Table 3. Cochrane search strategy.

1	((narcotic* near/1 free) or (narcotic* near/1 less) or (narcotic* near/1 spar*) or (non near/1 narcotic*) or (non near/1 opioid*)):ti,ab,kw
2	alfentanil/
3	buprenorphine/
4	butorphanol/
5	codeine/
6	dextropropoxyphene/
7	Fentanyl/
8	Hydrocodone/
9	Hydromorphone/
10	Meperidine/
11	Methadone/
12	Morphine/
13	Morphine Derivatives/
14	Nalbuphine/
15	Oxycodone/
16	Pentazocine/
17	Piritramide/
18	Remifentanil/
19	Sufentanil/
20	OR/1–20 (Opioid related terms)
21	((narcotic* near/1 free) or (narcotic* near/1 less) or (narcotic* near/1 spar*) or (non near/1 narcotic*) or (non near/1 opioid*)):ti,ab,kw
22	((opiat* near/1 free) or (opiat* near/1 less) or (opiat* near/1 spar*) or (opioid* near/1 free) or (opioid* near/1 less) or (opioid* near/1 spar*)):ti,ab,kw
23	21 OR 22 (opioid regime related term)
24	20 AND 23
25	(Adaptive Clinical Trial):ti,ab,kw (Word variations have been searched)
26	(‘adaptive clinical trial (topic)’):ti,ab,kw (Word variations have been searched)
27	Adaptive Clinical Trials as Topic
28	ct.fs.
29	controlled clinical trial or ‘controlled clinical trial (topic)’
30	double blind procedure
31	Double-Blind Method
32	multicenter study or ‘multicenter study (topic)’
33	placebo or placebo effect
34	pragmatic trial
35	exp randomized controlled trial or ‘randomized controlled trial (topic)’
36	(‘quasirandomised controlled trial’):ti,ab,kw (Word variations have been searched)
37	OR/25–36
38	24 AND 37
39	(newborn* or new-born* or neonat* or neo-nat* or infan* or baby* or babies* or toddler* or kid or kids or boy* or girl* or pubescen* or preadolesc* or prepubesc* or preteen or tween):ti,so
40	((exp animals or exp animal experimentation or nonhuman) not ((exp animals or exp animal experimentation or nonhuman) and exp human))
41	38 NOT (38 OR 39)