Archives of Current Research International

Background: Timely communication of critical complete blood count (CBC) results is an important quality indicator in laboratory medicine. However, factors associated with prolonged turnaround time (TAT) remain insufficiently characterised in tertiary-care settings.

Objective: To quantify total, analytical, and post-analytical TAT for critical CBC results communicated through a hospital alert system and to identify predictors of communication delay.

Methods: This retrospective cross-sectional study evaluated 544 CBCs with critical results recorded between January and June 2025 at a tertiary hospital in Brazil. Institutional critical-value thresholds included haemoglobin <6.0 or >18.0 g/dL, leukocyte counts <2.0 or >30.0 × 10⁹/L, platelet counts <50 or >1,000 × 10⁹/L, and the presence of circulating blasts. TAT was divided into analytical and post-analytical phases using timestamps for sample collection, technical release, and notification. Communication-time analyses included 487 records with available timestamps. Outcomes included TAT ≥2 h and ≥4 h and continuous log-transformed TAT.

Results: Median total TAT was 5.45 h (IQR 3.12–13.18), predominantly reflecting the analytical phase (median 3.86 h), while post-analytical notification time was shorter (median 0.62 h). Overall, 8.0% of cases had a total TAT ≤2 h and 37.0% had a total TAT ≤4 h. Inpatient ward origin was independently associated with TAT ≥4 h (OR 4.22, 95% CI 2.65–6.71). Leukocytosis and weekend collection were also associated with prolonged TAT.

Conclusions: Prolonged TAT for critical CBC results was associated primarily with operational and workflow-related factors. The analytical phase accounted for the largest proportion of total TAT, suggesting that inpatient sample logistics and weekend laboratory workflows may represent important targets for quality improvement.