Compliance with self-isolation and quarantine measures: literature review

Methods

This literature review is based on a process of searching for and assessing material on compliance with self-isolation and quarantine regimes. Searching was carried out between February 2021 and July 2021. A standard literature review has been undertaken, searching for scholarly research from across the globe. A first search was conducted using KandE, a Scottish Government online search engine covering several databases. Subsequently, searching was carried out on Google Scholar, PubMed and ScienceDirect. Search terms included "compliance", "self-isolation", "quarantine", "Covid" and "coronavirus". Further references have been added by means of the snowballing technique, where references in relevant studies are reviewed for additional evidence.

Priority has been given to sources pertaining to the Covid-19 pandemic. However, some work on self-isolation and quarantine regimes adopted during other infectious disease outbreaks has been included when this offered valuable lessons that can be applied to the current public health emergency.

The majority of the sources examined in this review were published between 2020 and 2021, with the exception of literature on other infectious disease outbreaks dating back to 2003.

The body of evidence selected consists of 97 studies. Many of these use robust research methods, both quantitative (such as surveys) and qualitative (such as interviews and focus groups). It has to be noted that not all the scholarly research presented here has been peer-reviewed: some was in the form of pre-prints at the time of the last search (12^th July 2021). Nonetheless, that has been included as the process of formal publication in a scholarly journal can be lengthy and there is a need to see and discuss the available findings immediately, given their potential in helping contain the spread of Covid-19.

The majority of the studies included in this review are based on self-reports of compliance with self-isolation and quarantine regulations. This is a limitation of the evidence base as self-reported evidence is affected both by recall bias (people are likely to overlook their infringement of rules) and social desirability bias (people might not be willing to admit that they have broken the rules). Together with that, there are other risks around self-report: it is likely that less compliant individuals are less knowledgeable about the guidelines and, as a consequence, unable to accurately judge their own compliance; and those who participate in research studies may also have a greater interest in helping tackle the pandemic than the average citizen, hence higher propensity to comply with guidelines^[10].

Although the geographical coverage of the scholarly research material was international, this review was limited to resources in English. This partly justifies the higher number of UK based studies included in this review and reflects the importance of exploring the approaches of the other nations in the UK to self-isolation, given Scotland's context as a 4 nations partner. There is very limited Scotland-specific literature available on self-isolation and quarantine.

Terminology

Technically, self-isolation differs from quarantine as it is the separation of people known to be infected with Covid-19 from those who are not in order to control the spread of the virus. Instead, quarantine is the separation of healthy asymptomatic individuals who have potentially been exposed to a communicable disease with the purpose of monitoring them and seeing whether they develop it. In practice, in the literature the two terms sometimes overlap and may be used in a variety of different ways, making the distinction between them blurred. These ambiguities are evident in the sources examined here, in which the terms 'self-quarantine' and 'confinement' also appear.

In this review, the distinction between the two terms aligns with the definitions adopted in Scotland where the term self-isolation refers to the obligation to stay at home for 10 days for those testing positive for Covid-19 (index cases) and for those who came into contact with them (contact cases) and some international travellers, while quarantine defines the 10-day isolation period spent in a managed hotel observed by other international travellers. The term quarantine is also used for isolation regimes implemented during previous infectious disease outbreaks, as there was no mention of other terms in the related literature.