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. 2020 Apr 15;2020(4):CD011621. doi: 10.1002/14651858.CD011621.pub4

Hall 2018.

Study characteristics
Methods Simulation study, non‐randomised cross‐over study
How was the simulation performed?
Prior to donning PPE volunteers were screened using Fluorescence Interactive Video Exposure System (FIVES) to ensure that there was no pre‐existing contamination on their skin or scrubs from the environment, previous tests or background fluorescence. Over disposable scrubs volunteers then donned the PPE ensembles under supervision by a buddy, and they were screened again prior to beginning the simulation exercise. After completing the exercise, volunteers were screened front and back using the FIVES system to qualitatively record contamination resulting from the simulation. PPE was then removed according to protocol under the supervision of a buddy, and screening was repeated to detect any post‐doffing contamination.
How was the exposure simulated?
'Violet' (Visualising Infection with Optimised Light for Education and Training) was a medical training manikin adapted to deliver simulants of 4 fluorochrome‐tagged body fluids during a scenario based on a doctor and nurse undertaking clinical procedures with a suspected‐case patient.
Participants N = 11 (7 nurses, 4 doctors)
Volunteer healthcare providers were recruited via calling notices at the participating Infectious Disease (ID) units, gave informed consent and were free to withdraw at any time. 11 volunteers completed the simulation exercise up to 10 times depending on their availability. 5 volunteers (including 1 further doctor and nurse) acted as 'buddies' to assist with doffing. All volunteers were experienced in using the PPE ensembles adopted by their respective ID units, but if they used an ensemble from another unit, they had to undergo training to practice donning and doffing 10 times or until deemed competent by a staff trainer. Limiting the number of volunteers reduced user attributable variation.
Interventions Intervention: different types of PPE compared
5 'suspected case' PPE ensembles used in different infectious disease units around the UK. All models met the guidance of the Advisory Committee on Dangerous Pathogens endorsed by Public Health England. PPE components met their relevant material standards. All were donned and dry‐doffed according to the specific protocol relevant to the ensemble. The PPE ensembles varied but could broadly be grouped as a 'gown model' or a 'coverall model' but each had slight differences (e.g. use of hood vs surgical cap, boots vs boot covers, and different glove lengths and number of pairs).
Control: basic‐level PPE (surgical mask, standard length apron, 1 pair short gloves, no standard footwear, scrubs and no buddy used for doffing)
Outcomes Contamination: fluorescent areas seen on skin or scrubs of the volunteer post‐doffing
Notes Location: UK; no conflict of interested reported; funding was provided by Health and Safety Executive (HSE); Bozena Poller was funded by the Healthcare Infection Society’s Graham Ayliffe Training Fellowship
Risk of bias
Bias Authors' judgement Support for judgement
Confounding NRS Low risk Differences related to:
  1. prior experience with PPE ‐ no

  2. healthcare qualification or education of HCW ‐ yes (nurses or physicians)

  3. age ‐ no information

  4. sex ‐ no information

  5. ambient temperatures ‐ no (restricted to 1 centre)

  6. stressful activities ‐ no (all performed similar tasks)

Selection Bias NRS Low risk Cross‐over trial; 11 participants did the simulation up to 10 times
Blinding of participants and personnel (performance bias)
All outcomes Low risk Participants knew which PPE they had on but it is unlikely that they could have influenced the outcome, which was an objective assessment by an observer.
Blinding of outcome assessment (detection bias)
All outcomes Unclear risk The judgement of the contamination is subjective and the assessors were aware of the type of equipment but it is unclear if this could have influenced the outcome assessment
Incomplete outcome data (attrition bias)
All outcomes Unclear risk Quote: "This resulted in a non‐trained volunteer participating in the role of the nurse for 1 simulation; their data were excluded from the final analysis, but their participation allowed data to be captured for their doctor partner. In total, 19, suspected case simulations captured 37 volunteers."
Selective reporting (reporting bias) Unclear risk No protocol provided
Other bias Low risk No other biases detected