Mayir Index – Research-Based Discriminant for Microcytic Anemias

Clinical Context & Rationale

The Diagnostic Challenge: Beta‑Thalassemia Trait (BTT) and Iron Deficiency Anemia (IDA) are the most common causes of microcytic hypochromic anaemia worldwide. Their overlapping CBC patterns often lead to misdiagnosis, unnecessary investigations, or delayed appropriate management.

Limitations of Classical Indices:

Mentzer (MCV/RBC): Population‑specific; poor performance in mild IDA and borderline cases.
England & Fraser (E&F): Hb‑dependent, affected by age, sex, pregnancy, and pre‑analytical factors.
Green & King (G&K): Hb‑based; underperforms in anaemic patients and haemoglobinopathies.
RDWI (MCV×RDW/RBC): Variable performance across ethnic groups; sensitive to RDW fluctuations.
Shine & Lal (S&L): MCH‑dependent; influenced by iron availability and erythropoiesis.

The Mayir Index Approach:
• Eliminates Hb – removes variability due to age, sex, pregnancy, and pre‑analytical factors.
• Integrates MCV, RBC, and RDW – captures both microcytosis and anisocytosis.
• Dynamic adjustment – tailored to age, sex, pregnancy, and ethnicity using global reference data.
• Confirmatory test integration – refines prediction using HbA2, ferritin, iron/TIBC, and HbF.
• Weighted final impression – transparent probabilistic output for each diagnostic category.

Integrated Algorithm 6‑Step Protocol

Step 1 – Calculation: Mayir Index computed from (MCV, RBC, RDW) – formula withheld for intellectual property protection.
Step 2 – Dynamic Cutoff Selection: Based on age, sex, pregnancy, and ethnicity (gray zone = cutoff ± 10).
Step 3 – Primary Classification: Index < cutoff → TT; cutoff ± 10 → Gray Zone; > cutoff+10 → IDA.
Step 4 – RDW Confirmation: If IDA, RDW > 15% supports IDA; RDW ≤ 15% raises suspicion for silent carrier.
Step 5 – Confirmatory Tests: HbA2, ferritin, iron/TIBC, HbF – each interpreted with evidence‑based thresholds.
Step 6 – Weighted Final Impression: All data integrated into a weighted model, producing percentage probabilities for IDA, TT, Mixed, ACD, and Other.

Patient Assessment Enter CBC & Demographics

Enter the required values in standard decimal format (e.g., RBC: 5.60, RDW: 16.80).

RBC (×10¹²/L)

MCV (fL)

RDW (%)

Age (years)

Sex

Pregnancy (if female)

Ethnicity / Region

Confirmatory Tests Optional

Enter any available results to refine the prediction and generate a weighted final impression.

HbA2 (%)

Ferritin (ng/mL)

Serum Iron (µg/dL)

TIBC (µg/dL)

HbF (%)

Key References

Foundational sources used for demographic adjustments and confirmatory thresholds.

WHO Haemoglobin Cutoffs (2024) Anemia thresholds by age, sex, and pregnancy.
Weatherall DJ (2001) Thalassaemia: a global health problem.
Camaschella C (2015) Iron-deficiency anemia: mechanisms and diagnosis.
Origa R (2017) Beta-thalassemia: genetics and clinical aspects.
Omuse G et al. (2018) CBC reference intervals in Kenyan adults (African population).
Qiao R et al. (2014) CBC reference intervals in Chinese Han population.
Lim E et al. (2015) Ethnic variations in laboratory tests (NHANES).
Patel AP (2018) Cutoffs for Western Indian population.
Sirdah et al. (2012) Discrimination indices in Palestine (comparative table).
Bessman JD et al. (1983) RDW > 15% as marker for IDA.
Mentzer WC (1973) Mentzer Index – classic discriminant.
BSH Guidelines (2014) HbA2 quantification for thalassemia screening.

Legal & Ethical Neutrality

Disclaimer: This tool is a research‑based decision support system providing probabilistic, supportive interpretations. It does not replace clinical judgment or laboratory confirmation. All results must be correlated with the patient’s full clinical history, physical examination, and additional laboratory findings. The final diagnosis and treatment decisions rest solely with the attending physician.