Validating the Online Self‐Administered Bleeding Assessment Tool (Self‐BAT) as a Screening Tool for Bleeding Disorders

1.

Dear Editor,

Symptomatic inherited bleeding disorders affect approximately 1 in 1000 individuals, yet only a minority have been identified and treated [1]. Difficulties in identifying and reporting abnormal bleeding symptoms are obstacles to obtaining a diagnosis. Women are disproportionately affected, as gynaecologic and obstetric manifestations of bleeding disorders are often difficult to quantify and are frequently overlooked or dismissed, despite their centrality to a diagnosis [2]. An estimated 30% of women experience heavy menstrual bleeding (HMB), and 30% of this cohort have an underlying bleeding disorder [3, 4]. However, around half of women experiencing this symptom seek medical care, despite 75% actively seeking information about their bleeding on the internet [3]. The high prevalence of information‐seeking online without adequate healthcare access among these individuals implies a need for accessible educational tools that appropriately advise people based on their bleeding symptoms before they reach a clinic. Without recognition of abnormal symptoms, many affected women are left undiagnosed and without appropriate management, leading to reduced health‐related quality of life and an increased risk of life‐threatening hemorrhage [5].

Bleeding assessment tools (BAT) play an important role in the clinical assessment of a patient's bleeding history. Developed by the International Society on Thrombosis and Haemostasis (ISTH) in 2010, the ISTH‐BAT provides a series of questions and associated scores to standardize quantitative reporting of bleeding symptoms [6]. However, the ISTH‐BAT was designed to be administered by health care providers, thus making it inaccessible for widespread public use. The Self‐BAT was developed in 2015, initially in a paper format used in primary care settings. This enabled patients to determine their bleeding scores independently in layperson terms [7]. The Self‐BAT has since been validated as a screening tool for von Willebrand Disease (VWD) [7], platelet function disorders (PFD) [8] and haemophilia carriership [9]. However, a large proportion of individuals do not have a primary care provider, limiting the opportunity to have their symptoms assessed using the paper Self‐BAT or ISTH‐BAT. Additionally, the vulnerability and stigma associated with bringing up bleeding concerns that have the potential to be normal still leaves people behind.

To address this, we have taken the validated paper version of the Self‐BAT and developed it into an online version (letstalkperiod.ca) to enhance public accessibility and awareness of the tool. The online Self‐BAT has language that is further simplified and includes skip logic to shorten the questionnaire (i.e., males do not see the HMB or post‐partum sections). Importantly, this tool can be completed from the comfort of home. In addition, patients can print their results, which they can bring as a comprehensive bleeding history to their medical appointment. We have recently shown that individuals referred to haematology for an abnormal online Self‐BAT were more likely to receive a diagnosis, and more likely to require interventions compared to those referred for other reasons [10]. This suggests that the Self‐BAT can identify those that would benefit from treatment with improved accuracy in comparison to standard referrals. Thus, to further examine its utility in undiagnosed patients, the current study seeks to validate the online Self‐BAT as a screening tool for bleeding disorders in a population of new referrals to haematology.

In this prospective study, patients referred to a tertiary haematology clinic in Kingston, Ontario, for evaluation of a possible bleeding disorder were approached by study personnel prior to their appointment and consented to complete the online Self‐BAT on an iPad. Once completed, their score sheet was saved and assigned a study ID number associated with the participant. Participants then underwent routine clinical assessment by the physician, including laboratory workup as deemed appropriate, and their expert‐administered bleeding score was calculated using the International Society on Thrombosis and Haemostasis (ISTH)‐BAT. Their categorical scores, from both the ISTH‐ and Self‐BAT, were also recorded (epistaxis, cutaneous bruising, minor wounds, oral cavity bleeding, GI bleeding, dental extractions, surgical bleeding, HMB, post‐partum haemorrhage, muscle haematomas, haemarthrosis, CNS bleeding, haematuria and other). Their charts were then reviewed to determine whether they received a diagnosis, and clinical and laboratory data were extracted. Those with a prior confirmed bleeding disorder diagnosis were excluded. This study protocol was approved by the Queen's University Health Sciences and Affiliated Teaching Hospitals Research Ethics Board (approval number: 6022227).

For analysis, patients were grouped based on diagnosis (bleeding disorder or no bleeding disorder). Bleeding disorder of unknown cause (BDUC) was included as a bleeding disorder diagnosis, defined as an abnormal bleeding score, as determined by a positive expert‐administered BAT, with non‐diagnostic laboratory tests and exclusion of other known causes. ISTH‐BAT and Self‐BAT scores, as well as standard haematological laboratory values (ferritin, haemoglobin concentration, PT, PTT, INR, FVIII:C, VWF:Ag and VWF:GPIbM) were compared across groups using Mann‐Whitney U tests. The Shapiro‐Wilk test was used to assess the underlying distribution of the continuous variables. Sensitivity, specificity, positive and negative predictive values were calculated (PPV and NPV, respectively). The intraclass correlation coefficient (ICC) and Spearman's Rho were used to examine the correlation between total and categorical Self‐ and ISTH‐BAT scores, respectively (p < 0.05 was considered significant).

A total of 63 female patients were recruited between 2016 and 2024 (Table 1). Only one male completed the study in this time frame (with a normal Self‐BAT and provider assessment), thus, this patient was excluded from analysis. Forty‐two (67%) were diagnosed with a bleeding disorder, including BDUC (n = 27; 43%), type 1 VWD (n = 9; 14%), PFD (n = 5; 8%), congenital dysfibrinogenemia (n = 1; 2%) and Ehlers‐Danlos Syndrome (EDS; n = 1; 2%), while 21 (33%) did not have a bleeding disorder. In the diagnosed group, mean Self‐BAT and ISTH‐BAT scores were significantly higher than those without a bleeding disorder (p < 0.001). VWF:Ag and VWF:GPIbM were significantly lower in the bleeding disorder group (p = 0.021 and 0.041, respectively).

TABLE 1.

Participant demographic and clinical data.

	No bleeding disorder (n = 21)	Bleeding disorder (n = 42)	p value
Female sex (%)	100	100	—
Age (years)	39.6 ± 15.2	39.7 ± 14.3	0.907
Self‐BAT score	6.2 ± 4.0	12.2 ± 6.0	<0.001
ISTH‐BAT score	4.6 ± 3.1	10.7 ± 3.2	<0.001
Ferritin (µg L−1)	48.2 ± 29.5	51.5 ± 46.1	0.783
Hemoglobin (g L−1)	135.7 ± 15.5	133.9 ± 13.6	0.362
PT (s)	12.2 ± 0.8	12.0 ± 0.8	0.309
PTT (s)	25.8 ± 3.5	26.3 ± 2.2	0.318
INR	1.0 ± 0.1	1.0 ± 0.1	0.926
FVIII:C (IU mL−1)	1.6 ± 0.5	1.4 ± 0.5	0.147
VWF:Ag (IU mL−1)	1.3 ± 0.7	1.0 ± 0.4	0.021
VWF:GPIbM (IU mL−1)	1.3 ± 0.5	1.1 ± 0.6	0.041

Note: Data expressed as mean ± SD, apart from sex (%); significance (p < 0.05) indicated in bold.

The ICC demonstrated significant positive correlation (0.738, 95% CI 0.601–0.833, p < 0.001) between total Self‐ and ISTH‐BAT scores (Figure 1). Cohen's kappa demonstrated moderate agreement between the two measures (0.559), with agreement on 85.7% of assessments. Similar to the paper version [10], an abnormal Self‐BAT (≥6 for females) has a sensitivity of 95.2%, specificity of 33.3%, PPV of 74.1%, and NPV of 77.8% for identifying a bleeding disorder using the expert assessment outcome (diagnosed vs. not diagnosed) as the gold standard. The ISTH‐BAT had an equal sensitivity (95.2%), a specificity of 66.7%, PPV of 85.1% and NPV of 87.5%. Furthermore, all categorical scores within the ISTH‐ and Self‐BAT were significantly correlated using Spearman's Rho, apart from cutaneous bruising (p = 0.150), muscle hematomas (p = 0.260) and other (p = 0.418), all of which had generally higher self‐reported scores. Only one patient experienced CNS bleeding and haematuria, so these categories were excluded from analysis.

FIGURE 1.

Scatterplot of Self‐ and ISTH‐BAT scores. Expert‐administered ISTH‐BAT scores (x axis) were plotted against Self‐BAT scores (y axis). The intraclass correlation coefficient (ICC) demonstrates significant positive correlation between the two measures (0.738, 95% CI 0.601–0.833, p < 0.001).

This study demonstrates that the online Self‐BAT can identify bleeding disorders with an equal sensitivity in comparison to the expert‐administered ISTH‐BAT without patients needing to leave their home, and without time and resource expenditure during medical appointments. For a screening tool, a high sensitivity and negative predictive value are of utmost importance to ensure that patients with an underlying bleeding disorder are not missed. Limitations of this study include the potential for bias when administering the Self‐BAT prior to assessment. While the Self‐BAT result was not disclosed to the physician until after the appointment, it is possible that patients may have chosen to disclose this information themselves. In addition, given the small sample size, there was a lack of male representation in this population. While most patients referred to the clinic are female, this limits the study's generalizability to males. Bleeding disorders present differently in males, and as such, their symptoms are interpreted differently in the Self‐BAT with a lower threshold for abnormal.

In combination with the educational resources available on letstalkperiod.ca, we believe this tool will enhance public awareness of abnormal bleeding symptoms, increase accessibility of the Self‐BAT and formulate an accurate bleeding history for reference in primary care appointments, providing support for hematology referrals. This will allow those with abnormal bleeding to self‐identify while providing validation of their concerns when seeking healthcare. With this, we hope to bridge the gap between those who have reduced quality of life due to bleeding and those who obtain diagnosis and treatment.

Author Contributions

J.G. and P.J. contributed to study conception and design. J.G. and M.A. recruited study participants. V.D., J.G. and M.C. contributed to data collection. W.H. performed statistical analysis. V.D. interpreted the data and wrote the manuscript. P.J. supervised research and interpreted the data. The first draft and final version of the manuscript was reviewed and approved by all authors.

Funding

This work was supported by the School of Medicine, Queen's University, Kingston, Ontario, Canada.

Ethics Statement

The study protocol was approved by the Queen's University Health Sciences and Affiliated Teaching Hospitals Research Ethics Board (approval number: 6022227) and was conducted in accordance with the Declaration of Helsinki; written informed consent was obtained.

Conflicts of Interest

P.J. receives consulting fees from Star/Vega Therapeutics, Roche and BioMarin. V.D., J.G., W.H., M.C. and M.A. have no potential competing interests to declare.

Data Availability Statement

Data are available upon reasonable request from the corresponding author, Paula James (jamesp@queensu.ca).