Supplementary Material for: Bone Marrow Aspiration: A Randomized Controlled Trial Assessing the Quality of Bone Marrow Specimens Using Slow and Rapid Aspiration Techniques and Evaluating Pain Intensity

<b><i>Background/Aims:</i></b> Bone marrow aspiration (BMA) is an essential procedure in the examination of hematological disorders, but there is limited evidence as to whether the aspiration rate affects specimen quality. We aimed to assess the specimen quality and pain intensity using slow (S-technique) or rapid (R-technique) aspiration. <b><i>Methods:</i></b> This was a single-center, prospective, randomized patient- and assessor-blinded study of 482 patients scheduled for BMA. Specimen quality was evaluated by grading bone marrow (BM) cellularity and counting the number of marrow particles. Pain was assessed using a visual analog scale (VAS). <b><i>Results:</i></b> We found a significant difference between the 2 groups with regard to the quality of specimens. For cellularity, the odds ratio (OR) for having a poor quality aspirate using the S-technique versus the R-technique was 3.05 [confidence interval (CI) 1.79-5.31]. For BM particles, the quality of specimens with the S-technique proved to be poor compared with the R-technique (OR 2.52; CI 1.51-4.28). We found a statistically significant difference of 1 VAS point (p < 0.001) of the median pain intensity in favor of the S-technique. <b><i>Conclusion:</i></b> Even though the pain intensity is significantly higher with the R-technique, the median difference is relatively small. We propose that the R-technique is preferable to the S-technique due to better specimen quality.