Table 2 Primary and Secondary Outcomes

Primary outcome

Overall responder

Showing 1 of the 3 followings:

 ≥ 50% decrease and absolute change ≥ 20 in VAS score on average pain intensity;

 ≥ 50% decrease and absolute change ≥ 20 in AUSCAN;

 ≥ 20% decrease and absolute change ≥ 10 in at least two measurements of VAS score on average pain intensity, AUSCAN and global assessment

Week 5

Secondary outcomes

Overall responder

Showing 1 of the 3 followings:

 ≥ 50% decrease and absolute change ≥ 20 in VAS score on average pain intensity;

 ≥ 50% decrease and absolute change ≥ 20 in AUSCAN;

 ≥ 20% decrease and absolute change ≥ 10 in at least two measurements of VAS score on average pain intensity, AUSCAN and global assessment

Week 8,

week 16

Pain

Change in VAS score from baseline on average pain intensity

Change in VAS score from baseline on maximal pain intensity

The proportion of participants with an at least 15-point decrease in VAS score from baseline on average pain intensity

Week 5,

week 8,

week 16

Physical function

Change in AUSCAN total score from baseline

Change in AUSCAN subscale scores including pain, stiffness and physical function from baseline

Change in FIHOA from baseline

Week 5,

week 8,

week 16

Patient global assessment

Change in patient global assessment of improvement from baseline

Week 5,

week 8,

week 16

Joint activity

Change in the number of painful joints from baseline

Change in the number of tender joints from baseline

Change in the number of swollen joints from baseline

Week 5,

week 8,

week 16

Hand strength

Change in hand grip strength from baseline

Change in hand pinch strength from baseline

Week 5,

week 8,

week 16

Quality of life

Change in WHOQOL-BREF from baseline

Week 5,

week 8,

week 16

Other outcomes

Participants' expectations for acupuncture at baseline

Blinding assessment right after the last session

Safety assessment during the trial

Proportion of participants taking rescue medication

Frequency and total dosage of rescue medication