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

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.

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.

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).

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.