Table 4

Self-reported side effects over the first week and between weeks 2 and 4 (week 4 follow-up)

Days 1–7Weeks 2–4
NaproxenColchicineOR (95% CI)
{p value}
NNTH (95%CI)*NaproxenColchicineOR (95% CI)
{p value}
NNTH (95%CI)*
N (%)†N (%)†Complete case†Imputed‡N (%)†N (%)†Complete case†Imputed‡
Nausea and/or vomiting21 (14.0)30 (20.5)1.82 (0.96 to 3.46)
{p=0.066}
1.28 (0.71 to 2.30)
{p=0.42}
311 (8-∞1 to 27-∞2)7 (5.2)5 (3.2)0.51 (0.14 to 1.83)
{p=0.30}
0.59 (0.19 to 1.90)
{p=0.38}
482 (24-∞2 to 24-∞1)
Dyspepsia20 (13.3)20 (13.7)0.89 (0.48 to 1.90)
{p=0.95}
1.09 (0.58 to 2.04)
{p=0.79}
981 (9-∞1 to 19-∞2)13 (9.7)8 (5.2)0.44 (0.17 to 1.15)
{p=0.094}
0.59 (0.24 to 1.45)
{p=0.25}
272 (14-∞2 to 26-∞1)
Abdominal pain16 (10.7)16 (11.0)1.07 (0.51 to 2.25)
{p=0.86}
0.83 (0.40 to 1.71)
{p=0.61}
532 (16-∞2 to 16-∞1)4 (3.0)8 (5.2)1.57 (0.44 to 5.53)
{p=0.49}
1.32 (0.43 to 4.09)
{p=0.63}
1081 (12-∞1 to 59-∞2)
Headache16 (10.7)30 (20.5)2.38 (1.21 to 4.68)
{p=0.012}
1.92 (1.03 to 3.55)
{p=0.039}
121 (51 to 3501)4 (3.0)4 (2.6)0.92 (0.22 to 3.86)
{p=0.91}
0.80 (0.21 to 3.10)
{p=0.75}
1712 (42-∞2 to 17-∞1)
Constipation29 (19.3)7 (4.8)0.20 (0.08 to 0.48)
{p<0.001}
0.24 (0.11 to 0.54)
{p<0.001}
72 (62 to 132)9 (6.7)6 (3.9)0.49 (0.16 to 1.54)
{p=0.22}
0.57 (0.21 to 1.55)
{p=0.27}
362 (19-∞2 to 31-∞1)
Diarrhoea30 (20.0)67 (45.9)3.54 (2.10 to 5.99)
{p<0.001}
3.31 (2.01 to 5.44)
{p<0.001}
41 (31 to 71)5 (3.7)10 (6.5)1.75 (0.58 to 5.26)
{p=0.32}
1.59 (0.54 to 4.66)
{p=0.40}
491 (9-∞1 to 60-∞2)
Skin rash3 (2.0)3 (2.1)1.13 (0.22 to 5.83)
{p=0.88}
1.06 (0.21 to 5.39)
{p=0.95}
8511 (13-∞1 to 64-∞2)3 (2.2)3 (1.9)0.98 (0.19 to 5.09)
{p=0.98}
0.97 (0.19 to 5.03)
{p=0.97}
15482 (56-∞2 to 13-∞1)
Any side effect(s)§91 (60.7)101 (69.2)1.49¶ (0.92 to 2.43)
{p=0.11}¶
1.60 (1.03 to 2.49)
{p=0.038}
101 (51 to 1421)37 (27.6)28 (18.2)0.58 (0.33 to 1.03)
{p=0.064}
0.71 (0.41 to 1.23)
{p=0.23}
162 (7-∞2 to 23-∞1)
  • OR for colchicine relative to naproxen (adjusted for age, gender and baseline pain score). †Analysis of complete data (days 1–7: n=291; five cases excluded due to missing baseline pain scores; week 4: n=283; five cases excluded due to missing baseline pain scores). ‡ Analysis of imputed data (n=399).

  • *Number needed to treatment harm (NNTH): 1for colchicine over naproxen; 2for naproxen over colchicine (based on imputed OR estimates and observed rates for the naproxen group).

  • †Complete response to side-effect questions: diary days 1–7 naproxen=150, colchicine=146; week 4 naproxen n=134, colchicine=154.

  • ‡Imputed data set: 200 in naproxen group; 199 in colchicine group (full ITT analysis).1

  • §Includes the side effects listed and ‘other’ (nominated free-text) side effects.

  • ITT, intention-to-treat.