Patient Safety & Medical Error Dr. Nick SevdalisClinical Safety Research Unit, Imperial CollegeNational Patient Safety Agency

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1. Some terminology Adverse event: injury suffered as a result of

treatment or hospitalisation

Other terms: iatrogenic injury, critical incident, sentinel event, patient safety incident etc

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Incidence: the early years

“…the actual mortality in hospitals…is very much higher than the mortality of the same class of diseases treated outside hospitals”

Florence Nightingale

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Incidence: the last 15 years Epidemiology of error Retrospective record reviews

USA (1991): 3.7% of hospital admissions suffered an adverse event

Australia (1999): 16.6% Denmark (2001): 9% New Zealand (2002): 12.9% Canada (2004): 7.5%

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Incidence: UK Retrospective record review

Vincent et al 2001: 10.8%-11.7%

Voluntary reporting system National Reporting & Learning System (2005): 4.9%

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Consequences: the patient Vincent et al. 1994

“While under anaesthetic they apparently cut a blood vessel in my womb, which led to severe haemorrhage … could only be stopped by giving me a hysterectomy so they say”

“A swelling on my cheek was diagnosed as a malignant tumour and part of my jaw and extensive tissue was removed without my consent. The lab. test showed that it was not a tumour, malignant or benign”

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Consequences: the doctor Christensen 1992

“I was really shaken. My whole feeling of self worth and ability was basically profoundly shaken”

“I was appalled and devastated that I had done this to somebody”

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Consequences: the NHS Vincent et al 2001

119 adverse events 999 extra bed days £290,268 extra costs for the Trusts

An Organisation with a Memory 2001 10,000 reported serious adverse drug reactions NHS pays £400 million in litigation Hospital acquired infections cost nearly £1billion

and 15% are regarded as preventable

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Conclusion

“The medical establishment has become a major threat to health”

Ivan Illich

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2. Definition of error Reason 1992

Failure of achieving the intended outcome in a planned sequence of mental or physical activities not attributable to chance

Error

Slip

correct plan, incorrect execution

Mistake

incorrect plan, correct execution

Violation: deliberate deviation from safe rule

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The person or the system?

The system model

The person model

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Error in the system (i) James Reason

© J. Reason

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Error in the system (ii) James Reason

© J. Reason

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Error in the system (iii) Zhang et al. 2004

Individual Team Organisation National regulations

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Example: error OF a surgeon…

Patient Risk

FactorsOutcomeTechnical skills

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…vs error IN surgery Vincent et al. 2005

Patient Risk

Factors

Individual skills (motor, cognitive etc.)

Teamwork & communication

Operative environment & procedures

Outcome

National regulations

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3. Surgery Multi-disciplinary team

Surgeon, Anaesthetist, Nurse ODA, Scrub Nurse, Circulating Nurse

Emergency or elective

Process Called from ward Put to sleep operation

recovery return to ward (discharge)

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Individual skills: decision-making Aims:

What does the decision-making process look like? Can we assess it reliably?

Methods: Management of patients with symptomatic

gallstone disease Interviews with 10 experienced surgeons Content-analysed by two reviewers

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Decision map

Average = 15.5 decisions/interview

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Cue utilisation Risk of conversion of a closed (i.e., key-hole)

cholecystectomy to an open one Methods: judgement analysis

Actual risk of conversion

Surgeon

observer

Cues

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Results (ii)Participant R2 Cues

1 0.758 Previous surgery, Biliary history, Age/co-morbidity

2 0.733 Biliary history, Previous surgery, Obesity

3 0.364 Previous surgery, Biliary history, Age/co-morbidity

4 0.650 Previous surgery, Biliary history, Obesity

5 0.603 Previous surgery, Biliary history, Race

6 0.388 Biliary history

7 0.613 Previous surgery, Biliary history, Age/co-morbidity

8 0.501 Previous surgery, Biliary history, Age/co-morbidity

9 0.434 Previous surgery, Biliary history

10 0.673 Previous surgery, Biliary history

11 0.397 Previous surgery, Age/co-morbidity, Obesity

12 0.649 Previous surgery, Biliary history

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Results (iii)

Spread of Beta weights for each cue

-0.2

0

0.2

0.4

0.6

0.8

1

Cue

Sta

nd

ard

ized

Bet

a w

eig

ht 1

2

3

4

5

6

7

8

9

10

11

12

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Teamwork Aims: Can we apply a model of surgical teamwork to the

surgical team? Tasks: Equipment, Patient, Communication Behaviours: Communication, Co-operation, Co-ordination, Leadership,

Monitoring/Awareness

Methods 50 general surgery and 50 urology procedures 3 operative stages (pre, intra-, and post-operative)

Task completion rates Behaviour ratings

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Results (i)Task Pre-op Op Post-op

Surg Urol Surg Urol Surg Urol

Equip 56% 61% 82% 91% 89% 95%

Comm 61% 71% 55% 57% 90% 84%

Patient 90% 94% 93% 93% 97% 92%

Overall 69% 77% 77% 80% 92% 90%

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Results (ii) Observed behaviours

1

2

3

4

5

6

communication coordination leadership monitoring cooperation

rati

ng

sc

ale

pre intra post

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Operative environment Operative environment:

Physical features Human element: distractions, interruptions

Aims: Can we observe the distractions/interruptions that occur during a typical procedure?

Methods 50 general surgery procedures Distraction types

Door openings, auditory, visual, operational

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Results (i)Absolute frequency of interference = 663 (13.26/operation)

Mean frequency of door opening during operations as a proportion of OP stage duration

0

0.25

0.5

0.75

1

OP1 OP2 OP3

Stage of operation

Fre

qu

en

cy p

er

min

ute

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Results (ii) Case-irrelevant communications (N = 167)

05

101520253035404550

ab

so

lute

fre

qu

en

cy

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National regulations 27 different crash call numbers in UK

hospitals (!)

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Conclusion: Error in the surgical system

Individual Team Organisation National regulations

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4. Conclusions Medical errors occur

Medical errors are costly

We are starting to understand their milieu Physical Human

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Future Basic research

Put some more flesh on the systems view of error Interdisciplinarity Funding: medium- to long-term projects

Interventions Common sense

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Thank you for your attention!

Questions, comments?