The goal of this observational study is to learn about the factors affecting the outcome (survival) of cardiopulmonary resuscitation in older persons in a hospital. The main questions it aims to answer are:

• Whether age would affect outcome
• Whether Charlson Comorbidity Index would affect outcome
• Whether the conditions (e.g. heart rhythm) immediately before resuscitation would affect survival.

Researchers would compare the patients who deceased with the patients who survived.

The goal of this review was to investigate the impact of age, existing medical conditions. and other factors before cardiac arrest in predicting outcome of in-hospital cardiopulmonary resuscitation (CPR) of older persons.

It was conducted on all patients aged ≥ 65, who underwent CPR in acute medical and geriatric wards (excluding Intensive Care Unit) in United Christian Hospital from January 2017 to December 2018.

Inclusion Criteria:

• All adults aged 65 or above with in-hospital cardiac arrest and undergoing CPR in wards of Department of Medicine and Geriatrics (excluding Intensive Care Unit (ICU)) in United Christian Hospital (total bed 1,174 with 16 ICU beds) in Hong Kong from 1 January 2017 to 31 December 2018
• In patients with multiple resuscitation events, only the first in-hospital CPR was included.

Exclusion Criteria:

• Patients with existing Do-Not-Attempt-Cardiopulmonary-Resuscitation (DNACPR) order
• Patients younger than 65 years old
• Out-of-hospital CPR in the index admission
• CPR occurred in ICU / Emergency Department / Operating Theatre / wards other than medical wards

All adults aged 65 or above with in-hospital cardiac arrest and undergoing CPR in wards of Department of Medicine and Geriatrics (excluding Intensive Care Unit (ICU)) in United Christian Hospital (a regional acute hospital with total bed 1,174 with 16 ICU beds) in Hong Kong from 1 January 2017 to 31 December 2018