Establishment of reference intervals for hematological parameters of adult population in the western region of Saudi Arabia.
Level 4 - case-series / case-control
Cross-sectional reference interval study
PubMed 36753498 · doi:10.1371/journal.pone.0281494
What was done
Blood samples from 409 healthy adult Saudi men and women in the western region of Saudi Arabia were evaluated following the International Federation of Clinical Chemistry (IFCC) harmonized protocol. Complete blood counts were measured on a Cell-Dyn Sapphire analyzer, and iron profiles were measured on Architect analyzers. Partitioning by sex and age was assessed using standard deviation ratio (SDR ≥0.4) and bias ratio (BR ≥0.57) thresholds. Reference intervals (RIs) were calculated parametrically with and without the latent abnormal values exclusion (LAVE) method.
What was found
Sex partitioning was necessary for red blood cell count, hemoglobin, hematocrit, red cell distribution width, erythrocyte sedimentation rate, iron, transferrin, ferritin, eosinophils, platelets, and plateletcrit, whereas age partitioning was not required for any analyte. Applying the LAVE method noticeably changed reference limits for erythrocyte and iron indices but not leukocyte indices. Post-LAVE reference intervals were 40.2% to 52.0% for male hematocrit and 33.6% to 44.5% for female hematocrit (with red blood cell ranges reported in the abstract under Hb as 4.56 to 6.22 ×10^6/μL for males and 3.94 to 5.25 ×10^6/μL for females). Both RBC and hematocrit distributions shifted higher relative to non-IFCC reference studies.
Why it matters
Demonstrates that local, population-specific reference intervals derived with standardized latent-exclusion methods differ from global manufacturer baselines, helping avoid misclassification of anemia and other hematological conditions in Saudi adults.
Limits
The cohort was restricted to 409 adults from a single geographic region (western Saudi Arabia), limiting immediate generalizability across the entire national population. The abstract mislabels red blood cell count units under the hemoglobin abbreviation and omits exact numerical intervals for several reported parameters, including white blood cell subsets and platelets.
Cited by
- supports One microliter of human blood contains approximately 4 million cells.