Factor | Number of trials | Number of patients | Relative risk of IBS symptoms persisting (95% CI) | p Value for the difference | I2 (p value) | |
Setting | ||||||
Secondary care | 7 | 369 | 0.57 (0.44 to 0.75) | 0.08 | 39.2% (0.13) | |
Tertiary care | 6 | 420 | 0.76 (0.64 to 0.91) | 0% (0.56) | ||
Criteria used to define IBS | ||||||
Rome I or II | 7 | 474 | 0.65 (0.50 to 0.84) | 0.86 | 41.7% (0.10) | |
Clinical diagnosis | 6 | 315 | 0.67 (0.54 to 0.83) | 11.7% (0.34) | ||
Method of randomisation | ||||||
Stated | 7 | 501 | 0.68 (0.54 to 0.85) | 0.66 | 35.8% (0.14) | |
Not stated | 6 | 288 | 0.63 (0.49 to 0.82) | 20.4% (0.28) | ||
Concealment of allocation | ||||||
Stated | 3 | 313 | 0.78 (0.63 to 0.96) | 0.12 | 5.1% (0.37) | |
Not stated | 10 | 476 | 0.62 (0.50 to 0.75) | 24.1% (0.22) | ||
Blinding | ||||||
Double | 12 | 754 | 0.70 (0.61 to 0.80) | 0.03 | 6.9% (0.38) | |
Not stated | 1 | 35 | 0.30 (0.13 to 0.59) | N/A | ||
Score on Jadad scale | ||||||
⩾4 | 10 | 651 | 0.70 (0.59 to 0.83) | 0.29 | 19% (0.26) | |
<4 | 3 | 138 | 0.51 (0.29 to 0.90) | 56.6% (0.10) |
CI, confidence interval.