There are pros and cons of increasing the proportion of single rooms. One of the commonly-cited pros is a reduction in HCAI. A recent UK study provides some evidence that C. difficlie infection, and MSSA / E. coli BSIs are not reduced by a move to a hospital with more single rooms, but that norovirus control is more effective when you have more single rooms.
A large UK NHS Trust moved from a multi-site old style hospital with a mixture of Nightingale wards and wards comprised of bays and single rooms with 10% single rooms overall, to a new hospital on a single site with 75% single rooms. The study design was simple: did the move result in a reduction in the rate of healthcare-associated C. difficile infection, MSSA and E. coli BSI, and number of wards closed and bed days lost for norovirus over 3 years before the move compared with 2 years after the move?
The findings are rather equivocal. The incidence of HA-CDI and E. coli BSI declined markedly when comparing the years before vs. after the move. However, the time series analysis could not detect a significant change in rate of decline, or a step-change in rate at the time of the move. This suggests that the incidence of these organisms reduced over the study period for reasons other than the introduction of a hospital with more single rooms. There was no movement in the rate of MSSA BSI over the study period. However, the number of ward closures and bed day losses due to norovirus was strikingly lower after the move to the new hospital. I found the lack of a chart especially challenging in interpreting the data reported in the study!
The findings of this study are reminiscent of a study published in the NEJM in the early 1980s (Maki et al.), which was a similar ‘natural experiment’ evaluating the impact of a hospital move on the rate of HCAI. The Maki study found that moving to a new hospital (and therefore the role of the environment) made no impact on endemic HCAI – and this view stood for a couple of decades! On the face of it, this study supports the idea that moving to single rooms does not reduce HCAI, but I don’t think that it can be seen as the definitive study on this topic, because:
- There is no control group (what else changed during this period?).
- The move was not only to a building with more single rooms, but to a new building with a different layout and very probably different staffing levels.
- Were the right indicators of HCAI included? If we were looking to make any conclusions about the role of single room in preventing HCAI, we’d need to know about the acquisition of colonisation with key pathongens, not sure CDI and BSI. (Worth noting that many BSIs have an endogenous source…)
- There was a marked reduction in norovirus ‘activity’ in the hospital. Whilst norovirus incidence is notoriously volatile from season to season, the reduction was striking (although, remember, no control group).
- There are studies with a much better design that do demonstrate a significant reduction in HCAI associated with a more to single rooms. The best example of this is a controlled study by Teltsch et al., who found that moving to an ICU with 100% single rooms resulted in a significant reduction in pathogens associated with ‘exogenous’ transmission and no reduction in pathogens associated with ‘endogenous’ transmission.
- There was no data to show that the level of compliance with basic IPC practice remained unchanged (e.g. hand hygiene compliance rates, such as they are).
Since this study used nationally reported data, it’s also possible to do something similar on a national level using Fingertips. If you hypothesise that more single rooms = less HCAI, then you ought to see a correlation between the proportion of single rooms in a hospital and the rate of HCAI. However, the Figure below shows that there is no meaningful correlation between the rate of healthcare-associated C. difficile and hospital-onset E. coli BSI and the proportion of single rooms in NHS hospitals. This crude comparison is perhaps confounded by the different types of NHS hospitals (e.g. specialist acute vs. district general vs. academic teaching), but is thought-provoking nonetheless.
Figure: Rate of (a) Trust-apportioned (healthcare-associated) C. difficile and (b) hospital onset E. coli BSI by acute NHS Trust plotted against the proportion of single rooms with ensuite facilities.
(a) Trust-apportioned (healthcare-associated) C. difficile. R2 = 0.04.
(b) Hospital-onset E. coli BSIs. R2 = 0.03.
In summary then, this study and my dabble on Fingertips support that the proportion of single rooms is not the critical factor in the key HCAI metrics reported nationally. Whilst I am not surprised to see this for the BSIs, I am a little surprised to see this for C. difficile. However, given the rudimentary design of these experiments, we need properly controlled studies before coming to firm conclusions.