Revealing the Nature of Chronic Obstructive Pulmonary Disease Using Self-tracking and Analysis of Contact Patterns: Longitudinal Study
Authors: Phanareth Klaus , Dam Astrid Laura , Hansen Martin A B C , Lindskrog Signe , Vingtoft Søren , Kayser Lars 
Published: August 2021

Background
Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death and is characterized by a progressive loss of pulmonary function over time with intermittent episodes of exacerbations. Rapid and proactive interventions may reduce the burden of the condition for the patients. Telehealth solutions involving self-tracking of vital parameters such as pulmonary function, oxygen saturation, heart rate, and temperature with synchronous communication of health data may become a powerful solution as they enable health care professionals to react with a proactive and adequate response. We have taken this idea to the next level in the Epital Care Model and organized a person-centered technology-assisted ecosystem to provide health services to COPD patients.

Objective
The objective is to reveal the nature of COPD by combining technology with a person-centered design aimed to benefit from interactions based on patient-reported outcome data and to assess the needed kind of contacts to best treat exacerbations. We wanted to know the following: (1) What are the incidences of mild, moderate, and severe exacerbations in a mixed population of COPD patients? (2) What are the courses of mild, moderate, and severe exacerbations? And (3) How is the activity and pattern of contacts with health professionals related to the participant conditions?

Methods
Participants were recruited by convenience sampling from November 2013 to December 2015. The participants’ sex, age, forced expiratory volume during the first second, pulse rate, and oxygen saturation were registered at entry. During the study, we registered number of days, number of exacerbations, and number of contact notes coded into care and treatment notes. Each participant was classified according to GOLD I-IV and risk factor group A-D. Participants reported their clinical status using a tablet by answering 4 questions and sending 3 semiautomated measurements.

Results
Of the 87 participants, 11 were in risk factor group A, 24 in B, 13 in C, and 39 in D. The number of observed days was 31,801 days with 12,470 measurements, 1397 care notes, and 1704 treatment notes. A total of 254 exacerbations were treated and only 18 caused hospitalization. Those in risk factor group D had the highest number of hospitalizations (16), exacerbations (151), and contacts (1910). The initial contacts during the first month declined within 3 months to one-third for care contacts and one-half for treatment contacts and reached a plateau after 4 months.

Conclusions
The majority of COPD patients in risk factor group D can be managed virtually, and only 13% of those with severe exacerbations required hospitalization. Contact to the health care professionals decreases markedly within the first months after enrollment. These results provide a new and detailed insight into the course of COPD. We propose a resilience index for virtual clinical management making it easier to compare results across settings.