Table 6 Reasons for each risk of bias item
Capra et al., 2011 [16] | Risk of bias Flow and timing (high risk): high risk due to the time intervals between the reference standard, index test and any other treatment administered was not stated in the study. Applicability concerns Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |
Gudala et al., 2017 [30] | Risk of bias Index test (Unclear): it was not stated if the index test was administered without prior knowledge of reference standard results. Furthermore, the use of Physicians assessment as a gold standard was not supported with any pre-defined threshold. Reference standard (Unclear): it was not stated in the study whether the reference standard was administered without prior knowledge of the index test results. Applicability concerns Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |
Lin et al., 2017 [17] | Applicability concerns Patient selection (high risk): The patient population selected for this study were exclusively surgical patients and therefore not entirely consistent with the target population for this review. Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |
Poiraudeau et al., 2001 [31] | Risk of bias Reference standard (high risk): examiner 1 of 3 was involved with initial patient clerking/examination which may have influenced interpretation of reference standard results. Flow and timing (high risk): All tests were done on the same day however the time intervals between tests were not specified. Applicability concerns Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |
Scholz et al., 2009 [12] | Applicability concerns Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |
Smart et al., 2012 [18] | Risk of bias Index test (high risk): index test was conducted with knowledge of the results of the reference standard. Applicability concerns Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |
Trainor et al., 2011 [32] | Risk of bias Patient selection (high risk): convenience sampling was used to recruit patients. Flow and timing (high risk): ‘small’ intervals were taken between each examiner conducting the index test (slump knee bend test), which have influenced test result. Applicability concerns Patient selection: due to small sample size in this study the applicability to the wider target population is poor. Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |
Urban et al., 2015 [33] | Risk of bias Patient selection (high risk): convenience sampling was used to recruit patients. Flow and timing (high risk): the index test was completed immediately after the clinical examination (reference standard) which may have influenced the results of the index test. Applicability concerns Patient selection: due to small sample size in this study the applicability to the wider target population is poor. Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |
Verwoerd et al., 2014 [34] | Risk of bias Patient selection (Unclear): unclear how the patient population was recruited. Index test (Unclear): It was not specified if the index test was completed without knowledge of the reference standard results. Applicability concerns Patient selection (high risk): the patient population consisted of those with “severe sciatica” and therefore not representative of those with mild and moderate symptoms. Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |
Vroomen et al., 2002 [19] | Applicability concerns Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |
Walsh et al., 2009 [14] | Risk of bias Reference standard (high risk): The reference standard was a neurodynamic test which has been found to have low diagnostic validity. Flow and timing (high risk): the SLR and slump test were performed immediately after the nerve palpation which may have affected the test findings. Applicability concerns Reference standard (Unclear): unclear as there is no clear gold standard for diagnosing NP in LBLP |