The center for lung cancer, the rehabilitation center, and the Green Cross Call Center worked closely together for this study. This study was conducted in lung cancer patients who were receiving outpatient chemotherapy or making regular outpatient visits after lung resection surgery. Enrollment commenced in August 2015 and a total of 50 patients were recruited from a single institution over 3 months (Figure 1). Subjects who owned an Android smartphone (4.3 version or later) were eligible to participate if they: (1) were over 18 and under 85 years old; (2) gave consent to participate in the study (3) had relatively stable co-morbid conditions; and (4) were willing to follow the protocol of the study. Subjects were excluded if: (1) giving feedback via a smartphone was deemed to be difficult for them, (2) they had a history of any other serious illness besides lung cancer, or (3) they had difficulties in performing rehabilitation exercises.
In total, 50 patients were enrolled. Among them, 46 were undergoing outpatient observation after lung resection surgery for lung cancer, while the remaining 4 patients were undergoing chemotherapy ± radiation treatment without surgical treatment for advanced lung cancer. The average age was 58.3±11.7 years, with 28 males (22 females) and the average body mass index (BMI) was 23.4±2.8 kg/m2. There were 27 patients with stage I, 6 with stage Ⅱ, 12 with stage Ⅲ, and 5 with Stage Ⅳ lung cancer. Of the 46 patients who underwent surgery, 35 underwent lobectomy, 8 underwent wedge resection, 2 underwent segmentectomy, 1 underwent pneumonectomy (Table 1). As for time between surgery and study enrollment, 20 patients were more than 1 year after surgery, 6 patients were more than 2 months and less than 1 year after surgery, and 12 patients were less than 2 months after surgery (Figure 2). During the study, 8 (16%) of the 50 patients dropped out. Among them were 5 patients (10%) who complained of the burden from taking measurements using the devices and inputting them into the app, 2 patients (4%) who were forced to stop due to cancer progression, and 1 patient (2%) who did not feel the need for the program. As a result, the data analysis was conducted on the remaining 42 patients.
All the remaining subjects visited the hospital three times over a three-month period, at six-week intervals. At the time of initial registration, patients completed a baseline QOL survey (EORTC-QLQ C30 and LC13). The EORTC-QLQ C30 is the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, which consists of a set of validated 30 core questions assessing QOL in cancer patients, and the EORTC-QLQ LC13 is a modular supplement containing 13 questions specific to lung cancer patients [13]. Also, patients completed a two-minute walk test to measure cardiorespiratory endurance, a 30-second chair stand test to measure lower extremity muscle strength, a handgrip strength test to measure upper extremity muscle strength, and the International Physical Activity Questionnaire-Short Form(IPQ-SF) [14]. Based on these results, patients received exercise prescriptions and training from rehabilitation specialists and visited the rehabilitation department again in the 6th and 12th week of study to receive additional exercise training as well as re-assess exercise performance (Figure 3). The SAP satisfaction survey was conducted when patients visited the hospital in the 6th and 12th weeks of the study, and QOL questionnaires that were executed at the beginning and end of the study were compared to each other.
1. Smart After-care Program (SAP)
1.1 Self-monitoring devices
We provided self-monitoring devices to all subjects and installed a Smart After-care app on their smartphones. Self-monitoring devices included a Bluetooth electronic sphygmomanometer (UA-851PBT-C, A&D electronics Co., Ltd., Shen Zhen, China), finger pulse oximeter (Nonin Onyx Vantage 9590, MN, USA), and digital spirometer (PF-200, Micro life Corporation, Widnau, Switzerland). The choice of devices was made taking into consideration the characteristics of lung cancer patients, allowing for blood pressure, heart rate, oxygen saturation, and FEV1 (Forced Expiratory Volume within 1 second) to be obtained every morning. All participants were instructed to enter their daily vital signs into their smartphones. In addition, all participants were instructed to respond to a 13-question checklist on their subjective physical state adapted for the physical characteristics of lung cancer patients in the app (Supplementary Figure 1). If participants failed to input the information properly after waking up, the app was set to sound an alarm at 8 a.m. and 10 a.m., and if the patient (1) failed to input the information for three consecutive days, (2) had an oxygen saturation of less than 95 percent, (3) had heart rate above 120 beats/minute or below 50 beats/minute, (4) had a systolic blood pressure above 180 mmHg or below 80 mmHg, (5) had a diastolic blood pressure above 110 mmHg, or (6) had an FEV1 that was reduced by more than 30% from their baseline, the counseling center was notified and called the patient (Supplementary Figure 2).
1.2 Smart After-care application
The Smart After-care app was made specifically for this study based, ran on the Android operating program, and included a personalized exercise program and diets for lung cancer patients in addition to recording vital signs. To encourage compliance with the prescribed exercise program, each movement was designed to be easy-to-follow using a video clip. The exercises consisted of muscle strength exercises using elastic bands, stretching exercises to increase flexibility, and breathing exercises to strengthen respiratory muscles. Maintaining good nutrition plays an important role in improving health as well as in the treatment of disease. Especially for cancer survivors, nutritional problems such as lack of appetite are frequent. To address these problems, in this study, the BMI of patients was calculated and classified as 6 grades according to the BMI classification criteria of the Korean Society of Obesity. Based on BMI grade, individual nutritional requirements were calculated using the Mifflin-St. Jeror formula [15]. And these individual nutritional requirements were divided into 8 groups, and 12 personalized diets were provided for each group through the app. Patients were able to check menu-specific nutrients, dietary calories, and special recipe videos at any time (Supplementary Figure 3).
2. Survey information
2.1 SAP satisfaction survey
The satisfaction survey consists of four main categories, as follows:
a. Overall satisfaction with the SAP and willingness to use it after this study (4 questions)
b. Opinions on the equipment and programs used in the SAP (6 questions)
c. Service usability assessment (7 questions)
d. Opinion on telephone health counseling by the counseling center (5 questions)
For each question, there were five response choices, as follows:
(1) Very good (Absolutely yes), (2) Good (Yes), (3) Fair (Average), (4) Poor (No), (5) Very poor (Absolutely no)
All the answers were standardized for statistical analysis. We investigated independent association between satisfaction level and relevant clinical factors through Kruskal-Wallis.
2.2 Quality of life Survey
The EORTC QLQ-30 consists of a functional scale and a symptom scale. The functional scale is divided into six categories, global health status (GHS), physical functioning (PF), role functioning (RF), emotional functioning (EF), cognitive functioning (CF), and social functioning (SF). The symptom scale consists of 8 symptoms, including nausea/vomiting, pain, dyspnea, insomnia, appetite, constipation, diarrhea. In addition, this study used the EORTC QLQ-LC13, developed as a QOL survey in lung cancer patients. The survey consists of 13 questions about cough, hemoptysis, dyspnea, sore mouth, dysphagia, peripheral neuropathy, alopecia, pain in the chest, pain in arm/shoulder, and other pain. Scores were calculated according to the EORTC QLQ-C30 version 3.0 scoring manual [16]. The QOL score changes for each area were compared through the Wilcoxon Signed-Rank Test (one-side, H1: Before < After).
3. Statistical analysis
Statistical analysis and processing of data was done using STATA 13. Continuous variables are represented by mean ± standard deviations, and categorical variables are presented as median values. For continuous variables, the post-war comparison within the group was done using the Wilcoxon Rank-Sum Test (one-side). A p-value of less than 0.05 was considered statistically significant.