Using Actigraphy and mHealth Systems for an Objective Analysis of Sleep Quality on Systemic Lupus Erythematosus Patients
Authors: Martínez M. Pilar , Guerrero-Contreras Gabriel , Miró Elena , Benghazi Kawtar , Sánchez Ana I. , Garrido José Luis , Prados Germán , Balderas-Díaz Sara 
Published: January 2017

Summary
Introduction: Although sleep alterations can be an important factor contributing to the clinical state of Systemic Lupus Erythematosus, there are no studies to adequately assess sleep quality in this type of disease.
Objectives: The aim of this work is to analyse the sleep quality of Systemic Lupus Erythematous (SLE) patients based on more objective information provided by actigraphy and mobile systems. The idea is to carry out a comprehensive study by analysing how environmental conditions and factors can affect sleep quality.
Methods: In traditional methods the information for assessing sleep quality is obtained through questionnaires. In this work, a novel method is proposed by combining these questionnaires that provide valuable but subjective information with actigraphy and a mobile system to collect more objective information about the patient and their environment. The method provides mechanisms to detect how sleep hygiene could be associated directly with the sleep quality of the subjects, in order to provide a custom intervention to SLE patients. Moreover, this alternative provides ease of use, and non-intrusive ICT (Information and Communication Technology) through a wristband and a mHealth system. The mHealth system has been developed for environmental conditions sensing. This consists of a mobile device with built-in sensors providing input data about the bedroom environment during sleep, and a set of services of the Environmental Monitoring System for properly managing the configuration, registration and fusion of those input data. In previous studies, this information has never been taken into account. However, the information could be relevant in the case of SLE patients. The sample is composed of 9 women with SLE and 11 matched controls with a mean age of 35.78 and 32.18, respectively. Demographic and clinical variables between SLE patients and healthy controls are compared using the Fisher exact test and the Mann-Whitney U test. Relationships between psychological variables, actigraphy measures, and variables related to environmental conditions are analysed with Spearman’s rank correlation coefficient.
Results: The SLE group showed poorer sleep quality, and more pain intensity, fatigue and depression than the healthy controls. Significant differences between SLE women and healthy controls in measures of actigraphy were not found. However, the fusion of the measures of the environmental conditions that were collected by the mobile system and actigraphy, has shown that light, and more specifically temperature have a direct relation with several measures of actigraphy which are related to sleep quality. It should be emphasize this result because usually the sleep problems are assessment through self-reported measures which had not revealed this association. Moreover, there are no previous studies that analyse these aspects in bedroom environments of SLE patients directly from objective measures.
Conclusions: The results indicate the need to complement the subjective evaluation of sleep with objective measures. The use of actigraphy in combination with a new mHealth system provides a complete assessment especially relevant to chronic conditions as SLE. Both systems incorporate this objective information directly from objective measures in a non-intrusive way. Moreover, the measures of bedroom environmental variables provide useful and relevant clinical information to assess what is happening daily and not occasionally. This could lead to more customized interventions and adapt the treatment to each individual.