Summary of findings per diabetes-specific PROM measuring physical functioning in people with type 2 diabetes, with a rating of the summarized result (+, −, ±, ?) and a grading of the quality of the evidence (H, M, L, V)
| PROM—subscale | Content validity | Structural validity | Internal consistency* | Cross-cultural validity | Measurement invariance | Reliability | Measurement error | Criterion validity | Hypotheses testing for construct validity | Responsiveness | ||||||
| Relevance | Comprehensiveness | Comprehensibility | Other instruments | Subgroups | Gold standard | Other instruments | Subgroups | Before–after intervention | ||||||||
| DFS—Daily activities42 | + (V) | + (V) | + (M) | ? | ? | Daily life: − (V) Dependence: + (V) | + (M) | ? | − (L) | |||||||
| DFS-SF—Dependence/daily life34 38 45 60 61 | + (L) | + (V) | + (M) | + (H) | + (H) | + (V) | + (L) | ± (H) | + (H) | ± (H) | ||||||
| PRO-DM-Thai—Physical function35 | + (L) | ± (L) | + (L) | + (H) | + (H) | – (V) | ||||||||||
| IWADL/APPADL—(Physical) activities of daily living36 46 | + (L) | + (V) | + (V) | + (L) | + (L) | + (M) | – (L) | ± (H) | ± (L) | |||||||
| QOLID—Physical endurance37 | ± (V) | ? | + (V) | + (V) | ? | ± (V) | – (H) | |||||||||
| DQLCTQ— Physical function44 | − (V) | ? | ± (V) | ? | + (L) | ± (H) | − (H) | |||||||||
| Diabetes-39— Energy and Mobility (pilot version, 14 items)43 | − (V) | – (V) | + (M) | + (M) | + (M) | ? | ||||||||||
| Diabetes-39— Energy and Mobility (15 items)39–41 43 48 51 59 | − (V) | – (V) | + (M) | + (H) | + (H) | + (M) | ± (H) | ± (H) | ||||||||
| Diabetes-39 Thai—Energy and Mobility (10 items)49 | − (V) | – (V) | + (M) | – (M) | ? | ± (M) | ± (H) | |||||||||
| Diabetes-39 German—Physical impairment (seven items)50 | ? | ? | ? | ? | ? | ? | + (H) | ? | ||||||||
| Diabetes-39 SF— Energy and Mobility (five items)48 | − (V) | – (V) | + (M) | + (H) | ||||||||||||
| C-CWIS—Physical symptoms and everyday living47 | – (V) | – (V) | + (L) | + (M) | + (M) | ? | + (V) | |||||||||
+: sufficient overall rating; −: insufficient overall rating; ±: inconsistent overall rating; ?: indeterminate overall rating; V: very low—we have very little confidence in the measurement property estimate, the true measurement property is likely to be substantially different from the estimate of the measurement property; L: low—our confidence in the measurement property is limited, the true measurement property may be substantially different from the estimate of the measurement property; M: moderate—we are moderately confident in the measurement property estimate, the true measurement property is likely to be close to the estimate of the measurement property, but this is a possibility that it is substantially different; H: high—we are very confident that the true measurement property lies close to that of the estimate of the measurement property.
*Per protocol of the COSMIN guideline for systematic reviews, the quality of evidence for internal consistency cannot be higher than the quality of evidence for structural validity.23
C-CWIS, Chinese Cardiff Wound Impact Schedule; COSMIN, COnsensus-based Standards for the selection of health Measurement INstruments; DFS, Diabetic Foot Ulcer Scale; DFS-SF, Diabetic Foot Ulcer Scale—Short Form; DQLCTQ, Diabetes Quality of Life Clinical Trial Questionnaire; IWADL/APPADL, Impact of Weight on Activities of Daily Living Questionnaire; PRO-DM-Thai, patient-reported outcomes instrument for Thai patients with type 2 diabetes; PROM, patient-reported outcome measure; QOLID, Quality of Life Instrument for Indian Diabetes Patients.