Clinical diagnostic model for sciatica developed in primary care patients with low back-related leg pain

doi:10.1371/journal.pone.0191852

PMC full text:

PLoS One. 2018; 13(4): e0191852.

Published online 2018 Apr 5. doi: 10.1371/journal.pone.0191852

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Table 3

Multivariable associations between the clinical assessment items and sciatica for model (i) and model (ii).

Item variable	Model (i)
Item variable	Beta	OR (95% CI)	Beta	OR (95% CI)
Subjective sensory changes	0.98	2.66 (1.20, 5.90)	NS	NS
Below knee pain	1.83	6.25 (2.80, 13.94)	0.76	2.13 (1.19, 3.83)
Leg pain worse than back pain	1.52	4.55 (1.89, 10.99)	1.08	2.94 (1.77, 4.89)
Leg pain intensity	NS	NS	0.14	1.15 (1.03, 1.29)
Positive cough / sneeze	NS	NS	0.92	2.50 (1.34, 4.65)
Neural Tension tests	3.07	21.63 (9.00,51.97)	0.56	1.76 (1.03, 3.00)
Neurological deficit	2.14	8.50 (3.80,19.01)	1.04	2.81 (1.69, 4.69)
Intercept	-3.25		-2.98
AUC		0.95 (0.93, 0.98)		0.82 (0.78, 0.86)

Abbreviations: OR, odds ratios; CI, confidence intervals; AUC, area under the receiver operating characteristic curve; NS, non-significant at p≤ 0.05

Model (i): Confidence ≥80% sciatica clinical diagnosis

Model (ii): Confidence ≥80% sciatica clinical diagnosis plus confirmatory magnetic resonance imaging (MRI) findings

The predicted probability of sciatica can be calculated using the following formulae

Model (i): Probability (sciatica⁺) = 1/ 1+exp -[-3.25 + (subjective sensory changes x 0.98) + (below knee pain x 1.83) + (leg pain worse than back pain x 1.52) + (neural tension x 3.07) + (neurological deficit x 2.14)].

Model (ii): Probability (sciatica⁺) = 1/ 1+exp -[-2.98 + (below knee pain x0.76) + (leg pain worse than back pain x 1.08) + (intensity leg pain x 0.14) + (positive cough/sneeze x 0.92) + (neural tension x 0.56) + (neurological deficit x 1.04)]