Patients that are subjected to a medium complex surgical intervention in neck (posterior) or lumbar spine (posterior) with instrumentation are motivated to stop smoking. The outcome data of patients that stop and that continue smoking will be compared. A group of non smokers is evaluated as a control group. Particularly clinical outcome is evaluated, as well as radiological outcome.

Rationale: Optimizing outcomes of instrumented neck and back surgery Objective: To demonstrate that smoking cessation in the postoperative period has a positive impact on the clinical and radiological outcomes of instrumented spine surgery Study design: This is a multicenter observational cohort study with three groups of patients indicated to undergo moderately complex instrumented spinal surgery: a group of patients who continue to smoke is compared with a group who stop smoking in the peri-operative period of time. In addition, the results of a group of patients who do not smoke are recorded. Follow-up moments are baseline, 2, 6 and 12 months after surgery.

Study population: Patients between 18 and 75 years of age, who are candidates for moderately complex instrumented surgery of the neck or low back. Patients undergoing surgery for malignancy or trauma are excluded.

Intervention: If patients indicate that they are open to quitting smoking, they will be offered the SineFuma program. After 4 weeks, testing of nicotine in the urine will check whether smoking has actually stopped.

Study parameters: Primary outcome measure is the Oswestry Disability Index (low back) or the Neck Disability Index (neck). Furthermore, the VAS leg pain (or arm pain) and VAS back pain (or neck pain), the Hospital Anxiety and Depression Scale, the EuroQol and the patient's perceived recovery will be evaluated. The bony fusion will be assessed radiologically by CT at 6 and 12 months.

This is a multicenter observational cohort study adjusted for age and ASA score.

Evaluation moments: Patients will be asked to complete questionnaires at baseline and 2, 6 and 12 months after surgery. Patients who indicate that they have stopped smoking will be asked to submit a urine sample. For smokers who have to quit first, there is a second baseline measurement at the time they are scheduled for surgery. Data will be collected per center and brought together in the Data Coordination Center in Leiden (LUMC).

Inclusion Criteria:

• candidates for moderately complex instrumented surgery of the neck or low back.

Exclusion Criteria:

• Patients undergoing surgery for malignancy or trauma are excluded.
• non Dutch speaking patients
• pregnancy