What do systematic reviews say?

Combination vs nicotine replacement therapy monotherapy

Combination leads to higher smoking cessation compared with single‐form nicotine replacement therapy (high certainty).

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 1.27 [1.17, 1.37]
  16 studies · 12169 participants
  High

Combination vs nicotine replacement therapy monotherapy

Combination showed no clear difference in overall serious adverse events compared with single‐form nicotine replacement therapy (low certainty).

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 4.44 [0.76, 25.85]
  5 studies · 2888 participants
  Low

Combination vs nicotine replacement therapy monotherapy

It is very uncertain whether combination changes treatment withdrawals compared with single‐form nicotine replacement therapy (very low certainty).

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 1.12 [0.57, 2.2]
  5 studies · 3070 participants
  Very low

Reduction and pharmacotherapy vs reduction alone

Reduction and pharmacotherapy showed no clear difference in subgroup: combination NRT; smoking cessation (≥ 6 month compared with reduction alone (low certainty).

• Smoking reduction interventions for smoking cessation 2019 · Cochrane Headline outcomes only
  RR 1.02 [0.61, 1.69]
  3 studies · 1124 participants
  Low

Longer vs shorter duration of combination nicotine replacement therapy

It is very uncertain whether longer changes smoking cessation ‐ 16 weeks versus 8 weeks compared with shorter duration of combination nicotine replacement therapy (very low certainty).

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 0.96 [0.75, 1.23]
  1 study · 637 participants
  Very low

Longer vs shorter duration of combination nicotine replacement therapy

Longer showed no clear difference in smoking cessation ‐ 6 weeks versus 2 weeks compared with shorter duration of combination nicotine replacement therapy (low certainty).

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 1.11 [0.94, 1.31]
  1 study · 987 participants
  Low

Longer vs shorter duration of combination nicotine replacement therapy

It is very uncertain whether longer changes overall SAEs ‐ 26 weeks versus 8 weeks compared with shorter duration of combination nicotine replacement therapy (very low certainty).

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 1.63 [0.6, 4.42]
  1 study · 544 participants
  Very low
• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 637 participants
  Very low
• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 987 participants
  Very low

Longer vs shorter duration of combination nicotine replacement therapy

• Different doses, durations and modes of delivery of nicotine replacement therapy for smoking cessation 2023 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Varenicline vs combination nicotine replacement therapy

Varenicline showed no clear difference in smoking abstinence at longest compared with combination nicotine replacement therapy (low certainty).

• Nicotine receptor partial agonists for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 1.02 [0.87, 1.2]
  5 studies · 2344 participants
  Low

Varenicline vs combination nicotine replacement therapy

Varenicline showed no clear difference in SAEs compared with combination nicotine replacement therapy (low certainty).

• Nicotine receptor partial agonists for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 2.15 [0.49, 9.46]
  4 studies · 1852 participants
  Low

Varenicline vs combination nicotine replacement therapy

Varenicline showed no clear difference in neuropsychiatric SAEs compared with combination nicotine replacement therapy (low certainty).

• Nicotine receptor partial agonists for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 4.69 [0.23, 96.5]
  2 studies · 764 participants
  Low

Varenicline vs combination nicotine replacement therapy

Varenicline showed no clear difference in cardiac SAEs compared with combination nicotine replacement therapy (low certainty).

• Nicotine receptor partial agonists for smoking cessation 2023 · Cochrane Headline outcomes only
  RR 0.32 [0.01, 7.88]
  2 studies · 819 participants
  Low