Table 1

Baseline characteristics of included patients

CharacteristicPTED
(N=179)
OM
(N=309)
Age—year (SD)45.3±12.445.7±11.3
Male sex—no (%)99 (55.3)180 (58.3)
Current smoker—no (%)43 (24.0)91 (29.5)
Body mass index—kg/m2 26.6±4.126.8±5.4
Paid employment—no (%)151 (84.4)242 (78.6)
Duration of sciatica—months4.2±3.04.2±2.9
Radiating pain in the right leg—no (%)84 (46.9)155 (50.2)
Sensory disturbances—no (%)161 (89.9)290 (93.3)
Muscle weakness—no (%)92 (51.4)183 (59.2)
Difference in deep-tendon reflexes in the knees—no (%)48 (26.8)81 (26.4)
Difference in deep-tendon reflexes in the ankles—no (%)42 (23.5)77 (25.1)
Level of disc herniation causing sciatica—no (%)
 L2–L32 (1.1)7 (2.3)
 L3–L415 (8.4)13 (4.2)
 L4–L568 (38.0)137 (44.3)
 L5–L61 (0.6)2 (0.6)
 L5–S193 (52.0)148 (47.9)
 L6–S102 (0.6)
Score on the Visual Analogue Scale of pain*
 Leg pain67.3±21.769.9±20.6
 Back pain48.7±27.645.4±29.7
Oswestry Disability Index†44.5±16.945.5±17.1
Score on the Visual Analogue Scale of quality of life‡46.8±19.948.8±21.9
SF-36 score§
 Physical component summary30.4±7.729.6±7.7
 Mental component summary47.4±10.846.5±11.3
Four-dimensional symptom questionnaire¶
 Distress9.7±7.29.3±7.4
 Depression1.0±1.91.1±2.2
 Anxiety1.3±2.41.5±2.7
 Somatisation6.8±4.37.2±5.1
Preference for PTED—no (%)85.577.9
  • One patient in the open microdiscectomy group had missing scores on the Oswestry Disability Index, VAS for QoL and back pain, Four-dimensional symptom questionnaire and Short-Form-36 at baseline. Values are means±SD.

  • *The visual-analogue scale scores the intensity of leg and back pain from 0 to 100 with higher scores indicating more pain.

  • †The Oswestry Disability Index measures functional disability from 0 to 100 with higher scores indicating more functional disability.

  • ‡The visual-analogue scale of quality of life scores the general quality of life from 0 to 100 with higher scores indicating a better quality of life.

  • §The SF-36 score can be summarized in a physical component summary and a mental component summary using normative data. Higher scores indicate a better quality of life.

  • ¶The four-dimensional symptom questionnaire measures distress in four categories.

  • PTED, percutaneous transforaminal endoscopic discectomy; QoL, quality of life; VAS, Visual Analogue Scale.