Kadanka 2002.

Methods	C: Coin toss Outcome assessor blind Exclusions during trial: 2 (patients initially allocated to the conservative group, but underwent surgery) Losses to FU: 19 between 24 and 36 months. In addition 5 patients who underwent surgery died during the same period
Participants	Czech Republic 68 patients (48 men and 20 women) age<75 Mild to moderate myelopathy (mJOA score>12)
Interventions	Rx :22 anterior decompression (with autograft, 15 had additional plating), 6 corpectomy and 5 laminoplasty Conservative treatment: intermittent cervical immobilization (soft collar), NSAIDs, intermittent bed rest
Outcomes	modified JOA score at onset, 6,12, 24 and 36 months after treatment evaluation of daily activities by video recording at onset, 6,12 ,24 and 36 months after treatment timed 10‐meter walk at onset, 6,12, 24 and 36 months after treatment self‐evaluation at onset, 6,12, 24 and 36 months after treatment
Notes	Ex: severe myelopathy (mJOA <12) FU: 3 years
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	coin toss
Allocation concealment?	Unclear risk	not stated
Blinding? patients	High risk
Blinding? care providers	Unclear risk	not stated, but unlikely
Blinding? outcome assessor	Low risk	"They were evaluated by two physicians blinded to the type of treatment"
Incomplete outcome data addressed? Withdrawal/drop‐out rate	High risk	Five surgically treated patients died during the follow‐up period, but their deaths were physically unrelated to the surgery 19 patients were lost to follow‐up between 24 and 36 months
Incomplete outcome data addressed? Intention‐to‐treat analysis	High risk	Two patients allocated to the conservative group underwent surgery and they were excluded from the analysis
Free of selective reporting?	Low risk
Similarity of baseline characteristics?	High risk	mJOA score substantially‐almost significantly‐ different between surgically and conservatively treated groups
Co‐interventions avoided or similar?	Unclear risk	A variety of non surgical interventions were administered to the conservatively treated patients
Compliance acceptable?	Low risk
Timing outcome assessments similar?	Low risk