The use of mobile technology has become part of the reality capable of changing the health services' paradigm. As a proof of that, nowadays, technology is seemed as a key tool in processes such as: data collection, epidemiological surveillance, health promotion, and disease prevention. Therefore, technological tools should be taken as an advantage to optimize the control or monitoring of patients with chronic diseases including those who require the use of home oxygen therapy.

Objective: Determine the efficiency of a mobile application for clinical monitoring of patients who require home oxygen therapy.

Methods A randomized-controlled clinical trial including individuals whose age is 18 years or older who have been diagnosed with Chronic Obstructive Pulmonary Disease (COPD) under treatment with home oxygen therapy. The sample will be divided in two groups: the intervention group will be made up of those who are followed up with the mobile app, and the control group will be made up of the patients who are followed up conventionally (regular visit of the respiratory caregiver). To measure the effect of the intervention, some outcomes variables will be taken as the recognition of self-management of dyspnea, number of exacerbations associated with oxygen therapy, and the frequency of underutilization of oxygen supplies.

The Continuous Home Oxygen-therapy (abbreviated as OCD in Spanish) refers to the supply of oxygen for continuous, general, and/or indefinite use at the home of patients with chronic hypoxemia. The purpose of this treatment is to prolong the life of the hypoxemic patient, improve exercise tolerance, and control clinical deterioration due to low oxygen saturation.

Contextualizing the use of home oxygen in Colombia, it was observed that there was an increase in the prevalence of COPD (Chronic Obstructive Pulmonary Disease) as well as the prescription of home oxygen in the first phases of the treatment. It was found that 3.176 patients were enrolled in the home care program without knowing their sociodemographic and epidemiological characteristics. The reason behind is that there are few epidemiological studies that refer to this therapy. However, Gonzales M. et al. emphasize that current indications should be reviewed and research carried out in order to determine guidelines for recommending home oxygen in patients with COPD.

Methods / Design Study Design A randomized controlled clinical trial divided in two parallel groups with a 3-months duration will be performed in order to evaluate the efficiency of a mobile application used for the monitoring of patients with home oxygen. The control group will be made up of individuals with oxygen therapy undergoing regular monitoring (periodic visits by the respiratory caregiver), and the intervention group formed by those who have conventional monitoring with the use of the mobile app called AppO2.

Sample's size calculation A total of 32 individuals (16 for the experimental group and 16 for the control one) would be necessary to recruit, for a 1:1 ratio, a power of 80% (beta error = 20%), a certainty of 95% (alpha error = 5%) and assuming that the intervention in the experimental group will cause a 3% increase with a ±6 standard deviation in recognition of self-management of dyspnea. A final size of 44 individuals has been established (22 for the EG and 22 for the CG) to minimise the effect of possible losses in statistical power.

Intervention:

The control group comprises patients who will be under the conventional follow-up of clinical assessment and control of home oxygen supplies. The intervention group will be monitored conventionally, and they will additionally have a mobile app, "AppO2". We will follow a consecutive sampling. Patients will be recruit as on the go. The allocation will be randomly performed using a statistical software called EPIDAT, 3.1.

Study variables

The following results variables and independent variables are suggested to achieve the proposed objectives:

Variables:

• Oxygen saturation through a pulse oximeter, capillary filling, respiratory rate, heart rate, duration time of the oxygen cylinder.
• Oxygen saturation and inspired fraction of oxygen relationship
• Borg dyspnea scale
• Oxygen saturation and inspired fraction of oxygen relationship
• Recognition of self-management of dyspnea and quality of life through the mobile app.
• Saint George questionnaire for the assessment of health-related (CVRS) quality of life Statistical analysis A descriptive analysis of the variables under study will be carried out by characterising the patients. Also, graphs and frequency tables will be constructed for the qualitative variables, and the calculation of central tendency measures (mean), dispersion (standard deviation), and position (limits of the distribution and range) for the quantitative variables.

For the bivariate analysis, the Student's T-test will be performed to compare two means, while for the qualitative variables, the chi-square test and Fisher's exact test will be used. For the analysis of three or more means, the repeated measures analysis of variance (ANOVA) will be calculated. Multiple linear regressions will be used to adjust the App use's impact and eliminate confounding factors. The standardized beta coefficients, the adjusted coefficient of determination, the residuals, etc., will be calculated. An alpha error <5% will be accepted for all statistical analyses, and confidence intervals will be calculated for 95% confidence (95% CI). For the complete statistical analysis, SPSS Statistics software, version 25.0 (IBM Corp), will be used.

Practical applicability The general objective of this protocol is to evaluate the efficiency of a mobile application in the follow-up of patients with home oxygen therapy through an intervention aimed at reducing exacerbations. Besides, an attempt will be made to identify the adequacy of the prescription of oxygen systems and establish the underutilisation of oxygen supplies at home. A two-group randomized clinical follow-up will be used to evaluate the intervention.

Inclusion Criteria:

• Individuals of 18 years of age and older
• Patient with PaO2 <60 mmHg, SO2 <89% and dyspnea. Patients with home oxygen therapy enrolled in-home care programs during the study period.
• Time of evolution of the disease greater to one year
• Patients who express their willingness to participate in the study through their informed consent.

Exclusion Criteria:

Patients with the following exceptional situations will be excluded from the study:

• Patients with invasive and/or non-invasive mechanical ventilation
• Patients with the inability to operate a mobile application or those who do not have a smartphone with an operating system (Android or iOS) and available data connection.