Table 1.

Summary of psychometric properties and criteria used to review measures.

Psychometric Property	Criteria
Reliability
Internal consistency   degree to which responses to all items on a scale are consistent [43]	Calculated correlations for total scale and domains [44]   - Cronbach's alpha (α) > 0.70 [42,44]   - Kuder-Richardson 20 (KR-20) > 0.70 [42,44]
Test-retest   reproducibility of scores on a scale over repeated administrations [44]	Second administration within 2-14 days [46] Calculated correlations for total scale, domains and items [47]   - Cohen's kappa coefficient (κ) > 0.60 [44]   - Pearson correlation coefficient (r) > 0.70 [42,44]   - Intraclass correlation coefficient (ICC) > 0.70 [42,44]
Validity
Face     subjective assessment of whether a scale 'appears' to measure what it is designed to measure [43]	Assessed as reasonable by those who administer/complete it [43]
Content     degree to which the content of a scale is representative of the issue being measured [43]	Reported item selection process [42,44] Content assessed by experts [42,44] Reported which aspects of the measure were revised [42,44]
Construct     way in which the internal structure of a scale relates to other conceptual constructs [44]	Stated hypothesis about correlations between measures [44]     - Convergent (r) > 0.40 or Divergent (r) < 0.30 [48] Calculated correlations between known-groups [42] Performed factor analysis [44]     - Eigenvalues > 1 [49]
Criterion   how well a scale agrees with existing "gold standard" measurement of the same issue [44]	Provided rationale for "gold standard" measure [44] Stated type of criterion validity (concurrent or predictive) [43] Reported proportions [44,50]     - Sensitivity - % with issue correctly classified [44,50]     - Specificity - % without issue correctly classified [44,50]
Responsiveness   sensitivity of a scale to detect clinically important change in an outcome or behaviour over time [42,50]	Reported floor/ceiling effects [51] - < 5% of respondents have highest or lowest score [51] Reported magnitude of change [42] - Effect size > 0.5 [42,44,50]
Acceptability   level of burden placed on those who complete the measure [42]	Reported response rate, missing items, reading level, time to complete [42]
Feasibility   level of burden placed on those who administer the measure [42]	Reported perceived time to administer, score, interpret [42]
Cross-cultural adaptation   conceptually, linguistically equivalent and display similar psychometric properties to the original form [42]	Confirmed reliability and validity reflects the original version [42]