Table 2

Embase search strategy

1narcotic analgesic agent/exp
2alfentanil/
3buprenorphine/
4butorphanol/
5codeine/
6dextropropoxyphene/
7Fentanyl/
8Hydrocodone/
9Hydromorphone/
10Meperidine/
11Methadone/
12Morphine/
13Morphine Derivatives/
14Nalbuphine/
15Oxycodone/
16Pentazocine/
17Piritramide/
18Remifentanil/
19Sufentanil/
20OR/1–20 (Opioid related terms)
21free:ti,ab
22‘opiat* free’:ti,ab OR ‘opiat* less’:ti,ab OR ‘opiat* spar*’:ti,ab OR ‘opioid* free’:ti,ab OR ‘opioid* less’:ti,ab OR ‘opioid* spar*’:ti,ab,kw
2321 OR 22 (opioid regime related term)
2420 AND 23
25‘randomised controlled trial’/exp
26‘controlled clinical trial’/de
27random*:ti,ab,tt
28‘randomization’/de
29‘intermethod comparison’/de
30placebo:ti,ab,tt
31(compare:ti,tt OR compared:ti,tt OR comparison:ti,tt)
32((evaluated:ab OR evaluate:ab OR evaluating:ab OR assessed:ab OR assess:ab) AND (compare:ab OR compared:ab OR comparing:ab OR comparison:ab))
33(open NEXT/1 label):ti,ab,tt
34((double OR single OR doubly OR singly) NEXT/1 (blind OR blinded OR blindly)):ti,ab,tt
35‘double blind procedure’/de
36(parallel NEXT/1 group*):ti,ab,tt
37(crossover:ti,ab,tt OR ‘cross over’:ti,ab,tt)
38((assign* OR match OR matched OR allocation) NEAR/6 (alternate OR group OR groups OR intervention OR interventions OR patient OR patients OR subject OR subjects OR participant OR participants)):ti,ab,tt
39(assigned:ti,ab,tt OR allocated:ti,ab,tt)
40(controlled NEAR/8 (study OR design OR trial)):ti,ab,tt
41(volunteer:ti,ab,tt OR volunteers:ti,ab,tt)
42‘human experiment’/de
43trial:ti,tt
44OR/25–43
45(((random* NEXT/1 sampl* NEAR/8 (‘cross section*’ OR questionnaire* OR survey OR surveys OR database or databases)):ti,ab,tt) NOT (‘comparative study’/de OR ‘controlled study’/de OR ‘randomised controlled’:ti,ab,tt OR ‘randomized controlled’:ti,ab,tt OR ‘randomly assigned’:ti,ab,tt))
46(‘cross‐sectional study’/de NOT (‘randomized controlled trial’/exp OR ‘controlled clinical trial’/de OR ‘controlled study’/de OR ‘randomised controlled’:ti,ab,tt OR ‘randomized controlled’:ti,ab,tt OR ‘control group’:ti,ab,tt OR ‘control groups’:ti,ab,tt))
47(‘case control*’:ti,ab,tt AND random*:ti,ab,tt NOT (‘randomised controlled’:ti,ab,tt OR ‘randomized controlled’:ti,ab,tt))
48(‘systematic review’:ti,tt NOT (trial:ti,tt OR study:ti,tt))
49(nonrandom*:ti,ab,tt NOT random*:ti,ab,tt)
50‘random field*’:ti,ab,tt
51(‘random cluster’ NEAR/4 sampl*):ti,ab,tt
52(review:ab AND review:it) NOT trial:ti,tt
53(‘we searched’:ab AND (review:ti,tt OR review:it))
54‘update review’:ab
55(databases NEAR/5 searched):ab
56((rat:ti,tt OR rats:ti,tt OR mouse:ti,tt OR mice:ti,tt OR swine:ti,tt OR porcine:ti,tt OR murine:ti,tt OR sheep:ti,tt OR lambs:ti,tt OR pigs:ti,tt OR piglets:ti,tt OR rabbit:ti,tt OR rabbits:ti,tt OR cat:ti,tt OR cats:ti,tt OR dog:ti,tt OR dogs:ti,tt OR cattle:ti,tt OR bovine:ti,tt OR monkey:ti,tt OR monkeys:ti,tt OR trout:ti,tt OR marmoset*:ti,tt) AND ‘animal experiment’/de)
57(‘animal experiment’/de NOT (‘human experiment’/de OR ‘human’/de))
58OR/45–57
5944 NOT 58
60teen OR youth OR adolescent OR juvenile OR child
6159 NOT 60
6224 AND 61