Table 1 Definitions of and Cut-off values for rating the Clinical Measurement Properties described in this Review

A measure of the consistency for the scores obtained between two rates that are measuring the same subject.

A property of which the stability of the result using the same outcome measure with the same group of subjects in a repeated test.

A reliability measure; ensuring all measurement items measure the same context.

Kappa^a

A preferred statistical measure for rating the inter-rate reliability; cut-off value: ≥ 0.70– acceptable [10, 16, 17].

Cronbach’s α^b

A statistical measure for rating the internal consistency; cut-off value: ≥ 0.70– acceptable [10, 18].

ICC^c

A statistical measure for rating the reliability; cut-off value: ≥ 0.70– acceptable [10].

Concurrent validity

A type of criterion validity; examining the consistency of the score obtained by the testing instrument compared with a gold standard.

Predictive validity

A type of criterion validity; measuring a correlation between the testing score and future events.

Construct validity

r^d

An essential measurement validity which assesses whether a testing instrument measures what it was made to measure by comparing hypothetical and non-criterion parameters.

A statistical measure for rating the correlation of linear relationship between two variables; cut-off values: > 0.75 - excellent; 0.50 to 0.75 - moderate; 0.25 to 0.49 - mild; < 0.25 – weak [14].

Diagnostic accuracy

ROC^e

An ability to discriminate the population with targeted health condition.

A statistical measure for expressing how well the measure can distinguish between two populations; cut-off values: 0.9 to 1.0 - excellent; 0.8 to 0.89 - very good; 0.7 to 0.79 - good; 0.6 to 0.69 - sufficient; 0.5 to 0.59 - insufficient; < 0.5 - no use [15].

An ability to detect the changes in health outcomes following the intervention.

MDC^f

A statistical measure for rating the response to changes which is not due to the measurement error.