Criteria/Definitions

A. Was the method of randomisation adequate? A random (unpredictable) assignment sequence. Examples of adequate methods are computer‐generated random numbers table and use of sealed opaque envelopes. Methods of allocation using date of birth, date of admission, hospital numbers, or alternation should not be regarded as appropriate. If the method of sequence generation will not reported the study will be scored as "unclear".

B. Was the treatment allocation concealed? 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 in order to score a "yes" (e.g. allocation by a central office unaware of subject characteristics, serially numbered, opaque, sealed envelopes, on‐site computer system combined with allocations kept in a locked unreadable; computer file that can be accessed only after the characteristics of an enrolled participant have been entered or other description that contained elements convincing of concealment); when the authors did not report an allocation concealment approach the study is scored as "unclear"; when the author reports a method as alternation or reference to case numbers, dates of birth, day of the week. Any procedure that is entirely transparent before allocation, such as an open list of random numbers or other description that contained elements convincing of not concealment the study is scored as "no"

C. Were the groups similar at baseline regarding the most important prognostic indicators? 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 measure(s).

D. Was the patient blinded to the intervention? The review author determines if enough information about the blinding is given in order to score a "yes."

E. Was the care provider blinded to the intervention? The review author determines if enough information about the blinding is given in order to score a "yes."

F. Was the outcome assessor blinded to the intervention? The review author determines if enough information about the blinding is given in order to score a "yes." If there are no information the study will be scored as "unclear".

G. Were co‐interventions avoided or similar? Co‐interventions should either be avoided in the trial design or be similar between the index and control groups to score a "yes". If there are no information the study will be scored as "unclear".

H. Was the compliance acceptable in all groups? The review author 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).

I. Was the drop‐out rate described and acceptable? 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 reasons given. If the percentage of withdrawals and drop‐outs does not exceed 20% for immediate and short‐term follow‐ups, 30% for intermediate and long‐term follow‐ups and does not lead to substantial bias a "yes" is scored. If there are no information the study will be scored as "unclear".

J. Was the timing of the outcome assessment in all groups similar? Timing of outcome assessment should be identical for all intervention groups and for all important outcome assessments. If there are no information the study will be scored as "unclear"

K. Did the analysis include an intention‐to‐treat analysis? All randomized patients are reported/analyzed in the group to which they were allocated by randomization for the most important moments of effect measurement (minus missing values), irrespective of noncompliance and co‐interventions.

criteria

Selection bias:
1. Representativeness of the exposed cohort
‐ truly representative of the average adolescents with scoliosis
‐ somewhat representative of the average adolescents with scoliosis
‐ selected group of adolescents with scoliosis
‐ no description of the derivation of the cohort

2. Selection of the non exposed cohort
‐ drawn from the same community as the exposed cohort
‐ drawn from a different source
"no description of the derivation of the non exposed cohort

3. Ascertainment of exposure
‐ secure record (e.g. clinical records)
‐ structured interview
‐ written self report
‐ no description

4. Comparability of cohorts on the basis of the design or analysis
‐ Most important factors of adjustment
‐ No adjustment

Attrition bias:
‐ complete follow up ‐ all subjects accounted for
‐ subjects lost to follow up unlikely to introduce bias (lost to follow‐up 5%)
‐ subjects lost to follow up > 5% and description provided of those lost

Detection bias:
‐ independent blind assessment
‐ record linkage
‐ self report or no blinding
‐ no description

Questions

1. Are the patients described in detail so that you can decide whether they are comparable to those that you see in your practice?
Yes/ No/ Unsure
2. Are the interventions and treatment settings described well enough so that you can provide the same for your patients?
Yes/ No/ Unsure
3. Were all clinically relevant outcomes measured and reported?
Yes/ No/ Unsure
4. Is the size of the effect clinically important?
Yes/ No/ Unsure
5. Are the likely treatment benefits worth the potential harms?
Yes/ No/ Unsure