How do you do?

John Rutherford, Dumfries

Or, are you any good doc?

Inputs• Qualifications• Courses• Staffing• Equipment• Protocols• Resuscitation training

Outcomes• Mortality• Complications• Logbooks• Success at techniques• Satisfaction surveys

Success at techniques

• You can record a yes/no for some events

• Intubated or unable, caudal inserted or not

• This can give a percentage result

• We cannot be perfect

• How much failure is acceptable?

Cusum

• Statistical technique

• Move along graph to right each time you do a technique

• Move up if fail

• Move down if succeed

• Upper and lower limits depend on acceptable and unacceptable failure rates

The technical bits…

• p0 acceptable failure rate

• p1 unacceptable failure rate

type 1 error type 2 error

• ln, loge

• h0= -b/(P+Q)• H1= -a/(P+Q)

• a = ln[(1-)/]• b = ln[(1- )/ ]

• P = ln[p1/p0]

• Q = ln[(1-p0)/(1-p1)]

• s = Q/(P+Q)

a 2.944439 attempts success?b 2.944439 1 yP -0.69315 2 yQ 0.117783 3 yh0 5.117523 lower boundry limit 4 yh1 -5.11752 upper boundry limit 5 ys -0.20471 6 y

7 yalpha 0.05 type 1 error 8 ybeta 0.05 type 2 error 9 yp0 0.2 unacceptable failure rate 10 yp1 0.1 acceptable failure rate 11 y

12 y1-s 1.20471 13 yNoofObs 14 y

21 15 y16 y17 y18 y19 y cusum lower boundry limitupper boundry limitattempts20 y -4.09421 5.117523 -5.11752 2021 y22

-6

-4

-2

0

2

4

6

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

lower boundry limit upper boundry limit cusum