The COVID-19 pandemic started in December 2019 in Wuhan, the Chinese province of Hubei. Compared to the period of the first epidemic wave (March to May 2020), in the period of the second epidemic wave (October 2020 to July 2021), deceased people have a more significant clinical complexit, as demonstrated by the higher number of comorbidities.The need to allocate significant amounts of healthcare resources to the COVID-19 emergency, deferral of routine healthcare visits, and invitation to avoid medical controls, if not strictly necessary, may have led to interruptions of disease management undersupply of chronic treatments. Consequently, the health status of patients with chronic pathologic conditions have worsened during and beyond the crisis. Patients with cancer, autoimmune disease, and immune deficiencies represented populations with varying immunocompetence, which made translate into higher susceptibility to SARS-CoV-2 and, for this reason, we defined them as frail populations.The main goal of the study was to propel the field of COVID-19 impact on particularly vulnerable categories of patients. The findings of this study could aid in determining the conditions under which healthcare organizations must operate in the event of a pandemic in order to protect patient's rights to care.

Inclusion Criteria:

• Written informed consent for participation in the study
• In the period between April 1, 2021, and September 31, 2022, all COVID-19 positive frail patients identified by molecular swabs taken at participating institutions were included in the study; ii) on a quarterly basis, a cohort of equal numbers of COVID-19 negative frail patients wre identified and paired by disease , gender, and age.

Exclusion Criteria:

• No exclusion criteria were identified

Frail populations (patients with cancer, autoimmune disease, and immune deficiencies)