Extent, nature and consequences of adverse events: results of a retrospective casenote review in a large NHS hospital.
OBJECTIVE
To estimate the extent, nature and consequences of adverse events in a large National Health Service (NHS) hospital, and to evaluate the reliability of a two-stage casenote review method in identifying adverse events.


METHODS
A two-stage structured retrospective patient casenote review.


METHODS
A large NHS hospital in England.


METHODS
A random sample of 1006 hospital admissions between January and May 2004: surgery (n = 311), general medicine (n = 251), elderly (n = 184), orthopaedics (n = 131), urology (n = 61) and three other specialties (n = 68).


METHODS
Proportion of admissions with adverse events, the proportion of preventable adverse events, and the types and consequences of adverse events.


RESULTS
8.7% (n = 87) of the 1006 admissions had at least one adverse event (95% CI 7.0% to 10.4%), of which 31% (n = 27) were preventable. 15% of adverse events led to impairment or disability which lasted more than 6 months and another 10% contributed to patient death. Adverse events led to a mean increased length of stay of 8 days (95% CI 6.5 to 9). The sensitivity of the screening criteria in identifying adverse events was 92% (95% CI 87% to 96%) and the specificity was 62% (95% CI 53% to 71%). Inter-rater reliability for determination of adverse events was good (kappa = 0.64), but for the assessment of preventability it was only moderate (kappa = 0.44).


CONCLUSIONS
This study confirms that adverse events are common, serious and potentially preventable source of harm to patients in NHS hospitals. The accuracy and reliability of a structured two-stage casenote review in identifying adverse events in the UK was confirmed.
Sari
Ali Baba-Akbari
AB
Department of Health Management and Economics, School of Public Health, University of Medical Sciences, Tehran, Iran.
Sheldon
Trevor A
TA
Cracknell
Alison
A
Turnbull
Alastair
A
Dobson
Yvonne
Y
Grant
Celia
C
Gray
William
W
Richardson
Aileen
A
D004739:England / Q000453:epidemiology; D005853:Geriatrics; D006779:Hospitals, Public / Q000592:standards* / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay; D008485:Medical Audit / Q000379:methods*; D019300:Medical Errors / Q000009:adverse effects / Q000145:classification / Q000401:mortality / Q000706:statistics & numerical data*; D008511:Medicine / Q000592:standards* / Q000706:statistics & numerical data; D009985:Orthopedics; D010043:Outcome and Process Assessment, Health Care / Q000379:methods*; D015995:Prevalence; D012189:Retrospective Studies; D017751:Safety Management; D013038:Specialization; D013222:State Medicine / Q000592:standards; D013503:Surgery Department, Hospital; D014572:Urology