Corral 2003.
| Methods | Single‐centre RCT (Spain) | |
| Participants | Quote: “Patients requiring non‐tunnelled insertion of a triple‐lumen central venous catheter (CVC), which remained in place for four or more days, were included in the study.” No exclusion criteria were given | |
| Interventions | SPC‐impregnated CVCs versus non‐impregnated CVCs | |
| Outcomes | Catheter colonization, CRBSI, skin colonization, all‐cause mortality in ICU and number of catheters removed prematurely | |
| Notes | Sources of funding: stated as none | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote: “First, ICU beds were divided randomly in two groups: the control group (CG) received a standard polyurethane catheter and the silver group (SG) an OVSC [Oligon Vantex silver catheter]. Second, nursing staff were rotated between the two groups according to a pre‐designed timetable. To avoid the possible influence of location, the two groups of beds were switched halfway through the study. At ICU admission, patients were allocated to beds by nursing staff, who were unaware of the catheter group assigned to the beds.” It was unclear how the random sequence was generated |
| Allocation concealment (selection bias) | Unclear risk | Quote: “First, ICU beds were divided randomly in two groups: the control group (CG) received a standard polyurethane catheter and the silver group (SG) an OVSC [Oligon Vantex silver catheter]. Second, nursing staff were rotated between the two groups according to a pre‐designed timetable. To avoid the possible influence of location, the two groups of beds were switched halfway through the study. At ICU admission, patients were allocated to beds by nursing staff, who were unaware of the catheter group assigned to the beds.” It was unclear how effective this method of randomization was in achieving concealment of allocation. There was a risk that the nurses who allocated the participants would gain knowledge of the pattern of allocation based on the "catheter type and bed" association after a period of observation, especially since the catheters evaluated were of different appearances |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | There was no specific statement about blinding, although blinding appeared highly unlikely as the catheters evaluated differed in appearance |
| Blinding of outcome assessment (detection bias) Microbiological outcomes like catheter colonization | Unclear risk | The author did not provide any statement about whether the outcome assessors were blinded |
| Blinding of outcome assessment (detection bias) Clinical outcomes like CRBSI | Unclear risk | The author did not provide any statement about whether the outcome assessors were blinded |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Quote: "Complete data were evaluated for 145 patients (83%) and 206 catheters (80%): 103 catheters in each group. The remaining 51 catheters (28 CG [control group] and 23 SG [SPC group]) were not cultured (23 were not cultured after removal as the protocol could not be carried out and 28 remained in place for less than four days)." The high proportion of excluded catheters and the seemingly dubious reasons for their exclusion (for example, violation of protocol and shorter than required indwelling time did not preclude the catheters from being cultured) placed the study at high risk of attrition bias |
| Selective reporting (reporting bias) | Unclear risk | All the major outcomes specified in the Methods were reported in sufficient details in the Results |
| Other bias | Low risk | None identified |