Wednesday, May 26, 2010

MRSA infection rates in Singapore hospitals

TODAY newspaper published a nice article on the efforts made by hospitals to control MRSA infections. The overall infection rates (over 6 public hospitals) have fallen from from 0.4/1000 patient days in 2007 to 0.3/1000 in 2009. Whoohoo...!!


Need to look at this in a bit more detail....

Here are the figures across 6 hospitals (2007-2009):

Year 2007 2008 2009

Overall: 0.4 0.4 0.3
AH 0.2 0.3 0.2
NUH 0.4 0.3 0.1
TTSH 0.5 0.5 0.3
CGH 0.2 0.3 0.2
KKWCH 0.1 0.1 0.1
SGH 0.6 0.6 0.4

Seems like not a clear pattern here. Yes, 3 hospitals showed a drop especially between 2008 and 2009. But a couple of hospitals had numbers bouncing around. And it is unclear if the overall improvement was heavily biased by NUH's spectacular drop in 2009. (I am actually quite appalled that our SGH is the dirtiest....

Actually part of the problem looking at these numbers is the lack of clarity in the definitions used in the collection of data. An earlier report by Straits Times had pointed this out, i.e. if the bug is on the skin when patient is admitted, and an infection occurs, it is not counted as an infection....

I looked at a MOH report by Dr Helen Goh in 2007. She had then defined the rate as being based on the CDC-NNIS methodology:

"The National Nosocomial Infections Surveillance (NNIS) system defines a nosocomial infection as a localized or systemic condition that a) results from adverse reaction to the presence of an infectious agent(s) or its toxin(s) and b) was not present or incubating at the time of admission to the hospital. For most bacterial nosocomial infections, this means that the infection usually becomes evident 48 hours (i.e., the typical incubation period) or more after admission5. The diagnosis of nosocomial infection is thus a combination of clinical findings and results of laboratory and other tests."

Assuming the definitions haven't changed and are consistent across all hospitals (of which I am doubful) ....... we should be able to splice her data with TODAY's info:

Year 2002 2003 2004 2005 2006 2007 2008 2009

Overall: 0.6 0.5 0.5 0.5 0.5 0.4 0.4 0.3
AH 0.3 0.3 0.3 0.2 0.3 0.2 0.3 0.2
NUH 0.8 0.8 0.9 0.8 0.7 0.4 0.3 0.1
TTSH 0.6 0.6 0.6 0.6 0.5 0.5 0.5 0.3
CGH 0.1 0.1 0.1 0.1 0.1 0.2 0.3 0.2
KKWCH 0.1 0.03 0.1 0.1 0.1 0.1 0.1 0.1
SGH 1.0 0.9 0.7 0.8 0.7 0.6 0.6 0.4

Yes, overall the improvement is to be applauded. SGH still looks incredibly filthy. KKWCH looks too good to be true, and CGH actually getting worse.


Anonymous said...

Before you make comments about SGH, you might want to consider the very different patient profile in SGH compared to say KKH. Is it sensible to compare the mortality in an oncology unit to an obstetric unit?

gigamole said... so? Perhaps you might want to enlighten us why you think SGH has more MRSA patients than the other general hospitals. In any case, as i understand it, this data identifies infections picked up from hospital stays rather than those having been brought it by patients.

Anonymous said...

Simple example : renal patients are easily colonized with MRSA (at least 50+ fold chance) for many reasons. SGH sees many more renal patients than anywhere else - maybe 70%+ of Singapore public hospital workload with TTSH and NUH taking up the rest. Ditto for oncology, complex orthopaedic, cardiothoracic, infectious disease, and haematology cases, where immunosuppressed patients, long stays, multiple procedures (all risk factors for MRSA) are the rule rather than the exception.

It's like reporting medical errors. Organizations that look error free are the most suspicious.

gigamole said...

fair 'nuff. I think those inter-hospital comparisons are actually quite silly as clearly the different institutions are apples and oranges. Plus it also depends of the individual hospital's commitment to report/collect good data. However, I am not so sure SGH patient profile is so different from NUH. (I wonder how much data massaging went into that spectacular drop? :) )

Having said that, assuming data definitions are comparable through the years, SGH's improvement has actually been quite impressive. Perhaps just a lot more work needs to be done with respect to those high risk environments you mentioned.

auntielucia said...

Hi Giga: have u ever thought that it's noy possible to get down to 0%? Besides patient profiles, u may want to consider their income profiles, staff profiles and visitor profiles..

And personally, I m not sure if all this washing hands business (there's even a World Hand Washing Day!) isn't more psychological than effective! Consider too what all the washing does to the hands and how much tt ultimately adds to the business at skin centers!

gigamole said...

Yup, not possible to get to zero....but should aim for as low as low can go. This is clearly a multifactorial problem, but to minimize the risk of the mrsa infection hospitals, the hospital has to be very committed to finding a solution.

Although I seem to be taking a dig at the system, actually the hospitals are making a real effort to tackling the problem. From a patient's perspective though, I would really hate to be the one who picks up an mrsa going in for an otherwise innocuous surgery ... and having to pay for it.

Paul said...

Your point on the definitions was spot on!

This is an incidence rate for new infections. When admission screening is rolled out, then there are much fewer new incident infections.

I think this anomaly is being addressed by using prevalence data instead and/or the UK approach of measuring all bloodstream infections

gigamole said...

Reckon they should quickly settle on a uniform and easily understood way of tracking the data. Otherwise it will just be a set of numbers that allows the hospital to pretend to look good.

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