Appendix 2

Data Extraction Form

Article:...... Reviewer:...... Date: ...... /...... /......

dd mm yy

Reference

General information

/ Data extracted

Verification of study eligibility

/ Correct population? yes no [fusion for lumbar degenerative conditions]
Correct intervention? yes no [minimally invasive surgical treatment of at least 10 patients]
Correct outcome? yes no [at least one of clinical, imaging, adverse event, or economic analysis]
Correct study design? yes no [comparison study, case series > 10 patients]

Methods

Study design (cohort) / Prospective
Retrospective

Population

Recruitment of patients
Place / Hospital/City/Country
Enrollment dates
Inclusion criteria
Exclusion criteria
Age
Sex
Primary diagnosis: / Check all that apply (note: if multiple diagnoses, whenever possible the outcomes [see results section] should be reported separately for each diagnosis; if not reported as such, please indicate below):
Degenerative disc disease/disc herniation n =_____; Spinal stenosis n =_____; Degenerative spondylolisthesis n =_____ ; Isthmic spondylolisthesis n =_____; Degenerative scoliosis n =_____; Other n =_____: ______
Total number of patients recruited
Number of patients who met inclusion criteria
Total number of patients followed
Interventions
Intervention group technique
Control group (1)
Control group (2)
Control group (3)
Outcomes
Who carried out the measurement?
What outcome measure(s) was used?
How was it measured?
Is the tool validated (as stated in the article)?
When was the intermediate followup?
What was measured?
How was it measured?
Is the tool validated?
When was final followup?
What was measured?
How was it measured?
Is the tool validated?
Analysis
Statistical technique used / Which tests? Alpha? Power? Sample size calculation? Software used
Intention-to-treat analysis? / Patients were analyzed according to the group in which they were randomized
yes no don’t know
Does technique adjust for confounding?
Number (or %) of followed up from each group
Results

Who completed the assessment?

/ Surgeon? yes no
Patient? yes no
Both? yes no
Quantitative results (eg, estimates of effect size, between-group p values) / If between-group comparisons are given, please use next page.
If no between-group comparisons are given, then report here the general results.
Qualitative results
Cost of intervention
Cost-effectiveness
Adverse effects or complications / If between-group comparisons are given, please use next page.
If no between-group comparisons are given, then report here the general results.
1. Comparison: (A)______(N = _____ ) vs (B) ______(N = _____ )
Outcome (clinical or imaging):______dichotomous (report n) continuous (report mean, SD)
Followup: ______(A): ______(B): ______
______(A): ______(B): ______
______(A): ______(B): ______
2. Comparison: (A)______(N = _____ ) vs (B)______(N = _____ )
Outcome (clinical or imaging):______dichotomous (report n) continuous (report mean, SD)
Followup: ______(A): ______(B): ______
______(A): ______(B): ______
______(A): ______(B): ______
3. Comparison: (A)______(N = _____ ) vs (B)______(N = _____ )
Outcome (clinical or imaging):______dichotomous (report n) continuous (report mean, SD)
Followup: ______(A): ______(B): ______
______(A): ______(B): ______
______(A): ______(B): ______
4. Comparison: (A)______(N = _____ ) vs (B)______(N = _____ )
Outcome (clinical or imaging):______dichotomous (report n) continuous (report mean, SD)
Followup: ______(A): ______(B): ______
______(A): ______(B): ______
______(A): ______(B): ______
5. Comparison: (A)______(N = _____ ) vs (B)______(N = _____ )
Outcome (complications):______dichotomous (report n) continuous (report mean, SD)
Followup: ______(A): ______(B): ______
______(A): ______(B): ______
______(A): ______(B): ______
6. Comparison: (A)______(N = _____ ) vs (B)______(N = _____ )
Outcome:______dichotomous (report n) continuous (report mean, SD)
Followup: ______(A): ______(B): ______
______(A): ______(B): ______
______(A): ______(B): ______
7. Comparison: (A)______(N = _____ ) vs (B)______(N = _____ )
Outcome:______dichotomous (report n) continuous (report mean, SD)
Followup: ______(A): ______(B): ______
______(A): ______(B): ______
______(A): ______(B): ______