The impact of a rapid home test on telehealth decision-making for influenza: a clinical vignette study

BACKGROUND: Home testing for influenza has the potential to aid triage and management decisions for patients with influenza-like illness. As yet, little is known about the effect of the home influenza testing on clinical decision-making via telehealth. The goal of this study was to determine the clinicians’ decision thresholds for influenza and whether the availability of a home influenza test affects clinical decisions. METHODS: We identified primary care physicians at 4 different sites in the US, largely via in-person continuing education meetings. Clinicians were asked for each vignette whether to treat empirically (“rule in”), ask the patient come to the clinic for further evaluation (“test”), or neither test nor treat (“rule out”). They were then given the results of a home influenza test, and were again asked to select from these three options. We measured the agreement of physician estimates of the likelihood of influenza with the probability based on a clinical prediction model. The test and treatment thresholds of influenza were determined based on mixed-effect logistic regressions. RESULTS: In total, 202 clinicians made 570 sets of clinical decisions. Agreement between estimated and actual probability of influenza was fair. The test and treatment thresholds were 24% (95% CI: 22% to 25%) and 63% (95% CI: 58% to 65%) before revealing the actual likelihood of influenza. After providing the results of a home flu test the thresholds were similar, 26% (95% CI: 24% to 29%) and 59% (95% CI: 56% to 62%). However, approximately half of clinicians changed their cliical management decision after being given the home influenza test result, largely by categorizing more patients in the “rule out” and “rule in” groups, and reducing the need for in-person evaluation from 41% of patients to only 20%. CONCLUSION: In the context of a telehealth visit for a patient with influenza-like illness, we identified a test threshold of approximately 25% and a treatment threshold of approximately 60%. Adding the home influenza test results reduced uncertainty and significantly decreased the need for in-person visits. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12875-022-01675-1.