Test-retest reproducibility of the multiple array probe leiden (MAPLe) in men with lower urinary tract symptoms

Research output: Contribution to conferenceAbstractAcademic


HYPOTHESIS/AIMS OF STUDY: Pelvic foor disorders are a hidden epidemic, associated with substantial stress and profound economic burden. Assessment of pelvic foor muscle (PFM) activity is difcult, due to a lack of simple to use and reliable measurement techniques. The Multiple Array Probe Leiden (MAPLe) enables assessment of PFM activity and is capable of diferentiating between muscle groups (1). Test-retest repeatability, performed on 20 healthy subjects, turned out to be moderate to excellent (1). Although the MAPLe is already in use in both clinical and research settings, we are unaware of studies examining the reliability of this probe among symptomatic patients. We aimed to evaluate the test-retest reproducibility of the MAPLe in male patients with lower urinary tract symptoms (LUTS). STUDY DESIGN, MATERIALS AND METHODS: Between April and October 2018, consecutive men aged ≥18 and referred to the urology department for moderate to severe LUTS were recruited. After informed consent, men completed symptom scores and underwent standardized physical examination and urofowmetry. Next, an anal MAPLe measurement was carried out in supine position, according to the manufacturers' protocol. This included three tasks: one minute rest, maximum voluntary contractions (MVC) and endurance contractions (EC). The summarizing result included a visual display and several variables: mean micro-voltage (μ V) during rest, and mean μ V, maximum (max) μ V and onset and ofset time during MVC and EC. The urologist decided which treatment was initiated. Irrespective of the treatment choice, all men were re-assessed after approximately 6-8 weeks. For this substudy, we selected men with a wait-and-see approach or α-blocker therapy, assuming that pelvic foor function was not afected in these groups. MAPLe measurements with errors were excluded. We calculated the average of the two assessments for each outcome, and as a measure of relative variability we estimated the coeficient of variation (CV) as standard deviation/mean∗100. Possible systematic errors were visualized using Bland-Altman Plots. Spearman correlation coeficient (SCC) was used to determine correlation, which was categorized as: 0.90 very high correlation. Intraclass correlation coeficient (ICC) was used to determine consistency, which was categorized as: 0.90 excellent consistency. Due to small sample sizes, data were expressed as median and interquartile range. Statistical analyses were performed using SPSS® version 24.0 for Windows. RESULTS: The study population included 57 men with moderate to severe LUTS, of whom 10 with wait-and-see and 11 with α-blocker therapy were selected for the test-retest assessment. Table 1 shows patient characteristics and average outcomes for both groups. In the α-blocker group Bland-Altman plots illustrated systematic error with overall lower max μ V and higher onset and ofset times during the second measurement. In the wait-and-see group proportional error was shown for EC (mean μ V) and MVC (ofset time). Overall, the reproducibility seemed poor according to the CV, SCC and ICC. The outcomes of max μ V and onset times particularly showed high variation, low to weak correlation and poor consistency in both groups. On the other hand, the mean μ V, especially in rest and EC, showed reasonable variations, moderate to high correlation and moderate to good consistency. The ofset time outcomes varied in both treatment groups. INTERPRETATION OF RESULTS: This is the frst study to examine the test-retest reproduci-bility of the MAPLe in men with LUTS. Our results showed poor test-retest reproducibility for the majority of outcomes of the MAPLe assessment. We feel that these results must be interpreted with caution, due to the small sample sizes, which has led to wide con-fdence intervals. It is yet unclear whether this outcome reffects a true problem with the MAPLe method itself or the in-fuence of other confounding factors. For example, the poor reproducibility might be caused by incorrect PFM contractions during testing and a learning effect of the participants. Another possible confounder is real change in PFM activity over time due to long follow up time and/or treatment. CONCLUDING MESSAGE: Although MAPLe enables assessment of PFM activity of different muscle groups (1), our study showed that it might be too early to use MAPLe to evaluate treatment response. In men with LUTS, test-retest analyses showed considerable variation between tests irrespective of a wait-and-see policy or a-blocker therapy. Future research should focus on improving the reproducibility of this innovative EMG probe.
Original languageEnglish
Number of pages2
Publication statusPublished - 1-Aug-2019
Event48th Annual meeting International Continence Society (ICS) - Gothenburg
Duration: 4-Sep-20196-Sep-2019


Conference48th Annual meeting International Continence Society (ICS)


  • alpha adrenergic receptor blocking agent
  • adult
  • clinical assessment
  • conference abstract
  • controlled study
  • drug therapy
  • endurance
  • epidemic
  • follow up
  • human
  • informed consent
  • learning
  • lower urinary tract symptom
  • major clinical study
  • male
  • muscle contractility
  • muscle contraction
  • muscle function
  • physical examination
  • reliability
  • reproducibility
  • rest
  • sample size
  • statistical analysis
  • stress
  • supine position
  • systematic error
  • treatment response
  • urologist
  • urology

Cite this