What do systematic reviews say?

5‐ASA vs placebo

5‐ASAs probably leads to lower clinical relapse compared with placebo (moderate certainty).

• Oral 5‐aminosalicylic acid for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 0.83 [0.72, 0.96]
  5 studies · 730 participants
  Moderate

5‐ASA vs placebo

It is very uncertain whether 5‐ASAs changes endoscopic recurrence compared with placebo (very low certainty).

• Oral 5‐aminosalicylic acid for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 0.83 [0.56, 1.24]
  3 studies · 537 participants
  Very low

Azathioprine or 6‐mercaptopurine vs placebo

Azathioprine or 6‐mercaptopurine probably leads to lower clinical relapse compared with placebo (moderate certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 0.79 [0.67, 0.92]
  3 studies · 408 participants
  Moderate

Azathioprine or 6‐mercaptopurine vs 5‐aminosalicylic acid (5‐ASA) (mesalazine)

It is very uncertain whether azathioprine or 6‐mercaptopurine changes radiologic relapse compared with 5‐aminosalicylic acid (very low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 0.92 [0.66, 1.28]
  1 study · 35 participants
  Very low

Azathioprine or 6‐mercaptopurine vs 5‐aminosalicylic acid (5‐ASA) (mesalazine)

Azathioprine or 6‐mercaptopurine showed no clear difference in adverse events compared with 5‐aminosalicylic acid (low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 0.89 [0.74, 1.07]
  4 studies · 346 participants
  Low

Azathioprine or 6‐mercaptopurine vs 5‐aminosalicylic acid (5‐ASA) (mesalazine)

It is very uncertain whether azathioprine or 6‐mercaptopurine changes serious adverse events compared with 5‐aminosalicylic acid (very low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 3.39 [1.26, 9.13]
  3 studies · 311 participants
  Very low

Azathioprine or 6‐mercaptopurine vs 5‐aminosalicylic acid (5‐ASA) (mesalazine)

Azathioprine or 6‐mercaptopurine may leads to higher withdrawal due to adverse events compared with 5‐aminosalicylic acid (low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 2.21 [1.28, 3.81]
  4 studies · 425 participants
  Low

Azathioprine or 6‐mercaptopurine vs anti TNF‐ɑ

It is very uncertain whether azathioprine or 6‐mercaptopurine changes clinical relapse compared with anti TNF‐α (very low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 2.89 [1.5, 5.57]
  3 studies · 139 participants
  Very low

Azathioprine or 6‐mercaptopurine vs anti TNF‐ɑ

It is very uncertain whether azathioprine or 6‐mercaptopurine changes endoscopic relapse compared with anti TNF‐α (very low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 3.67 [1.05, 12.81]
  4 studies · 157 participants
  Very low

Azathioprine or 6‐mercaptopurine vs anti TNF‐ɑ

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 117 participants
  GRADE not reported

Azathioprine or 6‐mercaptopurine vs anti TNF‐ɑ

Azathioprine or 6‐mercaptopurine showed no clear difference in adverse events compared with anti TNF‐α (low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 1.13 [0.83, 1.53]
  2 studies · 117 participants
  Low

Azathioprine or 6‐mercaptopurine vs placebo

Azathioprine or 6‐mercaptopurine showed no clear difference in endoscopic relapse compared with placebo (low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 0.85 [0.64, 1.13]
  2 studies · 321 participants
  Low

Azathioprine or 6‐mercaptopurine vs anti TNF‐ɑ

It is very uncertain whether azathioprine or 6‐mercaptopurine changes serious adverse events compared with anti TNF‐α (very low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 0.51 [0.17, 1.54]
  1 study · 84 participants
  Very low

Azathioprine or 6‐mercaptopurine vs anti TNF‐ɑ

Azathioprine or 6‐mercaptopurine showed no clear difference in withdrawal due to adverse events compared with anti TNF‐α (low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 3.97 [0.92, 17.22]
  3 studies · 139 participants
  Low

Azathioprine or 6‐mercaptopurine vs placebo

The review found no eligible studies for this question.

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Azathioprine or 6‐mercaptopurine vs placebo

Azathioprine or 6‐mercaptopurine showed no clear difference in adverse events compared with placebo (low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 1.36 [0.57, 3.27]
  2 studies · 168 participants
  Low

Azathioprine or 6‐mercaptopurine vs placebo

Azathioprine or 6‐mercaptopurine showed no clear difference in serious adverse events compared with placebo (low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 1.78 [0.39, 8.18]
  2 studies · 327 participants
  Low

Azathioprine or 6‐mercaptopurine vs placebo

Azathioprine or 6‐mercaptopurine showed no clear difference in withdrawal due to adverse events compared with placebo (moderate certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 0.9 [0.63, 1.29]
  3 studies · 408 participants
  Moderate

Azathioprine or 6‐mercaptopurine vs 5‐aminosalicylic acid (5‐ASA) (mesalazine)

Azathioprine or 6‐mercaptopurine showed no clear difference in clinical relapse compared with 5‐aminosalicylic acid (low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 1.05 [0.89, 1.24]
  4 studies · 347 participants
  Low

Azathioprine or 6‐mercaptopurine vs 5‐aminosalicylic acid (5‐ASA) (mesalazine)

It is very uncertain whether azathioprine or 6‐mercaptopurine changes endoscopic relapse compared with 5‐aminosalicylic acid (very low certainty).

• Azathioprine and 6‐mercaptopurine for maintenance of surgically‐induced remission in Crohn's disease 2019 · Cochrane Headline outcomes only
  RR 0.78 [0.52, 1.17]
  1 study · 35 participants
  Very low