Table 2.

Overview of themes and sub-themes

	Themes	Sub-themes	Overview
Barrier of testing	Low perceived risk from COVID-19	Low perceived severity of COVID-19	Individuals did not want to engage in testing when they perceived COVID-19 to not be a severe disease.
		Low perceived risk of contracting COVID-19	When individuals perceived they were unlikely to contract COVID-19, they felt it unnecessary to engage in testing.
		Low perceived severity after vaccination	People reported vaccines offering more protection than testing and that it is unnecessary to test after the vaccine.
	Mistrust in government	Lack of government ability to implement an effective testing programme	There was a lack of confidence the government would be able to implement effective testing.
		Lack of faith in the government handling the pandemic	There was a perception the government had not handled the pandemic well led to a less engagement with testing.
		Ulterior motives for introducing mass testing	Some did not want to engage in testing as they perceived there were ulterior motives for twice-weekly testing, such as to extend lockdown or to suppress freedom.
	Concern about taking a test	Perception that twice-weekly testing not normal	It was perceived that twice-weekly tests were not normal and concerns over how long the testing policy would last.
		Concern over what tests are used for	There was concern that the tests would be used to collect DNA and personal data.
		Discomfort associated with taking the tests	Engagement in taking tests was negatively impact with people reporting that tests were uncomfortable.
		Perceived health risks	There was concern that the tests would cause health risks (e.g., cancer) that led to people not engaging in testing.
	Perceived ineffectiveness of tests policy	Perceived inaccuracy of tests	There was a perception that the lateral flow tests were not accurate and would lead to false positives and false negatives.
		Potential negative impact of a negative test result	Some reported tests to be ineffective as a negative test may lead to people being over-confident but a negative test result only reflected your status at the time of testing.
		Perception that asymptomatic individuals will not be infectious	Tests were thought to be ineffective as it was believed asymptomatic individuals do not spread the virus.
		Perception that uptake of tests will be too low	People perceived there would be low uptake of twice-weekly testing.
		Lack of trust that others will test honestly	There was a perception that others would not test honestly and may lie about the results of their test.
	Perceived negative impact of twice-weekly testing policy	Inappropriate use of public money	There was the perception that the twice-weekly testing policy was a waste of money and directing resources away from the NHS.
		Financial impact of self-isolating	It was perceived the testing policy would not work as individuals did not have financial aid for self-isolation.
		Environmental impact of tests	There was concern over the negative environmental impact of the testing policy.
Facilitators of testing	Wanting to protect others		Individuals reported wanting to engage in testing to protect others from getting the virus.
	Positive perceptions of tests	Tests are accurate	Individuals perceived the tests to be accurate.
		Tests are accessible	Individuals perceived tests to be easily accessed.
		Tests are quick	There was a perception that tests were quick to do and quick to receive results.
	Desire to return to normal		Engaging in testing was encouraged by a perception that testing would help aid returning to normal.
	Perceived efficacy for reducing asymptomatic transmission		The perception that tests would be effective at reducing the asymptomatic spread of COVID-19.