Shoulder outcome measures: is there a right answer?

Purpose A number of outcome measures (instruments)
are used to assess shoulder pain and function in clinical
practice. No clear ‘gold standard’ exists and it is thought
that different instruments will give a different answer. Our
aim is to statistically compare four commonly used outcome
measures in a group of trauma patients and to identify
whether instruments which combine objective and
subjective components differ from those which are purely
subjective.
Methods Forty-four patients undergoing internal fixation
of proximal humeral fractures were recruited between 2003
and 2008. Each was asked to complete a number of outcome
measures: University of Los Angeles score (UCLA);
Constant and Murley score (Constant); Oxford Shoulder
Score (OSS); Quick form of the Disabilities of the Arm,
Shoulder and Hand questionnaire (QuickDASH). Each
were measured on a different scale but were standardised to
0–100 for comparison.
Results Purely subjective instruments gave higher scores
(better function and/or less pain). Statistical differences
were found between each pair of instruments (p\0.001),
except for the comparison between UCLA and QuickDASH
(p = 0.403). The study found inconsistencies between
instruments, with outcomes varying depending on whether
subjective or objective measurements were being assessed.
Conclusions Outcome measures are useful tools, but clinicians
need to be aware that their choice of instrument
should be made carefully, taking into account the reason
behind its use with regard to outcome.