New assessment tools that measure sleep vital signs: the SleepMed Insomnia Index and the Sleep Matrix

Richard K Bogan, Jo Anne Turner

SleepMed of South Carolina, Columbia, SC, USA

Abstract: Insomnia is the leading sleep disorder in the US; however, diagnosis is often problematic. This pilot study assessed the clinical value of a novel diagnostic insomnia questionnaire. The SleepMed Insomnia Index (SMI) was administered to 543 consecutive patients and 50 normal control subjects during a pilot study. Mean SMI scores were assessed based on subsequent sleep-related diagnoses. The SMI scores for patients with sleep-related disorders were significantly higher than those for the control group (p < 0.001) and highest for the 90 patients comprising the insomnia group. Analysis of the SMI scores from the 90 insomnia patients indicates a high degree of reliability (Cronbach’s alpha: 0.7). These data support our clinical experience with this diagnostic tool which indicates a strong likelihood of disrupted nighttime sleep in patients with high SMI scores. Following further validation, the SMI may prove to be a valuable tool for evaluating sleep disorders, specifically as an aid in the diagnosis of insomnia. The Sleep Matrix is a visual tool that quantifies a sleep complaint by combining scores from the Epworth Sleepiness Scale (ESS) and the SMI. The SMI measures an insomnia component while the ESS is an accepted measure of daytime sleepiness. The Sleep Matrix visually displays the complexity of the sleep complaint in an effort to differentiate insomnia with differing etiologies from other sleep disorders and measure treatment outcomes. To pilot test the Sleep Matrix, the tool was administered to 90 patients with insomnia and to 22 normal controls. Plots from the insomnia patients were concentrated into the “insomnia zone” while scores from the normal controls were located in the “normal zone” located in the lower left quadrant. Additional research using the Sleep Matrix could provide data that the tool could be utilized to visually aid the clinician in the diagnosis of unknown sleep complaints.

Keywords: insomnia, diagnosis, sleep disorders, tools