Tag: treatment effect

Posted on

Who Should Undergo Surgery for Degenerative Spondylolisthesis?

Spondylolisthesis

Spine 2013;38:1799–1811

Combined prospective randomized controlled trial and observational cohort study of degenerative spondylolisthesis (DS) with an as-treated analysis.

Objective. To determine modifi ers of the treatment effect (TE) of surgery (the difference between surgical and nonoperative outcomes) for DS using subgroup analysis. Summary of Background Data. Spine Patient Outcomes Research Trial demonstrated a positive surgical TE for DS at the group level. However, individual characteristics may affect TE.

Methods. Patients with DS were treated with either surgery (n = 395) or nonoperative care (n = 210) and were analyzed according to treatment received. Fifty-fi ve baseline variables were used to defi ne subgroups for calculating the time-weighted average TE for the Oswestry Disability Index during 4 years (TE = Δ Oswestry Disability Index surgery − Δ Oswestry Disability Index nonoperative ). Variables with signifi cant subgroup-by-treatment interactions ( P < 0.05) were simultaneously entered into a multivariate model to select independent TE predictors.

Results. All analyzed subgroups that included at least 50 patients improved signifi cantly more with surgery than with nonoperative treatment ( P < 0.05). Multivariate analyses demonstrated that age 67 years or less (TE − 15.7 vs. − 11.8 for age > 67, P = 0.014); female sex (TE − 15.6 vs. − 11.2 for males, P = 0.01); the absence of stomach problems (TE − 15.2 vs. − 11.3 for those with stomach problems, P = 0.035); neurogenic claudication (TE − 15.3 vs. − 9.0 for those without claudication, P = 0.004); refl ex asymmetry (TE − 17.3 vs. − 13.0 for those without asymmetry, P = 0.016); opioid use (TE − 18.4 vs. − 11.7 for those not using opioids, P < 0.001); not taking antidepressants (TE − 14.5 vs. − 5.4 for those on antidepressants, P = 0.014); dissatisfaction with symptoms (TE − 14.5 vs. − 8.3 for those satisfi ed or neutral, P = 0.039); and anticipating a high likelihood of improvement with surgery (TE − 14.8 vs. − 5.1 for anticipating a low likelihood of improvement with surgery, P = 0.019) were independently associated with greater TE.

Conclusion. Patients who met strict inclusion criteria improved more with surgery than with nonoperative treatment, regardless of other specific characteristics. However, TE varied signifi cantly across certain subgroups.

Level of Evidence: 3

Posted on

Who Should Have Surgery for Spinal Stenosis?

Spine 2012 ; 37 : 1791 – 1802

Study Design. Combined prospective randomized controlled trial and observational cohort study of spinal stenosis (SpS) with an as-treated analysis.

Objective. To determine modifiers of the treatment effect (TE) of surgery (the difference between surgical and nonoperative outcomes) for SpS using subgroup analysis.

Summary of Background Data. The Spine Patient Outcomes Research Trial demonstrated a positive surgical TE for SpS at the group level. However, individual characteristics may affect TE. No previous studies have evaluated TE modifiers in SpS.

Methods. SpS patients were treated with either surgery (n = 419) or nonoperative care (n = 235) and were analyzed according to treatment received. Fifty-three baseline variables were used to define subgroups for calculating the time-weighted average TE for the Oswestry Disability Index (ODI) over 4 years (TE = ΔODI surgery – ΔODI nonoperative ). Variables with significant subgroup × treatment interactions ( P < 0.05) were simultaneously entered into a multivariate model to select independent TE predictors.

Results. Other than smokers, all analyzed subgroups including at least 50 patients improved signifi cantly more with surgery than with nonoperative treatment ( P < 0.05). Multivariate analysis demonstrated: baseline ODI ≤ 56 (TE –15.0 vs. –4.4, ODI > 56, P < 0.001), not smoking (TE –11.7 vs. –1.6 smokers, P < 0.001), neuroforaminal stenosis (TE –14.2 vs. –8.7 no neuroforaminal stenosis, P = 0.002), predominant leg pain (TE –11.5 vs. –7.3 predominant back pain, P = 0.035), not lifting at work (TE –12.5 vs . –0.5 lifting at work, P = 0.017), and the presence of a neurological deficit (TE –13.3 vs . –7.2 no neurological deficit, P < 0.001) were associated with greater TE.

Conclusion. With the exception of smokers, patients who met strict inclusion criteria improved more with surgery than with nonoperative treatment, regardless of other specific characteristics. However, TE varied significantly across certain subgroups, and these data can be used to individualize shared decision making discussions about likely outcomes. Smoking cessation should be considered before surgery for SpS.

Proudly powered by WordPress