World J Oncol

World Journal of Oncology, ISSN 1920-4531 print, 1920-454X online, Open Access

Article copyright, the authors; Journal compilation copyright, World J Oncol and Elmer Press Inc

Journal website http://www.wjon.org

Original Article

Volume 3, Number 1, February 2012, pages 8-15

Symptom Clusters in Patients With Bone Metastases: A Sub-Analysis of Patients Reporting Exclusively Non-Zero BPI Scores

Figure 1. PROC TREE procedure generated dendrogram displaying three cluster solution and cluster hierarchy in 348 patients. One cluster (general activity, walk ability, normal work, and enjoyment) explained 53.9% of total variation; when adding worst pain, it explained up to 65.1% of total variation; when adding additional 3 items, the clusters explained up to 73.5% of total variation.

Figure 2. PROC TREE procedure generated dendrogram displaying two cluster solution and cluster hierarchy in 138 patients with non-zero record at baseline. One cluster (general activity, walk ability, normal work, and enjoyment) explained 45.6% of total variation; when adding worst pain, it explained up to 59.3% of total variation; when adding additional 3 items, the clusters explained up to 68.7% of total variation.

**Table 1.** Baseline Symptom Clusters in the Total Patient Sample (T) and Non-Zero Subgroup (NZ)
Symptom	PCA	EFA	HCA
^aPCA, Principal Component Analysis; EFA, Exploratory Factor Analysis; HCA, Hierarchical Cluster Analysis. ^bSymptoms with corresponding symbols indicate they were in the same cluster.^cDash indicates the symptom was not present in any clusters.
Worst Pain	Δ	Δ	Δ	Δ	Δ	—
General Activity	Δ	Δ	Δ	Δ	Δ	Δ
Walking Ability	Δ	Δ	Δ	Δ	Δ	Δ
Normal Work	Δ	Δ	Δ	Δ	Δ	Δ
Enjoyment of Life	Δ	Δ	Δ	Δ	Δ	Δ
Mood	Ο	Ο	---	Ο	Ο	Ο
Relations with others	Ο	Ο	---	Ο	Ο	Ο
Sleep	Ο	Ο	---	Ο	---	Ο

Table 1. Baseline Symptom Clusters in the Total Patient Sample (T) and Non-Zero Subgroup (NZ)

Symptom

PCA

EFA

HCA

T (n = 348)

NZ (n = 138)

T (n = 348)

NZ (n = 138)

T (n = 348)

NZ (n = 138)

^aPCA, Principal Component Analysis; EFA, Exploratory Factor Analysis; HCA, Hierarchical Cluster Analysis. ^bSymptoms with corresponding symbols indicate they were in the same cluster.^cDash indicates the symptom was not present in any clusters.

Worst Pain

—

General Activity

Walking Ability

Normal Work

Enjoyment of Life

Mood

---

Relations with others

---

Sleep

---

**Table 2.** Factor Loadings and Final Communality From the Principal Component Analysis of BPI Symptoms in the Non-Zero Subgroup at Baseline (n = 138)
	Component 1	Component 2	Final communality
^aBPI, Brief Pain Inventory. ^bSymptoms with bolded factor loadings were in the same cluster.
General activity	0.81	0.27	0.72
Normal work	0.81	0.25	0.72
Walking ability	0.72	0.07	0.53
Enjoyment of life	0.65	0.27	0.50
Worst Pain	0.57	0.18	0.36
Mood	0.23	0.82	0.72
Relations with others	0.30	0.79	0.72
Sleep	0.13	0.73	0.55
% of variance	46.3%	13.8%
Cronbach’s alpha	0.80	0.74
Eigenvalue	3.70	1.11

Table 2. Factor Loadings and Final Communality From the Principal Component Analysis of BPI Symptoms in the Non-Zero Subgroup at Baseline (n = 138)

Component 1

Component 2

Final communality

^aBPI, Brief Pain Inventory. ^bSymptoms with bolded factor loadings were in the same cluster.

General activity

0.81

0.27

0.72

Normal work

0.81

0.25

0.72

Walking ability

0.72

0.07

0.53

Enjoyment of life

0.65

0.27

0.50

Worst Pain

0.57

0.18

0.36

Mood

0.23

0.82

0.72

Relations with others

0.30

0.79

0.72

Sleep

0.13

0.73

0.55

% of variance

46.3%

13.8%

Cronbach’s alpha

0.80

0.74

Eigenvalue

3.70

1.11

**Table 3.** Factor Loadings and Final Communality Determined Using Exploratory Factor Analysis in Total Patient Sample at Baseline (n = 348)
	Factor 1	Final communality
General activity	0.86	0.73
Normal work	0.77	0.59
Walking ability	0.67	0.45
Enjoyment of life	0.84	0.70
Worst Pain	0.64	0.41
Mood	0.65	0.42
Relations with others	0.54	0.30
Sleep	0.54	0.29
% of variance	100%
Cronbach’s alpha	0.88
Eigenvalue	9.58

Table 3. Factor Loadings and Final Communality Determined Using Exploratory Factor Analysis in Total Patient Sample at Baseline (n = 348)

Factor 1

Final communality

General activity

0.86

0.73

Normal work

0.77

0.59

Walking ability

0.67

0.45

Enjoyment of life

0.84

0.70

Worst Pain

0.64

0.41

Mood

0.65

0.42

Relations with others

0.54

0.30

Sleep

0.54

0.29

% of variance

100%

Cronbach’s alpha

0.88

Eigenvalue

9.58

**Table 4.** Factor Loadings and Final Communality Determined Using Exploratory Factor Analysis in Non-Zero Subgroup at Baseline (n = 138)
	Factor 1	Factor 2	Final communality
General activity	0.80	0.26	0.71
Normal work	0.79	0.26	0.70
Walking ability	0.56	0.18	0.35
Enjoyment of life	0.62	0.31	0.37
Worst Pain	0.42	0.23	0.23
Mood	0.25	0.73	0.60
Relations with others	0.26	0.79	0.69
Sleep	0.23	0.46	0.27
% of variance	82.0%	17.9%
Cronbach’s alpha	0.80	0.74
Eigenvalue	8.49	1.86

Table 4. Factor Loadings and Final Communality Determined Using Exploratory Factor Analysis in Non-Zero Subgroup at Baseline (n = 138)

Factor 1

Factor 2

Final communality

General activity

0.80

0.26

0.71

Normal work

0.79

0.26

0.70

Walking ability

0.56

0.18

0.35

Enjoyment of life

0.62

0.31

0.37

Worst Pain

0.42

0.23

Mood

0.25

0.73

0.60

Relations with others

0.26

0.79

0.69

Sleep

0.23

0.46

0.27

% of variance

82.0%

17.9%

Cronbach’s alpha

0.80

0.74

Eigenvalue

8.49

1.86