Background
Methods
Study design and setting
Participants
The painDETECT questionnaire (PDQ)
Statistics
Baseline characteristics
Rasch analysis
Test-retest reliability
Results
Study sample
Baseline characteristics
low
|
n
|
moderate
|
n
|
high
|
n
|
p-value
| |
---|---|---|---|---|---|---|---|
RA | |||||||
Age (yrs) | 60(53.5–65) | 100 | 61(53–68.5) | 100 | 59(50–68.5) | 100 | 0.84 |
Duration (yrs) | 8(3–17) | 93 | 5.5(2–14) | 92 | 5(1–14) | 92 | 0.03a
|
PDQ score | 8(5–14) | 100 | 12(7–18) | 100 | 18(12–25) | 100 | <0.01 |
DMARD mono n (%) | 65(74) | 88 | 62(75) | 83 | 54(70) | 77 | 0.79 |
> 1 DMARD n (%) | 23(26) | 88 | 21(25) | 83 | 23(30) | 77 | 0.79 |
Biologics n (%) | 38(38) | 100 | 33(33) | 100 | 31(31) | 100 | 0.56 |
DAS28-crp | 2.2(1.8–2.7) | 100 | 3.9 (3.6–4.5) | 100 | 5.7(5.4–6.25) | 100 | <0.01 |
TJC 28 | 0(0–1) | 100 | 4(3–7.5) | 100 | 13(9–18) | 100 | <0.01 |
SJC 28 | 0(0–0) | 100 | 1(0–3) | 100 | 5.5(2–9) | 100 | <0.01 |
VAS pain mm | 25.5(13–41.5) | 100 | 50(32.5–65) | 100 | 75(57.5–86.5) | 100 | <0.01 |
VAS fatigue mm | 29(18.5–56) | 100 | 54(36.5–73.5) | 100 | 77.5(57–92.5) | 100 | <0.01 |
VAS global mm | 25.5(13.5–52.5) | 100 | 58.5(41.5–74) | 100 | 82.5(70.5–93.5) | 100 | <0.01 |
HAQ | 0.5(0.125–1) | 99 | 1(0.625–1.375) | 99 | 1.75(1–2.25) | 100 | <0.01 |
Crp mg/l | 3(1.5–5.5) | 100 | 7(3–14) | 100 | 23.5(11.5–39.5) | 100 | <0.01 |
IgM-RF n (%) | 69(80) | 86 | 64(79) | 81 | 58(78) | 74 | 0.96 |
Anti-CCP n (%) | 31(54) | 57 | 30(51) | 59 | 19(42) | 45 | 0.46 |
PsA | |||||||
Age (yrs) | 50.5(42–58) | 100 | 52(41.5–60) | 100 | 52(44–60) | 100 | 0.56 |
Duration (yrs) | 6(3–9) | 91 | 4.5(1–9.5) | 92 | 6(3–9) | 87 | 0.30 |
PDQ score | 9(5–12) | 100 | 14(9–18) | 100 | 19(14.5–24) | 100 | <0.01 |
DMARD mono n (%) | 69 (95) | 73 | 53(83) | 64 | 54 (81) | 67 | 0.04 |
> 1 DMARD n (%) | 4(5) | 73 | 11(17) | 64 | 13(19) | 67 | 0.04 |
Biologics n (%) | 55(55) | 100 | 44(44) | 100 | 41(41) | 100 | 0.11 |
DAS28-crp | 1.8(1.6–2.35) | 92 | 2.8(2.4–3.55) | 92 | 4.4(3.8–5.1) | 90 | <0.01 |
TJC 28 | 0(0–1) | 94 | 1(0–3.5) | 92 | 5(2–12) | 91 | <0.01 |
SJC 28 | 0(0–0) | 93 | 0(0–0) | 92 | 0(0–2) | 90 | <0.01b
|
BASDAI (0–100) | 21.5(13–28) | 98 | 52(41–64) | 98 | 77(71–85) | 99 | <0.01 |
BASFI (0–100) | 15.5(7–27) | 98 | 45.5(27–57) | 98 | 74(62–86) | 99 | <0.01 |
ASDAS | 1.5(1.1–1.8) | 97 | 2.8(2.5–3.1) | 97 | 4(3.7–4.5) | 98 | <0.01 |
VAS pain mm | 20.5(12–30) | 100 | 50(39.5–63) | 100 | 77 (68–88.5) | 100 | <0.01 |
VAS fatigue mm | 27(15–38) | 100 | 65(48–77) | 100 | 85(75–93) | 100 | <0.01 |
VAS global mm | 22(14–30) | 100 | 59.5(46–74) | 100 | 85.5(77–94) | 100 | <0.01 |
HAQ | 0.375(0–0.625) | 96 | 0.75(0.51.25) | 95 | 1.5(1–1.875) | 96 | <0.01 |
Crp mg/l | 2(1–4)
| 100 | 3(1.5–6) | 100 | 6(3–14) | 100 | <0.01 |
HLA-B27 n (%) | 7(54) | 13 | 10(53) | 19 | 7(58) | 12 | 0.95 |
SpA | |||||||
Age (yrs) | 45.5(36–53) | 100 | 43.5 (35–52.5) | 100 | 47(37–54) | 100 | 0.52 |
Duration (yrs) | 6(3–13) | 94 | 4.5(2–9) | 90 | 5(2–12) | 89 | 0.14 |
PDQ score | 8(5–13.5) | 100 | 15(9–19.5) | 100 | 17.5(10.5–22.5) | 100 | <0.01 |
DMARD mono n (%) | 24(100) | 24 | 21(84) | 25 | 26(96) | 27 | 0.06 |
> 1 DMARD n (%) | 0 (0) | 24 | 4(16) | 25 | 1(4) | 27 | 0.06 |
Biologics n (%) | 78(78) | 100 | 56(56) | 100 | 54(54) | 100 | <0.01c
|
BASDAI (0–100) | 22.5(14–34) | 100 | 49(39–61) | 100 | 72.5(65–83) | 100 | <0.01 |
BASFI (0–100) | 16(10.5–31.5) | 100 | 40.5(27–56) | 100 | 67.5(49–83.5) | 100 | <0.01 |
ASDAS | 1.7(1.3–1.90) | 100 | 2.9(2.5–3.1) | 100 | 4.1(3.8–4.5) | 100 | <0.01 |
VAS pain mm | 21.5(12–35) | 100 | 53.5(38–72) | 100 | 75.5(65.5–86) | 100 | <0.01 |
VAS fatigue mm | 31.5(17.5–48) | 100 | 65(45.5–81) | 100 | 83(71.5–92) | 100 | <0.01 |
VAS global mm | 24.5(15.5–36) | 100 | 61(46–78) | 100 | 84(74–92) | 100 | <0.01 |
Crp mg/l | 2(1–4) | 100 | 3(2–7) | 100 | 10(5–21) | 100 | <0.01 |
HLA-B27 n (%) | 28(82) | 34 | 20(63) | 32 | 20(67) | 30 | 0.17 |
RA | PsA | SpA |
p-value | |
---|---|---|---|---|
(n = 10) | (n = 10) | (n = 10) | ||
Female sex n (%) | 8 (80) | 5 (50) | 4 (40) | 0.266 |
Age (years) | 65 (62–68) | 58.5 (49–67) | 47 (32–52) | 0.005a
|
Duration (years) | 15.5 (8–24) | 8.5 (5–14) | 4 (2–6) | 0.017b
|
DMARD n (%) | 9 (90) | 9 (90) | 2(20) | 0.003 |
Biologics n (%) | 6 (60) | 7 (70) | 8(80) | 0.879 |
DAS28-CRP | 3.9 (3.7–4.2) | 3.7 (3.1–4.4) | - | 0.519 |
TJC 28 | 5.5 (4–10) | 6 (2–9) | - | 0.791 |
SJC 28 | 1 (1–4) | 0 (0–0) | - | 0.020 |
BASDAI (0–100) | - | 67 (34–83) | 28 (14–43) | 0.364 |
BASFI (0–100) | - | 60.5 (37–89) | 18 (13–32) | 0.212 |
ASDAS | - | 3.05 (2.4–3.8) | 2.1 (1.1–2.7) | 0.104 |
VAS pain mm | 43 (26–53) | 61.5(25–73) | 24.5 (19–41) | 0.331 |
VAS fatigue mm | 65 (40–79) | 63.5 (32–82) | 43 (26–67) | 0.397 |
VAS global mm | 50 (34–63) | 72 (32–87) | 29.5 (22–57) | 0.219 |
HAQ | 1.25 (0.875–2) | - | - | - |
Crp mg/l | 5.5 (1–10) | 4 (1–8) | 3.5 (1–9) | 0.939 |
HLA-B27 n (%) | - | 2(100)(n = 2) | 3(75)(n = 4) | 1 |
IgM-RF n (%) | 5(50) | - | - | - |
Anti-CCP n (%) | 5(50) | - | - | - |
Rating scale properties
Unidimensionality
Mean square - Z standard deviation | ||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
RA | PsA | SpA | All diagnoses | |||||||||||||
Item | Infit | Outfit | Infit | Outfit | Infit | Outfit | Infit | Outfit | ||||||||
1 | 0.82 | −2.4 | 0.8 | −2.3 | 1.04 | 0.6 | 1.06 | 0.7 | 0.91 | −1.1 | 0.95 | −0.5 | 0.92 | −1.7 | 0.94 | −1.2 |
2 | 0.93 | −0.9 | 0.86 | −1.5 | 0.72 | −3.8 | 0.67 | −3.4 | 0.84 | −2.0 | 0.79 | −1.8 | 0.84 | −3.5 | 0.80 | −3.5 |
3 | 1.04 | 0.5 | 1.01 | 0.2 | 0.99 | −.01 | 0.99 | −.01 | 1.02 | 0.3 | 1.01 | 0.2 | 1.01 | 0.2 | 1.00 | 0.1 |
4 | 1.01 | 0.2 | 0.97 | −0.3 | 1.08 | 1.0 | 1.02 | 0.2 | 1.0 | 0.0 | 0.93 | −0.6 | 1.03 | 0.6 | 0.97 | −0.4 |
5 | 1.14 | 1.7 | 1.09 | 1.1 | 1.09 | 1.2 | 1.07 | 0.9 | 1.14 | 1.7 | 1.11 | 1.3 | 1.12 | 2.5 | 1.09 | 1.9 |
6 | 1.14 | 1.7 | 1.21 | 1.9 | 1.24 | 2.9 | 1.26 | 2.4 | 1.08 | 1.0 | 1.12 | 1.1 | 1.14 | 2.9 | 1.19 | 2.9 |
7 | 0.98 | −0.2 | 0.99 | 0.0 | 0.91 | −1.2 | 0.84 | −1.8 | 1.04 | 0.6 | 1.05 | 0.6 | 0.99 | −0.1 | 1.00 | 0.0 |
Item difficulty | |||
---|---|---|---|
RA | PsA | SpA | Across all diagnosis |
5. Cold or heat painful (−0.93) | 5. Cold or heat painful (−0.85) | 5. Cold or heat painful (−0.79) | 5. Cold or heat painful (−0.86) |
3. Light touching painful (−0.02) | 1.Burning sensations (−0.2) | 7. Slight pressure pain (−0.32) | 7. Slight pressure pain (−0.10) |
1.Burning sensations (0.04) | 7. Slight pressure pain (−0.05) | 1.Burning sensations (−0.13) | 1.Burning sensations (−0.10) |
6. Numbness (0.04) | 3. Light touching painful (0.04) | 3. Light touching painful (−0.07) | 3. Light touching painful (−0.02) |
7. Slight pressure pain (0.06) | 6. Numbness (0.08) | 6. Numbness (0.00) | 6. Numbness (0.04) |
2.Tingling or prickling (0.25) | 2. Tingling or prickling (0.44) | 4. Sudden pain attacks (0.68) | 2. Tingling or prickling (0.46) |
4. Sudden pain attacks (0.45) | 4. Sudden pain attacks (0.50) | 2. Tingling or prickling (0.70) | 4. Sudden pain attacks (0.54) |
Precision and reproducibility
Test-retest reliability
n
| ||||||
---|---|---|---|---|---|---|
PDQ score < 13 | PDQ score 13–18 | PDQ score > 18 | ||||
Test | Retestc | Test | Retest | Test | Retest | |
RA | 4 | 4 | 3 | 4 | 3 | 2 |
PsA | 4 | 5 | 2 | 2 | 4 | 3 |
SpA | 7 | 7 | 2 | 1 | 1 | 2 |
In total | 15 | 16 | 7 | 7 | 8 | 7 |