001 randomized controlled trial.pt.
002 controlled clinical trial.pt.
003 Randomized Controlled Trials/
004 Random Allocation/
005 Double‐Blind Method/
006 Single‐Blind Method/
007 or/1‐6
008 Animal/ not Human/
009 7 not 8
010 clinical trial.pt.
011 explode Clinical Trials/
012 (clinical$ adj 25 trial$).tw.
013 ((singl$ or doubl$ or trebl$ or tripl$) adj(mask$ or blind$)).tw.
014 Placebos/
015 placebo$.tw.
016 random$.tw.
017 Research Design/
018 (latin adj square).tw.
019 or/10‐18
020 19 not 8
021 20 not 9
022 Comparative Study/
023 explode Evaluation Studies/
024 Follow‐Up Studies/
025 Prospective Studies/
026 (control$ or prospective$ or volunteer$).tw.
027 Cross‐Over Studies/
028 or/22‐27
029 28 not 8
030 29 not (9 or 21)
031 9 or 21 or 30
032 PAIN/pc, dt, rh, th [Prevention & Control, Drug Therapy, Rehabilitation, Therapy]
033 Chronic Disease/dt, pc, rh, th [Drug Therapy, Prevention & Control, Rehabilitation, Therapy]
034 (chronic adj3 pain).mp
035 Low Back Pain/
036 (low adj back adj pain).mp
037 or/ 32‐36
038 exp Analgesics, opioid/
039 codeine.mp.
040 fentanyl.mp.
041 hydrocodone.mp.
042 hydromorphone.mp.
043 levorphanol.mp.
044 meperidine.mp.
045 morphine.mp.
046 oxycodone.mp.
047 oxymorphone.mp.
048 pentazocine.mp.
049 propoxyphene.mp.
050 sufentanil.mp.
051 tramadol.mp.
052 or/ 38‐51
053 31 and 37 and 52

1 exp Clinical Trial/
2 exp randomization/
3 Double Blind Procedure/
4 Single Blind Procedure/
5 or/1‐4
6 exp animal/
7 Nonhuman/
8 6 or 7
9 exp human/
10 8 not 9
11 5 not 10
12 (clinical$ adj25 trial$).tw.
13 ((singl$ or doubl$ or trebl$ or tripl$) adj (mask$ or blind$)).tw.
14 exp Placebo/
15 placebo$.tw.
16 random$.tw.
17 methodology/ or latin square design/
18 (latin adj square).tw.
19 or/12‐18
20 19 not 10
21 20 not 11
22 comparative study/
23 evaluation/
24 Follow Up/
25 Prospective Study/
26 (control$ or prospective$ or volunteer$).tw.
27 Crossover Procedure/
28 or/22‐27
29 28 not 10
30 29 not (11 or 21)
31 30 or 21 or 11
32 exp Chronic Pain/
33 exp PAIN/pc, rh, dt, th [Prevention, Rehabilitation, Drug Therapy, Therapy]
34 exp Chronic Disease/pc, rh, dt, th [Prevention, Rehabilitation, Drug Therapy, Therapy]
35 33 and 34
36 32 or 35
37 (chronic adj3 pain$).tw.
38 exp Low Back Pain/
39 (low adj back adj pain$).tw.
40 or/36‐39
41 exp Narcotic Analgesic Agent/
42 codeine.mp.
43 fentanyl.mp.
44 hydrocodone.mp.
45 hydromorphone.mp.
46 levorphanol.mp.
47 meperidine.mp.
48 morphine.mp.
49 oxycodone.mp.
50 oxymorphone.mp.
51 pentazocine.mp.
52 propoxyphene.mp.
53 sufentanil.mp.
54 tramadol.mp.
55 or/41‐54
56 31 and 40 and 55

Validity Criteria

Operationalization

1. Was the method of randomization adequate?

1. A random (unpredictable) assignment sequence. Examples of adequate methods are computer generated random number tables and use of sealed or opaque envelopes. Methods of allocation using date of birth, date of admission, hospital numbers, or alternation should not be regarded as appropriate.

2. Was the treatment allocation concealed?

2. Assignment generated by an independent person not responsible for determining the eligibility of the patients. This person has no information about the persons included in the trial and has no influence on the assignment sequence or on the decision about eligibility of the patient.

3. Were the groups similar at baseline regarding the most important prognostic indicators?

3. In order to receive a 'yes', groups have to be similar at baseline regarding demographic factors, duration and severity of complaints, percentage of patients with neurological symptoms and value of main outcome measurement(s).

4. Was the patient blinded to the intervention?

4. Blinding should be adequate. The reviewer determines if enough information about blinding is given in order to score a 'yes'.

5. Was the care provider blinded to the intervention?

5. Blinding should be adequate. The reviewer determines if enough information about blinding is given in order to score a 'yes'.

6. Was the outcome assessor blinded to the intervention?

6. Blinding should be adequate. The reviewer determines if enough information about blinding is given in order to score a 'yes'.

7. Were co‐interventions avoided or similar?

7. Co‐interventions should either be avoided in the trial design or comparable between the index and control groups.

8. Was the drop‐out rate during the intervention period described and acceptable?

8. The number of participants who were included in the study, but did not complete the observation period or were not included in the analysis, must be described and the reasons given. If the percentage of withdrawals and drop‐outs does not exceed 20% for short‐term follow‐up and 30% for long‐term follow‐up and does not lead to substantial bias, a 'yes; is scored.

9. Was the compliance rate (in each group) acceptable?

9. The reviewer determines if the compliance to the interventions is acceptable, based on the reported intensity, duration, number and frequency of sessions for both the index intervention and control intervention(s).

10. Was the timing of the outcome assessment in both groups comparable?

10. Timing of outcome assessment should be identical for all intervention groups and for all important outcome assessments.

11. Did the analysis include an intention‐to‐treat analysis?

11. All randomized patients are reported/analyzed in the same group as allocated by randomization for the most important moments of effect measurement (minus missing values) regardless of non‐compliance and co‐interventions