What do systematic reviews say?

Aromatherapy vs placebo or control

• Aromatherapy for dementia 2020 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 206 participants
  Very low

Chemotherapy vs chemotherapy alone

• Salvage systemic therapy for advanced gastric and oesophago‐gastric junction adenocarcinoma 2020 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 448 participants
  High

GnRH agonist plus chemotherapy vs chemotherapy alone

It is very uncertain whether gnRH agonist plus chemotherapy changes adverse effects: hot flush compared with chemotherapy alone (very low certainty).

• Adjuvant gonadotropin‐releasing hormone analogues for the prevention of chemotherapy‐induced premature ovarian failure… 2019 · Cochrane Headline outcomes only
  RR 1.49 [0.16, 13.6]
  4 studies · 731 participants
  Very low

GnRH agonist plus chemotherapy vs chemotherapy alone

GnRH agonist plus chemotherapy showed no clear difference in adverse effects: vaginal dryness compared with chemotherapy alone (moderate certainty).

• Adjuvant gonadotropin‐releasing hormone analogues for the prevention of chemotherapy‐induced premature ovarian failure… 2019 · Cochrane Headline outcomes only
  RR 1.18 [0.68, 2.04]
  2 studies · 488 participants
  Moderate

Antibiotics vs placebo compared

Antibiotic therapy showed no clear difference in treatment harms (adverse events or side effects associated with… compared with placebo compared to placebo (low certainty).

• Antibiotic therapy versus no antibiotic therapy for children aged 2 to 59 months with WHO‐defined non‐severe pneumonia… 2021 · Cochrane Headline outcomes only
  RR 0.81 [0.6, 1.09]
  3 studies · 3253 participants
  Low

Brachytherapy vs brachytherapy plus radiotherapy

Brachytherapy showed no clear difference in adverse effects compared with brachytherapy plus radiotherapy (moderate certainty).

• Interventions for dysphagia in oesophageal cancer 2014 · Cochrane Headline outcomes only
  OR 1.17 [0.44, 3.15]
  2 studies · 554 participants
  Moderate

Pre‐emptive antifungal therapy vs empirical antifungal therapy

• Pre‐emptive antifungal therapy versus empirical antifungal therapy for febrile neutropenia in people with cancer 2022 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 1074 participants
  Very low

Laser therapy vs no laser therapy

• Laser therapy for retinopathy in sickle cell disease 2022 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 414 participants
  Low

Bevacizumab plus chemotherapy vs chemotherapy alone

Chemotherapy + bevacizumab showed no clear difference in severe adverse effects compared with chemotherapy (low certainty).

• Second‐line systemic therapy for metastatic colorectal cancer 2017 · Cochrane Headline outcomes only
  RR 1.07 [0.93, 1.25]
  4 studies · 1708 participants
  Low

Combination therapy vs monotherapy

It is very uncertain whether combination therapy changes withdrawals due to adverse effects compared with monotherapy (very low certainty).

• First‐line combination therapy versus first‐line monotherapy for primary hypertension 2020 · Cochrane Headline outcomes only
  RR 0.85 [0.53, 1.35]
  3 studies · 568 participants
  Very low

Brachytherapy vs brachytherapy plus radiotherapy

Brachytherapy showed no clear difference in adverse effects ‐ stricture compared with brachytherapy plus radiotherapy (high certainty).

• Interventions for dysphagia in oesophageal cancer 2014 · Cochrane Headline outcomes only
  OR 1.43 [0.16, 12.85]
  2 studies · 277 participants
  High

Initiation of prophylactic therapy guided by colonoscopy vs initiation of prophylactic therapy immediately after surgery

It is very uncertain whether initiation of prophylactic therapy guided by colonoscopy changes adverse effects ( compared with initiation of prophylactic therapy immediately after surgery (very low certainty).

• Colonoscopy‐guided therapy for the prevention of post‐operative recurrence of Crohn’s disease 2020 · Cochrane Headline outcomes only
  RR 0.58 [0.42, 0.82]
  1 study · 63 participants
  Very low

Chemotherapy vs best supportive care

Chemotherapy probably leads to higher severe adverse effects compared with best supportive care (moderate certainty).

• Second‐line systemic therapy for metastatic colorectal cancer 2017 · Cochrane Headline outcomes only
  RR 1.19 [1.01, 1.4]
  1 study · 279 participants
  Moderate

Positional therapy vs continuous positive airway pressure (CPAP)

• Positional therapy for obstructive sleep apnoea 2019 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 20 participants
  GRADE not reported

Physiotherapy with traction vs physiotherapy without traction

The review found no eligible studies for this question.

• Traction for low‐back pain with or without sciatica 2013 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Hypofractionated radiotherapy vs daily conventionally fractionated radiotherapy

• External beam radiation dose escalation for high grade glioma 2020 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 848 participants
  GRADE not reported

Timer watch plus standard urotherapy vs urotherapy alone

The review found no eligible studies for this question.

• Conservative interventions for treating functional daytime urinary incontinence in children 2019 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Balneotherapy vs melilotus officinalis

The review found no eligible studies for this question.

• Balneotherapy for chronic venous insufficiency 2023 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Balneotherapy vs dryland exercise

The review found no eligible studies for this question.

• Balneotherapy for chronic venous insufficiency 2023 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

First‐line chemotherapy vs BSC

• Chemotherapy versus best supportive care for extensive small cell lung cancer 2013 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 65 participants
  Very low