2.3 Inclusion criteria
Following patients were considered for enrolment in the study:
  1. Adult patients age > 18 years.
  2. All the patients who meet the diagnostic criteria of the National Institute of Health (NIH) Pakistan for COVID-19 infection,14 which are as follows:
  1. Clinical manifestations that include fever and pulmonary symptoms (cough, shortness of breath, chest pain, and tightness).
  2. Radiological findings of consolidation, ground-glass opacities (GGOs) either on chest X-ray or high-resolution computed tomography (HRCT).
  3. Real-time fluorescent reverse transcription-polymerase chain reaction (RT-PCR) of respiratory samples (nasal/oropharyngeal swab or tracheal secretions) positive for SARS-CoV-2.
After being enrolled in the study, the eligible patients were then segregated into the following two groups, based on diagnostic criteria and classification criteria of the NIH Pakistan:14
  1. The ‘general group’ that includes asymptomatic and mild cases.
  2. The ‘heavy group’ that includes moderate and severe cases.
The following criteria were used to define the two groups.