Chapter 4 110 Discussion The present study provides an overview of the correlation between outcomes of frequently performed anorectal function tests and compare their ability to measure dyssynergia. Furthermore, this study measured the level of agreement between DRE performed by the surgeon and the pelvic floor physical therapist in a tertiary referral center. Despite the surgeons and the pelvic floor physical therapist being experienced, performing several digital rectal examinations per day, the agreement of the anal pressure between their DRE was not perfect. The assessed tone during rest, squeeze and straining did not correlate in 22%, 22% and 16% respectively. To the best of our knowledge no literature concerning the interrater agreement of DRE has been published. Interrater agreement has only been studied in vaginal digital assessment concerning the pelvic floor function and digital rectal examination in the context of prostate cancer.31-33 Overall, the agreement was substantial to almost perfect. The small differences in classification of DRE between the surgeon and pelvic floor physical therapist may be explained by differences in interpretation of the indifferent movement of the pelvic floor. Not a single examination was classified both as relaxation and paradoxical movement. The correlation between the surgeons’ DRE, pelvic floor physical therapists’ DRE and the 3D-HRAM in our study was moderate and somewhat better for squeeze tone/ pressures than resting tone/pressures. Several studies compared DRE with ARM and showed an overall good agreement of pressures, however similar to our study, slightly better for squeeze pressures, but results are not consistent.9,15,34-39 For example, the study by Beatrice et al. showed that DRE correlates well, but not perfectly, with the ARM for resting pressures, r=0.71 (p<0.001).9 However, Orkin et al. observed an excellent agreement between DRE and the ARM for resting pressures (r=0.82) and for squeeze pressures (r=0.81).34 In contrast, Soh et al. described a poor agreement between DRE and ARM for resting pressures with a k-coefficient of 0.01 and a moderate agreement for squeeze pressure with a k-coefficient of 0.42.35 Pinto et al. showed a moderate to strong agreement for resting pressure with a Gamma index of 0.7 and a strong correlation of the squeeze pressures with a Gamma of 0.96.37 All studies – including ours – report that the examinations were performed by experienced examiners but the results vary considerably. Nevertheless, ARM can be performed with a variety of types of equipment, techniques, and study protocols, making results less reproducible and thus difficult to compare.40,41 A recent study by Prichard et al. described even significantly different results during ARM between operators despite
RkJQdWJsaXNoZXIy MTk4NDMw