We look at the advice released by the Department of Health, which led to the introduction of new coronavirus restrictions in Northern Ireland.
A range of new measures, including an extended break for schools and the closure of bars and restaurants, except for takeaways, and close-contact businesses were introduced in an attempt to halt the spread of Covid-19 .
The scientific evidence used by the Executive to decide to close businesses has been criticised after the document revealed some measures would have a limited effect on the transmission of the virus, but a bigger and more negative effect on the economy and livelihoods, particularly for lower paid workers and women.
The information was released as part of an "evidence bank" of documents published by the Executive around the Covid-19 pandemic.
Chief Scientific Adviser Professor Ian Young said, although the knock-on effect of parts of the shutdown seems low, it all adds up to lower the R number - and crucially the only other place to turn is for more stringent measures.
He called for people to look at the broader evidence that is widely available.
"We don't have a lot of levers left to pull," he said.
"It's exceptionally difficult to determine where someone acquires a case," he said, adding that "a range of actions" need to be considered to lower the transmission rate.
Health Minister Robin Swann said the Executive faced "difficult choices" when introducing new restrictions.
"There are uncertainties with every option, and costs to individuals, communities and the economy," the UUP MLA said.
“Debate is essential and I freely admit that there are no easy or good answers. What we have to find are the least worst options.
“What is undoubtedly true is that taking no action is not an option. Avoiding hard decisions on restrictions and letting the virus spread unchecked would be catastrophic for many people – as well as for our health service and indeed the economy.”
Here's what the evidence says:
Measures relating to personal contacts
The Executive was advised that a stay at home order or "lockdown" would have a very high impact on stopping the spread of Covid-19, but would come with a significant toll on health and wellbeing and require significant financial support.
A planned short stay at home order or "circuit breaker" and reducing contacts between members of different households within their home were likely to have a moderate impact, with a lesser negative impact on people overall.
Restricting outdoor gatherings and prohibiting large events was found to have a low impact on stopping the spread of the virus, with an estimated reduction in the R number of less than 0.05.
Working from home
Encouraging people to work from home whenever possible was found to have a moderate impact with a reduction in the R number of 0.2 to 0.4.
However, concerns were expressed around younger people and those on lower incomes being more likely to be unable to work from home and the potential for social isolation and increased domestic violence.
Alternating week in – week off, return to work
This was estimated to be able to reduce the R number by 0.1 by limiting the number of people in the workplace at any one time. It was noted the plan would likely cause logistical issues for some organisations and prove impossible for others.
Closure of bars, pubs, cafes and restaurants
A marginal impact on the virus by reducing the R number by 0.1-0.2 where as it would have a high impact on incomes and a psychological impact through lack of socialising for customers.
The Executive was advised that curfews are likely to have a "marginal impact" and allowing customers to sit outside "likely to be much lower risk".
Positive aspects considered included a drop in drug and alcohol misuse and improved messaging around the restrictions. Concerns were expressed about moving social gatherings to other venues - such as households - and making them harder to regulate.
Closure of indoor gyms, leisure centres, and fitness venues
This was found to have a potential reduction in R of up to 0.1, though precise estimation was deemed "very difficult".
Limited access to exercise facilities was deemed likely to have a negative impact on both physical and mental health, with cold winter weather making it harder for people to train outside.
Closure of places of worship/community centres
Closing churches could potentially reduce the R number by 0.1, with it having a direct impact on stopping vulnerable groups from catching the virus.
However, it was noted that closing places of worship could risk social division and anger if they shut ahead of recreational sectors such as pubs and that they also played a role in the community with the likes of foodbanks and childcare.
Closure of non-essential retail
Likely to have a "very minimal impact" on the R number while leading to loss of income for staff and loss of social activity for customers.
The Executive was told the move would improve the consistency of policies, but would require a support package for staff and businesses.
Closure of close-contact personal services (hairdressing, beauty therapy etc.)
The closure of hairdressers and similar outlets was estimated to lower the R number by up to 0.05, but it was noted each visit was likely to be high risk due to the duration of the close contact, but this was mitigated by the infrequency of people visiting such outlets.
Closing these businesses was found likely to disproportionately affect the poorest in society and women typically employed by such outlets and also psychologically affect customers.
Measures aimed at educational settings
Closing all schools could reduce the R number by 0.2-0.5. It was suggested closing secondary schools could be more effective with a reduction in R of 0.35.
However, it highlighted large disruption was likely to the lives of both children and parents.
Closing a whole school in response to an outbreak is likely to lower the R number by 0.12-0.45, while the closure of a class or year group when an outbreak was detected was deemed likely to have a low to moderate impact.
It was suggested alternating week-on, week-off school closure with half class sizes could reduce R by 0.1-0.2.
Closing further education was deemed likely to have a moderate impact, while closing higher education, including universities, was deemed to mean a 0.3 (0.2-0.5) reduction in R given the high likelihood of Covid-19 outbreaks in these settings. Quarantining new higher education students was judged likely to have a low impact.
Closing childcare facilities was deemed to have a low to moderate impact in stopping the spread of the virus.
Prohibition of visitors to hospitals and care homes
This measure was judged likely to have a low impact, with the majority of care home infections deemed to be coming from staff.
Also acknowledged was the high social and emotional impact on care home residents, those receiving end of life care and their relatives.
Shielding of high-risk individuals in their homes
Shielding was judged to have a low impact on stopping the transmission of the virus, with a moderate impact on deaths and hospitalisations.
The Executive was advised that the effects of shielding in the spring were "difficult to assess", but that it was likely to have a substantial social and emotional impact.
Increasing 'Covid security' in workplaces and other settings
This measure was judged to have a low impact as Covid security is "more impactful when social distancing is not in place".
Increasing the benefits from Covid security was deemed unlikely due to the actions already taken by many workplaces and businesses.
Requirement for use of face coverings outdoors
Wearing coverings outdoors was judged to have a "very low impact" on stopping the virus from spreading and it was noted that "anger" existed in the community between those that wear face masks and those who don't.
Concerns were expressed that requiring face coverings to be worn with little benefit could undermine the wearing of them overall.
Extending face coverings to indoor use
Requiring the use of face coverings in more venues was judged to have a low to moderate impact on spreading the virus, but could be beneficial in areas where social distancing is harder or ventilation is poorer.
It was noted the plan could cause issues in primary schools, particularly for pupils with speech or hearing difficulties.
Restricting use of public transport to key workers
This measure is judged to have a low impact and could provide logistics issues due to the requirement of entry points to check key worker status.
Imposing local travel restrictions (e.g. 5-mile limit for non-essential travel)
While this measure was judged to have a low to moderate impact on stopping the spread of the virus it was acknowledged it would cause major difficulties for hospital and care home visits, with "exemptions and enforcement likely to be very complicated".
Restricting travel between UK nations or between subnational regions
While this measure was judged to have a low impact it was noted it could be important around holiday periods when further and higher education students are returning home. Again complications around exemptions and enforcement were acknowledged.