Table 2.

NDI and other questionnaires

Study	Design Strength	Design limit	Measure	Results
Gay et al 2007	N = 23 Prospective longitudinal study	Small sample size; short 4 week treatment timeline follow-up; no minimum pain level required for study entry	NDI, NBQ	Both had similar sensitivity to change and responsiveness; acceptable internal consistency; good convergent validity with each other and strong correlation for pre and post treatment scores
Hoving et al 2003	N = 71 WAD patients Cross-sectional study	More women in study; mean scores low on some items and doesn’t allow for detection of improvement; only cross-sectional data collected and therefore did not look at change over time	NDI, NPQ	Correlate highly with each other; NDI only includes certain factors measured; emotional and social items are absent in both.
Resnick 2005	N = 11 Narrative review	Did not include all neck pain measures because some unavailable; did not include non-organic signs tools	BNQ, CNFDS, DRI, ABPS, FRI, NDI, NPAD, NPNPQ, PSFS, WDQ, VAS	NDI first outcomes measure for neck pain and ADLs; high reliability, internal consistency, construct validity and moderate correlation between NDI, VAS and MPQ; NDI more correlation with SF-36 than with CROM.
McCarthy et al 2007	N = 150 questionnaires; Prospective single cohort study	Did not do with specific defined neck pain populations; hospital setting; did not investigate responsiveness to change of the NDI or floor or ceiling effects of NDI.	NDI & short form-36 health survey	Both have good internal consistency; NDI high test-retest reliability, good reliability and validity; NDI compares well with SF-36; MDID for NDI around 10 points.
Ferreira et al 2010	74 Systematic review	Not all questionnaires include all ICF categories, therefore all will fall short of fulfilling the requirements; some items could not be classified; not all descriptions fit into ICF framework.	NDI, PDI, NPQ, CNFDS, NPDS, NBQ, FRI; all compared with the ICF	NDI had excellent reliability and convergent correlation with VAS; NBQ, NDI and NPDS all have well-balanced distribution of items for body function, activity and participation components (and are best fit to ICF bio-psycho-social framework)