Background
Methods
SAIL databank
Data linkage
Data linkage with PAS cohort
Potential benefits of using linked data
1. Retrospective and prospective tracking of patient pathways
2. Validation of patient-reported recall data
3. Objective measure of the cost of illness
4. Healthcare pathways and referral history
5. Profiling of patients
Results
An example using a patient with ankylosing spondylitis
GP Event Date | (sl) GP Read Codes: Descriptions | Comment |
---|---|---|
10 August | (i) fh1k: PREMIQUE 0.625 mg/5 mg tablets; (ii) b211: BEMDROFLUAZIDE 2.5 mg tablets; (iii) b211: BENDROFLUMETHIAZIDE 2.5 mg tablets; (iv) bxd2: SIMVASTATIN 20 mg tablets; (v) Bd35: ATENONOL 50 mg tablets | GP visit /Prescription collection |
31 August | 1969: Abdominal pain | System reporting of A&E admission on 30 August |
01 September | Discharge Summary | System reporting of A&E discharge summary (ref: 30 August A&E admission) |
17 September | (i) fh1k: PREMIQUE 0.625 mg/5 mg tablets; (ii) b211: BEMDROFLUAZIDE 2.5 mg tablets; (iii) b211: BENDROFLUMETHIAZIDE 2.5 mg tablets; (iv) bxd2: SIMVASTATIN 20 mg tablets; (v) Bd35: ATENONOL 50 mg tablets; (vi) j2ck: NAPROXEN 250 mg e/c tablets; (vii) 246..: O/E blood pressure; (viii) di21: PARACETAMOL 500 mg; (ix) 8B4: Repeat Prescription. | GP Visit |
23 September | (i) 52...: Plain Radiography; (ii) 52....:Plain X-Ray | GP visit |
07 October | (i) bd35: ATENONOL 50 mg tablets; (ii) b211: BEMDROFLUAZIDE 2.5 mg tablets; (iii) bxd2: SIMVASTATIN 20 mg tablets; (iv) 8CB..: Had a chinwag with patient; (v) 8CB..: Had a discussion with patient. | GP visit |
11 October | 9 N4..: Failed encounter | No visit |
28 October | (i) b211: BEMDROFLUAZIDE 2.5 mg tablets; (ii) b211: BENDROFLUMETHIAZIDE 2.5 mg tablets; (iii) bxd2: SIMVASTATIN 20 mg tablets; (iv) Bd35: ATENONOL 50 mg tablets (v) j2ck: NAPROXEN 250 mg e/c tablets | GP visit/prescription collection |
30 October | (i) j2ck: NAPROXEN 25 mg e/c tablets | Prescription collection |
04 November | (i) 9 N36: Letter from specialist; (ii) Letter from consultant | No visit |
Examples using the PAS cohort linked to GP data system
GP events and visits from the linked routine and questionnaire data
Number of GP 'events' from linked GP data (Mean [95% CI]) | Number of GP 'visits' from Questionnaire data | |||
---|---|---|---|---|
Patient Stratification Schemes | 5 year period | 1 year period | 3 month recall period | 3 months recall period |
Disease Severity Index
| ||||
Low (BASDAI < 40) (n = 72) |
61.92
[47.86-75.64] |
12.92
[9.96-15.87] |
2.81
[2.06-3.55] |
1.31
[0.98-1.63] |
High (BASDAI > = 40) (n = 72) |
80.28
[64.32-96.23] |
17.79
[14.04-21.54] |
4.25
[3.22-5.28] |
1.78
[1.34-2.21] |
Ratio (high/low BASDAI)
|
1.30
|
1.38
|
1.51
|
1.36
|
Disease Functional Index
| ||||
Low (BASFI < 40) (n = 71) |
49.15
[36.99-61.32] |
11.20
[8.38-14.02] |
2.75
[1.97-3.52] |
1.21
[0.87-1.55] |
High (BASFI > = 40) (n = 73) |
92.27
[76.34-108.21] |
19.40
[15.73-23.07] |
4.29
[3.29-5.29] |
1.86
[1.45-2.28] |
Ratio (high/low BASFI)
|
1.88
|
1.73
|
1.56
|
1.54
|
Age
| ||||
Age < 50 (n = 68) |
45.96
[34.05-57.87] |
10.46
[7.54-13.38] |
2.53
[1.65-3.41] |
1.44
[1.00-1.89] |
Age > = 50 (n = 76) |
93.43
[77.95-108.92] |
19.74
[16.27-23.21] |
4.42
[3.53-5.31] |
1.63
[1.30-1.97] |
Ratio (Age > = 50/Age < 40)
|
2.03
|
1.89
|
1.75
|
1.13
|
Sex
| ||||
Male (n = 113) |
75.52
[63.43-87.61] |
16.07
[13.32-18.83] |
3.69
[2.95-4.43] |
1.50
[1.21-1.79] |
Female (n = 31) |
54.58
[32.82-76.34] |
12.74
[7.82-17.66] |
2.93
[1.61-4.26] |
1.68
[0.95-2.40] |
Ratio (Male/Female)
|
0.72
|
0.79
|
0.79
|
1.12
|
Disease Symptom
| ||||
First Symptom at age < = 30 (n = 112) |
66.03
[54.94-77.11] |
14.39
[11.86-16.93] |
3.29
[2.61-3.98] |
1.46
[1.17-1.76] |
First Symptom at age > 30 (n = 32) |
88.47
[60.53-116.40] |
18.72
[12.45-24.99] |
4.34
[2.68-6.01] |
1.81
[1.11-2.51] |
Ratio (first sym. age > 30/age < = 30)
|
1.34
|
1.30
|
1.32
|
1.24
|
Linked routine GP data for medications
Parent Read Code | Disease Group | Retrospective | Prospective | |||
---|---|---|---|---|---|---|
10 year (n = 183) | 5 year (n = 164) | 1 year (n = 147) | 3 months (n = 120) | 3 months (n = 103) | ||
a
| Gastro-intestinal system drugs | 123 | 103 | 75 | 47 | 42 |
b
| Cardiovascular system drugs | 69 | 65 | 50 | 39 | 36 |
c
| Respiratory system drugs | 74 | 56 | 30 | 18 | 20 |
d
| Central nervous system drugs | 147 | 125 | 83 | 52 | 40 |
e
| Drugs for infectious diseases | 139 | 114 | 59 | 20 | 18 |
f
| Endocrine drugs | 63 | 56 | 29 | 19 | 13 |
g
| Obs/gynae/urinary drugs | 42 | 33 | 22 | 8 | 6 |
h
| Malignant & immunosuppr. drug | 19 | 13 | 9 | 8 | 8 |
i
| Haematology/dietetic drugs | 54 | 44 | 29 | 18 | 17 |
j
| Musculoskeletal & joint drugs | 157 | 134 | 89 | 59 | 52 |
k
| Eye drugs | 61 | 48 | 26 | 11 | 9 |
l
| Ear, nose & oropharynx drugs | 61 | 48 | 16 | 7 | 6 |
m
| Skin drugs | 105 | 90 | 46 | 23 | 17 |
n
| Immunology drugs & vaccines | 48 | 38 | 15 | 3 | 0 |
o
| Anaesthetics | 10 | 7 | 1 | 0 | 0 |
p
| Appliances & reagents etc. | 41 | 37 | 14 | 8 | 8 |
q
| Incontinence Appliances | 2 | 2 | 2 | 1 | 1 |
s
| Contrast media | 8 | 8 | 5 | 3 | 2 |
Routine GP data for associated diagnosis
Parent Read Code | Disease Group | Retrospective | Prospective | |||
---|---|---|---|---|---|---|
10 year (n = 183) | 5 year (n = 164) | 1 year (n = 147) | 3 months (n = 120) | 3 months (n = 103) | ||
A
| Infectious/parasitic diseases | 49 | 35 | 15 | 5 | 1 |
B
| Neoplasms | 26 | 16 | 1 | 0 | 0 |
C
| Endocr/nutr/metabolic/immun. | 42 | 26 | 7 | 0 | 0 |
D
| Blood/blood forming organs | 14 | 9 | 2 | 1 | 1 |
E
| Mental disorders | 35 | 26 | 10 | 4 | 0 |
F
| Nervous system/sense organ | 92 | 78 | 25 | 13 | 3 |
G
| Circulatory system diseases | 67 | 44 | 6 | 3 | 4 |
H
| Respiratory system disorders | 88 | 72 | 25 | 4 | 5 |
J
| Digestive system disorders | 81 | 47 | 14 | 6 | 7 |
K
| Genitourinary system diseases | 47 | 36 | 8 | 1 | 0 |
L
| Pregnancy/childbirth/puerperium | 1 | 0 | 0 | 0 | 0 |
M
| Skin/subcutaneous tissue diseases | 94 | 77 | 27 | 3 | 6 |
N
| Musculoskeletal/connective tissue | 149 | 110 | 36 | 9 | 11 |
P
| Congenital anomalies | 0 | 0 | 0 | 0 | 0 |
Q
| Perinatal conditions | 0 | 0 | 0 | 0 | 0 |
R
| Symptoms, signs, ill-defined conditions | 60 | 48 | 14 | 4 | 4 |
S
| Injury and self poisoning | 56 | 31 | 9 | 1 | 2 |
T
| Causes of injury/poisoning | 21 | 12 | 3 | 0 | 0 |
U
| External causes morbdty/mortlty | 2 | 1 | 0 | 0 | 0 |
Z
| Unspecified conditions | 29 | 22 | 5 | 3 | 1 |
Examples using the PAS cohort linked to OP and IP data systems
Number of OP Visits from linked data (Mean [95% CI]) | # of self-reported OP visits from Questionnaire | Average Number of IP admissions from linked data (Mean [95% CI]) | # of self-reported IP admissions from Questionnaire | |||||
---|---|---|---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
Patient Stratification Schemes | 5 year | 1 year | 3 month recall period | 3 months recall period | 5 year | 1 year | 3 month recall period | 3 months recall period |
Disease Severity Index
| ||||||||
Low (BASDAI < 40) (n = 119 & 133) |
16.78
[13.50-20.06] |
3.84
[2.96-4.72] |
0.87
[0.64-1.09] |
1.06
[0.76-1.36] |
2.43
[1.38-3.48] |
0.59
[0.26-0.91] |
0.11
[0.05-0.17] |
0.08
[0.03-0.13] |
High (BASDAI > = 40) (n = 117 & 163) |
21.89
[16.87-26.91] |
6.12
[4.29-7.95] |
1.51
[1.06-1.97] |
2.55
[1.54-3.55] |
3.01
[2.27-3.76] |
0.74
[0.51-0.97] |
0.17
[0.10-0.23] |
0.14
[0.07-0.21] |
Disease Functional Index
| ||||||||
Low (BASFI < 40) (n = 110 & 117) |
14.17
[11.23-17.12] |
3.05
[2.28-3.81] |
0.73
[0.53-0.93] |
0.90
[0.62-1.18] |
2.31
[1.06-3.55] |
0.46
[0.12-0.80] |
0.11
[0.05-0.17] |
0.05
[0.01-0.09] |
High (BASFI > = 40) (n = 126 & 179) |
23.80
[18.93-28.67] |
6.65
[4.92-8.39] |
1.59
[1.16-2.02] |
2.58
[1.64-3.52] |
3.04
[2.40-3.69] |
0.81
[0.58-1.04] |
0.16
[0.10-0.22] |
0.16
[0.09-0.23] |
Age
| ||||||||
Age < 50 (n = 90 & 164) |
18.29
[14.64-21.94] |
5.07
[3.10-7.03] |
1.30
[0.81-1.79] |
1.72
[0.80-2.65] |
1.91
[1.29-2.54] |
0.49
[0.24-0.74] |
0.16
[0.08-0.25] |
0.05
[0.01-0.09] |
Age > = 50 (n = 146 & 192) |
19.95
[15.65-24.24] |
4.91
[3.79-6.03] |
1.12
[0.84-1.39] |
1.84
[1.20-2.48] |
3.21
[2.31-4.11] |
0.77
[0.51-1.04] |
0.13
[0.08-0.18] |
0.15
[0.08-0.22] |
Sex
| ||||||||
Male (n = 183 & 218) |
18.20
[14.85-21.55] |
4.35
[3.48-5.22] |
1.02
[0.79-1.25] |
1.60
[1.08-2.12] |
2.47
[1.96-2.97] |
0.55
[0.40-0.69] |
0.13
[0.08-0.18] |
0.10
[0.05-0.15] |
Female (n = 53 & 76) |
23.15
[16.50-29.80] |
7.11
[3.71-10.52] |
1.77
[0.98-2.57] |
2.47
[0.95-4.00] |
3.59
[1.62-5.57] |
1.03
[0.40-1.66] |
0.16
[0.06-0.26] |
0.14
[0.05-0.24] |
Disease Symptom
| ||||||||
First Symptom at age < = 30 (n = 182 & 226) |
19.04
[15.51-22.57] |
4.81
[3.59-6.04] |
1.23
[0.92-1.54] |
1.85
[1.20-2.51] |
2.38
[1.95-2.81] |
0.58
[0.42-0.73] |
0.14
[0.09-0.19] |
0.10
[0.05-0.15] |
First Symptom at age > 30 (n = 54 & 70) |
20.22
[14.69-25.75] |
5.50
[3.86-7.14] |
1.04
[0.68-1.40] |
1.61
[0.95-2.27] |
3.97
[1.71-6.23] |
0.99
[0.33-1.65] |
0.16
[0.05-0.26] |
0.17
[0.06-0.28] |
OP visits
IP visits
Patient Stratification Schemes | Average Number of days as IP from Linked IP data (Mean [# attended][95% CI]) | ||
---|---|---|---|
5 years | 1 year | 3 months recall period | |
Disease Severity Index
| |||
Low (BASDAI < 40) |
10.82
[n = 100] [7.48-14.16] |
5.06
[n = 36] [3.04-7.07] |
1.43
[n = 14] [0.94-1.92] |
High (BASDAI > = 40) |
12.97
[118] [9.16-16.79] |
5.62
[58] [3.87-7.37] |
2.33
[24] [1.02-3.64] |
Disease Functional Index
| |||
Low (BASFI < 40) |
9.31
[81] [6.03-12.59] |
4.04
[25] [1.51-6.57] |
1.25
[12] [0.96-1.54] |
High (BASFI > = 40) |
13.57
[137] [9.99-17.15] |
5.90
[69] [4.36-7.44] |
2.35
[26] [1.13-3.56] |
Age
| |||
Age < 50 |
7.11
[75] [4.74-9.48] |
3.37
[30] [1.75-4.98] |
1.4
[15] [0.94-1.86] |
Age > = 50 |
14.55
[143] [10.90-18.19] |
6.36
[64] [4.63-8.09] |
2.39
[23] [1.03-3.75] |
Sex
| |||
Male |
12.13
[158] [9.22-15.04] |
4.93
[69] [3.47-6.38] |
2.00
[27] [0.90-3.10] |
Female |
11.72
[58] [6.14-17.31] |
6.83
[24] [3.79-9.87] |
2.00
[10] [0.57-3.43] |
Disease Symptom
| |||
First Symptom at age < = 30 |
10.96
[170] [8.14-13.77] |
4.65
[75] [3.31-6.00] |
1.38
[29] [1.12-1.64] |
First Symptom at age > 30 |
15.63
[48] [9.59-21.66] |
8.37
[19] [4.76-11.98] |
4.00
[9] [0.37-7.63] |
Discussion
Questionnaire (Time Interval) | Summary of Information |
---|---|
Baseline (0) | |
Not at work (3 Months) | Previous occupation, activity impairment questionnaire |
At work (3 months) | |
AS costs (9 months) | AS Cost questionnaire including detailed patient-level information about visits to health care facilities, professionals, AS related pathology and other tests, other conditions, medications, costs of various aspects of treatment and disability |
Exercise and Fatigue (15 months) | |
Medication (0,3,6,9,12,15 Months) | Medication |