A SYSTEMATIC REVIEW OF THE EFFECTS OF PSYCHOTHERAPY ...

generalizability (Shambo et al), or the reported results precluded making confident judgment
about the effectiveness of the intervention (Iannone).
4.2 Strength of the Research
In the aggregate, the quality of the evidence reviewed falls in the moderate to low range
of the criteria established for the GRADE system (EBM Guidelines Editorial Team, 2006). To be
considered moderate evidence, “Further research is likely to have an important impact on our
confidence in the estimate of effect and may change the estimate”, while low levels of evidence
are “… very likely to have an important impact on our confidence in the estimate of effect and is
likely to change the estimate’ [italics not in original] (p. 6).
4.3 Confidence Level for Recommendation
Only in the past few years has methodologically rigorous evidence begun to emerge in
the field of equine-facilitated/assisted psychotherapy and to date no randomized clinical trials,
considered the gold standard in research methodology, have been conducted. Taken as a whole,
this selection of studies illustrates the difficulties involved in assessing and isolating the effects of
psychotherapy employing equines; however, the promising levels of quantitative research
summarized in this review lend credibility to the employment of equine-assisted techniques as an
adjunct to traditional psychotherapy.
4.4 Limitations
This review examines the effectiveness of involving equines in the psychotherapeutic
process in an attempt to begin to answer the questions of most interest to clinicians. However,
because of the nature of this study, the results should be considered in light of several limitations.
One of the strengths of the systematic review is the effort to review the extant literature
objectively and with the same rigor that is the ideal in primary research. According to Gambrill
(2006), “Rigorous reviews are designed to minimize the likelihood that the effects of interventions
will be confused with the effects of biases and chance” (p. 292). If strong prior beliefs are held,
then a purely objective review will be difficult to achieve. For these reasons, it is recommended
that more than one individual be involved in the selection and evaluation of studies, and that the
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