Comparison of four pain scales in patients with hip fracture or other lower limb trauma.

Background: The applicability of the Visual Analogue Scale (VAS) has been questioned in the assessment of pain in the elderly. We compared VAS with three other pain scales, Verbal Rating Scale (VRS), Red Wedge Scale (RWS) and Box Scale (BS), in hip fracture patients.

Methods: VAS, VRS, RWS and BS were compared in 140 analysable patients undergoing surgery, 70 with hip fracture and 70 with other lower limb trauma. Pain scores were recorded once a day, repeated after 10 min, for 4 subsequent days starting pre-operatively. The primary endpoint was the rate of successful pain measurements in hip fracture patients and 90% was chosen as a sufficient level for an applicable pain scale.

Results: Age was different between the groups (hip fracture 78 ± 11, other trauma 49 ± 11 years, P<0.0001). In hip fracture patients, 67-83% of pain measurements were successful with VAS, 82-100% with VRS, 83-96% with RWS and 79-91% with BS. The success rate with VAS was significantly <90% on 2 days (P<0.0001) and with BS on 1 day (P=0.04). All the other success rates with the four scales in both groups were above or not different from 90%.

Conclusion: VRS and RWS were the most applicable scales, unlike VAS, which appeared to be an unreliable pain scale in perioperative hip fracture patients. In patients with other lower limb trauma, all four scales provided excellent applicability. Our results are in accordance with the accumulating evidence suggesting that VAS is not an ideal tool for pain measurement in the elderly.