Study design: A retrospective cohort study.
Objective: The aim of this study was to investigate the effect depression has on the improvement of patient-reported outcome measures (PROMs) following lumbar decompression.
Summary of background data: Decompression without fusion is a viable treatment option for lumbar spine stenosis. Depression reportedly has a negative impact on PROMs after certain types of spine surgery, though verification of this with new, more precise outcome measures is needed.
Methods: We included consecutive adult patients who underwent lumbar decompression for lumbar spine stenosis between 2016 and 2017 who had PROM information system (PROMIS) physical function, pain, depression, and Oswestry Disability Index (ODI) questionnaires completed preoperatively and at 6-month follow-up. Patients with a PROMIS depression score >50 or <50 were allocated to the depressed and not depressed groups, respectively. The cohorts were compared using unpaired t tests and repeated-measures two-way analysis of variance (ANOVA) with statistical significance taken at P < 0.05.
Results: The analysis included 55 patients without depression and 56 patients with depression. Depressed patients had worse preoperative PROMIS physical function (30.08 vs. 36.66, P = 0.005), PROMIS pain (69.36 vs. 64.69, P < 0.0001), and ODI scores (51.92 vs. 36.35, P < 0.0001). Similarly, the depressed group had worse postoperative PROMIS physical function (36.29 vs. 40.34, P = 0.005), PROMIS pain (60.16 vs. 54.87, P < 0.0001), and ODI scores (37.01 vs. 23.44, P = 0.0003). We observed a statistically significant interaction between depression status and pre to postoperative improvement in outcome for PROMIS physical function (F[1,109] = 102.5, P < 0.0001) and depression scores (F[1,109] = 15.38, P = 0.0002). No interaction was found for pain and ODI scores.
Conclusion: Our results suggest that depressed patients experience a greater magnitude of improvement in PROMIS physical function and depression scores than nondepressed patients. Despite this, depressed patients have worse postoperative outcomes for PROMIS physical function, depression, pain, and ODI. These findings are important for risk stratifying and treating depressed patients before lumbar spine decompression.
Level of evidence: 3.