Effectiveness of workplace social distancing measures in reducing influenza transmission: a systematic review

BMC Public Health

Table 2 Risk of bias in epidemiological studies of workplace social distancing, 2000–2017^*

First author, year published	Outcome	Confounding	Selection	Intervention classification	Intervention deviations	Missing data	Outcome measurement	Reported results	Overall
Rousculp, 2010 [27]	Attend work with severe ILI	Moderate^a	Low	Low	Low	Low	Moderate^b	Serious^c	Serious
Kumar, 2012 [28]	ILI	Serious^d	Low	Moderate^e	Low	Moderate^f	Moderate^b	Low	Critical
Lee, 2010 [29]	Seroconversion to 2009 influenza A(H1N1)	Serious^d	Low	Low	Low	Low	Low	Low	Serious

Abbreviations: ILI influenza-like illness
*Assessed using the Risk of Bias in Epidemiological Studies of Interventions (ROBINS-I) tool. Risk of bias for each domain is classified into four categories: low (study is comparable to a well performed randomized trial), moderate (study is sound for a non-randomized study but cannot be considered comparable to a well performed randomized trial), serious (study has some important problems), and critical (study is too problematic to provide any useful evidence on the effects of intervention)
^aA nonrandomized study is rarely at low risk of bias for confounding
^bSubjective outcome self-reported by participants who were aware of the intervention group
^cResults for attending work with ILI symptoms of any severity are not reported
^dInadequate or no adjustment
^eIntervention status was determined retrospectively
^fResponse rate was 56%