Diagnostic Accuracy of a Telephone Questionnaire for Fracture-Related Infections (FRIs)

Purpose: Fracture-related infections (FRIs) are a major cause of trauma-associated morbidity and mortality worldwide. Despite a recent definition of FRI, there is limited knowledge on its applicability to low- and middle-income countries (LMICs). Given the barriers to in-person clinical follow-up in these low-resource environments, we aimed to evaluate the diagnostic accuracy of a telephone questionnaire in identifying patients with FRIs after open tibia fracture fixation in Tanzania.

Methods: Patients from the Pilot GO-Tibia Randomized Control Trial were included in this study. Patients completed FRI-based telephone questionnaires 7-10 days prior to scheduled follow-ups at 6 weeks, 3 months, 6 months, 9 months, and 1 year. The telephone FRI questionnaire (tFRI) was adapted from the FRI Consensus Definition to include 2 “confirmatory” criteria questions for FRI (open wound and purulent drainage) and 3 “suggestive” criteria questions (any drainage, fever, and warmth) based on input from LMIC stakeholders. Tests of diagnostic accuracy were performed to identify the sensitivity and specificity between tFRI answers and adjudicated FRI diagnoses determined at the corresponding in-person follow-up.

Results: There were 234 complete questionnaires completed for 85 unique patients included in this study. The sensitivity and specificity of having any positive answer in the questionnaire was highest at 6 months (100% and 92.50%, respectively). For all time points pooled, the sensitivity was 71.43% and the specificity was 92.95%. Any drainage (suggestive) had the highest sensitivity (71.43%) while fever had the highest specificity (99.56%). For confirmatory criteria, sensitivity was 14.29% and specificity was 96.02%. Contrastingly, the sensitivity for suggestive criteria was higher at 71.43%, with a similar specificity at 93.83%.

Conclusion: The 5-item tFRI is sensitive and specific in diagnosis of FRI in LMICs. The presence of any drainage reported by phone identified the majority of patients with an FRI, and the specificities were high across confirmatory and suggestive criteria. Our study is one of the first to evaluate telephone questionnaires as a diagnostic tool for FRIs in patients with open tibia fractures in an LMIC. The tFRI may be a valid tool for surveillance for FRI in clinical care and research when major barriers challenge in-person follow-up.

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