Background
Methods
Participants and procedure
Measurements
Demographic aspects
Characteristics of pain
General health, anxiety, and depression
The pain Catastrophizing scale
The European quality of life 5 dimensions questionnaire instrument
Insomnia severity index
Health care costs
Statistics
Results
General characteristics of the total sample
Variables** (Mean ± SD; otherwise stated) | Total sample | Subgroup 1* | Subgroup 2†
| Subgroup 3‡
| Subgroup 4§
|
p valuea
|
---|---|---|---|---|---|---|
Total number of participants (n, %) | 2.294 (100.0) | 325 (14.6) | 516 (22.1) | 686 (29.9) | 767 (33.4) | |
Pain intensity (NRS7d), range 0–10 | 5.00 ± 2.0 | 6.5 ± 1.8 | 7.4 ± 1.9 | 4.1 ± 1.2 | 4.0 ± 1.5 | <0.001 |
Number of pain sites, range 1–45 | 5.7 ± 5.2 | 6.7 ± 5.0 | 11.5 ± 6.9 | 3.8 ± 2.3 | 3.9 ± 2.7 | <0.001 |
GWBS-Anxiety, range 0–25 | 6.3 ± 4.8 | 13.5 ± 3.8 | 6.10 ± 3.2 | 7.5 ± 3.3 | 1.9 ± 1.7 | <0.001 |
GWBS- Depression, range 0–20 | 5.5 ± 3.7 | 10.6 ± 3.2 | 5.2 ± 2.6 | 6.8 ± 2.4 | 2.1 ± 1.4 | <0.001 |
PCS, range 0–39 | 11.8 ± 8.6 | 24.1 ± 7.3 | 13.6 ± 7.5 | 10.2 ± 7.4 | 7.5 ± 4.9 | <0.001 |
The two-step cluster analysis
Description of the derived clusters
Comparisons between subgroups with respect to external variables
Variables | Subgroup 1* (n = 325) | Subgroup 2†
(n = 516) | Subgroup 3‡
(n = 686) | Subgroup 4§
(n = 767) |
p valuea
|
---|---|---|---|---|---|
Age (years)b
| 77.8 ± 7.7 | 76.0 ± 7.4 | 76.2 ± 7.3 | 73.1 ± 6.7 | <0.001 |
Sex (%) | <0.001 | ||||
Men | 36.3 | 36.2 | 39.7 | 45.0 | |
Women | 63.7 | 63.8 | 60.3 | 55.0 | |
Education (%) | <0.001 | ||||
High school (secondary) | 61.5 | 54.8 | 54.5 | 49.1 | |
Upper secondary school or vocational training ≥2 years | 23.7 | 26.0 | 25.7 | 26.9 | |
College or university for ≤2 years | 5.7 | 10.1 | 7.6 | 9.3 | |
College or university ≥3 years | 9.1 | 9.1 | 12.2 | 14.8 | |
Family status (%) | <0.001 | ||||
Married | 47.4 | 53.7 | 58.3 | 61.8 | |
Single | 3.7 | 6.0 | 4.7 | 5.3 | |
Divorced | 19.7 | 17.1 | 14.4 | 15.1 | |
Widowed | 29.2 | 25.3 | 22.6 | 17.7 |
Variables (mean ± SD) | Subgroup 1* (n = 325) | Subgroup 2†
(n = 516) | Subgroup 3‡
(n = 686) | Subgroup 4§
(n = 767) |
p valuea
|
---|---|---|---|---|---|
EQ-5D-index | 0.41 ± 0.4 | 0.56 ± 0.3 | 0.69 ± 0.2 | 0.76 ± 0.1 | <0.001 |
EQ-5D-VAS (0–100) | 45.9 ± 21.0 | 57.2 ± 21.6 | 64.3 ± 19.9 | 75.9 ± 17.2 | <0.001 |
GWBS general health | 5.1 ± 3.1 | 8.7 ± 5.1 | 9.8 ± 4.6 | 12.3 ± 2.1 | <0.001 |
Insomnia | 14.4 ± 5.2 | 11.7 ± 4.9 | 10.5 ± 4.5 | 7.5 ± 4.3 | <0.001 |
Outpatient annual care cost (Euros) | 2937 ± 3948 | 2586 ± 3580 | 2002 ± 3163 | 1751 ± 3335 | <0.001 |
Inpatient annual care cost (Euros) | 2368 ± 7948 | 1778 ± 6901 | 1395 ± 5975 | 878 ± 3782 | <0.001 |
Pain drug annual cost (Euros) | 116 ± 303 | 101 ± 236 | 35 ± 103 | 25 ± 88 | <0.001 |
Total annual drug cost (Euros) | 890 ± 1462 | 733 ± 1410 | 510 ± 942 | 406 ± 913 | <0.001 |
Total annual health care cost (Euros) | 6200 ± 10,405 | 5098 ± 9170 | 3907 ± 8526 | 3030 ± 6014 | <0.001 |
Clusters | |||||||||
---|---|---|---|---|---|---|---|---|---|
Subgroup 1* vs subgroup 4§
| Subgroup 2† vs subgroup 4§
| Subgroup 3‡ vs subgroup 4§
| |||||||
Variables | OR | 95% CI |
p value | OR | 95% CI |
p value | OR | 95% CI |
p value |
Age (years) | 1.02 | (0.98–1.07) | 0.203 | 1.00 | (0.97–1.04) | 0.750 | 1.02 | (0.99–1.05) | 0.144 |
Men (Reference group) | 1.00 | - | - | 1.00 | - | - | 1.00 | - | - |
Women | 1.29 | (0.72–2.32) | 0.390 | 1.22 | (0.77–1.93) | 0.383 | 0.90 | (0.61–1.34) | 0.627 |
High school (secondary) (Reference group) | 1.00 | - | - | 1.00 | - | - | 1.00 | - | - |
Upper secondary school or vocational training ≥2 years | 0.78 | (0.39–1.56) | 0.490 | 1.17 | (0.68–1.99) | 0.558 | 1.08 | (0.67–1.73) | 0.745 |
College or university for ≤2 years | 0.31 | (0.09–1.05) | 0.060 | 1.34 | (0.66–2.75) | 0.413 | 0.93 | (0.48–1.81) | 0.846 |
College or university ≥3 years | 0.85 | (0.34–2.16) | 0.748 | 0.65 | (0.31–1.37) | 0.266 | 0.86 | (0.47–1.57) | 0.630 |
Married (Reference group) | 1.00 | - | - | 1.00 | - | - | 1.00 | - | - |
Single | 1.34 | (0.35–5.14) | 0.661 | 1.53 | (0.61–3.92) | 0.366 | 1.05 | (0.43–2.61) | 0.903 |
Divorced | 1.92 | (0.91–4.01) | 0.082 | 0.93 | (0.51–1.72) | 0.829 | 1.17 | (0.69–1.98) | 0.557 |
Widowed | 1.23 | (0.57–2.63) | 0.594 | 1.07 | (0.58–1.98) | 0.827 | 0.96 | (0.54–1.68) | 0.888 |
EQ-5D-index | 0.02 | (0.01–0.03) |
<0.001
| 0.02 | (0.01–0.10) |
<0.001
| 0.30 | (0.06–2.24) | 0.281 |
EQ-5D-VAS (0–100) | 0.85 | (0.67–0.99) |
0.022
| 0.98 | (0.97–0.99) |
<0.001
| 0.99 | (0.99–1.01) | 0.874 |
GWBS general health | 0.45 | (0.56–0.68) |
<0.001
| 0.71 | (0.61–0.82) |
<0.001
| 0.66 | (0.62–0.72) |
<0.001
|
Insomnia | 1.23 | (1.17–1.28) |
<0.001
| 1.13 | (1.08–1.17) |
<0.001
| 1.10 | (1.07–1.14) |
<0.001
|
Outpatient annual care cost (Euros) | 1.10 | (1.02–1.07) |
0.008
| 1.06 | (1.01–1.12) |
0.029
| 1.00 | (1.00–1.00) | 0.132 |
Inpatient annual care cost (Euros) | 1.11 | (1.01–1.05) |
0.002
| 1.02 | (1.01–1.03) |
0.002
| 1.00 | (1.00–1.00) | 0.084 |
Pain drug annual cost (Euros) | 1.06 | (1.01–1.04) |
0.050
| 1.02 | (1.01–1.03) |
0.040
| 0.99 | (0.99–1.01) | 0.777 |
Total annual drug cost (Euros) | 1.05 | (1.01–1.13) |
0.041
| 1.02 | (1.01–1.04) |
0.050
| 1.00 | (1.00–1.00) | 0.579 |
Total annual health care cost (Euros) | 1.03 | (1.01–1.02) |
0.050
| 1.01 | (1.01–1.02) |
0.050
| 0.99 | (0.99–1.00) | 0.843 |
Discussion
-
We found four clusters based on pain intensity, spreading of pain on the body, anxiety, depression, and pain catastrophizing in older adults. In particular, we identified two high risk clusters (Subgroups 1 and 2) comprising one-third of the study sample and two less affected clusters (Subgroups 3 and 4) in terms of symptom severity.
-
Subgroup 1 was mainly described by increased psychological symptoms and Subgroup 2 was mainly described by increased pain intensity and pain spreading.
-
The multinomial logistic regression analysis revealed that, compared to Subgroup 4, Subgroups 1 and 2 were associated with decreased quality of life, decreased general health, increased insomnia, and increased health care costs and Subgroup 3 was associated with decreased general health and increased insomnia.