The aim of this study was to investigate the efficacy of a home-based pulmonary rehabilitation program with the support of teletechnology in COVID-19 survivors. The main questions it aims to answer were:

• The change of six-minute walk distance
• The change of time of one-minute sit-to-stand test
• The change of maximal strength of upper-limb, lower-limb and respiratory muscle
• The change of quality of life Participants in the home-based pulmonary rehabilitation group received teletechnology-assisted consultations (either by videotelephony or telephone calls) for every 1-2 weeks during the intervention period, and participants in the usual care group did not receive teletechnology-assisted consultations during the intervention period.

Inclusion Criteria:

• Patients are 20 years or more with severe (severe pneumonia) to critical (acute respiratory distress syndrome, sepsis, or septic shock) COVID-19 during hospitalization after deisolation.
• Patients are 65 years or more, or ever receiving oral antiviral treatment after deisolation.
• Patient have the ability to ambulate on level surface without direct contact of another person, have telecommunication device(s), and provide consent to receive teletechnology-assisted rehabilitation.

Exclusion Criteria:

• Patients are pregnant or planning for pregnancy.
• Patients have cognitive dysfunction, learning disability, uncontrolled arrhythmia or hypertension, or any medical diagnosis other than COVID-19 that would prominently influence their ability to follow instructions and perform exercise.