PMID- 29746963 OWN - NLM STAT- MEDLINE DCOM- 20190617 LR - 20190617 IS - 1878-1632 (Electronic) IS - 1529-9430 (Linking) VI - 18 IP - 12 DP - 2018 Dec TI - Patient phenotypes associated with outcome following surgery for mild degenerative cervical myelopathy: a principal component regression analysis. PG - 2220-2231 LID - S1529-9430(18)30208-0 [pii] LID - 10.1016/j.spinee.2018.05.009 [doi] AB - BACKGROUND CONTEXT: Predictors of outcome after surgery for degenerative cervical myelopathy (DCM) have been determined previously through hypothesis-driven multivariate statistical models that rely on a priori knowledge of potential confounders, exclude potentially important variables because of restrictions in model building, cannot include highly collinear variables in the same model, and ignore intrinsic correlations among variables. PURPOSE: The present study aimed to apply a data-driven approach to identify patient phenotypes that may predict outcomes after surgery for mild DCM. STUDY DESIGN: This is a principal component analysis of data from two related prospective, multicenter cohort studies. PATIENT SAMPLE: The study included patients with mild DCM, defined by a modified Japanese Orthopaedic Association score of 15-17, undergoing surgical decompression as part of the AOSpine CSM-NA or CSM-I trials. OUTCOME MEASURES: Patient outcomes were evaluated preoperatively at baseline and at 6 months, 1 year, and 2 years after surgery. Quality of life (QOL) was evaluated by the Neck Disability Index (NDI) and Short Form-36 version 2 (SF-36v2). These are both patient self-reported measures that evaluate health-related QOL, with NDI being specific to neck conditions and SF-36v2 being a generic instrument. MATERIALS AND METHODS: The analysis included 154 patients. A heterogeneous correlation matrix was created using a combination of Pearson, polyserial, and polychoric regressions among 67 variables, which then underwent eigen decomposition. Scores of significant principal components (PCs) (with eigenvalues>1) were included in multivariate logistic regression analyses for three dichotomous outcomes of interest: achievement of the minimum clinically important difference [MCID] in (1) NDI (/=5), and (3) SF-36v2 Mental Component Summary (MCS) score (>/=5). RESULTS: Twenty-four significant PCs accounting for 75% of the variance in the data were identified. Two PCs were associated with achievement of the MCID in NDI. The first (PC 1) was dominated by variables related to surgical approach and number of operated levels; the second (PC 21) consisted of variables related to patient demographics, severity and etiology of DCM, comorbid status, and surgical approach. Both PC 1 and PC 21 also correlated with SF-36v2 PCS score, in addition to PC 4, which described patients' physical profile, including gender, height, and weight, as well as comorbid renal disease; PC 6, which received large loadings from variables related to cardiac disease, impaired mobility, and length of surgery and recovery; and PC 9, which harbored large contributions from features of upper limb dysfunction, cardiorespiratory disease, surgical approach, and region. In addition to PC 21, a component profiling patients' socioeconomic status and support systems and degree of physical disability (PC 24) was associated with achievement of the MCID in SF-36 MCS score. CONCLUSIONS: Through a data-driven approach, we identified several phenotypes associated with disability and physical and mental health-related QOL. Such data reduction methods may separate patient-, disease-, and treatment-related variables more accurately into clinically meaningful phenotypes that may inform patient care and recruitment into clinical trials. CI - Copyright (c) 2018 Elsevier Inc. All rights reserved. FAU - Badhiwala, Jetan H AU - Badhiwala JH AD - Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto Western Hospital, 399 Bathurst St, Toronto, Ontario, Canada M5T 2S8. FAU - Witiw, Christopher D AU - Witiw CD AD - Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto Western Hospital, 399 Bathurst St, Toronto, Ontario, Canada M5T 2S8. FAU - Nassiri, Farshad AU - Nassiri F AD - Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto Western Hospital, 399 Bathurst St, Toronto, Ontario, Canada M5T 2S8. FAU - Jaja, Blessing N R AU - Jaja BNR AD - Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto Western Hospital, 399 Bathurst St, Toronto, Ontario, Canada M5T 2S8. FAU - Akbar, Muhammad A AU - Akbar MA AD - Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto Western Hospital, 399 Bathurst St, Toronto, Ontario, Canada M5T 2S8. FAU - Mansouri, Alireza AU - Mansouri A AD - Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto Western Hospital, 399 Bathurst St, Toronto, Ontario, Canada M5T 2S8. FAU - Merali, Zamir AU - Merali Z AD - Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto Western Hospital, 399 Bathurst St, Toronto, Ontario, Canada M5T 2S8. FAU - Ibrahim, George M AU - Ibrahim GM AD - Division of Neurosurgery, Department of Surgery, University of Toronto, The Hospital for Sick Children, 555 University Ave, Toronto, Ontario, Canada M5G 1X8. FAU - Wilson, Jefferson R AU - Wilson JR AD - Division of Neurosurgery, Department of Surgery, University of Toronto, St. Michael's Hospital, 30 Bond St, Toronto, Ontario, Canada M5B 1W8. FAU - Fehlings, Michael G AU - Fehlings MG AD - Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto Western Hospital, 399 Bathurst St, Toronto, Ontario, Canada M5T 2S8. Electronic address: michael.fehlings@uhn.ca. LA - eng PT - Journal Article DEP - 20180507 PL - United States TA - Spine J JT - The spine journal : official journal of the North American Spine Society JID - 101130732 SB - IM MH - Adult MH - Aged MH - Cervical Vertebrae/*surgery MH - Decompression, Surgical/*adverse effects MH - Female MH - Humans MH - Male MH - Middle Aged MH - Phenotype MH - Postoperative Complications/*epidemiology MH - Principal Component Analysis MH - Regression Analysis MH - Spinal Cord Diseases/*surgery OTO - NOTNLM OT - Cervical spondylotic myelopathy OT - Degenerative cervical myelopathy OT - Neck Disability Index OT - Principal component analysis OT - Quality of life OT - SF-36 OT - Spine surgery EDAT- 2018/05/11 06:00 MHDA- 2019/06/18 06:00 CRDT- 2018/05/11 06:00 PHST- 2017/12/01 00:00 [received] PHST- 2018/04/04 00:00 [revised] PHST- 2018/05/01 00:00 [accepted] PHST- 2018/05/11 06:00 [pubmed] PHST- 2019/06/18 06:00 [medline] PHST- 2018/05/11 06:00 [entrez] AID - S1529-9430(18)30208-0 [pii] AID - 10.1016/j.spinee.2018.05.009 [doi] PST - ppublish SO - Spine J. 2018 Dec;18(12):2220-2231. doi: 10.1016/j.spinee.2018.05.009. Epub 2018 May 7.