Sample
From November 2017 until August 2018, we collected IPOS data from 144 patients. However, 4 patients had to be excluded from the final sample because they did not complete full IPOS. Most of them were inpatients, only in 16 % of patients the place of care was at home provided by the home hospice. The number of patients from the hospital and hospice were similar (43 % vs 57 %). In the sample, there were few more women (64 %) and most of the patients suffered from oncological disease (81 %). The detailed description of the sample is in Table 1. Most of the patients (88.6 %) needed help in the completion of IPOS.
Table 1: Characteristics of the final sample
|
Number of patients (%)
|
Number of patients who completed IPOS twice
(%)
|
Number of patients who completed IPOS and PPS (%)
|
Number of patients who completed IPOS and ESAS (%)
|
Age
|
|
|
|
|
Range
Mean (SD)
18-55
56-65
66-75
76-85
>85
|
27-95 years
72.1 (12.98)
14 (10)
23 (16.4)
44 (31.4)
36 (25.7)
23 (16.4)
|
55-88 years
70.0 (10.54)
1 (7.1)
3 (21.4)
7 (50)
2 (14.3)
1 (7.1)
|
49-92 years
71.4 (11.01)
5 (12.5)
7 (17.5)
14 (35)
9 (22.5)
5 (12.5)
|
49-89 years
70.4 (13.03)
2 (14.3)
4 (28.6)
3 (21.4)
2 (14.3)
3 (21.4)
|
Sex
|
|
|
|
|
Men
Women
|
50 (35.7)
90 (64.3)
|
4 (28.6)
10 (71.4)
|
12 (30)
28 (70)
|
1 (7.1)
13 (92.9)
|
Marital status
|
|
|
|
|
Single
Married
Divorced
Widowed
Registered (homosexual marriage)
|
16 (11.4)
52 (37.1)
17 (12.1)
54 (38.6)
1 (.7)
|
2 (14.3)
6 (42.9)
2 (14.3)
4 (28.6)
0
|
2 (5)
18 (45)
5 (12.5)
15 (37.5)
0
|
1 (7.1)
4 (28.6)
1 (7.1)
8 (57.1)
0
|
Diagnosis
Cancer
Other
Not available
|
113 (80.7)
26 (18.6)
1 (.7)
|
13 (92,9)
1 (7.1)
0
|
39 (97.5)
1 (2.5)
0
|
14 (100)
0
0
|
Place of care
Hospice
Home hospice care
Hospital
|
57 (40.7)
23 (16.4)
60 (42.9)
|
6 (42.9)
5 (35.7)
3 (21.4)
|
20 (50)
20 (50)
0
|
14 (100)
0
0
|
Total
|
140
|
14
|
40
|
14
|
Table 2 presents descriptive statistics of all 17 IPOS items for the whole sample. We used the short names in the description of items, similarly as Sakurai et al. (14) and Sandham et al. (15) (14,15). As a part of the item analysis, we evaluated each item's difficulty and correlation with the total IPOS score (item-total correlation). The minimum item difficulty was 0.13 (Vomiting), the maximum was 0.6 (Poor mobility). All item-total correlations were higher than 0.3, the highest predictor of the total score was item measuring Weakness with item-total correlation 0.66.
Table 2 – Description of IPOS items:
Item
|
% response for each value score
|
M
|
SD
|
Mo
|
Item Difficulty
|
Item-total correlation
|
0
|
1
|
2
|
3
|
4
|
Pain
|
22.1
|
25.7
|
28.6
|
20
|
3.6
|
1.6
|
1.1
|
2
|
0.39
|
0.48
|
Shortness of Breath
|
51.4
|
19.3
|
10.7
|
14.3
|
4.3
|
1.0
|
1.3
|
0
|
0.25
|
0.32
|
Weakness
|
10
|
12.9
|
32.1
|
38.6
|
6.4
|
2.2
|
1.1
|
3
|
0.55
|
0.66
|
Nausea
|
53.6
|
22.9
|
12.1
|
9.3
|
2.1
|
0.8
|
1.1
|
0
|
0.21
|
0.46
|
Vomiting
|
74.3
|
9.3
|
9.3
|
6.4
|
0.7
|
0.5
|
1.0
|
0
|
0.13
|
0.37
|
Poor Appetite
|
28.6
|
17.1
|
24.3
|
26.4
|
3.6
|
1.6
|
1.3
|
0
|
0.40
|
0.58
|
Constipation
|
46.4
|
17.9
|
13.6
|
20.7
|
1.4
|
1.1
|
1.2
|
0
|
0.28
|
0.44
|
Sore Mouth
|
26.4
|
23.6
|
21.4
|
26.4
|
2.1
|
1.5
|
1.2
|
0
|
0.39
|
0.33
|
Drowsiness
|
18.6
|
17.1
|
37.1
|
25
|
2.1
|
1.8
|
1.1
|
2
|
0.44
|
0.48
|
Poor Mobility
|
10.7
|
9.3
|
22.9
|
43.6
|
13.6
|
2.4
|
1.2
|
3
|
0.60
|
0.49
|
Anxiety
|
32.1
|
14.3
|
32.1
|
15.7
|
5.7
|
1.5
|
1.2
|
0
|
0.37
|
0.58
|
Family Anxiety
|
10.7
|
10
|
30.7
|
32.1
|
16.4
|
2.3
|
1.2
|
3
|
0.58
|
0.50
|
Depression
|
40.7
|
16.4
|
31.4
|
9.3
|
2.1
|
1.2
|
1.1
|
0
|
0.29
|
0.50
|
Feeling at Peace
|
15
|
36.4
|
28.6
|
15
|
5
|
1.6
|
1.1
|
1
|
0.40
|
0.59
|
Share Feelings
|
30.7
|
29.3
|
16.4
|
17.9
|
5.7
|
1.4
|
1.3
|
0
|
0.35
|
0.44
|
Information
|
51.4
|
28.6
|
12.1
|
5.7
|
2.1
|
0.8
|
1.0
|
0
|
0.20
|
0.48
|
Practical Problems
|
52.9
|
20
|
17.1
|
7.1
|
2.9
|
0.9
|
1.1
|
0
|
0.22
|
0.45
|
M= mean; SD= standard deviation; Mo= modus
Influence of gender, age and place of care
The total IPOS score did not differ for men and women (t = -1.537, p = 0.127) nor did it correlate with the age of patients (r = 0.141, p = 0.096). However, we found a significant difference in the total IPOS score when comparing patients from hospices and patients from hospitals (t = -3.613, p < 0.001). More specifically, the average total IPOS score of patients from hospices was lower (38.75, SD = 9.11) than the average score of patients from hospitals (44.28, SD = 8.77).
Reliability
Cronbach’s alpha for 17 IPOS items (which are used for calculation of the overall score) was 0.789. Temporal stability was evaluated for all items separately as well as for the overall score. A one-way intra-class correlation coefficient of IPOS total score indicated a high level of temporal stability (ICC = 0.88, 95%CI: 0.56 - 0.94). Sufficient test-retest reliability was also supported by significant Spearman correlation between two total IPOS scores in T1 and T2 (r = 0.88, p < 0.05). For most of the items significant Spearman correlations were found as well as fair to good levels of weighted kappa, however, several items showed rather low temporal stability, mainly items called Family anxiety, Practical problems, Drowsiness or Anxiety. For more detailed results, please see Table 3.
Table 3 – Temporal stability:
|
T1
|
T2
|
Agreement
|
|
Mean (SD)
|
Mean (SD)
|
Agreement (%)
|
Agreement within one score (%)
|
Weighted kappa
(95 % CI)
|
Spearman correlation
|
Pain
|
1.6 (1.3)
|
1.4 (1.0)
|
35.7
|
92.9
|
0.66 (0.40-0.92)
|
0.69**
|
Shortness of Breath
|
1.0 (1.2)
|
1.4 (1.5)
|
57.1
|
78.6
|
0.60 (0.21-0.99)
|
0.62*
|
Weakness
|
1.5 (1.0)
|
1.9 (1.2)
|
50.0
|
78.6
|
0.54 (0.18-0.91)
|
0.54*
|
Nausea
|
0.9 (1.1)
|
0.6 (0.9)
|
35.7
|
92.9
|
0.59 (0.41-0.77)
|
0.49
|
Vomiting
|
0.7 (1.1)
|
0.4 (0.8)
|
64.3
|
85.7
|
0.58 (0.29-0.86)
|
0.77**
|
Poor Appetite
|
1.1 (1.3)
|
1.6 (1.3)
|
42.9
|
92.9
|
0.65 (0.31-0.99)
|
0.67**
|
Constipation
|
0.9 (1.2)
|
0.9 (1.2)
|
71.4
|
71.4
|
0.46 (-0.02-0.93)
|
0.51
|
Sore Mouth
|
1.6 (1.3)
|
1.5 (1.0)
|
57.1
|
92.9
|
0.60 (0.15-1.05)
|
0.63*
|
Drowsiness
|
1.1 (1.1)
|
1.9 (0.9)
|
7.1
|
71.4
|
0.33 (0.06-0.60)
|
0.43
|
Poor Mobility
|
2.1 (1.2)
|
2.4 (0.9)
|
42.9
|
85.7
|
0.41 (0.03-0.79)
|
0.53
|
Anxiety
|
1.0 (1.3)
|
1.2 (1.1)
|
28.6
|
71.4
|
0.31 (-0.11-0.72)
|
0.35
|
Family Anxiety
|
2.1 (1.1)
|
2.6 (0.8)
|
42.9
|
71.4
|
0.02 (-0.33-0.37)
|
0.53
|
Depression
|
0.7 (1.1)
|
0.5 (0.9)
|
71.4
|
92.9
|
0.74 (0.48-1.01)
|
0.83**
|
Feeling at Peace
|
1.1 (0.9)
|
1.2 (1.1)
|
57.1
|
85.7
|
0.54 (0.12-0.96)
|
0.50
|
Share Feelings
|
1.1 (1.4)
|
1.2 (1.1)
|
50.0
|
92.9
|
0.77 (0.56-0.98)
|
0.80**
|
Information
|
0.2 (0.6)
|
0.2 (0.4)
|
71.4
|
100.0
|
0.40 (-0.08-0.89)
|
0.32
|
Practical Problems
|
0.1 (0.4)
|
0.4 (0.7)
|
71.4
|
92.9
|
0.27 (-0.23-0.77)
|
0.32
|
IPOS
|
18.9 (9.8)
|
21.1 (7.2)
|
-
|
-
|
0.83a (0.56-0.94)
|
0.88**
|
*. Correlation is significant at the 0.05 level (2-tailed).
**. Correlation is significant at the 0.01 level (2-tailed).
a. One-way Intraclass Correlation Coefficient (ICC).
Exploratory factor analysis
Both Kaiser-Meyer-Olkin Measure of Sampling Adequacy (0.696) and Bartlett's test of sphericity (p<0.001) indicated that a factor analysis might be useful with our data. Based on the combination of Kaiser's criterion and Cattell's scree plot method, we decided to present the two-factor model as an output of EFA which explains 29.1% of the variance (Factor 1: 15.9%, Factor 2: 13.3%) and the factors showed a correlation of 0.316.
Table 4 – Factor loadings:
|
Factor 1
|
Factor 2
|
Anxiety
|
0.711
|
0.085
|
Feeling at peace
|
0.694
|
0.128
|
Depression
|
0.667
|
0.019
|
Information
|
0.531
|
0.066
|
Practical Problems
|
0.515
|
0.051
|
Share Feelings
|
0.431
|
0.109
|
Family Anxiety
|
0.374
|
0.258
|
Shortness of Breath
|
0.156
|
0.147
|
Nausea
|
0.017
|
0.607
|
Vomiting
|
-0.074
|
0.588
|
Poor Appetite
|
0.204
|
0.584
|
Weakness
|
0.403
|
0.513
|
Sore Mouth
|
-0.084
|
0.462
|
Drowsiness
|
0.173
|
0.429
|
Poor Mobility
|
0.220
|
0.381
|
Constipation
|
0.124
|
0.376
|
Pain
|
0.247
|
0.344
|
Convergent validity
Spearman´s correlation of the sum score of IPOS and PPS was found to be weaker than was expected by our hypotheses and non-significant (Rs(40) = -0.249; p = 0.121), correlation with ESAS showed to be on a moderate level (Rs(14) = 0.414; p = 0.141), however, not significant due to a very small research sample. Data from PPS and ESAS were not available from many patients so these results have to be considered preliminary only.