Table 2 Summary characteristics of outcome measures across the samples
From: Mapping the neck disability index to SF-6D in patients with chronic neck pain
Characteristic | Whole set (n = 272) | Derivation set (n = 180) | Validation set (n = 92) | |||
|---|---|---|---|---|---|---|
Mean (SD) | Median (IQR) | Mean (SD) | Median (IQR) | Mean (SD) | Median (IQR) | |
SF-6D | 0.52 (0.09) | 0.49 (0.45-0.56) | 0.53 (0.09) | 0.49 (0.47-0.58) | 0.5 (0.09) | 0.48 (0.45-0.55) |
NDI global scores | 28.46 (12.93) | 27 (18-40) | 28.98 (13.87) | 27.5 (18-43) | 27.4 (10.97) | 27 (18-34.75) |
Scores of 10 individual items | ||||||
Pain intensity | 3.47 (1.55) | 3 (2-5) | 3.52 (1.62) | 3 (2-5) | 3.37 (1.43) | 3 (2-5) |
Personal care | 2.14 (1.02) | 2 (2-3) | 2.17 (1.04) | 2 (2-3) | 2.1 (1) | 2 (1.25-3) |
Lifting | 2.63 (1.47) | 2 (2-4) | 2.7 (1.45) | 2 (2-4) | 2.5(1.5) | 2 (1-3.75) |
Reading | 3.08 (1.38) | 3 (2-4) | 3.12 (1.45) | 3 (2-4) | 3 (1.26) | 3 (2-4) |
Headaches | 2.67 (1.97) | 2 (1-4) | 2.68 (2.02) | 2 (1-5) | 2.63 (1.9) | 2 (1-3.75) |
Concentration | 2.94 (1.89) | 2 (1-5) | 3.02 (1.9) | 2.5 (1-5) | 2.8 (1.88) | 2 (1-4) |
Work | 2.74 (1.73) | 2.5 (2-3) | 2.77 (1.86) | 2 (2-5) | 2.7 (1.44) | 3 (1.25-3) |
Driving | 2.97 (1.88) | 3 (2-5) | 3.08 (1.94) | 3 (2-5) | 2.73 (1.74) | 2.5 (2-4) |
Sleeping | 2.58 (1.62) | 2 (1-4) | 2.72 (1.65) | 2 (1-4) | 2.3 (1.56) | 2 (1-3.75) |
Recreation | 3.23 (1.64) | 3 (2-5) | 3.22 (1.76) | 3 (2-5) | 3.27 (1.41) | 3.5 (2-4) |