Table 10 Results of studies assessing internal consistency of the instruments included in the review
Instrument | N (DMD subsample) | Mean (SD) Age (DMD subsample) | % Female (DMD subsample) | Country | Cronbach’s α | Rating of measurement property | |
|---|---|---|---|---|---|---|---|
Rating | Quality of evidence | ||||||
CWBS [35] | 60 | NR | 41.7 | India | 0.92 | + | Moderate |
DUKE [37] | 126 | 43 (6.1) | 57.4 | Taiwan | 0.81 | + | High |
FAPGAR [37] | 126 | 43 (6.1) | 57.4 | Taiwan | 0.89 | + | High |
FPQ [46]a | 336 (246 DMD) | 41.2 (6.2) for DMD carers | 84.2 (83.3 DMD) | Italy | Ranged from 0.66 to 0.87 | ? | High |
HADS (Anxiety) [32] | 82 (71 DMD) | 40.40 (6.98) | 100 | USA | 0.87 | + | Moderate |
HADS (Depression) [32] | 82 (71 DMD) | 40.40 (6.98) | 100 | USA | 0.8 | + | Moderate |
PAS [51] | 205 at baseline (147 at year 1, 144 at year 2) | 44 (8.7) | 100 | USA | 0.96 | + | High |
PPC [51] | 205 at baseline (147 at year 1, 144 at year 2) | 44 (8.7) | 100 | USA | 0.79 | + | High |
PSS [32] | 82 (71 DMD) | 40.40 (6.98) | 100 | USA | 0.89 | + | Moderate |
QRS [53] | 36 | 43.04 (5.52) | 69.44 | Canada | 0.86 | + | Low |
SF-36 [32]a | 82 (71 DMD) | 40.40 (6.98) | 100 | USA | Ranged from 0.76 to 0.88 | + | Moderate |
SNQ (subscale A) [46] | 336 (246 DMD) | 41.2 (6.2) for DMD carers | 84.2 (83.3 DMD) | Italy | 0.69 | − | High |
WAC-DBMD [51] | 205 at baseline (147 at year 1, 144 at year 2) | 44 (8.7) | 100 | USA | 0.89 | + | High |
ZBI (22 item) [60] | 475 | 44 (NR) | 81 | UK, US | 0.914 | + | High |
ZBI (12 item) [51] | 205 at baseline (147 at year 1, 144 at year 2) | 44 (8.7) | 100 | USA | 0.89 | + | High |