Table 1.

Search strategy in MEDLINE (via Pubmed)

1#	(((((((patient outcome assessment (Mesh)) OR ((outcome and process assessment (Mesh)))) OR treatment outcome (Mesh) OR instrumentation (sh) OR methods (sh) OR ‘Validation Studies’ (pt) OR ‘Comparative Study’ (pt) OR ‘psychometrics’ (MeSH) OR psychometr* (tiab) OR clinimetr* (tw) OR clinometr*(tw) OR ‘outcome assessment (healthcare)’ (MeSH) OR ‘outcome assessment’ (tiab) OR ‘outcome measure*‘(tw) OR ‘observer variation’ (MeSH) OR ‘observer variation’ (tiab) OR ‘Health Status Indicators’ (Mesh) OR ‘reproducibility of results’ (MeSH) OR reproducib* (tiab) OR ‘discriminant analysis’ (MeSH) OR reliab*(tiab) OR unreliab* (tiab) OR valid* (tiab) OR ‘coefficient of variation’(tiab) OR coefficient (tiab) OR homogeneity (tiab) OR homogeneous(tiab) OR ‘internal consistency’ (tiab) OR (cronbach* (tiab) AND (alpha (tiab) OR alphas (tiab))) OR (item (tiab) AND (correlation* (tiab) OR selection* (tiab) OR reduction* (tiab))) OR agreement (tw) OR precision (tw) OR imprecision (tw) OR ‘precise values’ (tw) OR test-retest(tiab) OR (test (tiab) AND retest (tiab)) OR (reliab* (tiab) AND (test(tiab) OR retest(tiab))) OR stability (tiab) OR interrater (tiab) OR inter-rater (tiab) OR intrarater (tiab) OR intra-rater (tiab) OR intertester (tiab) OR inter-tester (tiab) OR intratester (tiab) OR intra-tester (tiab) OR interobserver (tiab) OR inter-observer (tiab) OR intraobserver (tiab) OR intra-observer (tiab) OR intertechnician (tiab) OR inter-technician (tiab) OR intratechnician (tiab) OR intra-technician (tiab) OR interexaminer (tiab) OR inter-examiner (tiab) OR intraexaminer (tiab) OR intra-examiner (tiab) OR interassay (tiab) OR inter-assay (tiab) OR intraassay (tiab) OR intra-assay (tiab) OR interindividual (tiab) OR inter-individual (tiab) OR intraindividual (tiab) OR intra-individual (tiab) OR interparticipant (tiab) OR inter-participant (tiab) OR intraparticipant (tiab) OR intra-participant (tiab) OR kappa (tiab) OR kappa’s (tiab) OR kappas (tiab) OR repeatab*(tw) OR ((replicab* (tw) OR repeated (tw)) AND (measure (tw) OR measures (tw) OR findings (tw) OR result (tw) OR results (tw) OR test (tw) OR tests (tw))) OR generaliza* (tiab) OR generalisa* (tiab) OR concordance (tiab) OR (intraclass (tiab) AND correlation* (tiab)) OR discriminative (tiab) OR ‘known group’ (tiab) OR ‘factor analysis’ (tiab) OR ‘factor analyses’ (tiab) OR ‘factor structure’ (tiab) OR ‘factor structures’ (tiab) OR dimension* (tiab) OR subscale* (tiab) OR (multitrait (tiab) AND scaling (tiab) AND (analysis(tiab) OR analyses(tiab))) OR ‘item discriminant’ (tiab) OR ‘interscale correlation*’ (tiab) OR error(tiab) OR errors(tiab) OR ‘individual variability’ (tiab) OR ‘interval variability’ (tiab) OR ‘rate variability’ (tiab) OR (variability (tiab) AND (analysis (tiab) OR values (tiab))) OR (uncertainty (tiab) AND (measurement (tiab) OR measuring (tiab))) OR ‘SE of measurement’ (tiab) OR sensitiv* (tiab) OR responsive* (tiab) OR (limit (tiab) AND detection (tiab)) OR ‘minimal detectable concentration’(tiab) OR interpretab*(tiab) OR ((minimal (tiab) OR minimally (tiab) OR clinical (tiab) OR clinically (tiab)) AND (important (tiab) OR significant (tiab) OR detectable (tiab)) AND (change (tiab) OR difference (tiab))) OR (small* (tiab) AND (real (tiab) OR detectable (tiab)) AND (change (tiab) OR difference (tiab))) OR ‘meaningful change’ (tiab) OR ‘ceiling effect’ (tiab) OR ‘floor effect’ (tiab) OR ‘Item response model’ (tiab) OR IRT (tiab) OR Rasch (tiab) OR ‘Differential item functioning’(tiab) OR DIF(tiab) OR ‘computer adaptive testing’ (tiab) OR ‘item bank’ (tiab) OR ‘cross-cultural equivalence’ (tiab))))))
2#	(((((pressure biofeedback unit (Title/Abstract) OR pressure biofeedback units (Title/Abstract) OR unit, pressure biofeedback (Title/Abstract) OR units, pressure biofeedback (Title/Abstract) OR stabilizer (Title/Abstract) OR (Title/Abstract) OR stabiliser (Title/Abstract) OR stabilizers (Title/Abstract) OR biofeedback (Title/Abstract) OR biofeedbacks (Title/Abstract) OR craniocervical flexion test (Title/Abstract) OR cranio-cervical flexion test (Title/Abstract) OR cranio cervical flexion test (Title/Abstract) OR cranio cervical flexion (Title/Abstract)))))
3#	((((((Muscle, Neck (Title/Abstract) OR Muscles, Neck (Title/Abstract) OR Neck muscle (Title/Abstract)))) OR Neck muscles (MeSH Terms))) OR ((neck (MeSH Terms)) OR Necks (Title/Abstract) OR deep cervical flexor* (Title/Abstract) OR rectus capit* (Title/Abstract) OR longus colli (Title/Abstract) OR longus capiti (Title/Abstract)))
4#	1# AND 2# AND 3#