Inappropriate outcome measures for assessing the improvement due to methylprednisolone injections.
Dear Sir,
Dammers et al.1 reported that injection of methylprednisolone
proximal to the carpal tunnel may result in long term improvement in
patients with carpal tunnel syndrome. The primary outcome measure was
subjective symptomatic improvement as assessed by the patient at interview
with one of the authors. However, we feel that this is an inadequate
technique for measuring outcome.
A suitable quantitative technique should have been used for assessing
improvement, e.g. visual analogue scales. To be included in the study,
patients were assessed electrophysiologically prior to injection. Had the
patients been tested again after treatment, the initial test would have
provided a useful reference point for measuring functional improvement,
quantitatively.
Why was this study carried out? We wonder why there was an absence of
detailed comparisons with studies of intracarpal tunnel steroid injections
and feel that the study could have compared extra- to intracarpal tunnel
steroid injections rather than to placebo. This study merely served to put
their clinical practice of 20 years (which was known to be effective from
their own observations) on an evidence based footing.
We believe that this overall well-designed trial would have benefited
from more appropriate outcome measures. If the authors' aim was to provide
evidence for their clinical practice, we do not agree that this article
has achieved this.
Yours faithfully
Neil Smart Simon Hill John Holmes Elaine Clark Kevin Little
Competing interests: none
1. Dammers JWHH, Veering MM, Vermeulen M. Injection with
methylprednisolone proximal to the carpal tunnel: randomised double blind
trial. BMJ 1999;319:884-6.
Competing interests:
No competing interests
06 October 1999
Neil Smart
Stage 3 Medical Students
Simon Hill, John Holmes, Elaine Clark, Kevin Little
Department of Epidemiology and Public Health, The Medical School, University of Newcastle
Rapid Response:
Inappropriate outcome measures for assessing the improvement due to methylprednisolone injections.
Dear Sir,
Dammers et al.1 reported that injection of methylprednisolone
proximal to the carpal tunnel may result in long term improvement in
patients with carpal tunnel syndrome. The primary outcome measure was
subjective symptomatic improvement as assessed by the patient at interview
with one of the authors. However, we feel that this is an inadequate
technique for measuring outcome.
A suitable quantitative technique should have been used for assessing
improvement, e.g. visual analogue scales. To be included in the study,
patients were assessed electrophysiologically prior to injection. Had the
patients been tested again after treatment, the initial test would have
provided a useful reference point for measuring functional improvement,
quantitatively.
Why was this study carried out? We wonder why there was an absence of
detailed comparisons with studies of intracarpal tunnel steroid injections
and feel that the study could have compared extra- to intracarpal tunnel
steroid injections rather than to placebo. This study merely served to put
their clinical practice of 20 years (which was known to be effective from
their own observations) on an evidence based footing.
We believe that this overall well-designed trial would have benefited
from more appropriate outcome measures. If the authors' aim was to provide
evidence for their clinical practice, we do not agree that this article
has achieved this.
Yours faithfully
Neil Smart
Simon Hill
John Holmes
Elaine Clark
Kevin Little
Competing interests: none
1. Dammers JWHH, Veering MM, Vermeulen M. Injection with
methylprednisolone proximal to the carpal tunnel: randomised double blind
trial. BMJ 1999;319:884-6.
Competing interests: No competing interests