Background
Methods
Traditional approach to using statistical clustering techniques (low back pain example)
Novel approach of using statistical clustering techniques (low back pain example)
First stage clustering
Second stage clustering
Assessing clinical importance
Results
Example of this method applied (non-specific chest pain example)
Response options | Missing-ness | |
---|---|---|
Demographics domain | ||
Age | Years of age | 0 % |
Gender | Female/male | 0 % |
Previous history domain | ||
Risk factors for cardiovascular disease sum score of hypercholesterolemia, hypertension, diabetes, family history of cardiac disease, previous or current smoking (all scored yes/no) | 0 to 5 | 0 % |
Psychological domain (patient perception and coping) | ||
Does the pain originate from the heart? | Yes/possibly/no | 0.4 % |
Does the pain originate from the muscles and joints? | Yes/possibly/no | 0.2 % |
Are you afraid? | Yes/no | 0.2 % |
Pain domain | ||
Average chest pain episode duration | <10 min/10 min-1 hour/> 1 hour/continuous | 21.9 % |
Pain description ‘crushing pain’ | Yes/no | 0 % |
Pain description ‘tenderness’ | Yes/no | 0 % |
Pain description ‘sharp pains’ | Yes/no | 0 % |
Pain description ‘well defined’ | Yes/no | 0 % |
Pain description ‘diffuse’ | Yes/no | 0 % |
Pain description ‘burning’ | Yes/no | 0 % |
Pain description ‘tingling’ | Yes/no | 0 % |
Activity limitation domain | ||
SF36 physical function sum score | 0 to 100 scale (high scores better) | 3.5 % |
Diagnostic classification domain | ||
Danish Cardiologist’s Society classification ‘angina’ | No angina/typical/atypical/uncharacteristic/ unstable | 0.2 % |
Canadian Cardiovascular Society classification | Grades 0 to 3 | 1.6 % |
Palpation domain | ||
Anterior | ||
Springing - tenderness sterno/xiphoid junction | Yes/no | <1 % |
Springing - tenderness costosternal 2–3 right | Yes/no | <1 % |
Springing - tenderness costosternal 2–3 left | Yes/no | <1 % |
Springing - tenderness costosternal 3–4 right | Yes/no | <1 % |
Springing - tenderness costosternal 3–4 left | Yes/no | <1 % |
Springing - tenderness costosternal 4–5 right | Yes/no | <1 % |
Springing - tenderness costosternal 4–5 left | Yes/no | <1 % |
Springing - tenderness costosternal 5–6 right | Yes/no | <1 % |
Springing - tenderness costosternal 5–6 left | Yes/no | <1 % |
Springing - provoked pain sterno/xiphoid junction | Yes/no | <1 % |
Springing - provoked pain costosternal 2–3 right | Yes/no | <1 % |
Springing - provoked pain costosternal 2–3 left | Yes/no | <1 % |
Springing - provoked pain costosternal 3–4 right | Yes/no | <1 % |
Springing - provoked pain costosternal 3–4 left | Yes/no | <1 % |
Springing - provoked pain costosternal 4–5 right | Yes/no | <1 % |
Springing - provoked pain costosternal 4–5 left | Yes/no | <1 % |
Springing - provoked pain costosternal 5–6 right | Yes/no | <1 % |
Springing - provoked pain costosternal 5–6 left | Yes/no | <1 % |
Muscle tenderness/pain pectoralis maj. left | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain pectoralis min. left | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain intercostalis 2–3 left | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain intercostalis 3–4 left | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain intercostalis 4–5 left | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain intercostalis 5–6 left | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain intercostalis 6–7 left | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain pectoralis maj. right | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain pectoralis min. right | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain intercostalis 2–3 right | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain intercostalis 3–4 right | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain intercostalis 4–5 right | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain intercostalis 5–6 right | No tenderness/tenderness/pain | <1 % |
Muscle tenderness/pain intercostalis 6–7 right | No tenderness/tenderness/pain | <1 % |
Posterior | ||
Tender c4-5 paraspinalpost either left or right | Yes/no | 1 % |
Tender c5-6 paraspinalpost either left or right | Yes/no | 1 % |
Tender c6-7 paraspinalpost either left or right | Yes/no | 1 % |
Tender c7-th1 paraspinalpost left or right | Yes/no | 1 % |
Tender th1-2 paraspinalpost left or right | Yes/no | 1 % |
Tender th2-3 paraspinalpost left or right | Yes/no | 1 % |
Tender th3-4 paraspinalpost left or right | Yes/no | 1 % |
Tender th4-5 paraspinalpost left or right | Yes/no | 1 % |
Tender th5-6 paraspinalpost left or right | Yes/no | 1 % |
Tender th6-7 paraspinalpost left or right | Yes/no | 1 % |
Tender th7-8 paraspinalpost left or right | Yes/no | 1 % |
Tender th8-9 paraspinalpost left or right | Yes/no | 1 % |
Vertebral springing th1-2 | Yes/no | 1 % |
Vertebral springing th2-3 | Yes/no | 1 % |
Vertebral springing th3-4 | Yes/no | 1 % |
Vertebral springing th4-5 | Yes/no | 1 % |
Vertebral springing th5-6 | Yes/no | 1 % |
Vertebral springing th6-7 | Yes/no | 1 % |
Vertebral springing th7-8 | Yes/no | 1 % |
Vertebral springing th8-9 | Yes/no | 1 % |
Response option | Cluster1 | Cluster2 | Cluster3 | Cluster4 | Cluster5 | |
---|---|---|---|---|---|---|
Subgroup label | Low activity limitation, high fear, few palpation findings | Typical and atypical angina, short episode, pectoral tenderness | No palpation findings | Female, high fear, diffuse anterior tenderness | Typical angina, short episode, high activity limitation, pectoral tenderness | |
Cluster Size | 32 % | 26 % | 24 % | 10 % | 7 % | |
Cluster membership probability, | Median (interquartile range) | 100 % (100 % to 100 %) | 100 % (100 % to 100 %) | 100 % (100 % to 100 %) | 100 % (100 % to 100 %) | 100 % (100 % to 100 %) |
Demographic domain | ||||||
Age | Mean (SD) | 51.5 (11.0) | 55.4 (9.4) | 55.3 (10.3) | 54.5 (10.2) | 59.0 (9.0) |
Gender | Female | 42 % | 33 % | 27 % | 93 % | 36 % |
Previous history domain | ||||||
Cardiovascular risk factor Index | Mean (SD) | 1.9 (1.1) | 2.1 (1.1) | 2.0 (1.2) | 2.1 (1.1) | 2.4 (0.9) |
Psychological domain | ||||||
Self-perceived ‘Pain from muscle or joints’ | Possibly | 43 % | 42 % | 36 % | 41 % | 43 % |
Yes | 31 % | 32 % | 12 % | 38 % | 30 % | |
Self-perceived ‘Pain from heart’ | Possibly | 39 % | 35 % | 37 % | 40 % | 32 % |
Yes | 22 % | 52 % | 47 % | 29 % | 59 % | |
Self-perceived ‘Afraid’ | Yes | 94 % | 69 % | 77 % | 92 % | 82 % |
Pain domain | ||||||
Episode duration | <10 min | 38 % | 72 % | 59 % | 50 % | 68 % |
10 min-1 hour | 20 % | 18 % | 21 % | 21 % | 19 % | |
>1 hour | 9 % | 4 % | 6 % | 7 % | 4 % | |
Continuous | 34 % | 7 % | 14 % | 22 % | 9 % | |
Pain description ‘crushing pain’ | Yes | 73 % | 92 % | 80 % | 82 % | 92 % |
Pain description ‘tenderness’ | Yes | 73 % | 73 % | 73 % | 73 % | 73 % |
Pain description ‘sharp pains’ | Yes | 29 % | 18 % | 16 % | 28 % | 26 % |
Pain description ‘well defined’ | Yes | 4 % | 4 % | 3 % | 3 % | 5 % |
Pain description ‘diffuse’ | Yes | 4 % | 10 % | 3 % | 2 % | 8 % |
Pain description ‘burning’ | Yes | 7 % | 4 % | 4 % | 8 % | 5 % |
Pain description ‘tingling’ | Yes | 7 % | 17 % | 9 % | 7 % | 10 % |
Activity limitation domain | ||||||
SF36 physical function sum-score | Mean (SD) | 70.8 (9.9) | 67.0 (9.4) | 66.8 (11.9) | 58.9 (16.2) | 28.6 (8.9) |
Diagnostic classification domain | ||||||
Danish Cardiologist’s Society classification ‘angina’ | No angina | 45 % | 3 % | 23 % | 38 % | 8 % |
Typical | 9 % | 52 % | 31 % | 27 % | 77 % | |
Atypical | 17 % | 32 % | 24 % | 15 % | 6 % | |
Uncharacteristic | 30 % | 14 % | 21 % | 20 % | 10 % | |
Unstable | 0 % | 0 % | 1 % | 0 % | 0 % | |
Canadian Cardiovascular Society classification | Grade 0 | 65 % | 12 % | 27 % | 35 % | 3 % |
Grade 1 | 29 % | 35 % | 42 % | 41 % | 21 % | |
Grade 2 | 6 % | 48 % | 30 % | 23 % | 63 % | |
Grade 3 | 0 % | 4 % | 1 % | 1 % | 12 % | |
Palpation domain | ||||||
Sternoxiphoid springing tenderness | Yes | 16 % | 1 % | 9 % | 38 % | 0 % |
Costosternal springing tenderness 2/3 right | Yes | 11 % | 2 % | 0 % | 42 % | 5 % |
Costosternal springing tenderness 2/3 left | Yes | 15 % | 1 % | 0 % | 45 % | 3 % |
Costosternal springing tenderness 3/4 right | Yes | 14 % | 0 % | 1 % | 45 % | 5 % |
Costosternal springing tenderness 3/4 left | Yes | 22 % | 0 % | 0 % | 52 % | 3 % |
Costosternal springing tenderness 4/5 right | Yes | 15 % | 0 % | 1 % | 57 % | 3 % |
Costosternal springing tenderness 4/5 left | Yes | 45 % | 0 % | 1 % | 62 % | 5 % |
Costosternal springing tenderness 5/6 right | Yes | 11 % | 1 % | 1 % | 57 % | 3 % |
Costosternal springing tenderness 5/6 left | Yes | 30 % | 1 % | 3 % | 59 % | 0 % |
sternoxiphoid springing pain | Yes | 3 % | 0 % | 3 % | 7 % | 0 % |
Costosternal springing pain 2/3 right | Yes | 2 % | 1 % | 0 % | 7 % | 2 % |
Costosternal springing pain 2/3 left | Yes | 3 % | 1 % | 0 % | 8 % | 0 % |
Costosternal springing pain 3/4 right | Yes | 3 % | 0 % | 1 % | 9 % | 2 % |
Costosternal springing pain 3/4 left | Yes | 8 % | 0 % | 0 % | 8 % | 0 % |
Costosternal springing pain 4/5 right | Yes | 3 % | 0 % | 0 % | 14 % | 2 % |
Costosternal springing pain 4/5 left | Yes | 19 % | 0 % | 0 % | 12 % | 0 % |
Costosternal springing pain 5/6 right | Yes | 3 % | 0 % | 0 % | 10 % | 0 % |
Costosternal springing pain 5/6 left | Yes | 16 % | 0 % | 0 % | 12 % | 0 % |
Muscle tenderness pectoralis major left | Tenderness | 26 % | 72 % | 8 % | 47 % | 61 % |
Pain | 4 % | 23 % | 2 % | 18 % | 22 % | |
Muscle tenderness pectoralis minor left | Tenderness | 34 % | 82 % | 4 % | 61 % | 77 % |
Pain | 6 % | 11 % | 1 % | 15 % | 8 % | |
Muscle tenderness intercostal 2/3 left | Tenderness | 15 % | 50 % | 1 % | 69 % | 55 % |
Pain | 0 % | 3 % | 0 % | 8 % | 5 % | |
Muscle tenderness intercostal 3/4 left | Tenderness | 20 % | 30 % | 0 % | 80 % | 25 % |
Pain | 2 % | 0 % | 0 % | 7 % | 2 % | |
Muscle tenderness intercostal 4/5 left | Tenderness | 26 % | 13 % | 1 % | 86 % | 13 % |
Pain | 8 % | 1 % | 0 % | 10 % | 2 % | |
Muscle tenderness intercostal 5/6 left | Tenderness | 33 % | 5 % | 2 % | 78 % | 5 % |
Pain | 9 % | 0 % | 0 % | 15 % | 0 % | |
Muscle tenderness intercostal 6/7 left | Tenderness | 22 % | 1 % | 1 % | 75 % | 3 % |
Pain | 7 % | 0 % | 0 % | 13 % | 0 % | |
Muscle tenderness pectoralis major right | Tenderness | 20 % | 71 % | 9 % | 49 % | 73 % |
Pain | 2 % | 22 % | 0 % | 18 % | 13 % | |
Muscle tenderness pectoralis minor right | Tenderness | 23 % | 76 % | 3 % | 60 % | 73 % |
Pain | 1 % | 9 % | 0 % | 15 % | 12 % | |
Muscle tenderness intercostal 2/3 right | Tenderness | 13 % | 48 % | 0 % | 76 % | 54 % |
Pain | 1 % | 0 % | 0 % | 7 % | 2 % | |
Muscle tenderness intercostal 3/4 right | Tenderness | 10 % | 25 % | 1 % | 81 % | 25 % |
Pain | 1 % | 0 % | 0 % | 5 % | 2 % | |
Muscle tenderness intercostal 4/5 right | Tenderness | 12 % | 9 % | 0 % | 88 % | 5 % |
Pain | 0 % | 0 % | 0 % | 7 % | 0 % | |
Muscle tenderness intercostal 5/6 right | Tenderness | 14 % | 4 % | 0 % | 82 % | 0 % |
Pain | 0 % | 0 % | 0 % | 10 % | 0 % | |
Muscle tenderness intercostal 6/7 right | Tenderness | 8 % | 2 % | 0 % | 79 % | 0 % |
Pain | 1 % | 0 % | 0 % | 10 % | 0 % | |
Tenderness c4/5 paraspinal posterior | Yes | 10 % | 5 % | 2 % | 27 % | 3 % |
Tenderness c5/6 paraspinal posterior | Yes | 16 % | 8 % | 4 % | 26 % | 3 % |
Tenderness c6/7 paraspinal posterior | Yes | 14 % | 5 % | 3 % | 17 % | 3 % |
Tenderness c7/th1 paraspinal posterior | Yes | 7 % | 11 % | 1 % | 18 % | 10 % |
Tenderness th1/2 paraspinal posterior | Yes | 14 % | 27 % | 3 % | 29 % | 38 % |
Tenderness th2/3 paraspinal posterior | Yes | 29 % | 50 % | 5 % | 50 % | 64 % |
Tenderness th3/4 paraspinal posterior | Yes | 37 % | 46 % | 3 % | 58 % | 47 % |
Tenderness th4/5 paraspinal posterior | Yes | 45 % | 24 % | 3 % | 56 % | 29 % |
Tenderness th5/6 paraspinal posterior | Yes | 46 % | 9 % | 2 % | 45 % | 13 % |
Tenderness th6/7 paraspinal posterior | Yes | 42 % | 2 % | 1 % | 40 % | 5 % |
Tenderness th7/8 paraspinal posterior | Yes | 27 % | 1 % | 1 % | 36 % | 3 % |
Tenderness th8/9 paraspinal posterior | Yes | 16 % | 1 % | 0 % | 22 % | 3 % |
Posterior vertebral springing th1/2 | Yes | 7 % | 4 % | 0 % | 5 % | 12 % |
Posterior vertebral springing th2/3 | Yes | 12 % | 29 % | 1 % | 14 % | 25 % |
Posterior vertebral springing th3/4 | Yes | 18 % | 37 % | 0 % | 31 % | 25 % |
Posterior vertebral springing th4/5 | Yes | 15 % | 19 % | 0 % | 31 % | 20 % |
Posterior vertebral springing th5/6 | Yes | 19 % | 6 % | 0 % | 16 % | 10 % |
Posterior vertebral springing th6/7 | Yes | 18 % | 1 % | 1 % | 16 % | 2 % |
Posterior vertebral springing th7/8 | Yes | 14 % | 1 % | 1 % | 14 % | 0 % |
Posterior vertebral springing th8/9 | Yes | 12 % | 0 % | 2 % | 19 % | 0 % |
Response option | |||||||
---|---|---|---|---|---|---|---|
Domain: Demographic | |||||||
2 clusters
| Cluster1 | Cluster2 | |||||
Scoring pattern label
|
Older
|
Younger
| |||||
Cluster Size | 51 % | 49 % | |||||
Cluster membership probability | Median (interquartile range) | 90 % (79 % to 96 %) | 93 % (78 % to 100 %) | ||||
Age (years) | Mean (SD) | 62.6 (5.2) | 45.3 (6.3) | ||||
Gender | Female | 43 % | 39 % | ||||
Domain: Previous history
| |||||||
1 cluster
|
Previous history did not discriminate subgroups in two-stage clustering
| ||||||
Domain: Psychological
| |||||||
5 clusters
| Cluster1 | Cluster2 | Cluster3 | Cluster4 | Cluster5 | ||
Scoring pattern label
|
Uncertain of cause of pain and fearful
|
Believes cause from heart
|
Believes both from heart and musculoskeletal
|
Believes cause from musculoskeletal and less fearful
|
Believes cause from other cause and less fearful
| ||
Cluster Size | 44 % | 23 % | 16 % | 11 % | 6 % | ||
Cluster membership probability | Median (interquartile range) | 100 % (92 % to 100 %) | 99. % (99 % to 100 %) | 100 % (100 % to 100 %) | 95 % (95 % to 96 %) | 77 % (77 % to 100 %) | |
Self-perceived ‘Pain from muscle or joints’ | No | 10 % | 100 % | 0 % | 0 % | 75 % | |
Possibly | 85 % | 0 % | 1 % | 13 % | 25 % | ||
Yes | 5 % | 0 % | 99 % | 87 % | 0 % | ||
Self-perceived ‘Pain from heart’ | No | 15 % | 0 % | 0 % | 99 % | 94 % | |
Possibly | 83 % | 1 % | 1 % | 1 % | 6 % | ||
Yes | 3 % | 99 % | 99 % | 0 % | 0 % | ||
Self-perceived ‘Afraid’ | Yes | 99 % | 71 % | 83 % | 56 % | 50 % | |
Domain: Pain
| |||||||
2 clusters
| Cluster1 | Cluster2 | |||||
Scoring pattern label
|
Crushing pain
|
Not crushing pain
| |||||
Cluster Size | 77 % | 23 % | |||||
Cluster membership probability, median (interquartile range) | 97 % (94 % to 97 %) | 99 % (96 % to 99 %) | |||||
Episode duration | < 10 min | 59 % | 50 % | ||||
10 min-1 hour | 20 % | 20 % | |||||
> 1 hour | 5 % | 7 % | |||||
Continuous | 16 % | 24 % | |||||
Pain description ‘crushing pain’ | Yes | 100 % | 25 % | ||||
Pain description ‘tenderness’ | Yes | 3 % | 3 % | ||||
Pain description ‘sharp pains’ | Yes | 14 % | 52 % | ||||
Pain description ‘well defined’ | Yes | 3 % | 6 % | ||||
Pain description ‘diffuse’ | Yes | 6 % | 5 % | ||||
Pain description ‘burning’ | Yes | 4 % | 8 % | ||||
Pain description ‘tingling’ | Yes | 8 % | 19 % | ||||
Domain: Activity limitation
| |||||||
3 clusters
| Cluster1 | Cluster2 | Cluster3 | ||||
Scoring pattern label
|
None or light activity limitation
|
Moderate activity limitation
|
Severe activity limitation
| ||||
Cluster Size | 82 % | 11 % | 8 % | ||||
Cluster membership probability, median (interquartile range) | 100 % (100 % to 100 %) | 86 % (86 % to 86 %) | 99 % (82 % to 100 %) | ||||
SF36 physical function sum-score | Mean (SD) | 71.2 (7.4) | 49.0 (4.6) | 27.1 (6.9) | |||
Domain: Diagnostic classification
| |||||||
3 clusters
| Cluster1 | Cluster2 | Cluster3 | ||||
Scoring pattern label
|
Not heart
|
Typical angina
|
Maybe angina
| ||||
Cluster Size | 37 % | 35 % | 28 % | ||||
Cluster membership probability | Median (interquartile range) | 100 % (94 % to 100 %) | 100 % (85 % to 100 %) | 97 % (81 % to 100 %) | |||
Danish Cardiologist’s Society | No angina | 64 % | 3 % | 2 % | |||
classification ‘angina’ | Typical | 0 % | 89 % | 4 % | |||
Atypical | 1 % | 8 % | 65 % | ||||
Uncharacteri-stic | 34 % | 0 % | 29 % | ||||
Unstable | 0 % | 1 % | 0 % | ||||
Canadian Cardiovascular Society | Grade 0 | 87 % | 0 % | 8 % | |||
classification | Grade 1 | 13 % | 17 % | 84 % | |||
Grade 2 | 0 % | 76 % | 8 % | ||||
Grade 3 | 0 % | 7 % | 0 % | ||||
Domain: Palpation
| |||||||
6 clusters
| Cluster1 | Cluster2 | Cluster3 | Cluster4 | Cluster5 | Cluster6 | |
Scoring pattern label
|
No palpation findings
|
Local 5/6 signs and intercostal tenderness
|
Local 2/3/4 signs and pectoral tenderness
|
Pectoral tenderness
|
Paraspinal and pectoral tenderness
|
Generalised tenderness
| |
Cluster Size | 22 % | 19 % | 18 % | 16 % | 16 % | 8 % | |
Cluster membership probability, median (interquartile range) | 100 % (100 % to 100 %) | 100 % (100 % to 100 %) | 100 % (100 % to 100 %) | 100 % (100 % to 100 %) | 100 % (100 % to 100 %) | 100 % (100 % to 100 %) | |
Sternoxiphoid springing tenderness | Yes | 10 % | 22 % | 1 % | 1 % | 10 % | 34 % |
Costosternal tenderness 2/3 right | Yes | 0 % | 5 % | 1 % | 4 % | 16 % | 52 % |
Costosternal tenderness 2/3 left | Yes | 1 % | 7 % | 0 % | 2 % | 19 % | 56 % |
Costosternal tenderness 3/4 right | Yes | 2 % | 13 % | 1 % | 3 % | 12 % | 52 % |
Costosternal tenderness 3/4 left | Yes | 2 % | 25 % | 0 % | 0 % | 18 % | 54 % |
Costosternal tenderness 4/5 right | Yes | 1 % | 28 % | 1 % | 1 % | 4 % | 51 % |
Costosternal tenderness 4/5 left | Yes | 2 % | 77 % | 1 % | 1 % | 10 % | 52 % |
Costosternal tenderness 5/6 right | Yes | 1 % | 27 % | 1 % | 1 % | 0 % | 51 % |
Costosternal tenderness 5/6 left | Yes | 3 % | 55 % | 0 % | 0 % | 6 % | 51 % |
sternoxiphoid springing pain | Yes | 4 % | 3 % | 0 % | 0 % | 4 % | 4 % |
Costosternal springing pain 2/3 right | Yes | 0 % | 0 % | 0 % | 4 % | 1 % | 8 % |
Costosternal springing pain 2/3 left | Yes | 0 % | 1 % | 0 % | 1 % | 4 % | 10 % |
Costosternal springing pain 3/4 right | Yes | 0 % | 2 % | 1 % | 2 % | 2 % | 10 % |
Costosternal springing pain 3/4 left | Yes | 1 % | 7 % | 0 % | 0 % | 5 % | 10 % |
Costosternal springing pain 4/5 right | Yes | 0 % | 8 % | 1 % | 0 % | 1 % | 6 % |
Costosternal springing pain 4/5 left | Yes | 1 % | 36 % | 0 % | 0 % | 0 % | 4 % |
Costosternal springing pain 5/6 right | Yes | 0 % | 9 % | 0 % | 0 % | 0 % | 4 % |
Costosternal springing pain 5/6 left | Yes | 0 % | 29 % | 0 % | 1 % | 2 % | 6 % |
Muscle tenderness pectoralis major left | Tenderness | 1 % | 19 % | 78 % | 62 % | 38 % | 54 % |
Pain | 0 % | 3 % | 20 % | 28 % | 4 % | 24 % | |
Muscle tenderness pectoralis minor left | Tenderness | 2 % | 31 % | 83 % | 75 % | 40 % | 66 % |
Pain | 0 % | 6 % | 13 % | 8 % | 4 % | 20 % | |
Muscle tenderness intercostal 2/3 left | Tenderness | 1 % | 6 % | 58 % | 42 % | 24 % | 84 % |
Pain | 1 % | 0 % | 3 % | 1 % | 0 % | 12 % | |
Muscle tenderness intercostal 3/4 left | Tenderness | 1 % | 20 % | 36 % | 20 % | 18 % | 90 % |
Pain | 1 % | 2 % | 0 % | 0 % | 1 % | 8 % | |
Muscle tenderness intercostal 4/5 left | Tenderness | 3 % | 46 % | 12 % | 10 % | 5 % | 91 % |
Pain | 1 % | 15 % | 0 % | 1 % | 1 % | 6 % | |
Muscle tenderness intercostal 5/6 left | Tenderness | 2 % | 57 % | 5 % | 3 % | 4 % | 89 % |
Pain | 0 % | 21 % | 0 % | 0 % | 0 % | 6 % | |
Muscle tenderness intercostal 6/7 left | Tenderness | 1 % | 42 % | 1 % | 1 % | 0 % | 82 % |
Pain | 0 % | 14 % | 0 % | 1 % | 1 % | 8 % | |
Muscle tenderness pectoralis major right | Tenderness | 0 % | 16 % | 75 % | 74 % | 28 % | 56 % |
Pain | 0 % | 0 % | 21 % | 16 % | 4 % | 24 % | |
Muscle tenderness pectoralis minor right | Tenderness | 1 % | 17 % | 80 % | 68 % | 33 % | 66 % |
Pain | 0 % | 0 % | 11 % | 7 % | 1 % | 20 % | |
Muscle tenderness intercostal 2/3 right | Tenderness | 0 % | 9 % | 59 % | 38 % | 16 % | 90 % |
Pain | 0 % | 1 % | 0 % | 1 % | 1 % | 8 % | |
Muscle tenderness intercostal 3/4 right | Tenderness | 1 % | 15 % | 32 % | 15 % | 9 % | 90 % |
Pain | 0 % | 0 % | 0 % | 1 % | 1 % | 6 % | |
Muscle tenderness intercostal 4/5 right | Tenderness | 0 % | 27 % | 10 % | 4 % | 4 % | 90 % |
Pain | 0 % | 2 % | 0 % | 0 % | 0 % | 4 % | |
Muscle tenderness intercostal 5/6 right | Tenderness | 0 % | 30 % | 3 % | 1 % | 0 % | 89 % |
Pain | 0 % | 4 % | 0 % | 0 % | 0 % | 4 % | |
Muscle tenderness intercostal 6/7 right | Tenderness | 0 % | 17 % | 2 % | 2 % | 0 % | 84 % |
Pain | 0 % | 5 % | 0 % | 0 % | 0 % | 4 % | |
Tenderness c4/5 paraspinal posterior | Yes | 3 % | 6 % | 6 % | 1 % | 17 % | 27 % |
Tenderness c5/6 paraspinal posterior | Yes | 4 % | 13 % | 11 % | 3 % | 20 % | 26 % |
Tenderness c6/7 paraspinal posterior | Yes | 3 % | 13 % | 8 % | 3 % | 12 % | 19 % |
Tenderness c7/th1 paraspinal posterior | Yes | 1 % | 8 % | 18 % | 0 % | 9 % | 21 % |
Tenderness th1/2 paraspinal posterior | Yes | 2 % | 14 % | 50 % | 0 % | 20 % | 31 % |
Tenderness th2/3 paraspinal posterior | Yes | 3 % | 27 % | 89 % | 0 % | 46 % | 51 % |
Tenderness th3/4 paraspinal posterior | Yes | 1 % | 33 % | 78 % | 0 % | 54 % | 61 % |
Tenderness th4/5 paraspinal posterior | Yes | 1 % | 38 % | 40 % | 1 % | 59 % | 59 % |
Tenderness th5/6 paraspinal posterior | Yes | 1 % | 45 % | 13 % | 0 % | 53 % | 41 % |
Tenderness th6/7 paraspinal posterior | Yes | 1 % | 43 % | 1 % | 0 % | 45 % | 35 % |
Tenderness th7/8 paraspinal posterior | Yes | 3 % | 27 % | 2 % | 0 % | 26 % | 33 % |
Tenderness th8/9 paraspinal posterior | Yes | 2 % | 12 % | 0 % | 0 % | 17 % | 25 % |
Posterior vertebral springing th1/2 | Yes | 0 % | 8 % | 10 % | 2 % | 4 % | 2 % |
Posterior vertebral springing th2/3 | Yes | 1 % | 7 % | 41 % | 11 % | 18 % | 17 % |
Posterior vertebral springing th3/4 | Yes | 0 % | 21 % | 51 % | 11 % | 21 % | 26 % |
Posterior vertebral springing th4/5 | Yes | 0 % | 15 % | 31 % | 5 % | 18 % | 28 % |
Posterior vertebral springing th5/6 | Yes | 0 % | 14 % | 12 % | 0 % | 24 % | 17 % |
Posterior vertebral springing th6/7 | Yes | 1 % | 19 % | 2 % | 0 % | 19 % | 11 % |
Posterior vertebral springing th7/8 | Yes | 2 % | 12 % | 1 % | 2 % | 14 % | 11 % |
Posterior vertebral springing th8/9 | Yes | 5 % | 9 % | 1 % | 0 % | 10 % | 19 % |
Domain | Cluster 1 | Cluster 2 | |
---|---|---|---|
Subgroup label | Uncertain of cause and fearful, but not heart-related - with local thoracic 5/6 palpation findings. | Believes pain to be heart- or musculoskelet-al-related with crushing pain, and local thoracic 2/3 signs and pectoral tenderness. | |
Cluster size | 51 % | 49 % | |
Cluster membership probability | Median (interquartile range) | 100 % (99 % to 100 %) | 100 % (98 % to 100 %) |
Demographic | Younger | 42 %* | 62 % |
Older | 58 % | 38 % | |
Previous history | 0 % | 0 % | |
Only one cluster | 100 % | 100 % | |
Psychological | Uncertain of cause of pain and fearful | 88 % | 2 % |
Believes cause from heart | 1 % | 44 % | |
Believes both from heart and musculoskeletal | 0 % | 31 % | |
Believes cause from musculoskeletal and less fearful | 6 % | 14 % | |
Believes cause from other cause and less fearful | 5 % | 8 % | |
Pain | Crushing pain | 74 % | 89 % |
Not crushing pain | 26 % | 11 % | |
Activity limitation | None or light activity limitation | 88 % | 76 % |
Moderate activity limitation | 8 % | 13 % | |
Severe activity limitation | 4 % | 11 % | |
Diagnostic classification | Not heart | 71 % | 1 % |
Typical angina | 13 % | 61 % | |
Maybe angina | 16 % | 38 % | |
Palpation | No palpation findings | 23 % | 23 % |
Local 5/6 signs and intercostal tenderness | 36 % | 1 % | |
Local 2/3/4 signs and pectoral tenderness | 4 % | 32 % | |
Pectoral tenderness | 3 % | 30 % | |
Paraspinal and pectoral tenderness | 23 % | 8 % | |
Generalised tenderness | 11 % | 6 % |
Response option | Cluster1 | Cluster2 | |
---|---|---|---|
Subgroup label | Uncertain of cause and fearful, but not heart-related - with local thoracic 5/6 palpation findings. | Believes pain to be heart- or musculoskelet-al-related with crushing pain, and local thoracic 2/3 signs and pectoral tenderness. | |
Demographic domain | |||
Age | Mean (SD) | 52.2 (11.0) | 56.5 (9.2) |
Gender | Female | 44 % | 39 % |
Previous history domain | |||
Cardiovascular risk factor Index | Mean (SD) | 1.9 (1.1) | 22.2 (1.1) |
Psychological domain | |||
Self-perceived ‘Pain from muscle or joints’ | Possibly | 79 % | 1 % |
Yes | 9 % | 46 % | |
Self-perceived ‘Pain from heart’ | Possibly | 73 % | 1 % |
Yes | 3 % | 76 % | |
Self-perceived ‘Afraid’ | Yes | 94 % | 71 % |
Pain domain | |||
Episode duration | <10 min | 34 % | 57 % |
10 min-1 hour | 24 % | 20 % | |
>1 hour | 5 % | 6 % | |
Continuous | 37 % | 17 % | |
Pain description ‘crushing pain’ | Yes | 76 % | 90 % |
Pain description ‘tenderness’ | Yes | 0 % | 6 % |
Pain description ‘sharp pains’ | Yes | 25 % | 20 % |
Pain description ‘well defined’ | Yes | 3 % | 4 % |
Pain description ‘diffuse’ | Yes | 2 % | 8 % |
Pain description ‘burning’ | Yes | 6 % | 5 % |
Pain description ‘tingling’ | Yes | 7 % | 13 % |
Activity limitation domain | |||
SF36 physical function sum-score | Mean (SD) | 67.8 (SD 13.4) | 61.5 (SD 16.1) |
Diagnostic classification domain | |||
Danish Cardiologist’s Society | No angina | 49 % | 0 % |
classification ‘angina’ | Typical | 9 % | 56 % |
Atypical | 14 % | 30 % | |
Uncharacteristic | 28 % | 14 % | |
Unstable | 0 % | 0 % | |
Canadian Cardiovascular Society | Grade 0 | 67 % | 1 % |
classification | Grade 1 | 21 % | 47 % |
Grade 2 | 11 % | 46 % | |
Grade 3 | 0 % | 5 % | |
Palpation domain | |||
Sternoxiphoid springing tend | Yes | 21 % | 2 % |
Costosternal springing tenderness 2/3 right | Yes | 13 % | 4 % |
Costosternal springing tenderness 2/3 left | Yes | 15 % | 4 % |
Costosternal springing tenderness 3/4 right | Yes | 17 % | 3 % |
Costosternal springing tenderness 3/4 left | Yes | 23 % | 3 % |
Costosternal springing tenderness 4/5 right | Yes | 20 % | 1 % |
Costosternal springing tenderness 4/5 left | Yes | 40 % | 2 % |
Costosternal springing tenderness 5/6 right | Yes | 18 % | 1 % |
Costosternal springing tenderness 5/6 left | Yes | 32 % | 1 % |
sternoxiphoid springing pain | Yes | 5 % | 0 % |
Costosternal springing pain 2/3 right | Yes | 2 % | 1 % |
Costosternal springing pain 2/3 left | Yes | 3 % | 1 % |
Costosternal springing pain 3/4 right | Yes | 3 % | 1 % |
Costosternal springing pain 3/4 left | Yes | 6 % | 1 % |
Costosternal springing pain 4/5 right | Yes | 5 % | 0 % |
Costosternal springing pain 4/5 left | Yes | 15 % | 0 % |
Costosternal springing pain 5/6 right | Yes | 4 % | 0 % |
Costosternal springing pain 5/6 left | Yes | 13 % | 0 % |
Muscle tenderness pectoralis major left | Tenderness | 23 % | 54 % |
Costosternal springing pain 5/6 left | Pain | 6 % | 17 % |
Muscle tenderness pectoralis minor left | Tenderness | 31 % | 60 % |
Pain | 7 % | 7 % | |
Muscle tenderness intercostal 2/3 left | Tenderness | 18 % | 41 % |
Pain | 1 % | 3 % | |
Muscle tenderness intercostal 3/4 left | Tenderness | 23 % | 25 % |
Pain | 2 % | 1 % | |
Muscle tenderness intercostal 4/5 left | Tenderness | 29 % | 14 % |
Pain | 7 % | 1 % | |
Muscle tenderness intercostal 5/6 left | Tenderness | 32 % | 9 % |
Pain | 9 % | 0 % | |
Muscle tenderness intercostal 6/7 left | Tenderness | 21 % | 7 % |
Pain | 7 % | 0 % | |
Muscle tenderness pectoralis major right | Tenderness | 21 % | 55 % |
Pain | 3 % | 15 % | |
Muscle tenderness pectoralis minor right | Tenderness | 25 % | 54 % |
Pain | 2 % | 8 % | |
Muscle tenderness intercostal 2/3 right | Tenderness | 18 % | 39 % |
Pain | 2 % | 1 % | |
Muscle tenderness intercostal 3/4 right | Tenderness | 17 % | 23 % |
Pain | 1 % | 0 % | |
Muscle tenderness intercostal 4/5 right | Tenderness | 20 % | 11 % |
Pain | 1 % | 0 % | |
Muscle tenderness intercostal 5/6 right | Tenderness | 21 % | 7 % |
Pain | 2 % | 0 % | |
Muscle tenderness intercostal 6/7 right | Tenderness | 16 % | 6 % |
Pain | 2 % | 0 % | |
Tenderness c4/5 paraspinal posterior | Yes | 11 % | 5 % |
Tenderness c5/6 paraspinal posterior | Yes | 16 % | 6 % |
Tenderness c6/7 paraspinal posterior | Yes | 12 % | 5 % |
Tenderness c7/th1 paraspinal posterior | Yes | 7 % | 10 % |
Tenderness th1/2 paraspinal posterior | Yes | 14 % | 22 % |
Tenderness th2/3 paraspinal posterior | Yes | 27 % | 40 % |
Tenderness th3/4 paraspinal posterior | Yes | 32 % | 36 % |
Tenderness th4/5 paraspinal posterior | Yes | 35 % | 23 % |
Tenderness th5/6 paraspinal posterior | Yes | 35 % | 11 % |
Tenderness th6/7 paraspinal posterior | Yes | 31 % | 6 % |
Tenderness th7/8 paraspinal posterior | Yes | 22 % | 4 % |
Tenderness th8/9 paraspinal posterior | Yes | 16 % | 1 % |
Posterior vertebral springing th1/2 | Yes | 6 % | 4 % |
Posterior vertebral springing th2/3 | Yes | 9 % | 21 % |
Posterior vertebral springing th3/4 | Yes | 16 % | 25 % |
Posterior vertebral springing th4/5 | Yes | 14 % | 15 % |
Posterior vertebral springing th5/6 | Yes | 14 % | 7 % |
Posterior vertebral springing th6/7 | Yes | 14 % | 3 % |
Posterior vertebral springing th7/8 | Yes | 10 % | 3 % |
Posterior vertebral springing th8/9 | Yes | 11 % | 1 % |
Two-stage clustering | ||
---|---|---|
Subgroup 1 | Subgroup 2 | |
Uncertain of cause and fearful, but not heart-related - with local thoracic 5/6 palpation findings. | Believes pain to be heart- or musculoskeletal-related with crushing pain, and local thoracic 2/3 signs and pectoral tenderness. | |
Single stage clustering | ||
Subgroup 1 | ||
Low activity limitation, high fear, few palpation findings | 173 | 13 |
Subgroup 2 | ||
Typical and atypical angina, short episode, pectoral tenderness | 9 | 144 |
Subgroup 3 | ||
No palpation findings | 64 | |
Subgroup 4 | ||
Female, high fear, diffuse anterior tenderness | 44 | 16 |
Subgroup 5 | ||
Typical angina, short episode, high activity limitation, pectoral tenderness | 5 | 35 |