Table 2. Details of attributes to be collected during data extraction.

Categories	Attributes
Details of the study	Author and year of publication Study design Study objectives Geographic location and context of the study
Description of the study population	Inclusion/exclusion criteria Number of participants Demographic details—age, sex
Exposure assessment	The approach used for determining COVID-19 episode (e.g. self-report, medical records, diagnostic tests) Whether the episode required hospitalization
Outcome assessment	List of outcomes including determination of frailty Test/measurement method used to assess outcomes including frailty Reliability/validity of outcome measures Blinding of outcome assessor concerning history of COVID-19
Follow-up	Follow-up time interval Retention of participants Approach for handling missing data
Covariates or confounders	List of covariates considered in the statistical model (e.g. demographic, health history, living situation, hospitalization for COVID-19)
Statistical analyses	Statistical model used for assessing association/risk between COVID-19 episode and frailty Index for ascertaining effect size
Results	A list of variables, including COVID-19, was found to be associated with the development of frailty Effect size (e.g. regression coefficient, odds ratio, risk ratio) and associated p-value for the variables found to be significant