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Hospital acquired infection

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The burden that hospital-acquired infection places on the NHS has been starkly highlighted by a new report, whose highly readable executive summary is available as a pdf file [1].


Four thousand patients with a hospital stay of over 30 hours from medical, surgical, orthopaedic, urology, gynaecology, ENT, elderly care and obstetric (Caesarean section) units of a district general hospital were recruited over a 13 month period ending in May 1995. Complete inpatient data was available for 3980 of them with information on daily resource use. Patients who met preset definitions of hospital acquired infection (215 patients), and a sample of those who did not (1234 patients) were followed up post discharge with a questionnaire. The response rate was 71%. Data were excluded from 41 patients who died up to eight weeks after discharge, four of whom had a hospital acquired infection.


In hospital 7.8% of patients had one or more hospital acquired infections. After discharge, 19% of patients without a previously identified infection reported symptoms or treatment that met the criteria for an infection of urinary tract, chest or surgical wound.

During their stay in hospital, 13% of patients with a hospital acquired infection died, compared with 2% who did not acquire infection in hospital. Adjusted for age, sex, co-morbidity and other factors, the death rate was 7.1 (95%CI 4.3 to 11.7) times higher for infected than for uninfected patients.

The mean length of stay was eight days for uninfected patients. It was considerably longer for those with infections of any type (Figure 1). The mean cost of treatment was £1628 for uninfected patients. It was considerably greater for those with infections of any type (Figure 2).

Figure 1: Effect of hospital acquired infection on length of stay

Figure 2: Effect of hospital acquired infection on cost of treatment


Overall, hospital acquired infection resulted in an extra 14 days in hospital, a 10% chance of dying, an extra £3154 spent on healthcare and six extra days off work (Table). The study concluded that the economic burden of hospital acquired infection was about £1 billion a year for the NHS in England and affects 1 in 10 patients. The total number of bed days consumed by hospital acquired infection was estimated at about 3.6 million a year, or equivalent to about 27 400-bed hospitals working at 90% capacity.

Costs and consequences of hospital acquired infection
  No HAI HAI HAI effect
Mean costs (£) 1628 4782 3154
Mean stay (days) 8 22 14
Deaths (%) 2 13 11
Mean admission to work (days) 23 29 6

By any standards, this is stunning stuff from a detailed, large, and well conducted study. Even more stunning is the estimate that hospital acquired infection may kill about 5000 people a year in the UK. Bandolier 67 carried information about how simple handwashing protocols reduced hospital acquired infection by about half. Searching for other literature about mechanisms of preventing the problem did not provide anything of note, but perhaps we looked in the wrong place. Bandolier and ImpAct would like to hear from organisations that have tackled this successfully.


1 R Plowman et al. The socio-economic burden of hospital acquired infection. Executive summary at
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