Hospital mortality league tables: influence of place of death
http://www.100md.com
《英国医生杂志》
1 Unit of Health-Care Epidemiology, Department of Public Health, University of Oxford, Oxford OX3 7LF
Correspondence to: V Seagroatt valerie.seagroatt@dphpc.ox.ac.uk
Introduction
Dr Foster Ltd has published in-hospital death rates for 167 acute NHS hospital trusts (hereafter termed hospitals) in England over the three year period April 1999 to March 2002.1-5 The denominators were the number of episodes of admission to each hospital, as recorded in the hospital episode statistics system, and the numerators were the number of these episodes that ended in death. The rates were standardised by age, sex, source of admission, length of stay, and diagnosis, expressed relative to the rate for all hospitals combined, multiplied by 100, and termed hospital standardised mortality ratios (HSMRs). The report highlighted 15 hospitals with the highest and 15 with the lowest mortality ratios. The investigators showed that the probability of these being in the top or bottom 15 was not attributable to random error. We used data on these hospitals for our analysis but excluded London hospitals because of difficulty in determining their catchment areas. This left 11 hospitals with high ratios and nine with low ratios.
Statistics on place of death (NHS hospital, hospice, home, etc) of residents of different areas are published routinely.4 These were available for two of the three years on which the published hospital league tables were based (1999 and 2000). We used hospital episode statistics to identify the individual health authorities that corresponded most closely to the catchment area of the 20 selected hospitals, and we used the published figures on place of death to calculate the percentage of deaths of residents of each catchment area that occurred in NHS hospitals. We then adjusted the published HSMRs to allow for geographic differences in the percentages of deaths occurring in hospital in the hospitals' catchment areas. We did this by scaling down the values when proportionately more deaths of residents occurred in NHS hospitals compared with England as a whole and scaling up those when proportionately fewer deaths occurred in hospital. For instance, for every 1000 deaths of residents of Walsall Health Authority, on average 623 occurred in NHS hospitals. For England overall, the average was 546. We reduced the published HSMR for the Walsall hospitals, 126, by the scaling factor 0.88 (546/623), which gave an adjusted HSMR of 110.
The percentages of deaths of residents of health authorities that occurred in NHS hospitals varied from less than 45% in Plymouth and West Sussex to over 60% in Walsall and Sandwell (figure, and see table on bmj.com). In most cases the adjustment brought the HSMRs closer together and closer to 100. It also changed the rankings.
Comment
The good hospital guide. 6 April 2003. www.timesonline.co.uk (accessed 1 Aug 2003).
Ellis R. The Good Hospital Guide 2002. A deadly lottery: you are twice as likely to die at the worst hospitals. Mail on Sunday 2002 March 10.
Jacobson B, Mindell J, McKee M. Hospital mortality league tables. BMJ 2003;326: 777-8.
Review of the registrar general on deaths in England and Wales, 2000. Norwich: Stationery Office, 2000. (DH1, No 33.)
Hospital guide. www.drfoster.co.uk (accessed 1 Aug 2003).(Valerie Seagroatt, univer)
Correspondence to: V Seagroatt valerie.seagroatt@dphpc.ox.ac.uk
Introduction
Dr Foster Ltd has published in-hospital death rates for 167 acute NHS hospital trusts (hereafter termed hospitals) in England over the three year period April 1999 to March 2002.1-5 The denominators were the number of episodes of admission to each hospital, as recorded in the hospital episode statistics system, and the numerators were the number of these episodes that ended in death. The rates were standardised by age, sex, source of admission, length of stay, and diagnosis, expressed relative to the rate for all hospitals combined, multiplied by 100, and termed hospital standardised mortality ratios (HSMRs). The report highlighted 15 hospitals with the highest and 15 with the lowest mortality ratios. The investigators showed that the probability of these being in the top or bottom 15 was not attributable to random error. We used data on these hospitals for our analysis but excluded London hospitals because of difficulty in determining their catchment areas. This left 11 hospitals with high ratios and nine with low ratios.
Statistics on place of death (NHS hospital, hospice, home, etc) of residents of different areas are published routinely.4 These were available for two of the three years on which the published hospital league tables were based (1999 and 2000). We used hospital episode statistics to identify the individual health authorities that corresponded most closely to the catchment area of the 20 selected hospitals, and we used the published figures on place of death to calculate the percentage of deaths of residents of each catchment area that occurred in NHS hospitals. We then adjusted the published HSMRs to allow for geographic differences in the percentages of deaths occurring in hospital in the hospitals' catchment areas. We did this by scaling down the values when proportionately more deaths of residents occurred in NHS hospitals compared with England as a whole and scaling up those when proportionately fewer deaths occurred in hospital. For instance, for every 1000 deaths of residents of Walsall Health Authority, on average 623 occurred in NHS hospitals. For England overall, the average was 546. We reduced the published HSMR for the Walsall hospitals, 126, by the scaling factor 0.88 (546/623), which gave an adjusted HSMR of 110.
The percentages of deaths of residents of health authorities that occurred in NHS hospitals varied from less than 45% in Plymouth and West Sussex to over 60% in Walsall and Sandwell (figure, and see table on bmj.com). In most cases the adjustment brought the HSMRs closer together and closer to 100. It also changed the rankings.
Comment
The good hospital guide. 6 April 2003. www.timesonline.co.uk (accessed 1 Aug 2003).
Ellis R. The Good Hospital Guide 2002. A deadly lottery: you are twice as likely to die at the worst hospitals. Mail on Sunday 2002 March 10.
Jacobson B, Mindell J, McKee M. Hospital mortality league tables. BMJ 2003;326: 777-8.
Review of the registrar general on deaths in England and Wales, 2000. Norwich: Stationery Office, 2000. (DH1, No 33.)
Hospital guide. www.drfoster.co.uk (accessed 1 Aug 2003).(Valerie Seagroatt, univer)