Use of the McIsaac Score to Predict Group A Streptococcal Pharyngitis in Outpatient Nurse Phone Triage and Electronic Visits Compared With In-Person Visits: Retrospective Observational Study.

BACKGROUND: The McIsaac criteria are a validated scoring system used to determine the likelihood of an acute sore throat being caused by group A streptococcus (GAS) to stratify patients who need strep testing. OBJECTIVE: We aim to compare McIsaac criteria obtained during face-to-face (f2f) and non-f2f encounters. METHODS: This retrospective study compared the percentage of positive GAS tests by McIsaac score for scores calculated during nurse protocol phone encounters, e-visits (electronic visits), and in person f2f clinic visits. RESULTS: There was no difference in percentages of positive strep tests between encounter types for any of the McIsaac scores. There were significantly more phone and e-visit encounters with any missing score components compared with f2f visits. For individual score components, there were significantly fewer e-visits missing fever and cough information compared with phone encounters and f2f encounters. F2f encounters were significantly less likely to be missing descriptions of tonsils and lymphadenopathy compared with phone and e-visit encounters. McIsaac scores of 4 had positive GAS rates of 55% to 68% across encounter types. There were 4 encounters not missing any score components with a McIsaac score of 0. None of these 4 encounters had a positive GAS test. CONCLUSIONS: McIsaac scores of 4 collected during non-f2f care could be used to consider empiric treatment for GAS without testing if significant barriers to testing exist such as the COVID-19 pandemic or geographic barriers. Future studies should evaluate further whether non-f2f encounters with McIsaac scores of 0 can be safely excluded from GAS testing.

McIsaac score for group A streptococcal infection: Comparison of electronic visits versus face-to-face visits.

INTRODUCTION: Acute sore throat is a common complaint traditionally completed with an in-person visit. However, non-face-to-face telemedicine visits offer greater access at reduced cost. We evaluated patient/caregiver asynchronous text-based electronic visits (eVisits) for acute sore throat and whether there was concordance for individual components and total McIsaac score compared to a clinician's assessment. eVisits were completed by patients and/or their caregivers via a secure patient portal. METHODS: In this retrospective study, we manually reviewed charts between February 2017 and July 2019 of patients who had an eVisit, in-person visit and group A streptococcal (GAS) test performed on the same day for an acute sore throat. We calculated a McIsaac score for eVisits and in-person visits, and compared each component and total score using Cohen's kappa agreement statistic. RESULTS: There were 320 instances of patients who had an eVisit, in-person visit and GAS testing done on the same day. Approximately a third of eVisits were missing at least one McIsaac component, with the physical examination elements missing most commonly. Individual score congruence was moderate for cough (0.41), fair for fever (0.34) and slight for tonsillar swelling/exudate and lymphadenopathy (0.17 and 0.08, respectively), with total congruence being slight to fair (0.09-0.37). A McIsaac score of ≤1 showed moderate agreement (0.44). Visits with complete individual score components demonstrated improved congruence: substantial for cough (0.64), moderate for fever (0.57), fair for tonsillar swelling (0.3) and slight for lymphadenopathy (0.13). DISCUSSION: Overall agreement for individual score components was better for symptoms than it was for examination components, and was improved when data were complete. A McIsaac score of 1 or 0 had moderate agreement and thus could reasonably be safely used to exclude patients from GAS testing.