 , Richard Rothman  24 , Andrea Dugas  24 , M Lourdes Guerrero  15
Affiliations
Clinical Trial

Performance of the inFLUenza Patient-Reported Outcome (FLU-PRO) diary in patients with influenza-like illness (ILI)

John H Powers 3rd et al. PLoS One. .

Abstract

Background: The inFLUenza Patient Reported Outcome (FLU-PRO) measure is a daily diary assessing signs/symptoms of influenza across six body systems: Nose, Throat, Eyes, Chest/Respiratory, Gastrointestinal, Body/Systemic, developed and tested in adults with influenza.

Objectives: This study tested the reliability, validity, and responsiveness of FLU-PRO scores in adults with influenza-like illness (ILI).

Methods: Data from the prospective, observational study used to develop and test the FLU-PRO in influenza virus positive patients were analyzed. Adults (≥18 years) presenting with influenza symptoms in outpatient settings in the US, UK, Mexico, and South America were enrolled, tested for influenza virus, and asked to complete the 37-item draft FLU-PRO daily for up to 14-days. Analyses were performed on data from patients testing negative. Reliability of the final, 32-item FLU-PRO was estimated using Cronbach's alpha (α; Day 1) and intraclass correlation coefficients (ICC; 2-day reproducibility). Convergent and known-groups validity were assessed using patient global assessments of influenza severity (PGA). Patient report of return to usual health was used to assess responsiveness (Day 1-7).

Results: The analytical sample included 220 ILI patients (mean age = 39.3, 64.1% female, 88.6% white). Sixty-one (28%) were hospitalized at some point in their illness. Internal consistency reliability (α) of FLU-PRO Total score was 0.90 and ranged from 0.72-0.86 for domain scores. Reproducibility (Day 1-2) was 0.64 for Total, ranging from 0.46-0.78 for domain scores. Day 1 FLU-PRO scores correlated (≥0.30) with the PGA (except Gastrointestinal) and were significantly different across PGA severity groups (Total: F = 81.7, p<0.001; subscales: F = 6.9-62.2; p<0.01). Mean score improvements Day 1-7 were significantly greater in patients reporting return to usual health compared with those who did not (p<0.05, Total and subscales, except Gastrointestinal and Eyes).

Conclusions: Results suggest FLU-PRO scores are reliable, valid, and responsive in adults with influenza-like illness.

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Conflict of interest statement

Competing Interests: ED Bacci, NK Leidy, JL Poon, and S Stringer, are salaried employees of Evidera Evidence, Value & Access by PPD (Evidera). JH Powers is an employee of Leidos Biomedical Research. There are no patents, products in development or marketed products to declare. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. The view(s) expressed in this article are those of the author(s) and do not reflect the official policy or position of Uniformed Services University of the Health Sciences, The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., National Institutes of Health or the Department of Health and Human Services, Brooke Army Medical Center, Walter Reed National Military Medical Center, Landstuhl Regional Medical Center, the US Army Medical Department, the US Army Office of the Surgeon General, the Department of the Air Force, the Department of the Navy, the Department of the Army or the Department of Defense or the US Government. Mention of trade names, commercial products, or organizations does not imply endorsement by the US Government.

Figures

Fig 1
Fig 1. FLU-PRO domain and total score by diary days 1 to 14: Influenza-Negative Patients.
See this image and copyright information in PMC

References

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    1. Centers for Disease Control and Prevention (CDC) (2016) Overview of Influenza Surveillance in the United States.
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