Fredrik Tjernström1, Måns Björklund2, Eva-Maj Malmström3. 1. Department of Otorhinolaryngology, Head and Neck Surgery, S-221 85 Lund, Sweden. Electronic address: Fredrik.Tjernstrom@med.lu.se. 2. Department of Otorhinolaryngology, Head and Neck Surgery, S-221 85 Lund, Sweden. 3. Department of Neurology and Rehabilitation Medicine, Section for Specialized Pain Rehabilitation and Centre for Research and Development, Skåne University Hospital, S-22185 Lund, Sweden.
Abstract
UNLABELLED: We investigated test to retest reliability and intraindividual variability of Romberg ratios in quiet stance posturography. Thirty-six healthy young adults (17 males, 19 females aged 15-38 years) were divided into 3 groups with different time-intervals between consecutive trials (20 min, 3h and 24h respectively). Each group performed 5 posturography recordings in a randomized order of eyes open (EO) or closed (EC)+once after 3 months. We measured the torque variance in posturography and calculated Romberg ratios. Total postural sway as well as sway above and below 0.1Hz was analyzed. RESULTS: Test to retest reliability was found to be poor for Romberg ratios (intraclass correlation coefficients (ICC) <0.4) despite that the individual EO and EC posturography recordings were consistent. For sway >0.1Hz the Romberg ratios were found to be more consistent (fair to good, ICC 0.49-0.71). The variation between two consecutive tests (absolute difference (%)) was high when using the traditional Romberg ratio (EC/EO), but became less varied if an alternate formula that includes the total postural sway was used ((EC-EO)/(EC+EO)×100). CONCLUSION: In healthy young adults the evaluation of ratios from repeated quiet stance posturography show great intraindividual inconsistency. This questions the Romberg ratio as being a reliable tool for evaluation of postural performance and determination of sensory preference in postural control, at least in healthy controls. Whether test-retest reliability is acceptable in patient cohorts needs to be evaluated for proper validity of intervention and outcome studies and for detection of clinical relevance.
UNLABELLED: We investigated test to retest reliability and intraindividual variability of Romberg ratios in quiet stance posturography. Thirty-six healthy young adults (17 males, 19 females aged 15-38 years) were divided into 3 groups with different time-intervals between consecutive trials (20 min, 3h and 24h respectively). Each group performed 5 posturography recordings in a randomized order of eyes open (EO) or closed (EC)+once after 3 months. We measured the torque variance in posturography and calculated Romberg ratios. Total postural sway as well as sway above and below 0.1Hz was analyzed. RESULTS: Test to retest reliability was found to be poor for Romberg ratios (intraclass correlation coefficients (ICC) <0.4) despite that the individual EO and EC posturography recordings were consistent. For sway >0.1Hz the Romberg ratios were found to be more consistent (fair to good, ICC 0.49-0.71). The variation between two consecutive tests (absolute difference (%)) was high when using the traditional Romberg ratio (EC/EO), but became less varied if an alternate formula that includes the total postural sway was used ((EC-EO)/(EC+EO)×100). CONCLUSION: In healthy young adults the evaluation of ratios from repeated quiet stance posturography show great intraindividual inconsistency. This questions the Romberg ratio as being a reliable tool for evaluation of postural performance and determination of sensory preference in postural control, at least in healthy controls. Whether test-retest reliability is acceptable in patient cohorts needs to be evaluated for proper validity of intervention and outcome studies and for detection of clinical relevance.