Conducting methodologically rigorous randomized trials
and systematic reviews of specific rehabilitation inter-
ventions is complex. Rehabilitation entails a range of
activities aimed at promoting activity and participation.
Precise evaluation of rehabilitation interventions that
are traditionally tailored by a therapist or nurse to
meet the identified needs of an individual patient can
be very difficult to achieve within a randomized trial.
Particular problems include achieving consistency of
intervention by different staff to different patients on
different days, and documentation of the interven-
tion in a manner that would allow reproduction of
the treatments evaluated. While a key strength of the
randomized trial can be that patients and health
professionals are blind to the treatment given, it is
often impossible to achieve blinding when a therapist
is applying a manual treatment technique to a patient.
Many rehabilitation interventions are aimed at amelio-
rating a specific body function or promoting a specific
activity and it can be difficult to find a clinically
meaningful, reliable, valid measure of outcome which
is sensitive to changes occurring as a result of the
intervention. It could be argued that the particular
strengths of randomized trials lie, not with the evaluation
of specific treatments, but with the evaluation of more
general rehabilitation policies (e.g. policies for preventing
shoulder pain or bed sores).