How can clinicians choose between conflicting and discordant systematic reviews? A replication study of the Jadad algorithm.

INTRODUCTION: The exponential growth of published systematic reviews (SRs) presents challenges for decision makers seeking to answer clinical, public health or policy questions. In 1997, an algorithm was created by Jadad et al. to choose the best SR across multiple. Our study aims to replicate author assessments using the Jadad algorithm to determine: (i) if we chose the same SR as the authors; and (ii) if we reach the same results. METHODS: We searched MEDLINE, Epistemonikos, and Cochrane Database of SRs. We included any study using the Jadad algorithm. We used consensus building strategies to operationalise the algorithm and to ensure a consistent approach to interpretation. RESULTS: We identified 21 studies that used the Jadad algorithm to choose one or more SRs. In 62% (13/21) of cases, we were unable to replicate the Jadad assessment and ultimately chose a different SR than the authors. Overall, 18 out of the 21 (86%) independent Jadad assessments agreed in direction of the findings despite 13 having chosen a different SR. CONCLUSIONS: Our results suggest that the Jadad algorithm is not reproducible between users as there are no prescriptive instructions about how to operationalise the algorithm. In the absence of a validated algorithm, we recommend that healthcare providers, policy makers, patients and researchers address conflicts between review findings by choosing the SR(s) with meta-analysis of RCTs that most closely resemble their clinical, public health, or policy question, are the most recent, comprehensive (i.e. number of included RCTs), and at the lowest risk of bias.

Is the parvocellular red nucleus involved in cerebellar motor learning?

The anatomical connections of the parvocellular red nucleus (RNp) have led to the suggestion that it might participate along with the cerebellum in modifying old and developing new programs for the control of complex, compound, coordinated movements of multiple body parts. RNp projects to and excites the inferior olivary nuclear neurons, which send climbing fibers to excite neurons in contralateral cerebellar cortex and nuclei. RNp receives excitatory inputs from ipsilateral cerebral cortex (onto distal dendrites) and from contralateral cerebellar nuclei (onto proximal dendrites). We here further develop a hypothesis as to mechanism, and offer preliminary evidence from RNp inactivation studies in awake, trained macaques during modification of their gaze-reach calibration while wearing wedge prism spectacles.