Cervical Spondylotic Myelopathy - Cost Observational Surgical Trial
Conditions: Cervical Spondylosis With Myelopathy
Sponsor: Lahey Clinic

 
 
 
 
Cost-Effectiveness of Different Surgeries for CSM 
July 10, 2023 
 
 
Primary Investigator 
Zoher Ghogawala, MD – Department of Neurosurgery, Lahey Hospital and Medical Center, 
Burlington, Massachusetts 
 
 
Co-Investigators 
 Robert Whitmore, MD – Department of Neurosurgery, Lahey Hospital and Medical Center, 
Burlington, Massachusetts 
Art Eleanore, MPH – Department of Neurosurgery, Lahey Hospital and Medical Center, 
Burlington, Massachusetts 
Mohamad Bydon, MD – Department of Neurological Surgery, Mayo Clinic Rochester, Minnesota 
Giorgos D. Michalopoulos, MD – Department of Neurological Surgery, Mayo Clinic Rochester, 
Minnesota 
Konstantinos Katsos, MBBS – Department of Neurological Surgery, Mayo Clinic Rochester, 
Minnesota 
Bijan J. Borah, PhD – Department of Health Services Research, Mayo Clinic, Rochester 
Minnesota 
James P. Moriarty, MS - Department of Health Services Research, Mayo Clinic, Rochester 
Minnesota 
Ruchita Dholakia, MS, MBA - Department of Health Services Research, Mayo Clinic, Rochester 
Minnesota 
 
 

 
 
 
 
DESCRIPTION OF STUDY 
 
A. Purpose 
 
1. To determine if ventral surgery is more cost-effective compared to dorsal (fusion or 
 
laminoplasty) surgery. 
2. To determine the relative cost-effectiveness between anterior cervical discectomy and 
 
fusion (ACDF), posterior cervical fusion (PCF), and cervical laminoplasty. 
 
A. Background 
 
This study aims to compare the cost of care of anterior versus posterior surgical approaches 
for the management of Cervical Spondolytic Myelopathy (CSM).  Due to the significant gap in 
today’s literature, we aim to conduct a post hoc analysis of data from the randomized trial 
“Cervical Spondylotic Myelopathy Surgical Trial” (www.ClinicalTrials.gov; identifier: 
NCT02076113; LCID# 2013-085) to determine the cost effectiveness of various procedures 
as related to the management of CSM. Specifically, we aim to compare 1) the cost 
effectiveness of ventral surgery versus dorsal (fusion or laminoplasty) surgery; and 2) to 
determine the relative cost-effectiveness between anterior cervical discectomy with fusion 
(ACDF), posterior cervical fusion (PCF), and cervical laminoplasty.  
 
The aforementioned study that the proposed analysis is based on was conducted in 
collaboration between multiple academic institutions in North America. The resulting clinical 
and patient-reported outcomes from the CSM-S RCT suggested similar effectiveness in both 
anterior and posterior surgical approaches. Of note, the study showed that cervical 
laminoplasty, a relatively low instrumentation-related cost procedure, was effective in 
managing CSM. The findings of the proposed analysis will offer further consideration on 
patient financial burdens as related to CSM management to better improve related clinical 
decision-making for both patients and their providers.  
 
 
B. Specific Location of Study 
 
This is a post hoc analysis of data from a multicenter randomized clinical trial entitled “Cervical 
Spondylotic Myelopathy Surgical Trial” (www.ClinicalTrials.gov; identifier: NCT02076113), 
which took place in eleven institutions across North America. Data will be analyzed by Mayo 
Clinic statisticians specializing in cost analyses. 
 
C. Duration of Project 
 
Statistical analysis and manuscript writing is expected to be completed within a 12-month 
period. 
 
D. Research Plan1 

 
 
 
 
1. Post hoc analysis will be conducted on the following data that were collected during the 
trial (LCID#2013-085) The study flow schema is outlined in Figure 11 
 
1. Our post hoc study will utilize the health resource information, well-known quantitative 
scales to measure functional outcomes (SF-36, Oswestry Neck, mJOA, and EuroQol-
5D taken at pre-op, 3 months, 6 months, 1 year, 2 years, 3 years, 4 years, and 5 
years), costs related and incidence of re-operations and complications at 30 days and 
1 year after surgery to compare the costs related to each procedure: comparing the 
cost effectiveness of ventral surgery versus dorsal (fusion or laminoplasty) surgery 
and comparing the relative cost-effectiveness between anterior cervical discectomy 
with fusion (ACDF), posterior cervical fusion (PCF), and cervical laminoplasty. Quality 
of life measures (I.e. SF-36 as one overall score per timepoint) will be utilized to 
determine patient satisfaction with the procedure of choice and subsequently create a 
comprehensive snapshot for clinical decision making. Utilization of quality-of-life 
scales will help relate success of the procedure as deemed by the patient in relation 
to the related costs. 
2. Health resource utilization information was collected using patient diaries along with 
copies of all medical bills and receipts at 1 month, 3 months, 6 months, and 12 months 
post-operatively for all patients. Participants were asked to monitor days missed from 
work and days unable to perform usual activities, in addition to days missed from work 
for medical treatments or evaluations. 
 
2. The overall cost will be estimated for each patient from a societal perspective and will 
include the following components: 
I. 
 Index Hospitalization Cost – performed on all patients:  
 
• 
Hospital Costs: Total hospital charges (Total HC) will be used to estimate costs 
using hospital-specific and year-specific Medicare cost-to-charge ratios (CCR). 
The costs will be adjusted for inflation to the latest year of the study (2018) without 
a 3% discount. – Assumptions: cost-to-charge ratios for all hospitals and all 
relevant years will be provided. Data will be complete for all patients from all sites. 
• 
Hospital charges for specific revenue centers (i.e., radiology, pharmacy, 
physiotherapy, and occupational therapy) will be converted to costs using hospital-
specific and year-specific CCRs.  This will allow the identification of the major 
drivers of the difference in cost between the surgical strategies. A crosswalk 
between the revenue center and the cost center will have to be created. – 
Assumptions: Total hospital charges will be segmented out into the relevant 
revenue centers. All patients will have charges segmented in this manner. No 
major differences in how total hospital charges will be segmented by each site will 
exist. 
• 
For professional services (identified with either HCPCS code or CPT-4 codes) 
provided to patients during the index hospitalization, costs will be calculated using 
national reimbursement amounts from the appropriate Medicare fee schedules for 
the respective year. – Assumptions: Detailed line-item services of all HCPCS 
codes and CPT-4 codes (including any necessary billing modifiers) will be provided 
for all professional services. Data will be complete for all patients from all sites. 
 

 
 
 
 
II. 
One-year All-Cause Cost – performed on patients from sites capturing 1 year 
utilization:  
• 
One-year all-cause costs will be calculated for hospital and professional services 
in the manner described above.  – Assumptions: The same underlying 
assumptions described above. 
 
III. 
Time to Return to Work – performed on all patients reporting employment:  
• 
We will assume that the work halted for patients on the procedure date).  
• 
For patients to whom this outcome applies, we will compare different cohorts using 
return to work as a time-to-event outcome. 
o Lost wages will be estimated using the median weekly earnings in the US 
as reported by the Bureau of Labor Statistics.   
▪ 
Patients providing no employment information will be assumed to 
have zero lost wages. 
▪ 
Job-specific wages will not be estimated. 
 
IV. 
Index hospitalization costs and one-year all-cause costs will be combined with costs 
due to loss of productivity (indirect costs) to estimate total costs for each patient from 
a societal perspective. 
 
E. Data and Safety Monitoring Plan  
 
1. Deidentified data from the published primary study will be utilized for the post hoc analysis.  
 
F. Timepoints of Data Collection 
 
1. Data variables included in the analysis: 
 
I. 
Procedure costs and related costs; related CPT codes 
II. SF-36 (pre-op, 3 months, 6 months, and 1 years) 
III. EQ5D (pre-op, 3 months, 6 months, and 1 years) 
IV. Neck pain disability index (pre-op, 3 months, 6 months, and 1 years) 
V. Baseline Demographics 
VI. MJOA (pre-op, 3 months, 6 months, and 1 years) 
VII. Return to Work Status 1 Month, 3 Months, 6 Months, 1 Year 
VIII. 
Health Resource Utilization Diary (1 month, 3 months, 6 months, 1 year) 
IX. Inpatient Hospital and Rehabilitation Utilization Data 
X. Hospital-specific and year-specific Medicare cost-to-charge ratios 
 
2. Study Endpoints 
 
I. 
The primary endpoint will be the cost-effectiveness comparison between ventral and 
dorsal surgery in CSM.  

 
 
 
 
II. The secondary endpoint will be the cost-effectiveness comparison between dorsal cervical 
fusion and laminoplasty  
 
3. Data Timepoints 
I. 
Preop: SF36, EQ5D, neck pain disability index 
II. 
Procedure: related hospital costs, hospital-specific and year-specific Medicare cost-
to-charge ratio 
III. 
1 month: Complications and related costs (if applicable), health resource utilization 
diary, Return to Work Status 
IV. 
3 months: SF36, EQ5D, neck pain disability index, health resource utilization diary, 
Return to Work Status 
V. 
6 months: SF36, EQ5D, neck pain disability index, health resource utilization diary, 
Return to Work Status 
VI. 
1 year: SF36, EQ5D, neck pain disability index, health resource utilization diary, 
Return to Work Status 
 

 
 
 
 
Figure 1: Cervical Spondylotic Myelopathy Trial Study Flow Schema from CSM Trial1
 
 
 
 
 
 

 
 
 
 
Figure 2: Flow of Participants in the Cervical Spondylotic Myelopathy Surgical Trial1 
 

 
 
 
 
References 
1. 
Ghogawala Z, Benzel EC, Heary RF, et al. Cervical spondylotic myelopathy surgical trial: 
randomized, controlled trial design and rationale. Neurosurgery. Oct 2014;75(4):334-46. 
doi:10.1227/NEU.0000000000000479