Scottish Stroke Audit

1
Scottish Stroke Audit

• 3rd National Meeting
• 7th Dec 04

2
Welcome

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

3
Program

• Comparisons between hospitals
• Control charts
• Demonstration of real time data capture system
• Audit of swallow screening
• Update on MCNs on the Web

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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

5
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

6
Some statistical terms

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

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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?

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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 lt1day 50 or 30
• NHS QIS want 30 figure

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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.

10
Effect of sample size
11
A normal distribution
No. of patients
Mean 10 Median 10
Length of stay in Days
12
Length of stay
Mean 10 Median 10
No of people.
Length of stay (days)
Mean total no. of days / total no. of
people Median LOS where half the people have
longer ones and half shorter ones
13
A skewed distributione.g. length of stay in
acute stroke unit
No.
Mean 7.3 Median 6
Days
14
A very skewed distributione.g. delay to CT scan
No.
Mean 4.9 Median 3
Days
15
Quartiles (quarters)
No.
Mean 10 Median 10
Days
Interquartile range (IQR) (half the patients are
included)
16
Comparisons between hospitals

• A few hospitals which are currently collecting
  data are not included because too few data are
  available.

17
Inpatients
18
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

19
Variable data collection times
20
No. of admissions available for analysis Group 1
Ninewells estimates will have wide Confidence
intervals so differences are more likely to be
due to chance
21
No. of admissions per year Group 1
At Ninewells may be missing cases - not
identified or simply not yet discharged
22
No. of admissions available for analysis Group 2
23
No. of admissions per year Group 2
24
No. of admissions per year Group 3
25
No. of admissions per year -Group 4
The estimate in your hand out for St Johns is
incorrect
26
No. of admissions per year Group 5
27
Length of Stay in HospitalMean MedianGroup
1
Patients with longer LOS in Ninewells not yet
discharged Why is LOS shorter in ARI than
Edinburgh??
28
Length of Stay in HospitalMean MedianGroup
2
Length of Stay in HospitalMean MedianGroup
2
29
Length of Stay in HospitalMean MedianGroup
3
Length of Stay in HospitalMean MedianGroup
3
Two fold difference Monklands Falkirk - why?
30
Length of Stay in HospitalMean MedianGroup
4
Length of Stay in HospitalMean MedianGroup
4
31
Length of Stay in HospitalMean MedianGroup
5
Length of Stay in HospitalMean MedianGroup
5
Imprecise estimates because small
numbers Shetland a different model of service?
32
Proportions admitted to Stroke Unit Group 1
77 beds
42 beds
18 beds
Note the 95 CI vary with amount of data collected
33
Proportions admitted to Stroke Unit Group 2
Ayr Crosshouse are doing well! - ? chance
because only 3 month 7.6-8.3 pts/SU bed/yr cf 14
pts/SU bed/yr in Inverclyde
34
Proportions admitted to Stroke Unit Group 3
24 bed
24 beds
25 beds
30 beds
15 male
35
Proportions admitted to Stroke Unit Group 4
15 beds
14 beds
21 beds
17 beds
8 beds
0 beds
36
Proportions admitted to Stroke Unit Group 5
6 beds
Variable
37
Mean Delay in accessing SU Group 1
38
Mean Delay in accessing SU Group 2
39
Mean Delay in accessing SU Group 3
40
Mean Delay in accessing SU Group 4
X
41
Mean Delay in accessing SU Group 5
X
42
Proportion of admission in Stroke Unit Group 1
Reflects delay in admission entering SU and
exit from SU before discharge
X
43
Proportion of admission in Stroke Unit Group 2
44
Proportion of admission in Stroke Unit Group 3
45
Proportion of admission in Stroke Unit Group 4
X
46
Proportions of admission in Stroke Unit Group 5
X
X
47
Proportions scanned Group 1
ARI seem to be having problems getting scans
48
Proportions scanned Group 2
Delays in Ayr and Crosshouse
49
Proportions scanned Group 3
50
Proportions scanned Group 4
Raigmore and Victoria Hospital Kirkaldy having
problems
51
Proportions scanned Group 5
Shetland understandably not scanning all
patients Western Isles have excellent access to CT
52
Proportion of ischaemic stroke given aspirin
within 2 daysGroup 1
Does ARI perform well because they dont bother
to wait for CT?
53
Proportion of ischaemic stroke given aspirin
within 2 days Group 2
May be bad luck because of small numbers but odd
given excellent access to SU CT - are they
giving an alternative antiplatelet drug?
54
Proportion of ischaemic stroke given aspirin
within 2 days Group 3
55
Proportion of ischaemic stroke given aspirin
within 2 days Group 4
56
Proportion of ischaemic stroke given aspirin
within 2 days Group 5
57
Proportion of ischaemic stroke discharged on
secondary preventionGroup 1
X
Ninewells get most patients on triple therapy
58
Proportion of ischaemic stroke discharged on
secondary prevention - Group 2
59
Proportion of ischaemic stroke discharged on
secondary prevention - Group 3
60
Proportion of ischaemic stroke discharged on
secondary prevention - Group 4
VHK and QMH stand out
61
Proportion of ischaemic stroke discharged on
secondary prevention - Group 5
Statins not used in Western Isles
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Proportions of pts with ischaemic stroke and AF
discharged on Warfarin Group 1
X
Very varied use of warfarin in AF
63
Proportion of ischaemic stroke in AF given
Aspirin or Warfarin Group 2
Where columns add up to gt100 then combination
used?
64
Proportion of ischaemic stroke in AF given
Aspirin or Warfarin Group 3
?
?
Something odd about data from Lanarkshire
65
Proportion of ischaemic stroke in AF given
Aspirin or Warfarin Group 4
66
Proportion of ischaemic stroke in AF given
Aspirin or Warfarin Group 5
Proportion of ischaemic stroke in AF given
Aspirin or Warfarin Group 5
1 patient !
67
Discussion
68
Neurovascular clinics
69
No. of Neurovascular Clinic patients available
for analysis
70
Diagnoses in Neurovascular clinic
71
Diagnoses in Neurovascular clinic
72
Median delay from referral to assessment (days)
73
seen within 14 days of referral
74
Delays from Assessment to Duplex (days)
St Johns reported 3 year data - now
sorted Ninewells RIE get Duplex before clinic
and only few patients
75
Delays from Assessment to Brain scan for stroke
(days)
In some places scans are obtained before clinic
76
Delays from Assessment to Echo for stroke/TIA
(days)
X
X
X
77
Treatment of Definite Ischaemic events with
aspirin
78
of Definite Ischaemic events treated with
Clopidogrel
79
Treatment of Definite Ischaemic events with
aspirin dipyridamole
80
Mean delays from Last event to surgery (days)
81
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

82
Mean delays from Assessment to Duplex (days)
83
Treatment of Definite Ischaemic events with
dipyridamole
84
Treatment of Neurovascular clinic patients with
definite ischaemic events with BP lowering