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Global multicenter study establishes the reference range for ISTH Bleeding Assessment Tool scores in individuals
Yousra Tera1, Ryan Babensee2, Ahmad Ekhtiar3
1Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada; Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
Insights
The International Society on Thrombosis and Haemostasis Bleeding Assessment Tool (ISTH-BAT) reference range of 0-2 is appropriate for children under 18. However, a range of 0-3 may be considered for adolescent females aged 12-17.
Area of Science:
- Hematology
- Pediatric Medicine
- Clinical Diagnostics
Background:
- The International Society on Thrombosis and Haemostasis Bleeding Assessment Tool (ISTH-BAT) is crucial for screening inherited bleeding disorders.
- Current pediatric ISTH-BAT reference ranges (0-2) are not age- or sex-specific, unlike adult ranges.
- Developmental changes in adolescence and global healthcare disparities necessitate pediatric ISTH-BAT range validation.
Purpose of the Study:
- To establish age- and sex-specific reference ranges for the ISTH-BAT in individuals under 18 years.
- To validate the ISTH-BAT in a large, international pediatric cohort across diverse demographics.
- To assess the influence of age, sex, country, and income on ISTH-BAT scores in children.
Main Methods:
- Recruitment of healthy participants under 18 from 7 countries across 5 continents.
- Standardized ISTH-BAT assessments conducted by trained investigators.
- Stratification by age quartile, sex, country, and World Bank income classification; reference ranges defined by 2.5th-97.5th percentile.
Main Results:
- A total of 1,168 participants were included (mean age 7.7±5.2 years; 50.5% female).
- The overall ISTH-BAT reference range was 0-2, with no significant quartile differences (p=0.065).
- A significant age-related increase in ISTH-BAT scores >0 was observed (p<0.001), with females more frequently scoring >0 (p=0.02).
- Adolescent females (12-17 years) showed a 2.5th-97.5th percentile range of 0-3 (p=0.003).
- Scores varied by country and income (p≤0.001), but reference ranges remained stable.
Conclusions:
- The standard ISTH-BAT reference range of 0-2 is appropriate for individuals under 18 years.
- A revised ISTH-BAT range of 0-3 may be considered for adolescent females (12-17 years) in clinical decision-making.
- Further interpretation in clinical context is advised for referral decisions concerning bleeding scores in adolescent females.
Abstract:
The International Society on Thrombosis and Haemostasis (ISTH) Bleeding Assessment Tool (BAT) is widely used to screen for inherited bleeding disorders. Adult reference ranges are age- and sex-specific. However, a single reference range (0-2) is currently applied to all individuals under 18 years. Adolescent developmental changes and global differences in healthcare access may influence bleeding scores, necessitating validation in a large international pediatric cohort. We aimed to evaluate age- and sex-specific ranges for ISTH-BAT scores in individuals <18 years using an international dataset. Under the auspices of 2 ISTH Scientific Subcommittees, healthy participants <18 years were recruited from 7 countries across 5 continents. ISTH-BAT assessments were completed by trained investigators using a standard protocol. Participants were stratified by age quartile, sex, country, and World Bank income. Reference ranges were defined using the 2.5th to 97.5th percentile and assessed with 95% CIs. A total of 1168 participants were included (mean age ± SD, 7.7 ± 5.2 years; 50.5% female). The overall ISTH-BAT score reference range was 0 to 2. The overall distribution of scores across age quartiles was not statistically significantly different (P = .065). A significant positive trend in the proportion of participants with scores >0 was observed across increasing age quartiles (linear-by-linear association χ² = 47.3; P < .001). Females -more often than males- had a bleeding score > 0 (P = .02), with significant sex differences observed only in quartile 4 (P = .003). The 2.5th to 97.5th percentile for quartile 4 females was 0 to 3. Scores varied by country and income classification (P ≤ .001), but reference ranges remained stable. We conclude that the ISTH-BAT reference range of 0 to 2 is appropriate for individuals <18 years. For females (12-17 years), 0 to 3 may be considered and interpreted in conjunction with clinical context when guiding referral decisions.
