Under implementation condition, a nurse-led symptom distress screening program will be implemented using 5 implementation strategies including training, audit and feedback, facilitation and adaptable workflow.

The control condition is the usual clinical outpatient operation without the specific implementation program (i.e. applying the five implementation strategies including training, audit and feedback, facilitation and adaptable workflow) for standardized routine symptom distress screening. Prior to the start of the first 4-month control condition, we will meet each study unit and brief the staff about the purpose of this implementation study, as well as the introduction of the symptom distress screening tool. The symptom distress screening tool and referral forms will be given to the study sites. The staff are encouraged to screened and referred all eligible patients to JCICC, a local cancer care centre. In contrast to the intervention condition, there will be no half-day skill training workshop and no weekly audit and feedback report delivered and discussed with the site facilitator. We will keep the recording of the briefing session for fidelity assessment.

Five implementation strategies will be conducted individually for each of the study unit at the timepoint when the study unit is being randomly allocated to the implementation condition. For each study unit, all nurses will first receive a half-day training. Each study unit under the implementation condition will receive weekly audit and feedback reports to summarize the proportion of eligible patients, proportion of eligible patients being screened, proportion of patients appropriately referred to JCICC. The senior research assistant with a nursing background will receive training and mentoring from the PI and will be the guided facilitator. The guided facilitator will conduct weekly site visits to address operational issues arise during the implementation. Lastly, while the choice of symptom assessment tool and referral criteria are standardized and cannot be modified, the routine workflow for each study unit can be adjusted according to its context and resources.

The primary outcome (the measurement of the reach) is the changes in the number of eligible patients screened. Using a standardized reporting form, each study site will be asked to submit a weekly record of a total number of eligible patients per clinic and the number of patients screened.

The primary outcome (the measurement of the reach) is the changes in the number of eligible patients referred based on the predefined scores. Using a standardized reporting form, each study site will be asked to submit a weekly record of a total number of eligible patients per clinic and the number of patients referred.

The secondary outcome is the change in uptake of the referral, i.e. the proportion of referred patients accepting services.