Table 1 Predetermined hypotheses for evaluating the responsiveness of the QuickDASH and PSFS

1

The correlation between the QuickDASH/PSFS change score and the GROC is negative and moderate.

+

+

2

The ES and SRM of the QuickDASH/PSFS are < 0.2 for patients classifying themselves as ‘unchanged’ on the GROC.

+

–

3

The ES and SRM of the QuickDASH/PSFS are ≥0.5 for patients classifying themselves as ‘much improved’ on the GROC.

+

+

4

The correlation between the QuickDASH change score and the PSFS change score is moderate (> 0.30 and < 0.60).

Since both these PROMs measure the same construct (i.e. disability/function), we expected the magnitude of this correlation to be moderate.

+

+

5

The correlation between the QuickDASH/PSFS change score and the NRS change score is moderate (> 0.30 and < 0.60).

This hypothesis is based on the following research literature showing that PSFS correlates moderately with the NRS in upper extremity patients [5, 36].

–

+

6

The correlation between the NRS and QuickDASH change score is higher (at least 0.1) than the correlation between the NRS and PSFS change score.

Based on a recent study [35], and the understanding that the QuickDASH emphasise the construct of pain higher than the PSFS, we expected it to correlate higher with the NRS.

+

+

7

The correlation between the QuickDASH/PSFS change score and the SQK change score is moderate (> 0.30 and < 0.60).

This hypothesis is based on previous studies showing that fear of movement scales correlates moderately with shoulder disability scores [47, 48].

+

+

8

The correlation between the WA and PSFS change score is higher than the correlation between the WA and QuickDASH change score.

Recent studies show that shoulder patients report work/employment as PSFS items [6, 17]. The QuickDASH disability questionnaire used in this study does not capture work in a direct way [10]. Therefore, we expected lower correlation between the WA and QuickDASH compared to the correlation of WA and PSFS.

+

+

9

The correlation between the QuickDASH/PSFS change score and the HSCL-25 change score is low (< 0.30).

This rationale is based on previous studies showing that QuickDASH and PSFS correlates low with mental health component scores [49,50,51]. The Norwegian version of HSCL-25 has shown strong correlation with mental health scores [52].

–

+

n (%)

7/9 (77.8)

8/9 (88.9)