scottish stroke audit

Scottish Stroke Audit

3rd National Meeting7th Dec 04

Welcome

• NHS QIS funded audit - Oct 02 - 05• Original plan - 6 to 10 hospitals• Impact of CHD & Stroke strategy• NHS QIS standards and visits

Program

• Comparisons between hospitals • Control charts • Demonstration of real time data capture

system• Audit of swallow screening• Update on “MCNs on the Web”

How can these data help improve patient care?

• Identify variation in “performance” and to raise questions about cause of variation

• Identify methods which increase performance?

• Highlight services requiring more investment or re design

Reasons for variation in “Performance”

• Method of collection data• Definitions, case ascertainment and audit period

• Method of analysing data• Which numerator and denominator? • Chance• Actual performance of service

Some statistical terms

• Proportions (%)• 95% confidence intervals • Means and medians• Inter quartile range

Proportions

• Numerator / Denominator = Proportion• 100 patients admitted• 60 enter stroke unit• Proportion is 60/100 = 0.6 or 60%• We have had problems with denominators• NHS QIS ask % admitted SU within 1 day• Is denominator 60 or 100?

Denominators

• If admit 100 stroke patients• 60 enter the stroke unit• therefore 60% managed in a stroke unit• if half get into stroke unit within a day• % admitted to SU <1day = 50% or 30%• NHS QIS want 30% figure

95% confidence intervals• Measure the proportion entering your stroke

unit once• Calculate the 95% Confidence intervals• Measure the proportion a further 100 times

and one would expect 95 estimates to lie within the 95% confidence intervals.

Effect of sample size

No. instroke unit

No. ofstrokes

admitted

% instroke unit

95%confidenceintervals

12 20 60 36 - 81%

60 100 60 50 - 70%

300 500 60 56 - 64%

A normal distribution

02468

101214161820

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

Mean = 10Median = 10

Length of stay in Days

No. ofpatients

Length of stay


02468

101214161820

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

Length of stay (days)

No of people.

Mean = total no. of days / total no. of peopleMedian = LOS where half the people have longer ones and half shorter ones

A skewed distributione.g. length of stay in acute stroke unit

02468

101214161820

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

Mean = 7.3Median = 6

Days

No.

A very skewed distributione.g. delay to CT scan

02468

101214161820

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

Mean = 4.9Median = 3

Days

No.

Quartiles (quarters)

02468

101214161820

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


Days

No.

Interquartile range (IQR)(half the patients are included)

Comparisons between hospitals

A few hospitals which are currently collecting data are not included

because too few data are available.

Inpatients

Data collection periods vary

• Longer period will provide more patients and more precise estimates

• Longer period will include older data• Recent short period will not include patients

still in hospital - therefore may give biased estimates

Variable data collection times

RIE, Edinburgh 12 monthsWGH, Edinburgh 12 monthsNinewells 6 monthsAberdeen (ARI) 12 monthsAyr 3 monthsCrosshouse 3 monthsPaisley (RAH) 21 monthsInverclyde (IRH) 15 months

No. of admissions available for analysis – Group 1

0

200

400

600

800

1000

1200

RIE WGH Ninewells ARI

All ptsStroke pts

Ninewells estimates will have wide Confidence intervalsso differences are more likely to be due to chance

No. of admissions per year Group 1

0

100

200

300

400

500

600

700

800


Stroke pts

At Ninewells may be missing cases - not identified orsimply not yet discharged

0100200300400500600700800

Ayr

Crossh

ouse

Inver

clyde

RAHDGRI

All ptsStroke pts

No. of admissions available for analysis – Group 2

0

100

200

300

400

500

600

700

800

Ayr Crosshouse Inverclyde RAH DGRI

Stroke

No. of admissions per year – Group 2


0

100

200

300

400

500

600

700

800

Hairmyres Monklands Wishaw Falkirk Stirling

Stroke

No. of admissions per year -Group 4

0100200300400500600700800

Borders

St Joh

nsPert

h

Raigmor

eVH

QMH

Stroke pts

The estimate in your hand out for St Johns is incorrect


0102030405060708090

100

Oban VOL Shetland Western Isles

Stroke

Length of Stay in HospitalMean Median

Group 1

0

10

20

30

40

50

60

70

RIE WGH Ninewells ARIPatients with longer LOS in Ninewells not yet dischargedWhy is LOS shorter in ARI than Edinburgh??


Group 2

0

10

20

30

40

50

60

70



Group 2


Group 3

0

10

20

30

40

50

60

70



Group 3

Two fold difference Monklands & Falkirk - why?


Group 4

0

10

20

30

40

50

60

70

BGH St Johns Perth Raigmore VHK QMH


Group 4


Group 5

0

10

20

30

40

50

60

70



Group 5

Imprecise estimates because small numbers

Shetland a different model of service?

Proportions admitted to Stroke Unit – Group 1

0102030405060708090

100


Note the 95% CI vary with amount of data collected

77 beds 42 beds

18 beds


0102030405060708090

100


Ayr & Crosshouse are doing well! - ? chance because only 3 month7.6-8.3 pts/SU bed/yr cf 14 pts/SU bed/yr in Inverclyde

35 beds 43 beds

16 beds30 beds

10 beds


0102030405060708090

100


24 beds24 bed

25 beds 30 beds

15 male


0102030405060708090

100

Borders St Johns Perth Raigmore VH QMH

17 beds

15 beds

8 beds

0 beds

21 beds

14 beds


0102030405060708090

100


6 bedsVariable

Mean Delay in accessing SU – Group 1

0

2

4

6

8

10

12



0

2

4

6

8

10

12



0

2

4

6

8

10

12


X

Proportion of admission in Stroke Unit – Group 1

0102030405060708090

100


X

Reflects delay in admission% entering SU and exit from SU before discharge


0102030405060708090

100



0102030405060708090

100


X

Proportions of admission in Stroke Unit – Group 5

0102030405060708090

100


X X

Proportions scanned – Group 1

0102030405060708090

100


Scanned<=2days<=7days

ARI seem to be having problems getting scans


0102030405060708090

100

Scanned<=2days<=7 days

Delays in Ayr and Crosshouse


0102030405060708090

100

Scanned<=2 days<=7 days


0102030405060708090

100

Scanned<=2 days<=7 days

Raigmore and Victoria Hospital Kirkaldy having problems


0102030405060708090

100

Oban VOL Shetland WesternIsles

Scanned<= 2 days<= 7days

Shetland understandably not scanning all patientsWestern Isles have excellent access to CT

Proportion of ischaemic stroke given aspirin within 2 days

Group 1

0

10

20

30

40

50

60

70

80


Aspirin

Does ARI perform well because they don’t bother to wait for CT?

0

10

20

30

40

50

60

70

80


Proportion of ischaemic stroke given aspirin within 2 days–

Group 2

May be bad luck because of small numbers but odd given excellentaccess to SU & CT - are they giving an alternative antiplatelet drug?

0

10

20

30

40

50

60

70

80



Group 3


Group 4

0

10

20

30

40

50

60

70

80



Group 5

0

10

20

30

40

50

60

70

80


Proportion of ischaemic stroke discharged on secondary prevention

Group 1

0102030405060708090

100


AntithromboticStatinBP

X

Ninewells get most patients on triple therapy

0102030405060708090

100


Proportion of ischaemic stroke discharged on secondary

prevention - Group 2



0102030405060708090

100




0102030405060708090

100

Borders

St Joh

nsPert

h

Raigmor

eVH

QMH


VHK and QMH stand out



0102030405060708090

100


Statins not used in Western Isles

Proportions of pts with ischaemic stroke and AF discharged on

Warfarin – Group 1

0102030405060708090

100


WarfarinAntiplatelet

X

Very varied use of warfarin in AF

0102030405060708090

100


Proportion of ischaemic stroke in AF given Aspirin or

Warfarin– Group 2WarfarinAntiplatelet

Where columns add up to >100 then combination used?


Warfarin– Group 3

0102030405060708090

100



? ?Something odd about data from Lanarkshire


Warfarin– Group 4

0102030405060708090

100




Warfarin– Group 5

0102030405060708090

100




Warfarin– Group 5

1 patient !

Discussion

Neurovascular clinics

No. of Neurovascular Clinic patients available for analysis

0100200300400500600700800900

1000

RIEW

GH

Ninewell

sAyr

Crossh

ouse

Inver

clyde

RAHDGRI

St Joh

nsVHK

QMH

Straca

throOban

Diagnoses in Neurovascular clinic

010203040506070

RIEW

GH

Ninewell

sAyr

Crossh

ouse

Inver

clyde

RAH

StrokeTIAEyeOther

Diagnoses in Neurovascular clinic

010203040506070

DGRI

St Joh

nsVHK

QMH

Straca

throOban

StrokeTIAEyeOther

Median delay from referral to assessment (days)

01020304050607080

RIEW

GH

Ninewell

sAyr

Crossh

ouse

Inver

clyde

RAHDGRI

St Joh

nsVHK

QMH

Straca

throOban

% seen within 14 days of referral

0102030405060708090

100

RIEW

GH

Ninewell

sAyr

Crossh

ouse

Inver

clyde

RAHDGRI

St Joh

nsVHK

QMH

Straca

throOban

Delays from Assessment to Duplex (days)

0

5

10

15

20

25

30

RIEW

GH

Ninewell

sAyr

Crossh

ouse

Inver

clyde

RAHDGRI

St Joh

nsVHK

QMH

Straca

throOban

MeanMedian

St Johns reported 3 year data - now sortedNinewells & RIE get Duplex before clinic and only few patients

Delays from Assessment to Brain scan for stroke (days)

0

5

10

15

20

25

30

RIEW

GH

Ninewell

sAyr

Crossh

ouse

Inver

clyde

RAHDGRI

St Joh

nsVHK

QMH

Straca

throOban

MeanMedian

In some places scans are obtained before clinic

Delays from Assessment to Echo for stroke/TIA (days)

01020304050607080

RIEW

GH

Ninewell

sAyr

Crossh

ouse

Inver

clyde

RAHDGRI

St Joh

nsVHK

QMH

Straca

throOban

MeanMedian

XX X

Treatment of Definite Ischaemic events with aspirin

0102030405060708090

100

RIEW

GH

Ninewell

sAyr

Crossh

ouse

Inver

clyde

RAHDGRI

St Joh

nsVHK

QMHOban

At eventAssessmentRecommended

% of Definite Ischaemic events treated with Clopidogrel

0

5

10

15

20

25

Treatment of Definite Ischaemic events with aspirin & dipyridamole

01020304050607080

Mean delays from Last event to surgery (days)

1

10

100

WGH RAH DGRI

Conclusions

• We have seen considerable variation in the processes of care

• We need to understand these to strive to provide the best possible service for all

• No hospital can be complacent - there is room for improvement everywhere

Mean delays from Assessment to Duplex (days)

0.1

1

10

100

Mean

Treatment of Definite Ischaemic events with dipyridamole

01020304050607080


Treatment of Neurovascular clinic patients with definite ischaemic

events with BP lowering

0

20

40

60

80

100

120

RIEW

GH

Ninewell

sAyr

Crossh

ouse

Inver

clyde

RAHDGRI

St Joh

nsVHK

QMHOban


scottish stroke audit

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