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. 2011 Jul 6;2011(7):CD006207. doi: 10.1002/14651858.CD006207.pub4

Yu 2007.

Methods Case‐control study to analyse the risk factors associated with nosocomial outbreaks of SARS in hospital wards in Guangzhou and Hong Kong, China. The study was designed with the individual hospital wards as the units for data collection and analysis. Case wards were hospital wards in which super spreading events of SARS occurred, and control wards were hospital wards in which patient(s) with SARS were admitted, but no super spreading events occurred. A super spreading event is defined as the development of ≥ 3 new cases of SARS in a ward during the period from 2 to 10 days after the admission of an identifiable index patient or as the development of a cluster of ≥ 3 new cases of SARS in a ward during a period of 8 days but without any known sources of SARS
Participants Eighty‐six wards in 21 hospitals in Guangzhou and 38 wards in 5 hospitals in Hong Kong were included in the study. One ward in Guangzhou and 2 wards in Hong Kong did not participate and they were excluded from the analysis
Interventions Information related to 2 factors was collected: (1) environmental and administrative factors and (2) host factors. Environmental and administrative factors included physical factors, procedural or situational factors, and administrative factors pertaining to each ward. Host factors included symptoms, severity or dependency (for activities of daily living and behaviour changes), treatment or intervention, and comorbidity of the identified index patient in a case ward or in the first patient with SARS admitted in a control ward
Outcomes Laboratory: serological evidence: no
 
 Effectiveness: SARS (no definition)
 
 Safety: N/A
Notes The authors conclude that environmental risk factors were significantly associated with the occurrence of a super spreading event (clustering of ≥ 3 cases) included minimum distance between beds of ≤ 1 m and performance of resuscitation in the ward. Use of BIPAP ventilation and use of oxygen were the significant risk factors associated with the host patient. Of the administrative factors, allowing staff with symptoms to work also increased the risk. Providing adequate washing or changing facilities for staff was protective
 As disaggregate data are not reported we did not extract numerator/denominator data
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Unclear risk N/A
Allocation concealment (selection bias) Unclear risk N/A
Blinding (performance bias and detection bias) 
 All outcomes Unclear risk N/A
Incomplete outcome data (attrition bias) 
 All outcomes Unclear risk N/A
Selective reporting (reporting bias) Unclear risk N/A

AEs: adverse events
 AFH: Armed Forces Hospital
 ARI: acute respiratory infection
 ASR: adverse skin reactions
 A&E: accident and emergency
 BIPAP: Bilevel Positive Airway Pressure
 CCC: Child Care Centre
 CIs: confidence intervals
 CDC: Centers for Disease Control and Prevention
 CMF:citric acid: malic acid: sodium lauryl sulfate (a virucidal mixture added to tissue paper)
 CoV: coronavirus
 C‐RCT: cluster‐randomised controlled trial
 CXR: chest X‐ray
 DCC: daycare centre
 FRI: febrile respiratory illness
 GI: gastro‐intestinal
 HCW: healthcare worker
 HFH: Hanoi French Hospital
 HH: hand hygiene
 HR: high risk
 ICU: intensive care unit
 ILI: influenza‐like illness
 IRR: incident rate ratio
 ITT: intention‐to‐treat
 LRTI: lower respiratory tract infection
 m: metre
 MCU: medical convalescent unit
 MDCK: Madin Darby canine kidney cell line
 MS: monkey‐derived cell line
 N/A: not applicable
 NICU: neonatal intensive care unit
 NOS: Newcastle‐Ottawa Scales
 NTS: National Skin Centre
 OR: odds ratio
 PCR: polymerase chain reaction
 PCU: physical conditioning unit
 PPE: personal protective equipment
 RCT: randomised controlled trial
 RDS: respiratory distress syndrome
 RR: risk ratio
 RTI: respiratory tract infection
 RT‐PCR: reverse‐transcriptase polymerase chain reaction
 RSV: respiratory syncytial virus
 SAB: surfactant, allantoin and benzalkonium chloride
 SARS: severe acute respiratory syndrome
 SD: standard deviation
 SOPs: standard operating procedures
 S/S: signs/symptoms
 SOB: shortness of breath
 SCBU: special care baby unit
 UHR‐I: ultra high‐risk infection
 UHR‐S: ultra high‐risk SARS
 URTI: upper respiratory tract infection
 WBC: white blood cell
 WHO: World Health Organization