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

Journal Article (Journal Article)

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.

Full Text

Duke Authors

Cited Authors

  • Theophanous, RG; Vissoci, JRN; Wen, FH; Griffin, SM; Anderson, VE; Mullins, ME; Brandehoff, NP; Quackenbush, EB; Bush, SP; Toschlog, EA; Greene, SC; Sharma, K; Kleinschmidt, K; Charlton, NP; Rose, SR; Schwartz, R; Lewis, B; Lavonas, EJ; Gerardo, CJ

Published Date

  • December 2019

Published In

Volume / Issue

  • 13 / 12

Start / End Page

  • e0007935 -

PubMed ID

  • 31834923

Pubmed Central ID

  • PMC6934321

Electronic International Standard Serial Number (EISSN)

  • 1935-2735

Digital Object Identifier (DOI)

  • 10.1371/journal.pntd.0007935


  • eng

Conference Location

  • United States