Case manager-assisted rehabilitation for lumbar spinal fusion patients: an economic evaluation alongside a randomized controlled trial with two-year follow-up

OBJECTIVE: To examine the cost-effectiveness of case manager-assisted rehabilitation as an add-on to usual physical rehabilitation after lumbar spinal fusion, given the lack of any clinical benefits found on analysing the clinical data.

DESIGN: Economic evaluation alongside a randomized controlled trial with two-year follow-up.

SETTING: Patients from the outpatient clinics of a university hospital and a general hospital.

SUBJECTS: A total of 82 lumbar spinal fusion patients.

INTERVENTIONS: Patients were randomized one-to-one to case manager-assisted rehabilitation programme as an add-on to usual physical rehabilitation or to usual physical rehabilitation.

MAIN MEASURES: Oswestry Disability Index and EuroQol 5-dimension. Danish preference weights were used to estimate quality-adjusted life years. Costs were estimated from micro costing and national registries. Multiple imputation was used to handle missing data. Costs and effects were presented with means (95% confidence interval (CI)). The incremental net benefit was estimated for a range of hypothetical values of willingness to pay per gain in effects.

RESULTS: No impact of case manager-assisted rehabilitation on the Oswestry Disability Index or estimate quality-adjusted life years was observed. Intervention cost was Euros 3984 (3468; 4499), which was outweighed by average reductions in inpatient resource use and sickness leave. A cost reduction of Euros 1716 (-16,651; 20,084) was found in the case manager group. Overall, the probability for the case manager-assisted rehabilitation programme being cost-effective did not exceed a probability of 56%, regardless of willingness to pay. Sensitivity analysis did not change the conclusion.

CONCLUSION: This case manager-assisted rehabilitation programme was unlikely to be cost-effective.