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Table 2 Updated criteria for good measurement properties by Terwee et al. [27] and Prinsenet al [28]

From: Obstetric triage systems: a systematic review of measurement properties (Clinimetric)

Measurement Property

Rating a

Criteria

Structural validity

+

CTT:

CFA: CFI or TLI or comparable measure > 0.95 or RMSEA< 0.06 or SRMR < 0.08b

IRT/Rash:

No violation of unidimensionalityc: CFI or TLI or comparable measure > 0.95 or RMSEA,0.06 or SRMR < 0.08

AND

No violation of local independence residual correlations among thr items after controlling for the dominant factor < 0.20 or Q3’s < 0.37

AND

No violation of monotonicity: adequate looking graphs or item scalability > 0.30

AND

Adequate model fit:

ITR:χ2 > 0.01

Rasch: infit and outfit mean squares ≥0.5 and ≤ 1.5 OR Z- standardized values > − 2 and < 2

?

CTT: Not all information for “+” reported

ITR/Rasch: Model fit not repored

Criteria for “+” not met

Internal Consistency

+

At least low evidenced for sufficient structural validitye AND cronbach’s alpha (s) ≥ 0.70 for each unidimensional scale or subscalef

?

Criteria for “at least low evidenced for sufficient structural validitye” not met

At least low evidenced for sufficient structural validitye AND cronbach alpha (s) < 0.70 for each unidimensional scale or subscalef

Reliability

+

ICC or weighted Kappa ≥0.70

?

ICC or weighted Kappa not reported

ICC or weighted Kappa < 0.70

Measurement error

+

SDC or LoA < MICe

?

MIC not defined

SDC or LoA > MICe

Hypotheses testing for construct validity

+

The result is in accordance with the hypothesisg

?

No hypothesis defined (by the review team)

The result is not in accordance with the hypothesisg

Cross-cultural validity/ measurement invariance

+

No important differences found between group factors (such as age, gender, language) in multiple group factor analysis OR no important DIF for group factors (McFadden’s R2 < 0.02)

?

No multiple group factor analysis OR DIF analysis performed

Important differences between group factors OR DIF was found

Criterion validity

+

Correlation with gold standard ≥0.70 OR AUC ≥ 0.70

?

Not all information for “+” reported

Correlation with gold standard < 0.70 OR AUC < 0.70

Responsiveness

+

The result is in accordance with the hypothesisg OR AUC ≥ 0.70

?

No hypothesis defined (by the review team)

The result is not in accordance with the hypothesisg OR AUC < 0.70

  1. AUC = area under the curve, CFA = confirmatory factor analysis, CFI = comparative fit index, CTT = classical test theory, DIF = differential item functioning, ICC = intraclass correlation coefficient, IRT = item response theory, LoA = limits of agreement, MIC = minimal important change, RMSEA: Root Mean Square Error of Approximation, SEM = Standard Error of Measurement, SDC = smallest detectable change, SRMR: Standardized Root Mean Residuals, TLI = Tucker-Lewisindex
  2. a “+” = sufficient,” – “= insufficient, “?” = indeterminate
  3. b To rate the quality of the summary score, the factor structures should be equal across studies
  4. c unidimensionality refers to a factor analysis per subscale, while structural validity refers to a factor analysis of a (multidimensional) patient-reported outcome measure
  5. d As defined by grading the evidence according to the GRADE approach
  6. e This evidence may come from different studies
  7. f The criteria ‘Cronbach alpha < 0.95’ was deleted, as this is relevant in the development phase of a PROM and not when evaluating an existing PROM
  8. g The results of all studies should be taken together and it should then be decided if 75% of the results are in accordance with the hypotheses