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. 2019 Dec 13;13(12):e0007935.
doi: 10.1371/journal.pntd.0007935. eCollection 2019 Dec.

Validity and reliability of telephone administration of the patient-specific functional scale for the assessment of recovery from snakebite envenomation

Affiliations

Validity and reliability of telephone administration of the patient-specific functional scale for the assessment of recovery from snakebite envenomation

Rebecca G Theophanous et al. PLoS Negl Trop Dis. .

Abstract

Objectives: Although more than 1.8 million people survive snakebite envenomation each year, their recovery is understudied. Obtaining long-term follow-up is challenging in both high- and low-resource settings. The Patient-Specific Functional Scale (PSFS) is an easily administered, well-accepted patient-reported outcome that is validated for assessing limb recovery from snakebite envenomation. We studied whether the PSFS is valid and reliable when administered by telephone.

Methods: This is a secondary analysis of data from a randomized clinical trial. We analyzed the results of PSFS collected in-person on days 3, 7, 14, 21, and 28 and by telephone on days 10, 17, and 24. We assessed the following scale psychometric properties: (a) content validity (ceiling and floor effects), (b) internal structure and consistency (Cronbach's alpha), and (c) temporal and external validity using Intraclass Correlation Coefficient (ICC). Temporal stability was assessed using Spearman's correlation coefficient and agreement between adjacent in-person and telephonic assessments with Cohen's kappa. Bland Altman analysis was used to assess differential bias in low and high score results.

Results: Data from 74 patients were available for analysis. Floor effects were seen in the early post-injury time points (median: 3 (IQR: 0, 5) at 3 days post-enrollment) and ceiling effects in the late time points (median: 9 (IQR: 8, 10). Internal consistency was good to excellent with both in-person (Cronbach α: 0.91 (95%CI 0.88, 0.95)) and telephone administration (0.81 (0.73, 0.89). Temporal stability was also good (ICC: 0.83 (0.72, 0.89) in-person, 0.80 (0.68, 0.88) telephone). A strong linear correlation was found between in-person and telephone administration (Spearman's ρ: 0.83 (CI: 0.78, 0.84), consistency was assessed as excellent (Cohen's κ 0.81 (CI: 0.78, 0.84), and Bland Altman analysis showed no systematic bias.

Conclusions: Telephone administration of the PSFS provides valid, reliable, and consistent data for the assessment of recovery from snakebite envenomation.

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Conflict of interest statement

I have read the journal's policy and the authors of this manuscript have the following competing interests: Dr. Rose reports speakers bureau fees from BTG International Inc outside the submitted work. Dr. Greene reports receiving consulting fees and honoraria from BTGInternational Inc outside the submitted work. Drs. Gerardo, Charlton, Mullins, Lavonas and Kleinschmidt and Ms. Anderson report receiving prior study-related grants from BTG International Inc.

Figures

Fig 1
Fig 1. Bland Altman plot to display the difference between telephone and in-person administrations of the patient-specific functional scale.
Fig 2
Fig 2. Spearman correlation coefficient demonstrating strong linear correlation between telephone and in-person administrations of the patient-specific functional scale.

References

    1. Williams D, Gutierrez JM, Harrison R, et al. The Global Snakebite Bite Initiative: an antidote for Snakebite bite. Lancet. 2010;375(9708):89–91. 10.1016/S0140-6736(09)61159-4 - DOI - PubMed
    1. Lancet The. Snakebite-bite envenoming: a priority neglected tropical disease. Lancet. 2017;390(10089):2. - PubMed
    1. Kasturiratne A, Wickremasinghe AR, de Silva N, et al. The global burden of Snakebitebite: a literature analysis and modelling based on regional estimates of envenoming and deaths. PLoS Med. 2008;5(11):e218 10.1371/journal.pmed.0050218 - DOI - PMC - PubMed
    1. Harrison RA, Hargreaves A, Wagstaff SC, Faragher B, Lalloo DG. Snakebite envenoming: a disease of poverty. PLoS Negl Trop Dis. 2009;3(12):e569 10.1371/journal.pntd.0000569 - DOI - PMC - PubMed
    1. Harrison RA, Gutierrez JM. Priority actions and progress to substantially and sustainably reduce the mortality, morbidity and socioeconomic burden of tropical Snakebite. Toxins (Basel). 2016;8(12):e351. - PMC - PubMed

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