Table 2 Checklist for rating the clinimetric qualities of self-assessment instruments.
Clinimetric quality | Definition | Criteria to rate the clinimetric quality |
|---|---|---|
Content validity | The extent to which the domain of interest is comprehensively sampled by the items in the measure | 1) Patients and experts were involved during item selection/reduction 2) Patients were consulted for reading and comprehension Rating: + patients and experts were involved ± only patients were involved - no patient involvement ? no information found on content validity |
Readability | The questionnaire is understandable for all patients | Rating: + reading was tested and result was good - inadequate readability ? no information about readibility |
Reliability | The extent to which the same results are obtained on repeated administrations of the same measure when no change in physical functioning has occurred (reliability) or the extent to how precise the scores are on repeated measurements (agreement) | 1) Correlation coefficient (r > .70); limits of agreement, kappa or standard error of measurement are presented Rating: + adequate design, method and r > .70 ± doubtful method used - inadequate reliability or agreement ? no information found on reliability or agreement |
Internal consistency | The extent to which items in a subscale are inter-correlated; a measure of the homogeneity of the subscale | 1) Factor analysis was applied in order to provide the dimensionality of the measure 2) Cronbach's alpha between .70 an .90 for each subscale Rating: + adequate design, factor analysis; alpha: .70 – .90 ± doubtful method used - inadequate internal consistency ? no information found on internal consistency |
Construct validity | The extent to which scores relate to other measures in a manner that is consistent with theoretically derived hypothesis concerning the domains that are measured | 1) Hypotheses were formulated 2) Results were acceptable in accordance with the hypotheses Rating: + adequate design, results in accordance with the hypotheses ± doubtful method used - inadequate construct validity ? no information found on construct validity |
Floor-ceiling effects | The measure fails to demonstrate a worse score in patients who were clinically deteriorated and/or an improved score in patients who clinically improved | 1) Descriptive statistics of the distribution of scores were presented 2) 15% of the respondents achieved the highest or lowest possible score Rating: + no floor- and ceiling effects - > 15% in extremities ? no information found on floor-ceiling effects |
Responsiveness | The ability to detect important change over time in the concept being measured | 1) Hypotheses were formulated and results were in agreement 2) An adequate measure was used (effect size, standard response mean or comparison with external standard) Rating: + adequate design, method and result ± doubtful method used - inadequate responsiveness ? no information found on responsiveness |
Interpretability | The degree to which one can assign qualitative meaning to quantitative scores | Authors provided information on the interpretation of scores: 1) Presentation of means and standard deviations of scores 2) Comparative data in relevant subgroups 3) Information on the relationship of scores to well-known functional measures or clinical diagnosis 4) Information on the association between change in scores and patients global ratings of the magnitude of change they have experienced Rating: + 2 or more types of information was presented ± doubtful method used or doubtful description ? no information found on interpretability |
Minimally clinical important difference (MCID) | The smallest difference in scores in the domain of interest which patients perceive as beneficial and would mandate a change in patients' management | Information is provided about what difference in score would be clinically meaningful Rating: + minimally clinical important difference presented - no minimally clinical important difference presented |
Time to administer | Time needed to complete the measure | Rating: + less than 10 minutes - more than 10 minutes ? no information |
Administration burden | Ease of method used to calculate the questionnaire's score | Rating: + easy: summing up the items ± moderate: visual analogue score or simple formula - difficult: complex formula ? no information found on rating method |