The Impact Of a Standardised Transcranial Doppler Training Programme In Screening Children With Sickle Cell Disease: A European Multicenter Perspective

Routine use of Transcranial Doppler (TCD) screening is standard management for the prevention of Stroke in children with Sickle Cell Disease (SCD). However, due to a number of factors including the lack of adequately trained TCD operators, less than 50% of children with SCD are enrolled in TCD screening programmes in the USA and Europe.

This prospective, multi-centre study focused on the provision of TCD skills delivered through an educational programme. The study objectives were to determine the effectiveness of modular TCD training, to improve the quality and standardisation of TCD assessment and thereby facilitate an increase in the number of children screened.

The modular training programme comprised of a two-day course, covering theory and practical aspects of TCD and incorporating significant hands-on instruction. This was followed by local scanning with continuous monitoring and feedback from the training centre in the United Kingdom (UK). Competency evaluations were undertaken at the end of the instructional course and 6-12 months later when a log book of at least 50 scans was completed.

TCD results were collected prospectively from a consecutive series of children by certified operators at each centre. Data were compared with that acquired from the same patients in the year prior to the training programme using imaging and/or non-imaging TCD. Statistical analysis was performed using Pearson Chi-Square controlling for possible treatment bias.

Data were obtained from 326 patients (male 168 (51.5%); female 158 (48.5%); mean age 7.6±3.5, range 1-17) in the UK, Ireland and Italy. Genotypes were; HbSS 79%, HbSC 19%, HbSbetathalassemia° 1%, HbSbetathalassemia⁺ 1%. 462 pre-training scans (imaging and/or non-imaging TCD); 134 from the UK, 193 from Ireland and 135 from Italy, and 377 post-training scans were available; 114 from the UK, 167 from Ireland and 43 from Italy (Table). Statistical analysis revealed a significant difference in the STOP distribution between the three centres (C²=53, p<0.001) prior to training, with no treatment bias (no treatment C²=47, p<0.001; treatment n=82, C²=23, p<0.001). Anomalous technique between centres pre-training included the erroneous use of Doppler angle correction, poor vessel/Doppler angle optimisation and inconsistent STOP velocity thresholds for imaging and non-imaging studies. After training the STOP distribution was similar in the three centres (C²=7.1, p=0.311; no treatment C²=11, p=0.074; treatment n=81, C²=7.8, p=0.252). The consistent STOP distribution post-training, achieved using either imaging or non-imaging TCD, was attributed to standardisation of both technique and STOP velocity thresholds.

This multi-centre study demonstrated the success of a modular TCD training program in achieving consistent STOP classification in three European countries. To our knowledge, this is the first modular TCD training programme that has demonstrated efficacy when delivered in different European countries. This was achieved by improving the quality and standardisation of TCD using either imaging or non-imaging techniques and should facilitate the more widespread availability of competent TCD screening. This will have a significant public health impact across Europe where SCD patients are increasing due to immigration.

No relevant conflicts of interest to declare.