|
Practices (n)
|
Records reviewed per practice (n)
|
Estimation error (%)$
|
|---|
| | |
rHR* = 2
|
rHR* = 5
|
rHR* = 10
|
rHR* = 20
|
|---|
|
1
|
20
|
-
|
-
|
-
|
-
|
|
25
|
-
|
-
|
-
|
-
|
|
50
|
-
|
-
|
-
|
-
|
|
100
|
-
|
-
|
-
|
107
|
|
150
|
-
|
-
|
132
|
88
|
|
200
|
-
|
-
|
107
|
74
|
|
10
|
20
|
-
|
-
|
107
|
74
|
|
25
|
-
|
146
|
96
|
67
|
|
50
|
-
|
96
|
65
|
46
|
|
100
|
107
|
65
|
46
|
32
|
|
150
|
88
|
54
|
37
|
26
|
|
200
|
74
|
46
|
32
|
23**
|
|
20
|
20
|
-
|
107
|
74
|
51
|
|
25
|
-
|
96
|
65
|
46
|
|
50
|
107
|
65
|
46
|
32
|
|
100
|
74
|
46
|
32
|
23
|
|
150
|
60
|
37
|
26
|
18
|
|
200
|
51
|
32
|
23
|
16
|
|
50
|
20
|
107
|
67
|
46
|
32
|
|
25
|
96
|
58
|
41
|
29
|
|
50
|
65
|
41
|
29
|
20
|
|
100
|
46
|
29
|
20
|
14
|
|
150
|
37
|
23
|
17
|
12
|
|
200
|
32
|
20
|
14
|
10
|
|
100
|
20
|
74
|
46
|
32
|
23
|
|
25
|
65
|
41
|
29
|
20
|
|
50
|
46
|
29
|
20
|
14
|
|
100
|
32
|
20
|
14
|
10
|
|
150
|
26
|
17
|
12
|
8
|
|
200
|
23
|
14
|
10
|
7
|
|
150
|
20
|
60
|
37
|
26
|
18
|
|
25
|
54
|
33
|
23
|
17
|
|
50
|
37
|
23
|
16
|
12
|
|
100
|
26
|
17
|
12
|
8
|
|
150
|
21
|
13
|
10
|
7
|
|
200
|
18
|
12
|
8
|
6
|
|
200
|
20
|
52
|
32
|
23
|
16
|
|
25
|
46
|
29
|
20
|
14
|
|
50
|
32
|
20
|
14
|
10
|
|
100
|
23
|
14
|
10
|
7
|
|
150
|
18
|
12
|
8
|
6
|
|
200
|
16
|
10
|
7
|
5
|
|
250
|
20
|
46
|
29
|
20
|
14
|
|
25
|
41
|
26
|
18
|
13
|
|
50
|
29
|
18
|
13
|
9
|
|
100
|
20
|
13
|
9
|
6
|
|
150
|
17
|
10
|
7
|
5
|
|
200
|
14
|
9
|
6
|
5
|
|
300
|
20
|
42
|
26
|
18
|
13
|
|
25
|
37
|
23
|
17
|
12
|
|
50
|
26
|
17
|
12
|
8
|
|
100
|
18
|
12
|
8
|
6
|
|
150
|
15
|
10
|
7
|
5
|
| |
200
|
13
|
8
|
6
|
4
|
-
$Precision is expressed as percentage estimation error, averaged across 1000 simulated studies for each CRR scenario.
- *rHR (real harm rate): The actual, underlying ‘baseline’ harm rate, expressed as number of incidents/100 patients/year. The harm rates estimated by different CRR scenarios are not shown.
- **Example: In this CRR scenario, 10 practices each reviewed 200 records and the estimation error was ±23%, e.g. within ±23% of the rHR of 20 incidents/100patients/year. The estimation error (%) indicates the proximity between the harm rate estimated by that unique CRR scenario and the rHR. Smaller estimation errors therefore indicate greater precision. We defined acceptable precision as estimation errors < ±25%.
- Scenarios vary by numbers of practices reviewing records, number of records reviewed in each practice and real harm rates (rHR)*. The median rate ratios (MRR) between patients and practices are 2 and 1.2 respectively. The results are from the beginning of the simulated 12-month period.
