Variability of outcome measures among trials of topical Chinese herbal medicines for musculoskeletal injuries

Article type
Authors
Wang L1, Yuan Q1, Li X1, Li Y1
1Chinese Cochrane Centre, China
Abstract
Background: Traditional Chinese herbal medicines showed promising effects for musculoskeletal injuries. However, most trials addressing the effects of topical Chinese herbal medicines are of low quality, often with variable and subjective outcome measures.

Objectives: To assess the variability of outcome measures among trials of topical Chinese herbal medicines for musculoskeletal injuries.

Methods: We searched PubMed, EMBASE, CENTRAL, Chinese Biomedical Database, CNKI, and VIP from the inception to December 2010. Randomized trials of topical Chinese herbal medicines for musculoskeletal injuries were included. We analyzed the outcome measures of the trials.

Results: Forty-five trials were included. Seventeen trials reported the overall efficacy with four categories of “cured”, “excellent”, “good”, and “no effect”, and nineteen trials with three categories of “excellent”, “good”, and “no effect”. However, criteria to determine the efficacy varied among trials. Among seventeen trials, ten reported curing using “symptoms and physical signs of patients disappeared, and physical function recovered to normal level” three adding “overall improvement >95%” two using “>90%”. Two other trials did not report any definition of curing. The thresholds of “excellent” efficacy of overall improvement ranged from “>75%” (1 trial), “>70%” (6 trials), “>2/3” (11 trials), to “>50%” (2trials). Twelve trials described excellent as “symptoms disappeared and physical function recovered”, coinciding with the definition of “curing”. Four trials described “curing” as “symptoms and physical signs significantly improved”. Eight trials reported pain score reduction. Among them, five trials used visual analogue scales, three used a self-categorized numerical rating scale, and one used the WOMAC index.

Conclusions: The outcome measures of topical Chinese herbal medicines for musculoskeletal injuries greatly varied among trials, which may greatly influence the data extraction and synthesis, even mistakenly combining data for specific outcomes. Criteria to define the outcome measures and validated pain scores for Chinese herbal medicines are urgently required.