2. Methods
This was a mixed methods study to evaluate the deployment of a pilot COVID-19 weekly asymptomatic testing service (P-ATS: Figure 1) offered to students and staff who had face-to-face teaching responsibilities during this period. The study explored the uptake, adherence, acceptability and experiences of the P-ATS in students as well as assessing students’ anxiety and risk perceptions and the perceptions of university staff towards P-ATS implementation.
The study comprised of (i) a structured online survey for students administered at the end of deployment, (ii) a qualitative study involving interviews and focus groups with university students and staff conducted at the programme mid-point (students) and at the end of deployment (students and staff). The study design adheres to the standards for reporting qualitative research [7] and the consolidated criteria for reporting qualitative research guidelines [8] (see Supplementary File S1). A total pool of 215 undergraduate students (150 in their first year and 65 in their final year) and 70 staff were eligible to participate in the P-ATS.

2.1. Pilot Asymptomatic Testing Service (P-ATS)
The P-ATS was a pilot programme for SARS2 surveillance conducted in the early phases of the SARS2 pandemic at a semirural campus of a university in the UK. The objective of the programme was to define the baseline SARS-Coronavirus type 2 (SARS-CoV-2) infection rate and seroprevalence in a cohort of university students and staff and to measure changes over time.
Participation in P-ATS was on a voluntary basis and aimed to be complementary to the national testing strategy in the United Kingdom (UK). P-ATS was a completely independent initiative within the University to explore the value of SARS-Cov-2 testing in asymptomatic students. National guidelines for actions to be taken by symptomatic students were followed throughout. Any asymptomatic students testing positive in this pilot were advised to undertake a “Pillar 2” test, the results of which would be paramount (the University laboratory testing was a research test only), and hence would feed into the UK National Health Service (NHS) Test and Trace [9] mechanisms, if positive.
The P-ATS was offered to all 150 students in their first year (new arrivals in 2020 Cohort 1) as well as 65 final-year students going out into practice rotations in the Autumn term. A select group of 70 university staff who had face-to-face contact with students during the study period were offered the opportunity to join P-ATS if they wished, at any point during the programme.
The P-ATS was primarily targeted to students in their first year of study who were living in university accommodation on campus. All first-year students who had arrived in 2020 Cohort 1 were therefore eligible for the P-ATS and were offered the full programme which included a total of 12 PCR tests to be completed weekly over 12 weeks (10 swab tests, and 2 saliva tests) and up to 6 antibody tests from July to October 2020. In addition, a number of students in their final year were invited to join the P-ATS in September 2020. Eligible final-year students were those who were due to start certain 2-week rotation placements that required them to undertake PCR testing prior to attendance. A select number of final year participants therefore participated in the P-ATS between September and October 2020.
Newly arriving first-year students from 2020 Cohort 1 were accommodated on campus in cluster flats treated as a “household” and attended teaching sessions in “bubbles” through the study period to avoid exposure to larger groups of people. Final-year students mostly lived off campus and attended clinical rotation placements in the community during this year of study. The P-ATS start for eligible final-year students was staggered since they joined at different times according to academic timetabling and the start date of relevant placements. Final-year students joined the programme at different times, had fewer tests offered in total, with some students taking only one test, and others taking more if they changed rotation placement during the study period. Therefore, the total number of tests offered varied between students, although the testing offers and start date were consistent for those who were in their first year. The first- and final-year students who accessed P-ATS, therefore, had a different experience of both the service (with only first years offered the complete programme), and of university life more broadly.
For all P-ATS participants, swab, saliva and antibody test kits were collected by P-ATS participants, tests were self-administered and participants deposited samples at dedicated collection points on the university campus with social distancing rules applied.
The complete programme consisted of:(a) SARS2-PCR tests offered weekly for the 12-week study period (10× swab and 2× saliva);
(b) SARS2-antibody tests offered alternate weeks (6 x self-sampled finger-prick dried blood sample).
Individuals testing negative were informed by email correspondence to their cohort (indicating that all positive cases had been contacted). Individuals testing positive were personally advised of their result by a clinical virologist, and a central university team was notified so that the student could be safely cared for. This process included notification of Public Health England so that official test, track and trace could take place [9].

2.2. Participants, Recruitment and Sampling
All students who were eligible to take part in the P-ATS were invited to fill out the post-P-ATS evaluation survey (n = 215). Participants for the mid-point and post-P-ATS interviews and focus groups were recruited from the total pool of 285 individuals (first-year students: n = 150; final-year students: n = 65; staff: n = 70) who had been invited to take part in P-ATS. All students were invited to complete the survey, whether or not they had taken part in P-ATS. All students and staff who had taken part in P-ATS were invited to attend an interview or focus group. Recruitment to the mid-deployment group interview with students took place in weeks 6 and 9. Recruitment to the post-deployment survey and student interviews and focus group commenced in mid-October 2020 and continued for 16 days through weeks 12–14. Recruitment to the staff focus group took place post-deployment in week 13. The staff focus group included participants in clinical or non-clinical teaching or research roles, senior leadership, support staff (e.g., technicians) and staff with pastoral or welfare roles (e.g., tutors, student experience administrators). Students who were invited to interviews and focus groups included individuals of any gender, those living on or off campus, and those in their first or final year of study.
Ninety-nine students returned the post-P-ATS evaluation survey (46% response rate), 52 students and staff consented for the qualitative study via an online form and 41 subsequently took part in interviews or focus groups during the 16-day data collection window. Table 1 shows basic demographic information for interview participants.

2.3. Online Survey
All students who were eligible to take part in the P-ATS were invited to fill out the post-P-ATS evaluation survey using Jisc Online Surveys (see Supplementary File S2). The survey contained a mixture of closed and open-ended free-text questions exploring participants’ reasons for participating in the P-ATS (or not), experiences and engagement with the testing, perceived barriers and benefits of the programme and suggestions for improvement. Items explored students’ experiences of self-isolation and social distancing, COVID-19 risk perceptions and anxiety measured by the Generalized Anxiety Disorder scale (GAD-7) [10]. Generalized anxiety disorder (GAD) is one of the most common mental disorders, and the GAD-7 has demonstrated strong psychometric properties in population-based samples [10,11]. The measure has a range of 0 to 21, and a score of 10 or greater on the GAD-7 represents a reasonable cut point for identifying cases of GAD, with high sensitivity (89%) and specificity (82%) [10].

2.4. Qualitative Interviews and Focus Groups
The study explored the perceptions and experiences of staff and students who were invited to take part in the P-ATS. Qualitative data were collected from interviews and focus groups as well as free-text questions from the online survey. Thirty-one student participants (21 first year, 10 final year) took part in six individual interviews (n = 6), eight small group interviews with 2–3 participants (n = 20), and one focus group with 4–5 participants (n = 5) all held online using video-conferencing facilities. Two student group interviews took place at the programme mid-point (in weeks 6 and 9, respectively), all other interviews took place at the end of the P-ATS (weeks 12–14). A single focus group was held with 10 staff participants after programme end, at week 13. Interviews and focus groups were facilitated/moderated by a psychologist experienced in running focus groups (HB), and a study researcher who was a medical trainee (CC). Both had undertaken training in qualitative research and interview skills. Focus groups were conducted according to recommendations from NHS England’s focus group guide [12]. All interviews and focus groups followed the same questioning route (see Supplementary File S3), were audio-recorded and transcribed verbatim.

2.5. Reflexivity Statement
The research team members reflected on the impact of their background, training, beliefs and relationship to the research topic. Eleven of the authors conceptualised or were involved in operationalising the P-ATS being evaluated (JB, WI, JC, MB, JD, LF, PM, AF, JCh, AT, PT), although these researchers were not involved in evaluation data collection or analysis. Survey data were analysed by a researcher who was not involved in recruitment, intervention delivery or data collection (JH). Of the researchers who collected qualitative data, one had medical training (CC), and one was a psychologist (HB). Of the researchers who conducted thematic analysis, one was a nurse who had not collected data (LB), the other had moderated focus groups and conducted interviews (CC) which may have influenced interpretation but was mitigated by team reflexivity.

2.6. Data Analysis
Survey data were analysed using IBM PASW SPSS Version 25.0 (IBM, Armonk, NY, USA) (Supplementary File S6). Data cleaning procedures (e.g., identification outliers and missing data analysis) and key statistical assumptions underpinning t-tests, correlation, and linear regression (normality, linearity, homoscedasticity, and independence) were examined prior to data analysis. Qualitative data from interviews, focus groups and open-ended survey questions were analysed using inductive thematic analysis, which benefits from theoretical flexibility and simplicity in the identification of qualitative themes [13]. This process included the in-depth familiarisation and coding of data using NVivo 12 software, before sorting data in broader thematic concepts which represented sections of the data, later refined into the development of five key themes, and 13 subthemes. Two researchers (LB/CC) analysed qualitative data, using thematic analysis [13]. As this was an evaluation of a pilot uncontrolled complex intervention in a real-world setting, intended to directly inform ensuing mass SARS-Cov-2 testing approaches, a pragmatic and time-sensitive approach was taken to analysis. Three researchers were involved in the qualitative analysis (LB, CC, HB). One researcher coded all the interview data and generated the initial themes (LB), a second researcher (who had conducted interviews) then independently coded a subsample of four randomly selected transcripts, in order to compare and agree on themes through discussion. A third researcher (who had conducted interviews) then reviewed all the transcriptions to crosscheck against themes, confirm the themes and resolve any discrepancies between coders (HB). Consensus on the themes was achieved through discussion between all researchers. Combining qualitative data from different data sources and using two researchers for coding and analysis, enabled data and investigator triangulation.

2.7. Patient and Public Involvement
Student and staff views informed the study design and interview questioning guide at the point of study conception, via a Patient and Public Involvement and Engagement (PPIE) group. Students expressed a preference to be able to choose between individual or small group interview, and staff preferred to participate in a single large focus group. Study findings will be disseminated to all participants through this publication and lay summaries disseminated via the participating university.