Table 1. Elements of the SOPs followed by participants in the CDL RSC.

PCR, polymerase chain reaction.

Step	Description
Preparation	The preparation requires leadership and (if applicable) union buy-in and a clear assignment of responsibility. Key decisions include who will administer the RATs (a health care professional, a trained professional, or self-screening by the individual employees) and whether screening will be mandatory or voluntary.
Forms	There are a variety of mandatory requirements and forms included in the process: the letter of agreement, software licensing agreement, contact registration, team member registration, an invitation to the CDL RSC community Slack workplace, new screening site, screen preorder, certificate of inventory, and regular questionnaires on RATs used, cases detected, and operational challenges. These elements are critical to ensure program fidelity and quality.
RATs and supplies	Site leads need a process for calculating the number of screens that RATs required (number of participants × 2 per week × number of weeks × 1.05 to allow for spoilage and training). There may also be distinct types of equipment needed, including tables, chairs, timers, gloves, gowns, and biohazard waste bags. The Canadian government provides RATs. RAT orders were tracked through a CDL RSC form; CDL RSC coordinated directly with the supply chain managers in the federal and provincial governments to support shipment fulfillment. For on-site screening programs, inventory control requires daily checks and a full weekly inventory of all supplies.
Screening station layout and setup where applicable	While there is some flexibility, there are several requirements for screening stations if they are on-site. Waiting areas, traffic flow, and signage also need to be specified. Waiting areas, for example, require floor markings to allow people to be safely distanced.
Communications and registration	The program strongly encourages initial communication from the organization’s leadership. The goal is to provide sufficient information so that employees can understand the program’s purpose, make an informed decision about participation if voluntary, and give employees the opportunity to ask questions. A standard consent form is required for all participants (see text S2).
Screening frequency and booking	The program is anchored around regular screening, defined as at least twice every 7 days, as screening more frequently is needed with a less sensitive test to reduce transmission. It is continually emphasized that more frequent screening with a rapid turnaround time (i.e., isolating can happen right away) is as effective as less frequent screening with a more sensitive test. The days that testing is available need to be selected (e.g., Monday and Thursday) and communicated to employees.
Training	The program provides written materials and video guides that provide the necessary training for self- or supervised specimen collection. In addition, each screening kit comes with positive and negative control swabs. These control swabs validate that the screening devices are working correctly and that the administrator can perform and interpret the tests correctly.
Communicating results	Employees are immediately informed of results or declare if self-screening. This is automatic if using an application. It is recommended to collect another swab and repeat the RAT if inconclusive. To maintain confidentiality, any in-person or phone conversations must be in a private area where others cannot overhear. Furthermore, the participant should be able to ask questions. The employee should be told the next steps, including collecting their belongings, going home to self-isolate, and arranging a confirmatory diagnostic PCR test at a local assessment center. The organization also should begin their plan for internal contact tracing and notification processes once the confirmatory PCR test result is provided.
Data	To keep track of whether individuals are screened at least twice every 7 days, it is necessary to keep some identifying information for use only by the employer. A consent form and clear privacy policy are therefore required. In addition, data collected are deidentified before being sent to the CDL RSC central data infrastructure. This central data infrastructure is used to improve operations, prepare aggregated reports with public health authorities, and conduct evaluations.