Background/Objectives: Blood group antigen frequencies vary across ethnic populations and are critical for safe transfusion practice, inventory management, and alloimmunization prevention. This study aimed to determine ABO blood group, extended Rh phenotype (D, C, c, E, e), and K antigen frequencies among blood donors at the Riyadh Regional Blood Bank, and to examine their associations with donor ethnicity. Methods: This retrospective cross-sectional study analyzed 10,463 blood donors (January–December 2021) using the Immucor NEO Iris fully automated immunohematology analyzer. Donors were classified into five ethnic groups. Chi-square tests assessed associations (p < 0.05), the primary scientific contribution is the descriptive frequency data, with hypothesis testing presented as secondary and exploratory. Results: Most donors were male (95.2%). Blood group O+ was most prevalent (31.6%); AB− was rarest (0.9%). Rh D-positivity was 84.7%, lowest among Saudis (81.1%). The most frequent Rh phenotypes were CcDee (24.2%), ccDee (19.9%), and CCDee (17.7%). K antigen positivity was 13.7%. Significant associations were found between D antigen and ethnicity (p < 0.001), Rh phenotype and ethnicity (p = 0.003), and ABO and ethnicity (p < 0.001). A hypothesis-generating association between Rh phenotype and K antigen (p = 0.019) did not meet the Bonferroni-corrected threshold and is considered exploratory. Conclusions: This study provides, to our knowledge, one of the largest ethnically stratified blood group datasets from Riyadh to date. The high D-negativity among Saudi donors (18.9%) has direct implications for extended phenotyping protocols and rare donor registry development. The association between Rh phenotype and K antigen requires molecular confirmation before any biological or clinical conclusions can be drawn.

Background/Objectives: Transfusion-transmitted infections (TTIs) remain an important concern in blood safety. Nucleic acid amplification testing (NAT) shortens the diagnostic window period relative to conventional serological assays. This study aimed to determine the prevalence of Hepatitis B virus(HBV), Hepatitis C virus (HCV), and Human immunodeficiency virus (HIV) among blood donors and to evaluate concordance between NAT and conventional serological screening methods. Methods: A retrospective cross-sectional study was conducted at Riyadh Regional Laboratory from May 2021 to May 2022 and included 48,901 blood donors. Donor samples were tested for HBV, HCV, and HIV using serological assays (chemiluminescent immunoassays on the Abbott Alinity s system) and NAT. Data were analyzed using SPSS. Results: The prevalence of HCV was 0.149% by serological testing and 0.061% by NAT. HBV prevalence was 0.252% by serology and 0.264% by NAT, while HIV prevalence was 0.041% and 0.037%, respectively. NAT identified 25 seronegative but NAT-reactive donations, including 13 HBV, 11 HCV, and 1 HIV donation. A statistically significant difference between NAT and serology was observed for HCV (p < 0.001, McNemar’s test), but not for HBV (p = 0.180) or HIV (p = 0.317). Conclusions: The prevalence of major viral TTIs among blood donors was low, with HBV being the most frequently detected infectious agent. NAT and serological assays provide complementary information and support the continued use of combined screening strategies to enhance transfusion safety.

Objectives: Aggregate pre-analytical rejection rates conflate specimen-quality failures and administrative events, which require distinct mitigation protocols. We disaggregated rejection events to isolate specimen-quality failures and benchmarked them against global frameworks. Methods: We conducted a 25-month retrospective audit (July 2023 to August 2025) of test orders received by the Al Rass General Hospital laboratory. Using an AI-assisted classification protocol, we isolated pre-analytical Specimen Quality Failures from operational and administrative events. We mapped Specimen Quality Failure causes into IFCC WG-LEPS Quality Indicators (QIs) and evaluated via Six Sigma metrics, IFCC benchmarks, and Pareto analysis—stratified by laboratory section, sample type, priority, and work shift. Results: Of 905,018 test orders received, 35,476 were rejected (overall rejection rate 3.92%). However, the specimen-quality failures were 2.21% (σ = 3.51), with 15,495 entries excluded as operational events. Clotted samples (26.2%), hemolysis (23.0%), wrong sample type (20.2%), sample not received (7.8%), and insufficient volume (7.1%) together accounted for 84.3% of specimen quality failures (the Vital Few). Most individual categories scored Good (≥4.0) on Sigma, despite a pooled Sigma of 3.51 (Acceptable). Benchmarking against IFCC WG-LEPS targets showed that 6 of 13 quality indicators, including clotted sample, wrong sample type, and insufficient volume, fell Below Minimum, demonstrating divergent absolute internal process capability metrics and population-relative external benchmark performance signals. STAT samples had a lower specimen quality failure rate than Routine samples (1.25% vs. 2.51%). Although the morning shift accounted for 80.98% of total rejections, only 53.4% represented true specimen quality failures. Conclusions: Headline laboratory rejection rates are inflated by operational and administrative events, necessitating partitioned reporting models. While individual Westgard Sigma scores demonstrate satisfactory absolute process capability across most specimen quality failure categories, cross-referencing against population-relative IFCC targets contextualizes these results and identifies areas performing in the lower international quartiles. Quality improvement strategies require structural changes and workforce training.

Background: Pre-analytical errors account for the majority of failures across the total testing process. This study evaluated pre-analytical performance in a tertiary-care biochemistry laboratory in Riyadh, Saudi Arabia, using IFCC-aligned Quality Indicators (QIs), Six Sigma metrics, and structured Root Cause Analysis (RCA). Methods: A retrospective analysis of all biochemistry tests processed between January and December 2024 at a tertiary-care hospital was conducted. Rejected tests were classified into seven IFCC-aligned QI categories. Sigma metrics assessed process capability, Pareto analysis identified the vital few contributors, and RCA using the Ishikawa framework identified human, equipment, environmental, and process-related factors. Rejection patterns were described by department and work shift. Results: Of 845,647 tests performed, 10,783 (1.28%) were rejected, yielding an overall process capability of 3.89σ (Minimum Acceptable). Hemolysis was the leading cause (8186 tests; 75.92%) at 3.97σ, the only indicator classified as High against the IFCC WG-LEPS registry. The remaining six indicators demonstrated Good to Very Good performance (4.59σ–5.33σ). Pareto analysis identified hemolysis and inappropriate tube use (7.60%) as the vital few, jointly responsible for 83.52% of rejections. RCA implicated venipuncture technique, needle gauge selection, workload pressure, and prolonged tourniquet application as key contributors. The Emergency Department generated the highest inpatient rejection burden (38.7%). Conclusions: Although the overall rejection rate compared favorably with international benchmarks, hemolysis was the principal process vulnerability, with inappropriate tube selection as a secondary target. Recommended quality improvement strategies include structured phlebotomy training, real-time hemolysis index feedback, and Emergency Department-specific initiatives; structural solutions such as dedicated inpatient phlebotomy services warrant prospective evaluation alongside training-based interventions.

Background: Blood donation deferral poses a significant challenge to transfusion services worldwide, threatening blood supply adequacy and donor retention. Population-specific data on deferral epidemiology and subsequent donor return behavior in Saudi Arabia remain limited. This study aimed to characterize the prevalence, reasons, and demographic patterns of blood donation deferral at King Fahad Medical City (KFMC)—a major quaternary referral center in Riyadh—and to quantify the rate at which temporarily deferred donors re-engage with the donation process at the encounter level. Methods: A retrospective observational study was conducted on records of all registered volunteer blood donor encounters at KFMC from 1 January 2023 to 31 December 2024 (n = 60,290), extracted from the Hematos IIG blood bank information system. Donor demographics (age, sex, weight, nationality), deferral classification (temporary, permanent, indeterminate), deferral reason, pre-deferral donation frequency, and post-temporary-deferral donation frequency were analyzed. Inferential statistics employed the Chi-square test and Fisher’s exact test (significance threshold: p < 0.05). A multinomial logistic regression, restricted to the 10,681 encounters classified as temporarily deferred, identified correlates of post-deferral donation frequency, adjusted for donation frequency before deferral. Results: Of 60,290 registered donor encounters, 18,458 (30.6%) resulted in deferral. Male donors constituted 86.4% of deferrals; the 31–45-year age group accounted for 47.3%. The three leading deferral reasons were abnormal vital signs (39.4%), post-donation transfusion-transmitted infectious disease (TTID) screening reactivity (35.6%), and low hemoglobin (14.0%). Sex-stratified analysis revealed that among female donors, low hemoglobin (40.50%) exceeded abnormal vital signs (35.50%) as the leading reason. Among the 10,681 encounters classified as temporarily deferred, 86.70% did not return to donate within the observation window. In a multinomial regression restricted to this subgroup, donation frequency before deferral was the strongest correlate of return (OR 21.02, 95% CI 14.94–29.58 for three or more subsequent donations among donors with ≥3 prior donations vs. none), and deferral for abnormal vital signs was also associated with higher odds of return (OR range 3.55–4.60, all p < 0.001). Conclusions: Nearly one-third of blood donor encounters at this tertiary center resulted in deferral, with abnormal vital signs and TTID screening reactivity as the predominant reasons. The low re-engagement rate (13.30%) among temporarily deferred donors underscores a need for structured follow-up programs, particularly for first-time donors, for whom an established donation history was the strongest predictor of return. Sex-specific interventions—targeting hemoglobin optimization in female donors and cardiovascular risk factor awareness in male donors—are warranted to reduce the deferral burden and safeguard the blood supply.

Background: Blood transfusion is a life-saving intervention but is associated with adverse reactions in a subset of recipients. An acute transfusion reaction (ATR) is defined as any unfavorable response occurring within 24 h of blood component administration. This retrospective observational study aimed to determine the frequency and characteristics of ATRs at King Saud Medical City (KSMC), Riyadh, Saudi Arabia. Methods: We conducted a retrospective study using data from the Transfusion Medicine Laboratory (TML) at KSMC between January 2019 and December 2023. Demographic, clinical, and laboratory data from 238 confirmed ATR records were analyzed using SPSS v21.0. Chi-square, Mann–Whitney U, and risk ratio analyses were performed; p < 0.05 was considered statistically significant. Results: Among 238 patients (59.2% female; mean age 33.7 ± 18.5 years), allergic reactions were the most frequent ATR (70.2%, n = 167), followed by febrile non-hemolytic transfusion reactions (FNHTRs); (24.4%, n = 58). Packed red blood cell (PRBC) transfusion was the most commonly implicated product (82.4%; n = 196; p < 0.001). Fever, rash, itching, and chills were significantly associated with specific reaction subtypes (p < 0.001). The pattern of post-transfusion workup differed significantly across reaction types (p < 0.001). Age, gender, ward distribution, and reaction timing were not significant predictors of ATR occurrence. Conclusions: Allergic reactions are the predominant ATR form at KSMC. Demographic variables are not reliable predictors of ATR. Strengthening hemovigilance systems and clinician education is recommended to improve transfusion safety.