Effect of analgesic therapy on clinical outcome measures in a randomized controlled trial using client-owned dogs with hip osteoarthritis

BMC Veterinary Research

Research Article

Elizabeth M Cozzi¹  Peer B Jacobson¹  Brett Nemke²  Jason A Bleedorn²  Susannah J Sample²  Peter Muir²  Zeev Schwartz²  Susan L Schaefer²  Gerianne Holzman²  Sarah Malek² 

[1] Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL, USA;Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA;

关键词: Dog;    Hip;    Osteoarthritis;    Outcome measures;    Clinical trial;    Carprofen;    Tramadol;    ABT-116;   

DOI  :  10.1186/1746-6148-8-185

 received in 2012-03-29, accepted in 2012-09-17,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundPain and impaired mobility because of osteoarthritis (OA) is common in dogs and humans. Efficacy studies of analgesic drug treatment of dogs with naturally occurring OA may be challenging, as a caregiver placebo effect is typically evident. However, little is known about effect sizes of common outcome-measures in canine clinical trials evaluating treatment of OA pain. Forty-nine client-owned dogs with hip OA were enrolled in a randomized, double-blinded placebo-controlled prospective trial. After a 1 week baseline period, dogs were randomly assigned to a treatment (ABT-116 – transient receptor potential vanilloid 1 (TRPV1) antagonist, Carprofen – non-steroidal anti-inflammatory drug (NSAID), Tramadol - synthetic opiate, or Placebo) for 2 weeks. Outcome-measures included physical examination parameters, owner questionnaire, activity monitoring, gait analysis, and use of rescue medication.ResultsAcute hyperthermia developed after ABT-116 treatment (P < 0.001). Treatment with carprofen (P ≤ 0.01) and tramadol (P ≤ 0.001) led to improved mobility assessed by owner questionnaire. Nighttime activity was increased after ABT-116 treatment (P = 0.01). Kinetic gait analysis did not reveal significant treatment effects. Use of rescue treatment decreased with treatment in the ABT-116 and Carprofen groups (P < 0.001). Questionnaire score and activity count at the end of treatment were correlated with age, clinical severity at trial entry, and outcome measure baseline status (SR ≥ ±0.40, P ≤ 0.005). Placebo treatment effects were evident with all variables studied.ConclusionTreatment of hip OA in client-owned dogs is associated with a placebo effect for all variables that are commonly used for efficacy studies of analgesic drugs. This likely reflects caregiver bias or the phenomenon of regression to the mean. In the present study, outcome measures with significant effects also varied between groups, highlighting the value of using multiple outcome measures, as well as an a priori analysis of effect size associated with each measure. Effect size data from the present study could be used to inform design of future trials studying analgesic treatment of canine OA. Our results suggest that analgesic treatment with ABT-116 is not as effective as carprofen or tramadol for treatment of hip arthritis pain in client-owned dogs.

【 授权许可】

Unknown   
© Malek et al.; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.